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R L Jones

Publications and source records attributed to R L Jones.

At least 73 records · Page 4Linked to original sources
PubMed1998

Characterization of a calmodulin-binding transporter from the plasma membrane of barley aleurone.

We have used Arabidopsis calmodulin (CaM) covalently coupled to horseradish peroxidase to screen a barley aleurone cDNA expression library for CaM binding proteins. The deduced amino acid sequence of one cDNA obtained by this screen was shown to be a unique protein of 702 amino acids with CaM and cyclic nucleotide binding domains at the carboxyl terminus and high similarity to olfactory and K+ channels. This cDNA was designated HvCBT1 (Hordeum vulgare CaM binding transporter). Hydropathy plots of HvCBT1 showed the presence of six putative transmembrane domains, but sequence alignment indicated a pore domain that was unlike the consensus domains in K+ and olfactory channels. Expression of a subclone of amino acids 482-702 in Escherichia coli generated a peptide that bound CaM. When a fusion protein of HvCBT1 and green fluorescent protein was expressed in barley aleurone protoplasts, fluorescence accumulated in the plasma membrane. Expression of HvCBT1 in the K+ transport deficient Saccharomyces cerevisiae mutant CY162 showed no rescue of the mutant phenotype. However, growth of CY162 expressing HvCBT1 with its pore mutated to GYGD, the consensus sequence of K+ channels, was compromised. We interpret these data as indicating that HvCBT1 acts to interfere with ion transport.

Amino Acid Sequence↗
PubMed1998

Calcium, magnesium, and potassium in hair of deer from areas of contrasting soil productivity.

Differences in mineral nutrient composition of soils have been considered to affect health and population characteristics of free-ranging animals, particularly herbivores. Contents of Ca, Mg, and K in hair of female fawn white-tailed deer (Odocoileus virginianus) were measured for eight consecutive years to determine if soil and annual effects occurred in two areas of contrasting soil productivity in Illinois. Soil differences may account for some of the autumnal weight difference (7.2 kg for 4 yrs of observation) observed in fawn does from the areas. Ca, Mg, and K were assayed, because these macronutrients were known to differ in soils of the areas and were presumed to differ in forages. In 6 of the 8 yrs, at least one element was significantly different (P < or = 0.05) between areas. Significant (P < or = 0.05) differences for K occurred in 5 yr, for Ca in 4 yr, and for Mg in 2 yr. Ca and Mg were lower in hair in 7 yr from deer collected from the area in which extractable Ca and Mg were higher in soils; that is, hair Ca and Mg levels tended to be inversely related to levels of plant-available Ca and Mg in soil. For 7 of the 8 yr, K content was lower in hair from the area of lower soil K content. Within one area, between-year differences occurred for Ca and K and for Ca and Mg in the other area. Between-year differences in diet selection and annual climatic effects on mineral uptake of forages, among other factors, may account for some of the latter differences. Results for hair analyses suggest that macronutrient differences in Ca, Mg, and K occur in the diets of these populations and may account for some of the weight difference observed between the areas.

Animals↗
PubMed1998

Nicotine and cotinine replacement when nicotine nasal spray is used to quit smoking.

Nicotine nasal spray (NNS) is generally considered to be an effective smoking cessation aid, but all studies to date of NNS effectiveness have also utilized group therapy sessions or frequent laboratory visits to support their subjects' stop smoking efforts. We studied 50 volunteers before they attempted to quit smoking and again at 1, 2 and 3 months after they received NNS to assist them in quitting smoking. No other stop smoking intervention was used, which more closely mimics the common practice of many individuals trying to stop smoking with the aid of a nicotine replacement product but without other supportive interventions. We found that 50% of the subjects quit smoking for the first month, 34% were still abstinent after 2 months and 32% quit smoking for 3 months. Those who quit smoking for the entire 3 months and who continued regular NNS use throughout had 67% cotinine replacement at the end of the first month, while another group which quit smoking for only the first month with the aid of NNS had 42% cotinine replacement at the end of that month. Our data confirm that NNS is an effective smoking cessation aid, but our abstinent rate at 3 months is slightly lower than in other studies in which group therapy was provided. Our data also indicate that higher NNS-induced cotinine replacement during the first month of quitting smoking (suggesting more frequent use of NNS) is associated with longer term quit-smoking success rate.

