Iodinated organic molecule as tag for inductively coupled Plasma-mass spectrometry aptamer assays

Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) aptamer-based assays using metallic nanostructures or chelates as exogenous tags have gained growing attention in the last decade. We describe here a proof-of-concept study based on the exploitation of a simple organic molecule as a tag, i.e.l-thyroxine carrying four iodine atoms detectable by ICP-MS. A solid-phase assay involving the structure-switching format was deployed for the detection of the small molecule l-tyrosinamide as model target. The overall design involved (i) a reporter agent consisting of a DNA aptamer incorporating a single l-thyroxine label at its end and (ii) a capture agent, which is a partially complementary strand, immobilized on a microplate. Limit of detection in the nanomolar range was reported. The present labeling approach was further developed for the detection of a model protein (α-thrombin), using a sandwich mode, and proved effective in a biological matrix. We believe that the l-thyroxine tagging method could become a simple and robust alternative to commonly used labeling methods for ICP-MS aptamer-based assays.

Orientational ordering in the low-temperature stable phases of deuterated thiophene

The stable structures of deuterated thiophene C4D4S were investigated at 155 (phase III), 115 (phase IV), 100 and 1.5 K (phase V) by neutron powder diffraction. At 155 K, thiophene is orthorhombic with space group Pbnm. Although there is some degree of in-plane orientational disorder, molecules begin to order along two symmetrically equivalent main orientations. At 115 K the structure is incommensurate, with a wavevector q ≃ 0.55a*. At 100 K and below, there is a doubling of the a cell parameter and the structure space group is P21. For the first time, it is shown that, unlike C4H4S, phase V of C4D4S is not an orientational glass: thiophene molecules are perfectly ordered and are oriented within the molecular plane along two alternating directions, corresponding to the two main orientations observed at 155 K. This ordering probably originates in the slowing down of the in-plane reorientational dynamics upon deuteration.

[Harassment of personnel in contact with the public: from experiencing aggressive behaviour to preventing it]

The Agricultural Social Mutual Insurance System (MSA) has been mobilised to support a corporate approach in the perspective to decrease mortal acts of violence or aggression. The plan brought together the skills of all the companies' actors (management, hygiene committees, safety and working conditions committee, occupational health and safety at work, and salaried workers). The MSA occupational health departments carried out a situational inventory (through a survey of salaried workers exposed to the risk of aggression). An intervention methodology was addressed to the occupational medical practitioners (PECVAT Protocol). A corporate framework agreement has specified the plan that was developed by company and the actors concerned. Finally, an evaluation enabled them to define the level at which this prevention intervention should be implemented.

Substance P post-synaptically potentiates glutamate-induced currents in dorsal vagal neurons

We examined the post-synaptic actions of glutamate, N-methyl-D-aspartate (NMDA) and substance P on dorsal vagal neurons, using the patch-clamp technique on brainstem slices of young rats. The vagal neurons were identified electrically and histologically. All vagal neurons responded to glutamate and NDMA and about 30% to substance P, with dose-dependent inward currents. The glutamate-induced currents were blocked partially by either CPP (3((R)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid) or CNQX (6-cyano-7-nitro-quinoxaline-2,3-dione), indicating that these currents resulted from the activation of at least two types of glutamate receptors: NMDA receptors and AMPA/kainate receptors. The NK1 receptor-selective antagonist, RP67580, blocked substance P-induced currents, suggesting that NK1 receptors do coexist with NMDA receptors and AMPA/Kainate receptors. Substance P potentiated the effects of glutamate. This potentiation lasted 10-20 min and was blocked by CPP and by RP67580, but not by CNQX, demonstrating that the increase in glutamate-induced currents resulted from the interaction between NK1 receptors and NMDA channels. These results provided the first evidence that the receptors for substance P and glutamate coexist on dorsal vagal neurons and interact with each other to modulate visceral efferent functions.

[Common fibular nerve lesions. Etiology and treatment. Apropos of 146 cases with surgical treatment]

PURPOSE OF THE STUDY

Common peroneal nerve lesion on the lateral aspect of the knee is one of the most frequent neurologic injury of the lower limb. We reported the results of surgical procedure for each etiological group.

