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E J Jones

Publications and source records attributed to E J Jones.

15 recordsLinked to original sources
PubMed2001

Identification, cloning, and expression of a functional phenylalanyl-tRNA synthetase (pheRS) from Staphylococcus aureus.

Phenylalanyl-tRNA synthetase (pheRS) is unique among aminoacyl tRNA synthetases in that it is a heterotetrameric enzyme composed of two alpha-subunits and two larger beta-subunits. In prokaryotes, the alpha- and beta-subunits of pheRS are encoded by the genes pheS and pheT, respectively. In this report we describe the isolation of a DNA fragment (3.52 kb) containing the pheS and pheT genes from a Staphylococcus aureus (WCUH29) genomic DNA library. Both genes, found as a part of transcriptional operon, were predicted to encode polypeptides which showed strong primary and structural similarity to prokaryotic phenylalanyl-tRNA synthetase alpha- and beta- subunits. We describe the high-level overexpression and purification of recombinant S. aureus pheRS using pheS and pheT genes as part of an artificial operon in Escherichia coli. For comparative analysis we also report a procedure for the purification of native pheRS from S. aureus (Oxford Strain) and demonstrate that Michaelis-Menten parameters for both recombinant and native enzyme, at least for phenylalanine tRNA aminoacylation are comparable.

Amino Acid Sequence↗
PubMed2001

Property loss estimation for wind and earthquake perils.

This article describes the development of a generic loss assessment methodology, which is applicable to earthquake and windstorm perils worldwide. The latest information regarding hazard estimation is first integrated with the parameters that best describe the intensity of the action of both windstorms and earthquakes on building structures, for events with defined average return periods or recurrence intervals. The subsequent evaluation of building vulnerability (damageability) under the action of both earthquake and windstorm loadings utilizes information on damage and loss from past events, along with an assessment of the key building properties (including age and quality of design and construction), to assess information about the ability of buildings to withstand such loadings and hence to assign a building type to the particular risk or portfolio of risks. This predicted damage information is then translated into risk-specific mathematical vulnerability functions, which enable numerical evaluation of the probability of building damage arising at various defined levels. By assigning cost factors to the defined damage levels, the associated computation of total loss at a given level of hazard may be achieved. This developed methodology is universal in the sense that it may be applied successfully to buildings situated in a variety of earthquake and windstorm environments, ranging from very low to extreme levels of hazard. As a loss prediction tool, it enables accurate estimation of losses from potential scenario events linked to defined return periods and, hence, can greatly assist risk assessment and planning.

Journal Article↗
PubMed2000

Serotonergic regulation of mRNA expression of Arc, an immediate early gene selectively localized at neuronal dendrites.

Arc (activity regulated, cytoskeleton associated protein) is an effector immediate early gene that is selectively localized in the neuronal dendrites. Elevation of brain 5-HT by the combined administration of the monoamine oxidase inhibitor, tranylcypromine (TCP, 5 mg/kg, i.p.), and the 5-HT precursor L-tryptophan (L-TP, 100 mg/kg, i.p.), increased Arc mRNA abundance in the cingulate, orbital, frontal and parietal cortices as well as in the striatum but a reduction was observed in the CA1 region of the hippocampus. The 5-HT releasing agent p-chloroamphetamine (PCA, 5 mg/kg, s.c.) also increased Arc mRNA in the cortical and striatal areas. Depleting brain 5-HT with the tryptophan hydroxylase inhibitor, p-chlorophenylalanine (pCPA, 300 mg/kg, i.p. for two days), on the other hand, significantly attenuated the increase in Arc mRNA induced by tranylcypromine and L-tryptophan (TCP/L-TP). Pretreatment with the 5-HT2 receptor antagonist ketanserin (2 mg/kg, i.p.) significantly attenuated the effect of TCP/L-TP in the cortex but only partially in striatum and did not affect the reduction in the CA1 region. The 5-HT2 agonist DOI (0.2, 1 and 2 mg/kg, i.p.) dose-dependently increased Arc mRNA abundance in cortical areas with a pattern similar to that of TCP/L-TP and PCA. DOI, however, had much weaker effects on Arc mRNA in the striatum and did not have any significant effect in the CA1, CA3 and the dentate gyms (DG) of the hippocampus. Pretreatment with ketanserin completely blocked the effect of DOI on Arc expression. These data suggest that Arc mRNA expression can be induced in the cortex by increases in extracellular 5-HT and that 5-HT2 receptors play a major part in mediating such effects. Additional 5-HT receptors as well as other neurotransmitters may also be involved, particularly in the striatum and in CA1 subfield of the hippocampus. Overall, our data suggest that expression of Arc mRNA is highly responsive to changes in brain 5-HT functions, and may provide a sensitive marker of postsynaptic 5-HT2(2A and 2C) receptor functions.

