Decreased expression of GPC1 in human skin keratinocytes and epidermis during ageing.

BACKGROUND: Glypicans (GPCs) are heparan sulfate cell membrane proteoglycans containing glycosylphosphatidylinositol (GPI) anchor. They play important role in cell behavior by activating/presenting numerous growth factors and cytokines. OBJECTIVES: The expression of GPCs was investigated in primary culture of skin keratinocytes sampled from healthy donors of different age. MATERIALS AND METHODS: Primary keratinocytes from healthy female donors aged from 20 to 89 years old (n = 30) were either isolated from breast or abdominal skin samples (n = 27) or purchased (n = 3). GPCs expression was examined by qPCR, immunohistochemistry and western blot. Its role in proliferation induced by fibroblast growth factor 2 (FGF2) was also studied. RESULTS: Glypican 1 (GPC1) was the major expressed GPC in human keratinocytes. Its expression was up to two orders of magnitude higher than other GPCs and was significantly decreased with the age of the donors. It was localized at the cell surface and associated with intracellular granules. In skin sections, GPC1 was mainly localized in basal layer of epidermis. Shedding of GPCs decreased the proliferative effect of FGF2, confirming their role of modulator of growth factor effects on keratinocytes. These results established GPC1 as an important player in epidermis biology and skin ageing.

[Fever as the presenting manifestation of colon cancer: a case series of 11 patients]. / Fièvre révélatrice d'un cancer colique: 11 observations.

INTRODUCTION: Fever happens frequently in colon cancer but it is rarely the presenting manifestation. PATIENTS AND METHODS: We report a case series of patients with colon cancer revealed by fever in the three military hospitals in Paris. RESULTS: Of the 11 patients studied, seven were men and four were women, and their mean age was 70 years. Cancer was localized in the sigmoid colon (n=6), left colon (n=3) and right colon (n=2). Cancer staging (UICC TNM classification 2002) was respectively pTis (n=1), I (n=4), II (n=3) and III (n=3). Fever was the only reason for admission and two patients had a recurrent fever of unknown origin. All patients but one had bacterial infection. Blood cultures grew up in six cases, Escherichia coli (n=3), Streptococcus gallolyticus (ex bovis) (n=2) and anaerobic bacteria (n=1). There was one case of infective endocarditis caused by S. gallolyticus. Imaging showed a liver abscess (n=3) and a colon cancer complicated by an abscess (n=3). In seven patients, a familial history of colon cancer and symptoms of underlying colic disease were present (neglected rectal bleeding, iron deficiency anaemia, clinical evidence of an abdominal mass). CONCLUSIONS: Fever may reveal colon cancer at an early stage. Its main cause is a bacterial infection, such as bacteremia or abscess. Fever of unknown origin is a rare presentation. Detailed history, careful clinical examination and analysis of imaging contribute to recommend the prescription of colonoscopy.

[Tropical sprue in an expatriate]. / Sprue tropicale chez un expatrié.

INTRODUCTION: Tropical sprue is a postinfective malabsorption syndrome that occurs in some tropical endemic areas. CASE REPORT: A 65-year-old Caucasian patient, with no significant past medical history, living in Cambodia for 10 years, presented with a 23 kg weight loss and chronic diarrhea. Clinical examination was unremarkable. Laboratory tests showed a moderate nutritional deficiency syndrome. The upper gastrointestinal endoscopy showed duodenal villous atrophy and histological analysis confirmed subtotal villous atrophy with important intraepithelial lymphocytosis. The diagnosis of tropical sprue was considered on the epidemiological, clinical and biological context, and the absence of other cause of villous atrophy. A three-month duration treatment with antibiotics, folic acid and vitamin B12 was initiated. The clinical course was favorable with disappearance of diarrhea in 15 days. One year later, the patient had resumed his usual weight, and laboratory tests and duodenal biopsies were normal. CONCLUSION: The diagnosis of tropical sprue should be systematically discussed in any malabsorption syndrome with villous atrophy in a patient living or having lived in the tropics.

