Biomedical subjects

P G Jones

Publications and source records attributed to P G Jones.

At least 19 recordsLinked to original sources

PubMed2006

Resting energy expenditure and body composition of Labrador Retrievers fed high fat and low fat diets.

A high dietary fat intake may be an important environmental factor leading to obesity in some animals. The mechanism could be either an increase in caloric intake and/or a decrease in energy expenditure. To test the hypothesis that high fat diets result in decreased resting energy expenditure (REE), we measured REE using indirect calorimetry in 10-adult intact male Labrador Retrievers, eating weight-maintenance high-fat (HF, 41% energy, average daily intake: 8018 +/- 1247 kJ/day, mean +/- SD) and low-fat (LF, 14% energy, average daily intake: 7331 +/- 771 kJ/day) diets for a 30-day period. At the end of each dietary treatment, body composition measurements were performed using dual-energy X-ray absorptiometry. The mean +/- SD REE was not different between diets (4940 +/- 361 vs. 4861 +/- 413 kJ/day on HF and LF diets respectively). Measurements of fat-free mass (FFM) and fat mass (FM) also did not differ between diets (FFM: 26.8 +/- 2.3 kg vs. 26.3 +/- 2.5 kg; FM: 3.0 +/- 2.3 vs. 3.1 +/- 1.5 kg on HF and LF diets respectively). In summary, using a whole body calorimeter, we found no evidence of a decrease in REE or a change in body composition on a HF diet compared with LF diet.

Absorptiometry, Photon↗

PubMed2006

[Annulated heterocycles from methyl 6-chloro-5-formyl-2-methyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3-carboxylate].

The pyridone 1a reacts with POCl3/DMF to yield the title compound 2a. After irradiation of 2a the enolether 3 is isolated, as shown by an X-ray structure determination. The pyridine 4 obtained by dehydrogenation of 2a leads under reductive conditions to the benzo[c][2,7]naphthyridines 5-7. The reaction of 4 with o-phenylenediamine gives the benzimidazole 8, while using 2-aminophenol or 2-aminothiophene respectively the pyrido[2,3-b[1,5]benzoxazepine 11 and the corresponding benzothiazepine 12 are obtained.

Heterocyclic Compounds↗

PubMed2006

[Contribution to the erythroquine and thalleioquine reaction].

The 8,8'-biquinoline-5,5'-diones 2A are formed by the erythroquine and thalleioquine reaction from the 6-methoxyquinolines 1 as model compounds. The red substances 2A react with hydrochloric acid to yield the yellow biquinolinedihydrochlorides 3. The structure of 3b dihydrate is determined by X-ray crystal analysis. The redox properties of 2A are investigated by voltammetric methods.

Hydrochloric Acid↗

PubMed2006

[Derivatives of exemestane--synthesis and evaluation of aromatase inhibition].

The irreversible aromatase inhibitor exemestane (6) reacts with nitromethane and sodium ethanolate to yield the Michael adduct 9. The aldehyde 10 is obtained by Nef reaction of the nitro compound 9 and affords the 1,4-dihydropyridine (DHP) 11 by Hantzsch reaction using methyl beta-aminocrotonate in acetic acid. The new compounds showed a reduced inhibitory potency towards aromatase (IC50 values: 9, 0.91 microM; 10, 2.5 microM; 11, 10 microM) compared to 6 (IC50 = 0.23 microM). The 1,4-DHP 11 was dehydrogenated with CAN or electrochemically (E1/2 =1.18 V) to yield the corresponding pyridine 12.

Androstadienes↗

PubMed2005

High-resolution characterization of the canine DLA-DRB1 locus using reference strand-mediated conformational analysis.

Several methods exist for genotyping class II DLA gene polymorphisms in the dog. The most accurate method is sequence-based typing, which involves direct sequencing of polymerase chain reaction products. However, this method is expensive and unsuitable for large-scale studies. Recently, reference strand-mediated conformation analysis (RSCA) has been shown to be effective for characterizing major histocompatibility complex genes in humans, sheep, horse, and cats. RSCA is a cheap and rapid method, ideal for large epidemiological studies. We have developed RSCA for typing DLA-DRB1 in the dog. Control panels including dogs typed by sequence-based typing and cloned major histocompatibility complex class II alleles in plasmids were used to establish migration patterns for each allele using 20 different fluorescent labeled references, of which 5 were selected to allow for clear identification and discrimination of all known DLA-DRB1 alleles. We have compared 168 dogs typed by RSCA for DLA-DRB1 and characterized by sequence-based typing, with less than 1% discrepancy. These differences were due to missing alleles because of a weak polymerase chain reaction. To date, we have RSCA-typed 1,394 dogs. RSCA is likely to become the method of choice for characterizing DLA genes in the dog and will prove a useful tool for dissecting the immune response of dogs in clinical studies.

Alleles↗

PubMed2005

[Benzo[h][1 ,6]naphthyridines from dimethyl 1,2-dihydro-2-(2-nitrophenyl)-pyridine-3,5-dicarboxylate].

