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Biomedical subjects

M Jay

Publications and source records attributed to M Jay.

At least 19 recordsLinked to original sources
PubMed2001

No evidence for linkage between COMT and schizophrenia in a French population.

Catechol-O-methyltransferase is a candidate in the predisposition to schizophrenia both because of its function and the position of its gene. A multipoint non-parametric linkage analysis and a transmission disequilibrium test were performed on 42 multiplex families genotyped for Pml I and Bcl I polymorphisms using two definitions of the affected phenotype. Neither linkage nor preferential transmission of any allele or haplotype was detected, failing to replicate previous positive findings.

Alleles↗
PubMed2001

Concordance of deficit and non-deficit subtypes in siblings affected with schizophrenia.

Deficit and non-deficit subtypes were examined for their concordance in 83 sibling pairs of 109 schizophrenic patients belonging to 46 multiply affected families. Using a sib-pair method, we have found that the distribution of deficit and non-deficit syndromes in sibling pairs of schizophrenic patients differed significantly from chance expectation. This familial aggregation suggests that the syndrome may be used to define phenotypes for genetic studies.

Adult↗
PubMed2001

The domestication syndrome within Hybrid Perpetuals roses: the effect of unconscious selection on flavonoids.

Cultivated GallicanaexChinenses hybrids of roses, namely Hybrid Perpetuals, were compared with their parents as to morphology, petal colour, flavonol and anthocyanin metabolism. Morphology exhibited clear patterns of hybridity. An objective measure of petal lightness (L) indicated that Hybrid Perpetuals were submitted to a selection pressure favouring dark-flowered cultivars. When compared to the parental flavonoid metabolisms, Hybrid Perpetuals exhibited increased synthesis of anthocyanin and quercetin. High amounts of anthocyanin in Hybrid Perpetuals resulted from the selection of deeper-coloured flowers. High amounts of quercetin were correlated with enhanced anthocyanin synthesis, so that this originality of the flavonol metabolism was interpreted on biogenetic ground as a repercussion of this same selection pressure. Finally, the patterns of variation of flavonol glycosides within the Hybrid Perpetuals reflected the indirect selection pressure for the quercetin end-products, and with the ancestral hybridizations for the kaempferol derivatives.

Journal Article↗
PubMed2001

Chemical diversification trends in Astragalus caprinus (Leguminosae), based on the flavonoid pathway.

Flavonoid glycosides of Astragalus caprinus (Leguminosae) were investigated; more than 30 glycosides were found in leaf material, based on the aglycones kaempferol, quercetin and their methylated derivatives. Among them 14 compounds were found in significant amounts and showed a contrasting distribution. They could be ordered into three groups: polyglycosides, acylated polyglycosides and methylated polyglycosides. The distribution of these compounds was studied within a large collection of individual plants harvested in Tunisia; the results showed a relationship between metabolic trends and ecological diversification.

Journal Article↗
PubMed2001

Two new glycosides from Astragalus caprinus.

A new glycoside of flavonol (1) and a new glycoside of a cycloartane-type triterpene (2) were isolated from the leaves and the roots of Astragalus caprinus, respectively. Their structures were elucidated in turn by spectroscopic data interpretation as 3-O-[[beta-D-xylopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->6)][beta-D-apiofuranosyl(1-->2)]]-beta-D-galactopyranosyl kaempferol (1) and 3-O-(beta-D-xylopyranosyl)-24-O-(beta-D-glucopyranosyl)-20,25-epoxycycloartane-3beta,6alpha,16beta,24alpha-tetrol (2).

Flavonoids↗
PubMed2001

Methods for the recovery and purification of polyene antifungals.

Despite the development of newer antifungal drugs, the polyene antifungals continue to be the most potent broad-spectrum fungicides available for clinical use. The incidence and severity of fungal infections are on the rise, underscoring the need for new and more effective antifungal drugs. Thus, the search for new polyene antifungals is ongoing. The limited solubility, polymorphic character, and inherent chemical instability of these compounds make their economical recovery and purification from mass culture challenging problems in biotechnology. This article provides a comprehensive review of the methods that have been developed for the recovery and purification of amphotericin B and nystatin, the two most important polyenes currently in clinical use.