Administration, Intranasal↗
PubMed1998

Herniography in the investigation of groin pain in adults.

Herniography is a useful investigation in adults with unexplained groin pain in whom there is no clinical evidence of a hernia, thus ensuring appropriate surgery. The technique is described, normal anatomy and different types of hernias illustrated.

Adult↗
PubMed1998

Gibberellin signaling.

Recent findings provide insights into the gibberellin signaling system in plants. Genes for gibberellin biosynthetic enzymes have been cloned, and an emerging theme is that gibberellin biosynthesis is negatively regulated by gibberellin responses. Mutants defective in gibberellin signaling have been analyzed, and an important finding is that gibberellin represses growth inhibition. The list of intracellular gibberellin signal-transduction elements has been expanded to include G-proteins and protein kinases.

Arabidopsis↗
PubMed1998

Characterization of a prostanoid EP3-receptor in guinea-pig aorta: partial agonist action of the non-prostanoid ONO-AP-324.

Contraction of guinea-pig isolated aorta induced by the prostaglandin E analogue sulprostone (1-400 nM) has a lower maximum response (40%) than that of phenylephrine or U-46619 (TP-receptor agonist). A prostanoid EP3-receptor subtype is involved based on agonist potency ranking: equi-effective molar ratios (EMR) are sulprostone (EC50 approximately equal to 23 nM) 1.0, SC-46275 0.11, misoprostol 2.2, gemeprost 3.3, PGE2 5.4, 17-phenyl PGE2 6.0, GR-63799 8.9. GR-63799, which contains a bulky ester group, is relatively more potent on neuronal EP3 preparations than on the aorta. ONO-AP-324, a relative of the non-prostanoid prostacyclin mimetic series, behaves as an EP3 partial agonist on the aorta, inhibiting sulprostone responses but acting synergistically (in a similar manner to sulprostone) with phenylephrine; it may be a useful pharmacological tool for studying EP3-receptors. Sulprostone contractions are markedly suppressed in zero-Ca2+ bathing fluid containing either 2 mM EDTA or 50 microM EGTA, and by Cd2+ (500 microM), but are usually unaffected by nifedipine (0.3 microM) and verapamil (4.44 microM). Influx of Ca2+, but not through L-type Ca2+-channels, appears to be the major contractile mechanism. The guinea-pig aorta is a valuable addition to the vascular EP3 preparations available and may increase our knowledge of the mechanisms whereby Gi-coupled receptors mediate vasoconstriction (c.f. 5-HT1B/D- and alpha2-receptors). The possibility of certain EP3 agonists distinguishing EP3-receptor isoforms is discussed.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1998

Morphological and functional features of endometrial decidualization following long-term intrauterine levonorgestrel delivery.

Irregular bleeding remains a common reason for the discontinuation of progestin-only contraception. The levonorgestrel releasing intrauterine system (LNG-IUS) has profound morphological effects upon the endometrium. Specific features are gland atrophy and extensive decidual transformation of the stroma. Morphological changes in the endometrium may be associated with perturbation of mechanisms regulating normal endometrial function. This study describes endometrial stromal and glandular features prior to and up to 12 months following insertion of the LNG-IUS. Comparison is made with first trimester decidua. In order to elucidate further mechanisms governing endometrial function with local intrauterine delivery of LNG, we here report histological features consistent with decidualization; a significant increase in granulocyte-macrophage colony stimulating factor (GM-CSF) immunoreactivity in decidualized stromal cells; glandular and stromal prolactin receptor expression and an infiltrate of CD56 + large granular lymphocytes and CD68 + macrophages. We are unaware of previous reports which have documented longitudinally both morphological and functional observations in endometrium exposed to local intrauterine levonorgestrel delivery. These studies demonstrate that long-term administration of intrauterine levonorgestrel results in features of altered morphology and function. No correlation was apparent between the end points in the study and the bleeding patterns described by the subjects. Further evaluation of these features in the context of menstrual bleeding experience may contribute to a better understanding of this troublesome side-effect which often leads to dissatisfaction and discontinuation of the intrauterine system.

