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R S Jones

Publications and source records attributed to R S Jones.

At least 55 records · Page 3Linked to original sources
PubMed1998

Comparison of carprofen and pethidine as postoperative analgesics in the cat.

The postoperative analgesia and sedation in cats given carprofen (4.0 mg/kg bodyweight by subcutaneous injection preoperatively) was compared to that in cats given pethidine (3.3 mg/kg bodyweight by intramuscular injection postoperatively) in a controlled, randomised, blinded, multicentre clinical trial. Further dosing with the particular analgesic was allowed if a cat was exhibiting unacceptable pain. In total, 57 carprofen cases and 59 pethidine cases were evaluated. Significantly fewer cats in the carprofen group required additional doses of analgesic, and mean pain scores were significantly lower from four hours after ovariohysterectomy, and at 18 to 24 hours after castration, compared to the pethidine group. In conclusion, carprofen provided as good a level of postoperative analgesia as pethidine, but of a longer duration (at least 24 hours) and was well tolerated. It thus provides an option for 'pre-emptive analgesia' in cats about to undergo surgery.

Analgesics, Opioid↗
PubMed1998

The Drosophila esc and E(z) proteins are direct partners in polycomb group-mediated repression.

The extra sex combs (esc) and Enhancer of zeste [E(z)] proteins are members of the Drosophila Polycomb group (Pc-G) of transcriptional repressors. Here we present evidence for direct physical interaction between the esc and E(z) proteins using yeast two-hybrid and in vitro binding assays. In addition, coimmunoprecipitation from embryo extracts demonstrates association of esc and E(z) in vivo. We have delimited the esc-binding domain of E(z) to an N-terminal 33-amino-acid region. Furthermore, we demonstrate that site-directed mutations in the esc protein previously shown to impair esc function in vivo disrupt esc-E(z) interactions in vitro. We also show an in vitro interaction between the heed and EZH1 proteins, which are human homologs of esc and E(z), respectively. These results suggest that the esc-E(z) molecular partnership has been conserved in evolution. Previous studies suggested that esc is primarily involved in the early stages of Pc-G-mediated silencing during embryogenesis. However, E(z) is continuously required in order to maintain chromosome binding by other Pc-G proteins. In light of these earlier observations and the molecular data presented here, we discuss how esc-E(z) protein complexes may contribute to transcriptional silencing by the Pc-G.

Amino Acid Sequence↗
PubMed1998

Perioperative plasma cortisol concentration in the horse.

The cortisol response to anaesthesia and surgery was studied in 2 groups of horses undergoing either abdominal or non-abdominal surgery. The preoperative mean plasma cortisol concentration (pcc) of 381.7 nmol/l (s.d. 254.7) was markedly higher in the abdominal group than the early-morning mean pcc of 115.6 nmol/l (s.d. 78.4) in the non-abdominal group. During halothane anaesthesia and surgery the mean pcc increased significantly (p < 0.05) from the preoperative mean of 119.2 to 215.9 nmol/l (s.d. 79.8) after 30 min of surgery in the non-abdominal group. In the abdominal group a decrease occurred after induction of anaesthesia and surgical preparation, but increased during surgery to a mean pcc of 418.1 nmol/l (s.d. 236.5). In the postoperative period a large decrease in the mean pcc occurred after 24 h in the abdominal group. It was only after 60 h that the pcc (153.2 nmol/l) equalled the pcc of the non-abdominal group (171.4 nmol/l) at 24 h. The slow decline over 60 h could be an indication of the prolonged recovery associated with abdominal surgery in the horse.

Abdomen↗
PubMed1998

Use of image cytometry to classify biliary and ampullary adenocarcinomas.

OBJECTIVE: To create an objective classification system to perform TNM classification of ampullary adenocarcinoma and cholangiocarcinoma using image cytometric data derived from Feulgen-stained tumor nuclei. STUDY DESIGN: Surgically resected cases of ampullary adenocarcinoma and cholangiocarcinoma with established TNM classifications were selected on the basis of available formalin-fixed, paraffin-embedded tissue. Fifteen numerical variables related to morphometric, densitometric and textural features of each tumor nucleus were recorded. We employed a methodology based on multivariate statistical tools to characterize the association of morphonuclear variables with TNM classification. The first step consisted of identifying and selecting representative nuclei of each T class. From this "purified" data set an objective classification system was created. The classification system was assessed using internal and external validation. RESULTS: Employing ANOVA, all 15 variables were significantly associated with T classification, 11 of 15 with N and 4 with M. Multivariate analysis was employed to distinguish between T1, T2 and T3 lesions. Our methodology correctly classified 76% of T1 nuclei, 47% of T2 nuclei and 84% of T3 nuclei. Heterogeneity within an individual tumor was defined in 61% of cases included in the training set. Complete concordance between pathologic classification and the classification system was observed in 71% of an independent validation.