Amphotericin B↗
PubMed2001

Monitoring the retention of a protein antigen in complete Freund's adjuvant, alum, and pluronic F-127 gel formulations by X-ray fluorescence.

Adjuvants function by protecting antigens from rapid degradation or dispersal. The effectiveness of experimental adjuvants can be assessed by measuring antibody titers to the antigen of interest or, less frequently, by evaluating the retention and distribution of antigen at the application site. In this study, we used X-ray fluorescence (XRF) to monitor the release of an iodinated protein (I-bovine serum albumin) from several adjuvant formulations after its subcutaneous injection in rats. The interaction of the tagged antigen with an external Am-241 source leads to the emission of iodine X-rays from the application site; the number of these X-rays is proportional to the concentration of the protein remaining at the injection site. The disappearance of the iodine X-rays, and hence the antigen, from the injection site followed first-order kinetics for all adjuvant formulations tested; mean half-life values were as follows: in 50% Freund's adjuvant, 17.1 +/- 1.1 h; in 4-hour-old 25% Alum, 11.78 +/- 0.08 h; in 4-h-old 50% Alum, 13.2 +/- 2 h; in 3-day-old 50% Alum, 15.8 +/- 1.5 h; and in 240 mg/mL Pluronic F-127, 7.9 +/- 0.7 h. We conclude that XRF is an easy, reliable, noninvasive method to monitor the retention of antigens in these adjuvant solutions.

Alum Compounds↗
PubMed2001

Three new flavonol malonylrhamnosides from Ribes alpinum.

Three new flavonol malonylrhamnosides, 3-O-(4"-O-malonyl)-alpha-L-rhamnopyranosides of mearnsetin, myricetin and quercetin respectively, together with the corresponding mearnsitrin, myricitrin, quercitrin and the 4-O-methyl phloracetophenone 2-O-beta-D-glucopyranoside, were isolated from the leaves of Ribes alpinum and fully characterized by spectrocopic methods including 2D NMR.

Glycosides↗
PubMed2000

Scintigraphic Measurement of Liquid Holdup in Foam Fractionation Columns.

The profile of liquid holdup in foam fractionation columns was studied as a function of time by the use of a nuclear scintigraphic imaging technique. Sodium [(99m)Tc]pertechnetate was employed as the imaging agent and served as a marker for the amount of water present in the foam during the foam fractionation of bovine serum albumin. A gamma scintigraphic camera fitted with a pinhole collimator was used to acquire the data in a dynamic manner. The greatest changes in the liquid holdup of the foam were observed in the region just above the foam-retentate interface, particularly when a gas dispersion frit with large nominal frit porosity was employed to generate the foam. Beyond these first few centimeters, the volume fraction of water in the foam did not change appreciably. This suggests that under the conditions employed, increases in foam column height would not substantially improve the performance of the foam fractionation of bovine serum albumin. In the case of foam generated with a frit of small porosity, the liquid holdup profile indicated a higher fraction of water than observed with the larger frit. The use of scintigraphic imaging can provide valuable data concerning the liquid fraction that is not easily obtained with methods previously used in the study of drainage in foam fractionation columns. Copyright 2000 Academic Press.

Journal Article↗
PubMed2000

Foam fractionation of binary mixtures of lysozyme and albumin.

A nitrogen gas-based foam fractionation method was employed to separate model proteins, bovine serum albumin (BSA) and hen egg white lysozyme, from each other. Fractionation was characterized by the separation ratio and by recovery of proteins in the retentate as a function of the nominal pore size of the gas dispersion frit and solution conditions (pH and ionic strength). For binary mixtures of the proteins at pH 7.4, and ionic strength (mu) of 0.18 M, the recovery of lysozyme and the separation ratio were both dependent on the frit size employed to generate the foam. At low ionic strength (mu = 0.01 M), separation was only somewhat greater with the small pore size frits, although at values significantly lower than those found for high ionic strength. The diminished separations appear to be due to the only slight changes in recoveries observed for BSA and lysozyme.%Separation ratios of lysozyme from BSA in solutions either of high or low ionic strength were maximal at pH values equal to or less than the isoelectric point (pI) of BSA. Separation ratios were lower when foaming was carried out under low compared with high ionic strength. The recovery of lysozyme was enhanced by foaming from solutions of low pH and high ionic strength. Recoveries of BSA were greatest when the molecule was negatively charged. Electrical interactions between the positively charged lysozyme and negatively charged BSA may explain the diminished separation ratios and enhanced recoveries. Enzyme activity studies of lysozyme remaining in the retentate showed no change from prefoam activity.