Adult↗
PubMed1998

Localization and temporal expression of prolactin receptor in human endometrium.

Extrapituitary PRL is synthesized by the decidualized endometrial stromal cells from the mid to late secretory phase in the nonpregnant cycle and throughout pregnancy. The function of PRL in the uterus is unknown, but the temporal expression indicates a role in implantation and placentation. PRL is a powerful immunoregulatory agent, and thus, a role in modulating endometrial leukocytes may be envisaged. To investigate the site of action of PRL, immunohistochemistry was conducted to localize the PRL receptor (PRL-R). In addition, ribonucleic acid was extracted and reverse transcriptase-PCR for PRL-R was conducted. PRL-R protein was immunolocalized to the glandular epithelium and a subset of stromal cells from the mid to late secretory phase of the menstrual cycle and in early decidua. PRL-R transcripts were also detected from the late secretory phase and first trimester decidua. These findings indicate that the receptor is expressed in a temporal pattern similar to that of PRL. PRL-R expression in the glandular epithelium is consistent with a role in regulating glandular activity. Furthermore, immunoreactivity for PRL-R in a subset of stromal cells may be evidence for paracrine interactions between decidualized cells or an immunoregulatory role for PRL.

Decidua↗
PubMed1998

Effects of positive end-expiratory pressure on oscillated flow rate during high-frequency chest compression.

OBJECTIVE: To investigate the effects of positive end-expiratory pressure (PEEP) on end-expiratory lung volume (EELV) and mean oscillated flow rate (VOSC) during high-frequency chest compression (HFCC) in normal subjects and patients with severe COPD. DESIGN: Comparative study. SETTING: Pulmonary function and lung mechanics laboratory, University of Alberta Hospitals. PARTICIPANTS: Six normal subjects (five male; one female) and six patients with clinically stable COPD (five male; one female) with hypercapnia. INTERVENTIONS: A pneumatic vest system was operated at 10 Hz with a mean chest wall pressure of 16 cm H2O to provide the HFCC. A closed-circuit spirometer system permitted measurement of HFCC- and PEEP-induced changes in EELV that were expressed as per cent baseline functional residual capacity (FRC). An isothermic chamber connected near the mouthpiece permitted measurement of VOSC. RESULTS: For the normal subjects, HFCC caused a significant decrease in EELV to 82.0% of FRC (p < or = 0.01) and the addition of 4.8+/-0.5 cm H2O of PEEP during HFCC increased EELV to 97.5% FRC. In the COPD patients, HFCC decreased EELV to 92.3% of FRC (p < or = 0.01), and the addition of 3.7+/-1.0 cm H2O of PEEP increased EELV to 98.4% FRC. For the normal subjects, increasing EELV to near FRC caused VOSC during expiration to increase 14.6% (p < or = 0.01), but there was no significant effect on VOSC during inspiration (5.1% increase). In the COPD patients, PEEP increased VOSC during both inspiration (30.5%) and expiration (57.0%) (both, p < or = 0.01). CONCLUSIONS: Addition of a modest amount of PEEP during HFCC prevents the decrease in EELV and increases VOSC during both phases of spontaneous breathing in COPD patients. This higher VOSC during HFCC+PEEP may improve the effectiveness of HFCC in clearing mucus from the lungs of patients with airway disease.

Adult↗
PubMed1998

Exercise after acute hyperbaric oxygenation: is there an ergogenic effect?

The purpose of this study was to determine the effects of a 1-h exposure to 2.0 atm abs (202.6 kPa) and 100% oxygen on subsequent maximal O2 consumption (VO2max), ventilation threshold (VT), lactate threshold (LT), and muscle oxygenation (%Mox) during incremental exercise to maximum on a cycle ergometer. Two baseline exercise tests (T1 and T2) were performed on separate occasions without prior exposure to hyperbaric oxygen (HBO2) and a third test (T3-HBO2) was performed after (22.5 +/- 5.6 min) HBO2 Near infared spectroscopy was used to monitor oxygenation of the left vastus lateralis muscle during T2 and T3-HBO2. No significant differences were observed between VO2max VT, or LT among any of the exercise tests. There was no significant difference in %Mox between T2 and T3-HBO2 except at 235 W where there was a significant elevation in %Mox during T3-HBO2 relative to T2. These results suggest that prior exposure to HBO2 (100% O2 at 2 atm abs for 1 h) has no ergogenic effect on subsequent incremental exercise performance.

