Conformation of the hypervariable region L3 without the key proline residue.

The refined structure of the Fab fragment of the monoclonal antibody CRIS-I (IgG2a kappa) against the leukocyte differentiation antigen CD5, determined at 1.9 A resolution with an agreement R-factor of 18.3%, reveals a variant of the canonical conformations proposed for the light chain complementarity determining region L3 (CDR-L3). This is the first Fab structure available with a kappa light chain in which the CDR-L3 lacks the key proline residue in either position 94 or 95. The conformation found could be significant for about 10% of the murine IgG molecules with kappa light chains without proline in their CDR-L3 sequences.     

Inositol Hexakisphosphate (Phytic Acid) Enhances Ca2+Influx and D-[3H]Aspartate Release in Cultured Cerebellar Neurons

Inositol hexakisphosphate (InsP6) increased 45Ca2+ uptake in cultured cerebellar granule cells. This increase was concentration dependent (EC50 = 20 microM), exhibited slow kinetics, and was present after 5 days of cell maturation in culture. InsP6 also enhanced D-[3H]aspartate release in cerebellar granule cells at 11-12 days in vitro. Stimulation of 45Ca2+ uptake was also produced by inositol pentakisphosphate but not by inositol 1,3,4,5-tetrakisphosphate. The increase in 45Ca2+ influx induced by InsP6 was independent of extracellular Na+ and was only partially reduced by the organic calcium channel blocker nifedipine. The intrinsic action of InsP6 was not affected by competitive or noncompetitive glutamate receptor antagonists. In addition, stimulations of 45Ca2+ uptake by InsP6 and glutamate were additive. These data provide evidence that InsP6 directly activates a specific population of neurons in the CNS.     

Sterols of some red algae

The sterol composition of 17 red algae has been determined. Only C-27 sterols have been found in substantial amounts; details of the structural elucidation of liagosterol (cholesta-5,23-diene-3β,25-diol) are given. The possible taxonomic significance of the sterol distribution is briefly discussed.     

Drug induced Kounis syndrome: does oxidative stress play a role?

Background

Kounis syndrome (KS) has been described as the coincidental occurrence of acute coronary syndromes during an allergic reaction with cardiac anaphylaxis. It is caused by inflammatory mediators released after exposure to drugs, food, environmental and other triggers. Oxidative stress occurring in various inflammatory disorders causes molecular damage with the production of advanced oxidation products (AOPPs) and advanced glycation end products (AGEs).

Case presentation

Markers of oxidative stress were evaluated in a patient who had experienced KS after antibiotic administration in order to investigate the possible role of these molecules in KS. No data, up to now, are available on biomarkers of oxidative stress in patients with drug-induced KS.

Conclusions

AOPPs, but not AGEs, were significantly increased in the KS affected patient compared to controls as already reported in mastocytosis affected patients.

     

Immunohistochemical identification and comparison of glial cell lineage in foetal, neonatal, adult and neoplastic human adrenal medulla

The differentiation of glial cells in developing, neonatal, adult and neoplastic human adrenal medulla has been studied immunohistochemically. From 8 to 28 weeks' gestational age, S-100 protein and its β-subunit revealed two different glial cell populations in adrenal glands, namely Schwann-like and sustentacular cells. Schwann-like cells were spindle-shaped cells forming a continuous layer around groups of sympathetic neuroblasts, often in contact with Schwann cells of nerve fibres entering neuroblastic groups. Sustentacular cells were round or oval cells with dendritic cytoplasmic processes; they were not associated with nerve fibres and mingled both with sympathetic neuroblasts and differentiating chromaffin cells. The developmental fate of Schwann-like cells was different from that of sustentacular cells. Schwann-like cells disappeared from the 28th week of gestational age, in association with the disappearance of sympathetic neuroblastic groups, and they were rarely found in neonatal and adult adrenal medulla. In contrast, sustentacular cells persisted between medullary chromaffin cells, and their number and dendritic cytoplasmic processes progressively increased from foetus to adult. In eight cases of primitive adrenal neuroblastic tumours of neonatal age (five undifferentiated neuroblastomas and three ganglioneuroblastomas), Schwann-like cells were found at the periphery of tumoral nests with a lobular growth pattern, while rare sustentacular cells were associated with neuroblasts. In two cases of adult phaeochromocytomas, only sustentacular cells were detected between chromaffin tumoral cells. Our findings suggest that the glial cell types and their distribution in primitive adrenal medulla tumours closely resemble those observed during development in the groups of adrenal sympathetic neuroblasts and in the clusters of chromaffin cells     

Keratinophilic fungi from soil of Brittany,France

The Present work reports the study of the distribution of keratinophilic fungi isolated from 39 samples of soil collected in Brittany, France. Keratinophilic fungi were isolated from 35 (92.3%) of the samples studied. The most frequently found species wereFusarium moniliforme, Penicillium viridicatum and an unidentified species ofAcremonium. The other fungi isolated were members of the generaChrysosporium, Gliocladium, Mucor, Trichoderma andTrichophyton.     

Confocal multilaser focusing and single-laser characterization of ultraviolet excitable stains of cellular preparations

BACKGROUND: The aims of this study were (1) to realign cellular preparations when spots and structures are excited by different lasers of a confocal laser scanning microscope (multilaser studies); (2) to avoid the use of realigment methods by selecting fluorochromes that can be excited by only one laser (single-laser experiments). METHODS: In multilaser studies, we used propidium iodide fluorescent beads, as well as tetramethyl rhodamine isothiocyanate (TRITC), fluorescein isothiocyanate (FITC), and 4'-6 diamidino-2-phenylindole (DAPI)-stained human cancer lines. They were excited using HeNe, argon, and ultraviolet (UV) argon laser lines of a confocal laser scanning microscope. Single-laser experiments using UV excitation only were performed using europium as a model for magnetic resonance paramagnetic contrast agents. Nuclei of human cancer lines and tissue were counterstained by DAPI and cytoplasms were labeled with ELF-97 substrates. Factor analysis of medical images (FAMIS) and correlation methods were used to realign shifted images, focus images, and characterize each fluorochrome when necessary. RESULTS: In multilaser studies, superimposition of factor images corrected Z shifts and correlation methods provided X, Y correction values. In single-laser experiments, each fluorochrome was clearly distinguished in the group of fluorochromes. Estimated images in both studies showed colocalizations of structures. CONCLUSIONS: It is possible to characterize differences in the focus and alignment of fluorescent probes and to correct them. It is also possible to study colocalization of UV excitable fluorochromes (DAPI, ELF-97, europium) in cellular and tissular preparations via multilaser or single-laser experiments.     

Antibiotic resistance patterns of coliforms isolated from six protected wetlands in the southeast of Spain

Coliforms and thermotolerant coliforms were isolated from six protected lakes in the Antequera area of Spain in order to assess the sanitary quality of these wetlands. The thermotolerant coliform group consisted of several bacterial genera with a wide spectrum of antibiotic resistance. Resistance amongEscherichia coli strains was correlated with the origin of the sample and three homogeneous groups of wetlands were distinguished. One of them, which corresponded to wetlands where fæcal indicators were indigenous, exhibited no correlation between these bacteria and fæcal pollution. Non-coli strains showed a similar range of antibiotic susceptibility for this group. In the other two groups a fæcal pollution was detected and antibiotic resistance forE. coli strains established the origin of pollution.