Animals↗
PubMed1999

Occupational performance needs of a shelter population.

Practice in shelters for people who are homeless is an exciting and challenging opportunity for occupational therapists. However, there is a paucity of knowledge about the occupational performance needs of this population. In the present study, 25 persons at a shelter were interviewed using the Canadian Occupational Performance Measure (COPM). Data were analyzed using both qualitative and quantitative methods. Several major themes emerged including spirituality, "we want what everyone wants", choosing satisfaction, diverse health concerns, power of relationships, the importance of environment to well-being, and poverty. Altruism in the midst of adversity and individuality were minor themes. Instrumental activities of daily living, such as access to employment, financial management, housing, and recreation, were reported as more important than basic activities of daily living. Participants and interviewers also responded to general questions regarding the use of the COPM in the assessment process. The COPM was found to be useful for assessing the occupational performance needs of this population, but should be augmented by inquiry about environmental concerns, relationships, housing, and spirituality.

Adolescent↗
PubMed1997

N-Type calcium channels in the developing rat hippocampus: subunit, complex, and regional expression.

The expression of multiple classes of voltage-dependent calcium channels (VDCCs) allows neurons to tailor calcium signaling to functionally discrete cellular regions. In the developing hippocampus a central issue is whether the expression of VDCC subtypes plays a role in key phases such as migration and synaptogenesis. Using radioligand binding and immunoblotting, we show that some N-type VDCCs exist before birth, consistent with a role in migration; however, most N-VDCC subunit expression is postnatal, coinciding with synaptogenesis. Immunoprecipitation studies indicate that the increased expression of N-VDCCs in early development occurs without subunit switching because there is no change in the fraction of beta3 subunits in the N-VDCC alpha1B-beta3 heteromers. Fluorescence imaging of cell surface N-VDCCs during this period reveals that N-VDCCs are expressed on somata before dendrites and that this expression is asynchronous between different subfields of the hippocampus (CA3-CA4 before CA1-CA2 and dentate gyrus). Our data argue that N-VDCC expression is an important cue in the genesis of synaptic transmission in discrete hippocampal subfields.

Animals↗
PubMed1996

Lack of effect of methotrexate on the expression of constitutive hepatic cytochromes P450 in the male rat.

1. The effects of methotrexate (MTX) on the expression of selected constitutive cytochrome P450 (CYP) isozymes in the liver of male rats at the catalytic activity and mRNA levels were examined. 2. Male rats received a single intraperitoneal injection of MTX (4 mg/kg) or vehicle and were killed, 1, 2, 7 or 14 days following drug administration. 3. Hepatic microsomes were used for determination of total CYP content, NADPH-CYP reductase activity, aminopyrine N-demethylase activity, and androstenedione (AD) hydroxylation activity; total RNA was also isolated from liver and was used for hybridization analysis of CYP isozyme expression at the mRNA level. 4. MTX did not affect any of the following parameters at any time-point in comparison with the corresponding vehicle control: body weight, liver weight, hepatic microsomal protein content, total CYP content, NADPH-CYP reductase activity, aminopyrine N-demethylase activity, AD 6 beta- and 7 alpha-hydroxylase activity, and CYP3A2 mRNA content. 5. The major male-specific CYP isozyme, 2C11, was down-regulated by MTX treatment as revealed by a marginal (25%), but statistically significant decrease in AD 16 alpha-hydroxylase activity at day 14 and a marginal (18%), but statistically significant decrease in CYP2C11 mRNA content at day 14. 6. In comparison with other antineoplastic drugs that have been examined, MTX appears to possess a lesser capacity for modulation of hepatic CYP enzymes.