Chemical Fractionation↗
PubMed2000

Novel frameshift mutations in the RP2 gene and polymorphic variants.

Mutations in the RP2 gene located on Xp11.23 are associated with X-linked retinitis pigmentosa (XLRP), a severe form of progressive retinal degeneration which leads to complete loss of vision in affected males. To date, 14 different mutations in the RP2 gene have been reported to cause XLRP, the majority of which lead to a coding frameshift within the gene and predicted truncation of the protein product. We here report two novel frameshift mutations in RP2 identified in XLRP families by PCR-SSCP and direct sequencing, namely 723delT and 796-799del. Four single nucleotide polymorphisms (SNPs) within the coding region of RP2 are also described (105A>T, 597T>C, 844C>T, 1012G>T), the first polymorphisms to be reported within this gene of unknown function, two of which alter the amino acid sequence. The current study extends the XLRP mutation profile of RP2 and highlights non-pathogenic coding sequence variations which may facilitate both functional studies of the gene and analysis of intragenic allelic contribution to the phenotype.

Alternative Splicing↗
PubMed2000

Activation of mesolimbic dopamine function by phencyclidine is enhanced by 5-HT(2C/2B) receptor antagonists: neurochemical and behavioural studies.

Administration of the non-competitive NMDA receptor antagonists phencyclidine (PCP) (0.6-5 mg/kg s.c.) and MK-801 (0.1-0.8 mg/kg s.c. ) dose-dependently increased locomotor activity in the rat. Pre-treatment of rats with SB 221284 (0.1-1 mg/kg, i.p.) a 5-HT(2C/2B) receptor antagonist or SB 242084 (1 mg/kg, i.p.) a selective 5-HT(2C) receptor antagonist, doses shown to block mCPP induced hypolocomotion, significantly enhanced the hyperactivity induced by PCP or MK-801. Neither compound altered locomotor activity when administered alone. Furthermore, systemic administration of PCP (5 mg/kg s.c.) increased nucleus accumbens dopamine efflux in the rat to a maximum of approximately 220% of basal, 40-60 min after administration. Pre-treatment with the 5-HT(2C/2B) receptor antagonist SB 221284 (1 mg/kg, i.p.) and the 5-HT(2C) receptor antagonist SB 242084 (1 mg/kg i.p.) failed to affect nucleus accumbens dopamine efflux per se but significantly enhanced the magnitude and duration of the increase induced by PCP. However, the time course of the neurochemical and behavioural effects were qualitatively and quantitatively different, suggesting the potential involvement of other neurotransmitter pathways. Nevertheless, the present results provide behavioural and neurochemical evidence which demonstrate that, in the absence of effects per se, blockade of 5-HT(2C) receptors enhanced the activation of mesolimbic dopamine neuronal function by the non-competitive NMDA receptor antagonists PCP and MK-801.

Aminopyridines↗
PubMed2000

Kaitiakitanga: protecting New Zealand's native biodiversity.

Kaitiakanga is a Maori word meaning guardianship. It is a word that has become central to New Zealand's efforts to conserve native biodiversity as well as encapsulating the new emphasis on inclusion of Maori cultural values and land concerns.

Animals↗
PubMed1999

Photobinding of [gamma-(32)P] ATP gamma-benzophenone to the surface of a polyurethane membrane in the preparation of a beta-particle-emitting balloon catheter.