[Prolonged fever: specific issues in the young adult population]. / Les fièvres prolongées: problématique chez l'adulte jeune.

Early studies on prolonged fever date back to the 1960s. Fifty years later, prolonged unexplained fever remains a diagnostic challenge to the general internists. Although the aetiologies of prolonged fevers have not changed much in the general population, the distribution between the various causes is not the same anymore. A regular decrease in infectious and neoplastic causes is noticed whatever the age. Prolonged fevers related to inflammatory disorders and fevers that remain of unknown origin still represent approximately 30 to 50% of the cases. In the young adult population, as in the older patients, prolonged fevers can be attributed to four groups: infection, inflammation, neoplasic and other aetiologies (including drug-related fevers). In the young adult population, the management of prolonged fever presents some specific issues that are the purpose of this review coupled with our own experience. The prognosis of undiagnosed prolonged fever is usually favourable, as a life-threatening aetiology is exceptionally diagnosed during the follow-up if the initial management was complete and accurate.

Early events prior to visual symptoms in the apoplectic form of grapevine esca disease.

Plant infection by pathogens generates various forms of symptoms. Most of them have been described as soon as they become visible, whereas preceding, discrete signs during incubation are poorly or not understood. In Vitis vinifera, esca-related pathogenic fungi inhabit living trunk wood and induce the so-called apoplexy, a sudden wilting of leaves within a few days. To further understand the apoplexy expression, the period preceding symptom appearance was investigated by following physiological and molecular markers associated with photosynthetic mechanisms and stress responses. Within the week preceding symptoms, drastic physiological alterations of photosynthesis were registered in pre-apoplectic vines, as revealed by a decrease in gas exchange, changes in chlorophyll fluorescence, and repression of photosynthesis-related genes. In the meantime, expression of defense-related genes was induced and amplified during symptom expression. Water-stress-related genes were specifically investigated because water transport may be impeded by clogging xylem vessels due to esca-causing fungi. Neither of the tested water-stress-related genes was affected in pre-apoplectic grapevine leaves whereas these genes were downregulated in drying leaves. Our results suggest that, during incubation of esca apoplexy, grapevine perceives some signals (likely fungi-originated toxins) and reacts by reducing photosynthesis and triggering defense mechanisms.

[Difficult diagnosis of a pancreatic paraganglioma]. / Diagnostic difficile d'un paragangliome pancréatique.

INTRODUCTION: The paraganglioma is a rare tumour that can sometimes develop near to the pancreatic gland and can occasionally mimic an intra pancreatic mass. Invasive investigations with puncture or primary surgical resection must be avoided because of the risk of vital complications. EXEGESIS: We report on the case of a 41 years old woman presenting with a mass apparently affecting the pancreatic gland. She also presented with malaises. Paraganglioma was suspected because of the malaises and the blood pressure crises. The diagnosis was permitted by the findings of high urinary metanephrine levels. So the tumour was resected without previous fine needle aspiration and with specific anaesthetic measures. No complication was observed. CONCLUSION: When a patient presents with a pancreatic mass, physician must carefully take into account the possibility of a paraganglioma particularly when malaises are present.

PAV1, the first virus-like particle isolated from a hyperthermophilic euryarchaeote, "Pyrococcus abyssi".