MATERIAL AND METHODS

In the peroneal nerve entrapment group, we individualised 62 fibular tunnel syndroms (55 idiopathic, 4 postural, 3 dynamic), and 16 external compression. Traumatic causes were represented by 22 varus injuries of the knee and by 11 fractures, 16 iatrogenic lesions, 2 wounds, 5 wound sequelae, 2 contusions and 1 burn. Tumoral group was represented by 7 intraneural ganglionic cyst and 2 extraneural tumour (1 exostosis and 1 chondromatosis of the proximal tibio fibular joint). All patients underwent surgical procedure. Neurolysis was performed when the nerve was in continuity. Suture or nerve grafting was performed in the other cases. In the case of intraneural ganglionic cyst, a complete tumoral excision was realised.

RESULTS

Eighty-three per cent of excellent and good results were obtained for the fibular tunnel syndrom, 62.5 per cent for external compression, 36 per cent for varus injury of the knee, 78 per cent for the other traumatic causes and 89 per cent for tumoral lesions.

DISCUSSION

This report confirms that the result depends on the etiology of the common peroneal nerve lesion. We propose surgical treatment within 2 to 4 months for the patients without clinical and electrophysiological improvement. If there is doubt on the continuity of the nerve, we propose an earlier surgical treatment. Our results were in general satisfactory except when a nerve graft was necessary furthermore if it was a traction injury and if the length of the graft was longer than 6 centimeters.

Protective role of gamma interferon in experimental pulmonary paracoccidioidomycosis

We have developed a murine model of pulmonary infection by Paracoccidioides brasiliensis in which resistance was associated with immunological activities governed by gamma interferon (IFN-gamma). To better characterize this model, we measured type 1 and type 2 cytokines in the lungs and investigated the effect of endogenous IFN-gamma depletion by monoclonal antibodies in the course of infection of susceptible (B10.A) and resistant (A/Sn) mice. At weeks 4 and 8 after infection, lungs from susceptible animals presented levels of IFN-gamma, interleukin-4 (IL-4), IL-5, and IL-10 higher than those in resistant mice. In both mouse strains, neutralization of endogenous IFN-gamma induced exacerbation of the pulmonary infection, earlier fungal dissemination to the liver and spleen, impairment of the specific cellular immune response resulting in significantly lower delayed-type hypersensitivity reactions, and increased levels of immunoglobulin G1 (IgG1)- and IgG2b-specific antibodies. Histopathological analysis demonstrated that depletion of IFN-gamma changes the focal granulomatous lesions found in the lungs of B10.A and A/Sn mice into coalescent granulomata which destroy the pulmonary architecture. These results suggest that irrespective of the mouse strain, IFN-gamma plays a protective role and that this cytokine is one major mediator of resistance against P. brasiliensis infection in mice.

Determination of pyrazinamide and its main metabolites in rat urine by high-performance liquid chromatography

A new high-performance liquid chromatograhic procedure for simultaneous determination of pyrazinamide (PZA) and its three metabolites 5-hydroxypyrazinamide (5-OH-PZA), pyrazinoic acid (PA), and 5-hydroxypyrazinoic acid (5-OH-PA), in rat urine was developed. 5-OH-PZA and 5-OH-PA standards were obtained by enzymatic synthesis (xanthine oxidase) and checked by HPLC and GC-MS. Chromatographic separation was achieved in 0.01 M KH2PO4 (pH 5.2), circulating at 0.9 ml/min, on a C18 silica column, at 22 degrees C. The limits of detection were 300 microg/l for PZA, 125 microg/l for PA, 90 microg/l for 5-OH-PZA and 70 microg/l for 5-OH-PA. Good linearity (r2>0.99) was observed within the calibration ranges studied: 0.375-7.50 mg/l for PZA, 0.416-3.33 mg/l for PA, 0.830-6.64 mg/l for 5-OH-PZA and 2.83-22.6 mg/l for 5-OHPA. Accuracy was always lower than +/- 10.8%. Precision was in the range 0.33-5.7%. The method will constitute a useful tool for studies on the influence of drug interactions in tuberculosis treatment.