The reaction of 2-nitrobenzaldehyde with methyl propiolate and ammonium acetate in acetic acid yields 2,6-dinor-nifedipine (1a) and as a by-product not the dimethyl 2,5-dicarboxylate isomer, but the rac. 1,2-dihydropyridine (DHP) 1b, as proven by X-ray analysis. The benzo[h][1,6]naphthyridines 4-6 are synthesized from the oxidation product 2b and the photo-product 3b. The compounds 6 represent starting materials for potential anti-malarial agents.

Antimalarials↗

PubMed2005

[12-acyl-6,1 2-dihydro-6-phenyl-[1 ]benzofuro[2,3-c]- and -[1,5]benzothieno[2,3-c]-[1 ,5]-benzothiazepines--tetracyclic diltiazem derivatives].

The reaction of the tetracycles 1 with chloroacetylchloride yields the amides 2. The structure of 2a was proven by X-ray analysis. The amides 2 exist as diastereomers in solution because of planar chirality. From the N-chloroacetyl compounds only 2a, b could be substituted with diethylamine to give 3a, b. Reduction experiments of 3a, b with DIBAH do not afford diltiazem analogues; instead, the starting compounds la, b are formed by hydrolysis.

Benzofurans↗

PubMed2005

[Color reaction of chlorhexidine and proguanil with hypobromite].

Colour reaction of chlorhexidine and proguanil with hypobromite The antimalarial agent proguanil reacts with hypobromite to yield the red coloured (E)-3-[(4-chlorophenyl)imino]-N-isopropyl-3H-1,2,4-triazol-5-amine (6B). The structure of 6B was proven by X-ray. The red colour obtained by the test for the disinfectant chlorhexidinedihydrochloride Ph. Eur. with hypobromite is probably attributable to a corresponding chromophore.

Antimalarials↗

PubMed2005

[Biphenyl derivatives as by-products from the synthesis of 4-aryl-4H-pyrans].

The reaction of the 1,5-diketones 1 with acetic anhydride/acetic acid in the presence of zinc chloride yields the 4-aryl-4H-pyrans 2 as main products. The annulated lactone 3 and the cyclohexene derivatives 5 are isolated as by-products. The configuration of the cyclohexanone 4a and the cyclohexenes 5 are deduced from nmr spectroscopic methods. The structure of 5b is confirmed by X-ray crystal analysis.

Biphenyl Compounds↗

PubMed2003

Disappearance of back-to-back high-pT hadron correlations in central Au+Au collisions at sqrt[s NN ] =200 GeV.

Azimuthal correlations for large transverse momentum charged hadrons have been measured over a wide pseudorapidity range and full azimuth in Au+Au and p+p collisions at sqrt[s(NN)]=200 GeV. The small-angle correlations observed in p+p collisions and at all centralities of Au+Au collisions are characteristic of hard-scattering processes previously observed in high-energy collisions. A strong back-to-back correlation exists for p+p and peripheral Au+Au. In contrast, the back-to-back correlations are reduced considerably in the most central Au+Au collisions, indicating substantial interaction as the hard-scattered partons or their fragmentation products traverse the medium.

Journal Article↗

PubMed2003

Azimuthal anisotropy and correlations in the hard scattering regime at RHIC.

Azimuthal anisotropy (v(2)) and two-particle angular correlations of high p(T) charged hadrons have been measured in Au+Au collisions at sqrt[s(NN)]=130 GeV for transverse momenta up to 6 GeV/c, where hard processes are expected to contribute significantly. The two-particle angular correlations exhibit elliptic flow and a structure suggestive of fragmentation of high p(T) partons. The monotonic rise of v(2)(p(T)) for p(T)<2 GeV/c is consistent with collective hydrodynamical flow calculations. At p(T)>3 GeV/c, a saturation of v(2) is observed which persists up to p(T)=6 GeV/c.

Journal Article↗

PubMed2003

[Pyrano[3,4-c]quinolines from 1-desaza--oxa-nifedipine].

Pyrano[3,4-c]quinolines from 1-desaza-1-oxa-nifedipine The reaction of the 1,5-diketone 1 with acetic anhydride/acetic acid in the presence of zinc chloride yields the 1-desaza-1-oxa-nifedipine 2 and the annulated lactone 3 as a by-product. The structures of 2 and 3 are confirmed by X-ray structure analysis. The pH-dependent reduction of the nitro group from 2 leads to the pyrano[3,4-c]quinolines 4Aa, b by ring closure. The cyclic hydroxamic acid 4Aa represents a weak, non-selective inhibitor of 5-, 12- and 15-lipoxygenase of human full-blood.

Chromatography, High Pressure Liquid↗

PubMed2003

[Isomeric phenanthridines from 1,2-dihydro-5-methyl-2'-nitro-[1,1'-biphenyl]-2,6-dicarboxylic acid esters].