We describe the first virus-like particle of a hyperthermophilic euryarchaeote which was discovered in a strain of "Pyrococcus abyssi" previously characterized in our laboratory. This particle, named PAV1, is lemon-shaped (120 nm x 80 nm), with a short tail terminated by fibers, and resembles the virus SSV1, the type member of the Fuselloviridae, isolated from Sulfolobus shibatae. Sensitivity of the virus-like particle to organic solvents and detergents suggested that the envelope of PAV1 may contain lipids in addition to proteins. It contains a double-stranded circular DNA of 18 kb which is also present in high copy number in a free form in the host cytoplasm. No integrated form of the PAV1 genome could be detected in the host chromosome. Under standard growth conditions, the host cells continuously release PAV1 particles into the culture supernatant without spontaneous lysis, with a maximum reached in the late stationary phase. UV, gamma irradiation, treatment with mitomycin C, and various physiological stresses had no effect on PAV1 production. Screening of a large number of Thermococcales isolates did not permit to find a sensitive host. These results suggest that PAV1 persists in the host strain in a stable carrier state rather than a prophage.

Role of the regulatory gene pl in the photocontrol of maize anthocyanin pigmentation.

The pl gene encodes a regulatory protein that controls the transcription of a number of structural genes of the anthocyanin biosynthetic pathway in maize. pl alleles have been classified phenotypically into two categories: dominant (Pl) alleles lead to intense, light-independent pigmentation in vegetative and floral organs of the plant; recessive "sun-red" alleles (pl) lead to light-dependent red pigmentation in which only tissues exposed to light become pigmented. Based on these observations, two alternate pathways leading to anthocyanin synthesis in the plant have been proposed: one requiring light and the other bypassing the light requirement through the action of Pl. To evaluate this hypothesis, we have analyzed light-independent and light-dependent alleles of pl. Sequence analysis revealed that the two types of alleles have very distinct promoters but have the capacity to encode very similar proteins. The protein encoded by one recessive allele was shown to be functional in transient assays. Measurements of husk mRNA levels by quantitative polymerase chain reaction showed that sun-red pl alleles are expressed at much lower levels than a Pl allele, but their expression is increased approximately sixfold by exposure to light. These results lead to the conclusion that the sun-red pl alleles are not null; instead, they synthesize functional mRNA and protein. We propose that the light-dependent pigmentation observed in pl plants is the result of a threshold effect in which light exposure boosts pl mRNA expression past a crucial level necessary to generate sufficient PL protein molecules to activate transcription of the anthocyanin structural genes.

Empirical solvation models in the context of conformational energy searches: application to bovine pancreatic trypsin inhibitor.

Continuum solvation models that estimate free energies of solvation as a function of solvent accessible surface area are computationally simple enough to be useful for predicting protein conformation. The behavior of three such solvation models has been examined by applying them to the minimization of the conformational energy of bovine pancreatic trypsin inhibitor. The models differ only with regard to how the constants of proportionality between free energy and surface area were derived. Each model was derived by fitting to experimentally measured equilibrium solution properties. For two models, the solution property was free energy of hydration. For the third, the property was NMR coupling constants. The purpose of this study is to determine the effect of applying these solvation models to the nonequilibrium conformations of a protein arising in the course of global searches for conformational energy minima. Two approaches were used: (1) local energy minimization of an ensemble of conformations similar to the equilibrium conformation and (2) global search trajectories using Monte Carlo plus minimization starting from a single conformation similar to the equilibrium conformation. For the two models derived from free energy measurements, it was found that both the global searches and local minimizations yielded conformations more similar to the X-ray crystallographic structures than did searches or local minimizations carried out in the absence of a solvation component of the conformational energy. The model derived from NMR coupling constants behaved similarly to the other models in the context of a global search trajectory. For one of the models derived from measured free energies of hydration, it was found that minimization of an ensemble of near-equilibrium conformations yielded a new ensemble in which the conformation most similar to the X-ray determined structure PTI4 had the lowest total free energy. Despite the simplicity of the continuum solvation models, the final conformation generated in the trajectories for each of the models exhibited some of the characteristics that have been reported for conformations obtained from molecular dynamics simulations in the presence of a bath of explicit water molecules. They have smaller root mean square (rms) deviations from the experimentally determined conformation, fewer incorrect hydrogen bonds, and slightly larger radii of gyration than do conformations derived from search trajectories carried out in the absence of solvent.