Phenobarbital metabolism by hepatocytes isolated from rat

In order to test the validity of the use of hepatocytes as an alternative to studies of metabolism in live animals, phenobarbital (PB) was applied at 37 degrees C to isolated rat hepatocytes, which had been previously induced by PB. The metabolites were extracted by ethyl acetate, at various pH, and identified and evaluated by GC-MS. PB was not metabolized to p-hydroxyphenobarbital as is usually the case in living animals, but it was transformed into sulphoconjugated 2-phenyl-gamma-butyrolactone. This pathway, beta-hydroxylation of the ethyl side chain followed by lactonization, previously described as a secondary metabolic pathway occurring during intoxications, was here the only observed biodegradation. These results show that it is not possible to use hepatocytes as an alternative to live animals.

Cloning and sequence analysis of a signal peptidase I from the thermophilic cyanobacterium Phormidium laminosum

Type I signal peptidases are a widespread family of enzymes which remove the presequences from proteins translocated across cell membranes, including thylakoid and cytoplasmic membranes of cyanobacteria and thylakoid membranes of chloroplasts. We have cloned and sequenced a signal peptidase gene from the thermophilic cyanobacterium Phormidium laminosum which is believed to encode an enzyme common to both membrane systems. The deduced amino acid sequence is 203 residues long and although the overall similarity among signal peptidases is rather low there are a number of identifiable conserved regions present. The P. laminosum enzyme is predicted to have a single transmembrane domain, in contrast to other Gram-negative bacterial sequences, but similar to other type I signal peptidases.

GC-MS determination of phenobarbitone entrapped in poly-epsilon-caprolactone nanocapsules

In order to evaluate the concentration of a hydrophilic drug, phenobarbitone, in a suspension of poly-epsilon-caprolactone nanocapsules, a gas chromatographic-mass spectrometric procedure, performed after methylation of the drug, was developed and validated. Free phenobarbitone (in solution in the liquid phase), released phenobarbitone (after opening the nanocapsules with ethyl acetate) and total entrapped phenobarbitone (after extraction with methylene chloride), were measured. Experimental results for four lots with various concentrations showed that the highest preparation of entrapped drug (80%) was obtained for a total concentration of 3.64 mg ml-1 in the nanocapsule suspension.

Plasma fluphenazine levels measured by high-performance liquid chromatography in patients treated with depot injections

Fluphenazine (CAS 69-23-8) concentrations in plasma of schizophrenic patients after oral (fluphenazine hydrochloride, Moditen) or intramuscular (fluphenazine enanthate, Moditen Retard, or fluphenazine decanoate, Modecate) administration of drug were measured by means of high-performance liquid chromatography. The extracted compound was identified by gas chromatography with mass selective detector. Pharmacokinetics of fluphenazine has been studied.

Freezing cocultured human blastocysts

OBJECTIVE

To determine the possibility of obtaining good pregnancy rates (PRs) after freezing and thawing cocultured blastocysts.

DESIGN

Human blastocysts were frozen first according to a protocol available from literature. Two other protocols including the addition of glycerol were designed to improve the results.

SETTING

All the patients were under clinical management at the Institut Rhonalpin pour l'Etude de la Reproduction Humaine in Lyons, France.

PATIENTS

Patients involved in the in vitro fertilization program have had their supernumerary embryos frozen according to the three protocols presented here.

MAIN OUTCOME MEASURES

Embryo recovery after freezing and thawing. Clinical and ongoing pregnancies after embryo transfer (ET).

RESULTS

A protocol including sucrose addition and reduction of steps in the preparation of the blastocysts for freezing gave us a 21% PR per transfer (15 ongoing) of 101 transfers (106 thawings).

CONCLUSIONS

Freezing of cocultured human blastocysts allow good PRs. This can represent an alternative for repeated failures of ETs at early stages.