Adult↗
PubMed1997

Outbreak of Salmonella infantis infection in a large animal veterinary teaching hospital.

During the past 11 years, there have been numerous reports of outbreaks of salmonellosis involving horses in veterinary teaching hospitals. Some of these outbreaks have been associated with Salmonella serotypes not commonly associated with infection of horses. Salmonella infantis is among the more common Salmonella serotypes isolated from human beings, and is an important pathogen in the broiler chicken industry. However, it was not commonly isolated from horses or cattle on a national basis between 1993 and 1995. In this report, we describe an outbreak of S infantis infection among large animals, primarily horses, in a veterinary teaching hospital and the control measures that were implemented. Factors that appeared to be key in control of this outbreak in this hospital included providing biosecurity training sessions for hospital personnel, adopting a standard operating procedure manual for biosecurity procedures, installing additional handwashing sinks throughout the facility, painting the interior of the facility with a nontoxic readily cleanable paint, replacing the dirt flooring in 4 stalls with concrete flooring, and removing noncleanable surfaces such as rubber stall mats, wooden hay storage bins, and open grain bins. Our experience with this outbreak suggests that although it is virtually impossible to eliminate Salmonella organisms from the environment, minimizing contamination is possible. Prevention of nosocomial infection must be approached in a multifaceted manner and care must be taken to search out covert sources of contamination, especially if standard intervention procedures do not prevent spread of the disease.

Animals↗
PubMed1997

The laryngeal mask airway: a new standard for airway evaluation in thoracic surgery.

BACKGROUND: Thoracic surgeons typically perform fiberoptic bronchoscopy (FOB) before thoracotomy, usually on the day of the operation after intubation with a single-lumen endotracheal tube (ETT) and before insertion of a double-lumen ETT. This routine requires two laryngoscopies and two intubations. The laryngeal mask airway (LMA) is an airway device developed in England and approved by the Food and Drug Administration in 1991 for clinical use in the United States. It requires neither mask ventilation nor laryngoscopy and allows FOB visualization of the epiglottis, larynx, and entire trachea. We assessed the LMA as an alternative to a single-lumen ETT for FOB before thoracotomy. METHODS: Through prospective assessment, 50 patients underwent FOB after insertion of an LMA before thoracotomy. Pulse rate, blood pressure, ease of insertion of the LMA, quality of FOB, and complications of LMA insertion were assessed. RESULTS: During LMA insertion, blood pressure and pulse rate increased less than 5% from baseline in all patients. The LMA was inserted successfully in all patients within 10 seconds. No complications occurred as a result of LMA insertion. CONCLUSIONS: Insertion of the LMA causes minimal hemodynamic response. From the time of induction of general anesthesia, insertion of the LMA is quick, simple, and safe and eliminates the need for endotracheal intubation with a single-lumen ETT before double-lumen tube insertion. The LMA, in contrast to the ETT, allows a complete survey of the larynx and trachea. The LMA is autoclavable, reusable, and cost effective. Therefore, in patients who require FOB immediately before thoracotomy, LMA use should be the standard for airway evaluation.

Bronchoscopy↗
PubMed1997

CT assessment of jugular foramen dominance and its association with hand preference.

Three hundred and seven normal CT scans of the head were prospectively analysed to assess jugular foramen dominance. After assessment, hand preference was elicited. Of these, 276 were right-handed and 31 were left-handed. Of the right-handed patients: 180 had a larger jugular foramen on the right; 63 had a larger jugular foramen on the left; and in 33 no difference could be discerned. Of the left-handed patients: 11 had a larger jugular foramen on the right; 16 had a larger jugular foramen on the left; and in four no difference could be discerned. The results suggested a significant association between jugular foramen dominance and hand preference.

Chi-Square Distribution↗