The maize auxotrophic mutant orange pericarp is defective in duplicate genes for tryptophan synthase beta.

orange pericarp (orp) is a seedling lethal mutant of maize caused by mutations in the duplicate unlinked recessive loci orp1 and orp2. Mutant seedlings accumulate two tryptophan precursors, anthranilate and indole, suggesting a block in tryptophan biosynthesis. Results from feeding studies and enzyme assays indicate that the orp mutant is defective in tryptophan synthase beta activity. Thus, orp is one of only a few amino acid auxotrophic mutants to be characterized in plants. Two genes encoding tryptophan synthase beta were isolated from maize and sequenced. Both genes encode polypeptides with high homology to tryptophan synthase beta enzymes from other organisms. The cloned genes were mapped by restriction fragment length polymorphism analysis to approximately the same chromosomal locations as the genetically mapped factors orp1 and orp2. RNA analysis indicates that both genes are expressed in all tissues examined from normal plants. Together, the biochemical, genetic, and molecular data verify the identity of orp1 and orp2 as duplicate structural genes for the beta subunit of tryptophan synthase.

New determinations and simplified representations of macromolecular surfaces.

Several new methods or improvements of older algorithms determining the different pieces of molecular surface are presented. Their improvement in time and their complexity are discussed. Only the indexes of the atoms on which the pieces are relying are, in fact, determined, since their explicit representation from these numbers varies according to the 3D capabilities of the graphic workstation (dots, grid, etc.), and this generation is not C.P.U. consuming. To have a simplified representation of the surface of macromolecules, a polyhedron with planar triangular faces is then introduced: Each concave triangular surface piece is replaced with planar triangles relying on its three atomic centers, while saddle-shaped rectangles and convex pieces are wholly ignored. A minimal data structure of the polyhedron is then proposed, which contains only topological informations, since no coordinates have been generated. If the atomic radius is then considered to be constant (independent of atomic type), the surface of a set of N points is now defined by the choice of a subset with a topology. This choice is controlled by a parameter of rugosity (the atomic radius). Contrary to Voronoi polyhedrons partition, which gives a topology for a set of N points, our approach gives a topology only for the exterior points of this set. A few applications of this very simple definition of molecular surface are then discussed: the 3D interactive manipulation of macromolecules, the steric intermolecular recognition, and the determination of local and global properties of the surface.

Role of protein kinase C in chick embryo skeletal myoblast fusion.

The involvement of Ca2+ and PGE1 in myoblast fusion has been well documented. Extracellular Ca2+ is essential for myoblast adhesion, alignment, and fusion. There is an obligatory increase in Ca2+ influx immediately preceding fusion and the Ca2+ ionophore A23187 promotes precocious fusion. PGE1 receptors appear just prior to fusion, and an antagonist of PGE1 binding to cell surface receptors blocks fusion when added prior to Ca2+ influx. Finally, exogenous PGE1 induces precocious fusion. The present study was an initial test of the hypothesis that membrane protein phosphorylation by protein kinase C (PKC) links PGE1 receptor occupancy and the increase in Ca2+ influx. Our conclusion that PKC is an essential component in the regulation of myoblast fusion is based in part on the following evidence: (1) an activator of PKC, the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA), at low concentration and for a brief exposure period, induces precocious fusion and stimulates Ca2+ influx; (2) 4 alpha-phorbol-12,13-didecanoate, an inactive analog of TPA, has no discernible effect on fusion or Ca2+ influx; (3) 1-oleoyl-2-acetyl glycerol, an analog of endogenous diacylglycerol (DAG) which activates PKC, promotes precocious fusion, as does the DAG kinase inhibitor R59022 (6-[2-[4-[(4-fluorophenyl)phenylmethylene]-1-piperidinyl]ethyl]-7- methyl-5H-thiazole-[3,2 alpha]-pyrimidin-5-one) which raises the level of endogenous DAG by inhibiting its catabolism; (4) 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7), a highly potent PKC inhibitor, reversibly blocks myogenesis at a point between alignment and fusion; and (5) H-7 also blocks the normal increase in Ca2+ influx preceding fusion.