Gas chromatographic-mass spectrometric method for analysis of a pyrimido-s-triazine and some of its metabolites in dog urine

3-Phenylpyrimido-[3,4-a]-s-triazines exhibit antiparasitic, antibacterial and antifungal activity. In order to study the metabolism of these heterocycles, 9,9-diethyl-3-phenyl-6,8-dioxo-2,3,4,5,6,7,8,9-octahydropyrimido[3 ,4-a]-s- triazine (TZ) was administered to dogs. Three potential metabolites were synthesized, and these models were identified and quantified with gas chromatography-mass spectrometry. The heterobicyclic compounds, TZ and its hydroxy derivative, underwent thermal degradation under chromatographic conditions. Dog urine spiked with the model metabolites was extracted, and the substances were quantified. The urine of dogs treated with TZ was studied, and two of the potential metabolites were recovered, identified and quantified.

[Treatment and secondary prophylaxis with fluconazole for oropharyngeal candidiasis in HIV-positive patients. A mycological analysis of failures]

This prospective study evaluated the in vitro susceptibility of Candida albicans isolates recovered from the oral cavity of AIDS/ARC patients before and during long-term therapy with fluconazole. Thirty adults (15 with ARC and 15 with AIDS) with a first episode of thrush candidiasis were given oral fluconazole (Triflucan 50 mg; one capsule daily) for at least three months. Fungal susceptibility testing was performed before treatment, after one month, and at last follow-up (range 3.5-12 months; mean 5.7 months). MICs were determined using the agar dilution method with casitone (Difco 259-01) as the test medium at pH 7.2-7.4. There were two initial clinical failures (one with high MICs before and under treatment and one with an intermediate MIC initially and a rise in MIC under fluconazole). Four patients developed a clinical relapse with no change in MICs (which were low or intermediate). In six patients, clinical symptoms resolved but carriage of C. albicans persisted (low MICs). In 18 patients, clinical resolution with eradication of C. albicans was achieved. These data suggest that (1) clinical failures may be associated with in vitro resistance; (2) relapses under fluconazole maintenance therapy may develop in patients with advanced HIV disease despite the lack of change in the susceptibility of strains.

Putative neurotransmitters in the red nucleus and their involvement in postlesion adaptive mechanisms

A variety of putative neurotransmitters has been described in the red nucleus (RN). Measurement of neurotransmitter biochemical markers and study of their specific localizations using morphological techniques in lesion and deafferentation of the RN indicate the participation of glutamate (Glu) in corticorubral transmission and the presence of GABA in RN intrinsic neurones. The cerebellorubral projection may contain at least two populations of fibres, the one using acetylcholine and the other Glu as neurotransmitter. The presence of a serotoninergic input was also demonstrated. Selective deafferentations of the RN, particularly from its cerebellar input, result in biochemical and immunohistochemical responses indicative of increased corticorubral glutamatergic and local GABAergic transmission. These adaptive changes of neuronal transmission as well as the previously described sprouting of corticorubral nerve terminals may contribute to functional recovery after cerebellectomy in adult animals.

GABA nerve endings in the rat red nucleus combined detection with serotonin terminals using dual immunocytochemistry

Immunocytochemical methods were used to examine the ultrastructural features and cellular interrelationships of GABA and serotonin afferent fibers to the rat red nucleus. GABAergic nerve endings were identified in two ways, either using a pre-embedding immunoperoxidase procedure with an antibody against glutamate decarboxylase, the GABA-synthesizing enzyme, or after post-embedding immunogold labelling with an anti-GABA antibody. With the latter approach, it was possible to simultaneously visualize the GABAergic and serotoninergic innervation of the red nucleus (magnocellular part) in electron microscope preparations. This procedure involved GABA labelling of ultrathin sections obtained from specimens previously immunostained for serotonin using the pre-embedding peroxidase-antiperoxidase technique. The doubly stained sections showed gold and peroxidase markers to be present in two distinct populations of axonal varicosities. Unlike the GABAergic nerve endings, which were found to be profusely distributed throughout the nucleus, the serotonin nerve endings were relatively scarce. They contacted dendrites of large-sized neurons usually endowed with several GABA-gold labelled terminals. Not uncommonly, direct appositions between serotonin and GABA-positive terminals were also encountered. These data provide morphological evidence that red nucleus outputs may be dually regulated by GABAergic and serotoninergic afferents, while suggesting that presynaptic GABA/serotonin interactions might also play a significant part in red nucleus functions.