PURPOSE: The goal of this study was to photochemically bind 5'-[gamma-(32)P]-azido-ATP gamma-benzophenone ((32)P-ATP-BPA) to a polyurethane surface. Expandable balloon catheters composed of (32)P-coated polyurethane have the potential for preventing restenosis following percutaneous transluminal coronary angioplasty. METHODS: After extensive preparation and cleaning of polyurethane disks, 10 microL of the radioactive ATP-BPA reagent (specific activity = 9.4 Ci/mmol) was applied to the surface. After drying, the membrane disks were exposed ultraviolet radiation (254 nm; 6,000 microwatts/cm(2)) for up to 2 h and subsequently washed. The amount of (32)P bound to the membrane disks was determined by Cerenkov counting in a liquid scintillation counter. The effect of the labeling solution composition (solvent, presence of potassium or manganese ions, addition of surfactants, etc.) on photobinding efficiency was determined. RESULTS: The efficiency of attaching the (32)P-ATP-BPA reagent to the polyurethane surfaces was markedly dependent upon the cleaning and pretreatment conditions. Following detailed washing and rinsing steps, a photobinding efficiency of 36.4+/-3.6% was obtained with 10 min UV exposure time using (32)P-ATP-BPA solutions that were 95/5 methanol/water by vol. Increasing the concentration of the (32)P-ATP-BPA reagent did not improve the photobinding efficiency; however, the total amount of (32)P bound to the disks was increased. CONCLUSIONS: Photochemical methods can be employed to attach beta(-)-emitting radionuclides to polymers that are employed as balloon catheters. The preparation of the polymeric material (washing, rinsing, and drying) is critically important in maximizing the amount of (32)P-ATP-BPA that can be bound to the polymer.

Adenosine Triphosphate↗
PubMed1999

Difference between RP2 and RP3 phenotypes in X linked retinitis pigmentosa.

AIM: X linked retinitis pigmentosa (XLRP) has two genetic loci known as "RP2" and "RP3". Clinical features reported to differentiate RP2 from RP3 include a higher prevalence of myopia and primary cone dysfunction in RP2, and late onset night blindness and tapetal reflex in RP3. Members from 14 XLRP families were examined in an attempt to verify these differences. METHODS: 16 affected males and 37 females from 14 XLRP families assigned as either RP2 or RP3 by haplotype analysis and/or by heterogeneity analysis were examined. Members of all 14 families who were willing to participate but unavailable for examination were contacted and detailed interviews carried out. RESULTS: No clear phenotypic differences were found that could be used to reliably differentiate RP2 from RP3 with respect to myopia and onset of night blindness. The tapetal reflex was also found to be present in carriers of both RP2 and RP3. CONCLUSIONS: XLRP is a heterogeneous class of rod degenerative disorders with no clear phenotypic differentiation between the two genetic loci RP2 and RP3. There is a continuum of clinical presentations which can be seen in both RP2 and RP3, but the features within a given family tend to be consistent. However, interfamilial variability is prevalent leading to a wide range of clinical presentations and more than one abnormal allele at each gene locus cannot be excluded.

Adult↗
PubMed1998

Anticipation in schizophrenia: no evidence of expanded CAG/CTG repeat sequences in French families and sporadic cases.

A decrease in age of onset of schizophrenia through consecutive family generations (anticipation) has been found in several studies. Anticipation is known to result from expansion of CAG repeats in genes that determine several neurodegenerative disorders. In a previous study we analysed 26 unilineal two-generation French pedigrees and found clinical evidence of anticipation. A 10-year mean reduction in age of onset of schizophrenia was found in the second generation compared with the parental generation. The repeat expansion detection method was used to screen for CAG expansion in 21 of the 26 families with evidence of anticipation for the disease and in 59 sporadic schizophrenics and 59 controls. Comparison of the frequency distributions of CAG/CTG repeat size observed in schizophrenics and controls showed no significant difference, even when we considered familial (P = 0.23) and sporadic (P = 0.25) affected individuals separately. These results do not support the association between long CAG repeats and schizophrenia. However, the possibility that expansions with fewer than 40 repeats are involved in schizophrenia cannot be excluded.

Adult↗