Animals↗
PubMed1996

Regulation of constitutive rat hepatic cytochromes P450 by 3-methylcholanthrene.

1. Induction of cytochrome P450 (CYP) enzymes of the CYP1A subfamily by aromatic hydrocarbons such as 3-methylcholanthrene (MC) is accompanied by down-regulation of other CYPs that are expressed constitutively in rat liver. 2. We examined the time-course of the effects of MC on the expression of CYP2C11 and 3A2 in the liver of male rats at the catalytic activity, apoprotein and mRNA levels. 3. A single intraperitoneal dose of MC (50 mg/kg) caused an increase in total hepatic microsomal CYP and haem content, and a marked induction of CYP1A1 catalytic activity (7-ethoxyresorufin O-deethylase) and apoprotein. The activity of NADPH-cytochrome P450 reductase was not altered. 4. MC treatment decreased CYP2C11 and 3A catalytic activity (testosterone 16 alpha- and 6 beta-hydroxylase respectively) and apoprotein, and there was a trend for suppression of 2C11 and 3A2 mRNA. Following this initial down-regulation, CYP2C11 catalytic activity and 3A catalytic activity and apoprotein were elevated above control levels. Although CYP2C11 and 3A2 mRNA levels showed a similar trend, these effects did not achieve statistical significance. 5. CYP2C11 and 3A2 appear to be regulated by MC at a pre-translational level. CYP2C11 suppression will serve as a valuable model for study on the mechanisms by which aromatic hydrocarbons act to negatively influence gene expression.

Animals↗
PubMed1991

Changes in metabolites, metabolic hormones, and luteinizing hormone before puberty in Angus, Braford, Charolais, and Simmental heifers.

We determined changes in insulin, glucose, free fatty acids (FFA), growth hormone (GH), insulin-like growth factor I (IGF-I) and LH before puberty in Angus, Braford, Charolais, and Simmental heifers. Our primary objective was to identify metabolites and metabolic hormones that serve as metabolic cues for onset of puberty. Angus (n = 12). Braford (n = 7), Charolais (n = 9), and Simmental (n = 7) heifers were assigned at weaning (289 +/- 25 d of age; 264 +/- 23 kg) to open-sided pens with slotted floors, and they were fed a corn silage-concentrate diet formulated to provide gains of .91 kg/d. Puberty was defined as the 1st d (d 0) that serum progesterone (determined in blood samples collected at weekly intervals) exceeded 1 ng/ml. Blood samples were collected before and after feeding at 15-min intervals for 8 h at 21-d intervals before puberty in a subsample of heifers (at least five per breed). Angus and Simmental heifers weighed less and were younger (P less than .05) at puberty than Charolais and Braford heifers. Serum FFA before feeding and frequency of LH release increased (P less than .05) from d-40 +/- 3 to d-17 +/- 3 in all breeds. Conversely, concentrations of insulin were greater (P less than .05) at -40 than at -17 d from puberty in Angus, but not in Braford, Charolais, or Simmental heifers. Frequency of GH release was greater at d -40 than at d -17 in Angus heifers; however, in Braford and Charolais heifers frequency of GH release was greater at d -17 than at d -40. Concentrations of IGF-I (measured every 2 wk) increased linearly (P less than .07) from d -56 to 0 from puberty in Angus but not in other breeds. In conclusion, frequency of LH release and concentrations of FFA increased before puberty in all breeds; however, consistent changes in other metabolites and hormones were observed only in Angus heifers.