[Diagnosis and treatment of fetal tachycardia. Apropos of 2 cases]

Fetal echocardiographic studies were performed in 2 patients referred for evaluation of cardiac dysrythmias. Supra-ventricular tachycardia were diagnosed in the 2 patients. Appropriate prenatal treatment can not avoid premature deliveries in one case. Evaluation of in utero cardiac arrhythmias and monitoring of in utero therapy are discussed.

The opine synthase genes carried by Ti plasmids contain all signals necessary for expression in plants

Signals necessary for in vivo expression of Ti plasmid T-DNA-encoded octopine and nopaline synthase genes were studied in crown gall tumors by constructing mutated genes carrying various lengths of sequences upstream of the 5' initiation site of their mRNAs. Deletions upstream of position -294 did not interfere with expression of the octopine synthase gene while those extending upstream of position -170 greatly reduced the gene expression. The estimated size of the octopine synthase promoter is therefore 295 bp. The maximal length of 5' upstream sequences involved in the in vivo expression of the nopaline synthase gene is 261 bp. Our results also demonstrated that Ti plasmid-derived sequences contain all signals essential for expression of opine synthase genes in plants. Expression of these genes, therefore, is independent of the direct vicinity of the plant DNA sequences and is not activated by formation of plant DNA and T-DNA border junction.

Isolation and characterization of DNA sequences from Triticum aestivum which function as origins of replication in Saccharomyces cerevisiae

Recombinant YIp5 plasmids with the DNA from Triticum aestivum are capable of autonomous replication in Saccharomyces cerevisiae. The URA transformants are unstable without selection pressure, and transformation of yeast cells with these plasmids occurs at high frequency. The cloned sequences were characterized and analyzed to state their belonging to Triticum tribe.

[Auto-immunity and ovarian failure (author's transl)]

The authors report the case of a 17 year-old girl presenting with primary amenorrhea. Investigations showed that it was due to auto-immune hypogonadism. Such an etiology is rarely found in ovarian insufficiencies. In the reported case, there was no other associated auto-immune disorder. Two types of anti-ovarian antibodies are known: antibodies to steroid-producing cells and antibodies to germ-cells. The first ones are found in patients presenting with auto-immune Addison's disease, and are directed against antigens common to ovary and adrenal glands and their presence does not imply ovarian dysfunction. The second ones are more specific and found chiefly in patients with sterility and amenorrhea; they are divided into 2 subgroups: antibodies against the cytoplasm of the ovacyte antibodies and antibodies against zona pellucida. In patients with primary ovarian insufficiency, the presence of such antibodies should always be investigated.

[The role of mycoplasma in sterility. A study of 150 sterile women (author's transl)]

150 women who were being treated for sterility had their cervical mucus searched for T. mycoplasma. Group I: 123 women who had no obvious cause for sterility. 45.5 per cent had T. mycoplasma (56/123). Group II: Out of 27 women who had a major cause for sterility there were 48 per cent (13/27) who were carriers of T. mycoplasma. The incidence of T. mycoplasma in control fertile women was 53 per cent (16/30). After treatment with Doxycycline: 5 pregnancies were obtained out of Group I, which is 8.9 per cent. none in Group II. The mycoplasma seems to play a very minor role in sterility. Its incidence is identically the same in women who are sterile or normally fertile. With treatment only a very small percentage (8.9 per cent) of pregnancies were obtained in carriers of mycoplasma who did not have another obvious cause for their sterility.

[Histologic and immunologic study of the testis after ligation of the vas deferens in dogs]

We wanted to study the effect of bilateral ligature and section of the deferentia of 12 dogs from the histological and immunological aspects. We looked for circulating anti-sperm antibodies and anti-basal membrane of the testes antibodies at the same time as histological study to find out what happened to these lesions after epididymo-deferential anastomosis had been carried out 16 weeks later. The histological lesions (disappearance of exfoliation of the germ cells and of necrobiosis of these cells) disapperared after anastomosis. Anti-basal membrane antibodies were never found. Anti-testicular circulating auto-antibodies were never found. Anti-sperm antibodies appeared between 1 and 5 months after ligature and then disappeared a few months later. Failures to fertilise after epiddidymo-deferential anastomoses therefore do not seem to be due to these two factors.