[Our experience of spinal anesthesia for transurethral resection of the bladder and prostate. Retrospective study of 334 patients operated in 1986]. / Notre expérience de la rachianesthésie pour résection transurétrale de vessie et de prostate. Etude rétrospective de 334 patients opérés en 1986.

Retrospective study of one years is performed on 334 patients who undergo transurethral surgery. Spinal anesthesia is used in 263 cases, general anesthesia in 71. Spinal administration of local anesthetics (lidocaine hyperbaric 5% or bupivacaine 0.5%) or opioid (Pethidine 1 mg/kg) have been used in old patients without any complication. The advantages are less blood uses, early stand up, no discontinuity in oral nutrition. For our team there are only few contra-indications for spinal anesthesia: blood coagulation abnormalities or some very rare heart diseases.

Catalase has only a minor role in protection against near-ultraviolet radiation damage in bacteria.

In bacterial cells near-ultraviolet radiation (NUV) generates H2O2 which can be decomposed by endogenous catalase to H2O and O2. To assess the roles of H2O2 and catalase in NUV lethality, we manipulated the amount of intracellular catalase (a) by the use of mutant and plasmid strains with altered endogenous catalase, (b) physiologically, by the addition of glucose, and (c) by induction of catalase synthesis with oxidizing agents. Not only was there no direct correlation between NUV-resistance and catalase activity, but in some cases the correlation was inverse. Also, while there was correlation between NUV and H2O2 sensitivity for most strains tested, there were a number of exceptions which indicates that the modes of killing were different for the two agents.

[Clinical use in adults of 2 new muscle relaxants: atracurium and vecuronium]. / Utilisation clinique chez l'adulte de deux nouveaux myorelaxants: l'atracurium et le vécuronium.

115 general and urologic surgery adult patients, ASA class I-II, were divided in four groups according to initial bolus and relaxant used: group A atracurium 0.6 mg X kg-1, group B 0.5 mg X kg-1, group C vecuronium 0.1 mg X kg-1 and group D pancuronium 0.1 mg X kg-1. When the single twitch recovered to 25% of control height (T25), subgroups were individualized depending on whether repeat doses of 1/3 of initial bolus were given or not, and whether reversal was spontaneous or obtained by a standard dose of neostigmine 2.5 mg and atropine 1.25 mg. By ulnar nerve stimulation at the wrist, the force of thumb adduction was recorded on a polygraph; single twitch (tw), train of four (tof) and ratio tof 4/1 (Rtof) were measured. Anaesthesia was induced with thiopentone and fentanyl without premedication and maintained with fentanyl and N2O in oxygen; the trachea was intubated once the block was at its maximum. The onset time of maximal block was 5 min for groups A, B and C, and 7.9 min for group D. T25 was 39.9 +/- 8.5 min for group A, 34.4 +/- 9.7 min for group B, 28.9 +/- 9.9 min for group C and 70.7 +/- 25.9 min for group D. A Rtof equal to 75% was achieved in less than 65 min with atracurium and vecuronium, but much later with pancuronium. Reversal at T25 was efficient, but not really required, for atracurium and vecuronium, but necessary and useful for pancuronium.(ABSTRACT TRUNCATED AT 250 WORDS)

[Accidental overdose of intrathecal morphine. Treatment with intravenous naloxone alone]. / Surdosage accidentel en morphine intrarachidienne. Traitement par naloxone intraveineuse seule.

A case of opiate accidental overdose is reported where 8 mg morphine were given by spinal injection. The rapid onset respiratory depression was treated by naloxone alone administered as a continuous infusion (6 mg), together with additional intravenous injections.