Age Factors↗
PubMed1986

Serving two masters: a dilemma in general practice.

General practitioners are the custodians of large quantities of confidential information, and they are often asked to use this to furnish reports for third parties. The implications of consenting to the disclosure of information for such purposes are frequently ill understood by patients. If there is a possibility that such disclosure may disadvantage the patient, the doctor should discuss the matter personally with the patient before releasing any information.

Adult↗
PubMed1984

Connections made by transplants to the cerebral cortex of rat brains damaged in utero.

Homografts consisting of pieces of neocortex or dissociated cortical cells were transplanted from fetal rats into the cortex of newborn, microcephalic hosts. The cortex of the hosts lacked cells of the superficial layers, as a result of prenatal administration of a cytotoxic drug methylazoxymethanol. Grafts exhibited an internal organization with a tendency to form a molecular layer, and alternating cell and fiber zones, although these were not consistently oriented with respect to the host cortex. Both pyramidal and nonpyramidal cells survived. Some grafts were shown to receive callosal connections. Axonal outgrowth from transplanted neurons to several host brain areas was demonstrated with retrograde tracers. Outgrowth occurred not only to the contralateral cortex, in which the host's own callosal projection was deficient, but also to the thalamus and spinal cord, in which the host projection was intact. Thus, grafted fetal cortex is capable of making connections in the methylazoxymethanol-damaged host, but the pattern of connections made is not influenced by host deficiencies.

Afferent Pathways↗
PubMed1980

The quality of diabetic care in a London health district.

In order to assess the quality of care in a community-wide sample of diabetic patients, a study was performed on 217 such patients identified in three group practices in an east London health district. Only 46% of the patients were currently attending a hospital. In the two years before review, 64% of patients had had their blood pressure recorded and 59% had had retinal examinations. Levels of glycosylated haemoglobin were significantly higher in patients on insulin than in those on oral regimes (P = 0.0004). The mean level of glycosylated haemoglobin was higher in patients from Social Classes III, IV, and V than in patients from Social Classes I and II (P = 0.005), but there was no difference in level between those patients attending hospital and those attending their general practitioners after accounting for differences in these two populations (P = 0.19). Over 50% of all diabetic patients in this study had levels of glycosylated haemoglobin which may indicate vulnerability to microvascular disease.

Catchment Area, Health↗
PubMedDate not supplied

A pilot Diabetic Support Service based on family practice attenders: comparison with diabetic clinics in east London.

A pilot Diabetic Support Service (DSS) based on a computer register was devised for diabetic patients identified within three group practices in an inner city district of London. Of 159 eligible diabetics, 142 were followed over 2 years. Glycosylated haemoglobin (GHb) monitoring and adequacy of clinic reviews were audited. Care achieved by the DSS was compared with conventional Diabetic Clinic (DC) management of a sample of 200 diabetics from the same district. Serial GHb measurements were made on 66.2% of DSS and 44.5% of DC patients: GHb fell significantly only in DSS patients (13.1% to 11.4%). Proportional falls in GHb were comparable in each DSS treatment group (diet alone, oral hypoglycaemic agents, and insulin) and for hospital attenders and non-attenders equally. The planned clinical reviews were achieved in 40.1% of DSS patients entered (29% GP only, 54% of clinic attenders) and in 15% of DC patients (plus 75% fundal and blood pressure examination). The study led to provision of a formal diabetic clinic annual review system, diabetic mini-clinics in two of the three group practices, and the appointment of two Diabetic Liaison Sisters. With administrative simplification the system is to be made available to all diabetics in the District through their GPs during 1986-8.

Adult↗