Hydrolysis of the dienamine function of the dihydrobiphenyls 3 leads to a mixture of the tautomers 4A-C (NMR). The structures of the starting material 3a and the products 4cA and 4bC are confirmed by X-ray crystal analysis. The biphenyls 5 are formed by dehydrogenation of 3 with iodine, whereas 4b produced the additional iodinated compound 6. 4b reacts with manganese dioxide to yield the phenol 7a. Irradiation of the dihydrobiphenyls 3 with UV-A light gives the nitrosobiphenyls 8. In contrast, the nitrobiphenyl 7b and the lactam 10a are formed as photo products from 4c. The reduction of the nitro group of 5 with Fe/AcOH leads to the isomeric phenanthridines 10 and 11 by cyclization, whereas after reaction with Zn/NH4Cl the cyclic hydroxamic acids 12 and 13 are isolated. Compound 7a reacts with Zn/acetate buffer to yield only the hydroxamic acid 12. Ring closure takes place on treating the nitrosobiphenyls 8 with conc. hydrochloric acid, to yield the chloro-substituted hydroxamic acids 14. The half wave potentials of the dihydrobiphenyls 3 and 4 are measured by anodic oxidation using a rotating platinum electrode by means of differential pulse voltammetry. The dienamines 3 are more sensitive towards oxidation than the reference drug nifedipine; in contrast, the carba-analogues 4 are much more stable. The cyclic hydroxamic acids 13 and 14a are tested for their ability to inhibit 5-, 12- and 15-lipoxygenase. Compound 13 represents a weak inhibitor of 5-lipoxygenase in human whole blood.

Chemical Phenomena↗

PubMed2002

Coherent rho(0) production in ultraperipheral heavy-ion collisions.

The STAR Collaboration reports the first observation of exclusive rho(0) photoproduction, AuAu-->AuAurho(0), and rho(0) production accompanied by mutual nuclear Coulomb excitation, AuAu-->Au*Au*rho(0), in ultraperipheral heavy-ion collisions. The rho(0) have low transverse momenta, consistent with coherent coupling to both nuclei. The cross sections at sqrt[s(NN)]=130 GeV agree with theoretical predictions treating rho(0) production and Coulomb excitation as independent processes.

Journal Article↗

PubMed2002

Centrality dependence of high-p(T) hadron suppression in Au+Au collisions at sqrt[s(NN)]=130 GeV.

Inclusive transverse momentum distributions of charged hadrons within 0.2<p(T)<6.0 GeV/c have been measured over a broad range of centrality for Au+Au collisions at sqrt[s(NN)]=130 GeV. Hadron yields are suppressed at high p(T) in central collisions relative to peripheral collisions and to a nucleon-nucleon reference scaled for collision geometry. Peripheral collisions are not suppressed relative to the nucleon-nucleon reference. The suppression varies continuously at intermediate centralities. The results indicate significant nuclear medium effects on high-p(T) hadron production in heavy-ion collisions at high energy.

Journal Article↗

PubMed2002

Synthesis of the first 2,3-dihydro-1,2,3-azadiphosphete complex.

Synthesis of the first 2,3-dihydro-1,2,3-azadiphosphete complex was achieved via thermal reaction of a 2H-azaphosphirene complex in o-xylene, whereby a 2,5-dihydro-1,3-diaza-2,5-diphosphinine complex and a further unidentified byproduct were formed; the structure of the title compound was established through an X-ray single-crystal diffraction study.

Journal Article↗

PubMed2002

Azimuthal anisotropy of K(0)(S) and Lambda+Lambda production at midrapidity from Au+Au collisions at sqrt[s(NN)]=130 GeV.

We report STAR results on the azimuthal anisotropy parameter v(2) for strange particles K(0)(S), Lambda, and Lambda at midrapidity in Au+Au collisions at sqrt[s(NN)]=130 GeV at the Relativistic Heavy Ion Collider. The value of v(2) as a function of transverse momentum, p(t), of the produced particle and collision centrality is presented for both particles up to p(t) approximately 3.0 GeV/c. A strong p(t) dependence in v(2) is observed up to 2.0 GeV/c. The v(2) measurement is compared with hydrodynamic model calculations. The physics implications of the p(t) integrated v(2) magnitude as a function of particle mass are also discussed.

Journal Article↗

PubMed2002

Midrapidity Lambda and Lambda(macro) production in Au+Au collisions at the square root of [s(NN)]=130 GeV.

We report the first measurement of strange (Lambda) and antistrange (Lambda macro) baryon production from square root of [s(NN)]=130 GeV Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC). Rapidity density and transverse mass distributions at midrapidity are presented as a function of centrality. The yield of Lambda and Lambda; hyperons is found to be approximately proportional to the number of negative hadrons. The production of Lambda; hyperons relative to negative hadrons increases very rapidly with transverse momentum. The magnitude of the increase cannot be described by existing hadronic string fragmentation models alone.

Journal Article↗