Adenocarcinoma↗
PubMed1997

Pancreatic adenocarcinoma in the pregnant patient: case report and review of the literature.

BACKGROUND: In this case report, the authors discuss the presentation and treatment of pancreatic adenocarcinoma in a pregnant woman. Pancreatic adenocarcinoma is extremely rare in the pregnant patient. Only three cases of pancreatic adenocarcinoma diagnosed antepartum have been reported. METHODS: A case report and a review of the literature are reported. RESULTS: The authors report a case of pancreatic adenocarcinoma in a pregnant woman at 17 weeks' gestation. Endoscopic retrograde cholangiopancreatography with stent placement and a pancreaticoduodenectomy were performed successfully. CONCLUSIONS: Pancreatic adenocarcinoma is very rare in the pregnant patient. However, pancreaticoduodenectomy can be performed successfully. To the authors' knowledge, this is the first report of a pregnant woman treated with pancreaticoduodenectomy for pancreatic adenocarcinoma.

Adenocarcinoma↗
PubMed1997

The future is now.

Explore the source record for details and available documents.

Hospital Mortality↗
PubMed1997

Sensory-perceptual abnormalities in autism: a case for more research?

Sensory-perceptual abnormalities in people with autism are discussed from two perspectives: published firsthand accounts and existing psychological research evidence. A range of abnormalities, including hyper- and hyposensitivity, sensory distortion and overload, and multichannel receptivity and processing difficulties, are described in firsthand accounts and frequently portrayed as central to the autistic experience. A number of dangers are inherent in uncritically accepting these accounts at face value and in any wider generalization to the autistic population as a whole. Evidence from clinical studies suggests that unusual sensory responses are present in a majority of autistic children, that they are manifested very early in development, and that they may be linked with other aspects of autistic behavior. In addition, experimental studies using a range of indices have found evidence of unusual responses to sensory stimuli in autistic subjects. However the clinical and experimental research to date suffers from serious methodological limitations and more systematic investigation is warranted. Key issues for future psychological research in the area are identified.

Arousal↗
PubMed1997

Electrophysiological characterisation of tachykinin receptors in the rat nucleus of the solitary tract and dorsal motor nucleus of the vagus in vitro.

1. Recent studies have shown antagonists at the NK1 subtype of receptor for tachykinins are antiemetics and suggested that this may result from blockade of tachykinin-mediated synaptic transmission at a central site in the emetic reflex. 2. We have used intracellular recording in vitro to study the pharmacology of tachykinins in the nucleus of the solitary tract (NST) and dorsal motor nucleus of the vagus (DMNV). 3. Neurones in the NST were depolarized by substance P (SP), the presumed endogenous ligand for the NK1 receptor and these effects were mimicked by the NK1 agonists, SP-O-methylester (SPOMe), GR73632 and septide; however, SP was nearly an order of magnitude less potent than the latter two agonists. 4. In the DMNV, SP and NK1 receptor agonists evoked similar depolarising responses but SP appeared to be more potent than in the NST and was closer in potency to the other agonists. 5. NK1-receptor antagonists blocked responses to septide and GR73632 in the NST but had little effect on responses to SP and SPOMe. In contrast, in the DMNV the NK1-receptor antagonists blocked responses to septide and GR73632 but also reduced responses to SP and SPOMe. 6. Neurokinin A (NKA) was almost equipotent with septide and GR73632 in depolarizing both NST and DMNV neurones but these effects were not mimicked by a specific NK2-receptor agonist. Responses to NKA were unaffected by an NK2-receptor antagonist; however, the depolarizing effects of NKA were blocked by NK1-receptor antagonists. 7. Neurones in both DMNV and NST were unaffected by the endogenous NK3-receptor ligand, neurokinin B and by a specific agonist for this site, senktide. 8. The results with NK1 receptor agonists and antagonists suggest that the septide-sensitive NK1 site is involved in the excitation of both NST and DMNV neurones. The 'classical' NK1 receptor may play more of a role in the DMNV and a third unknown site may be responsible for the depolarizing response to SP in the NST. The effects of NKA are best interpreted as an action at the septide-sensitive NK1 site. This raises the possibility that anti-emetic action of the NK1 antagonists may be due to blockade of NKA transmission at the septide-sensitive site.

Animals↗
PubMed1997

Measurement of cardiac output in standing horses by Doppler echocardiography and thermodilution.

Measurement of cardiac output by Doppler echocardiography were compared to simultaneous measurements by thermodilution in 9 conscious horses. In the Doppler technique, mean blood flow velocities for estimation of cardiac output were recorded from the aorta and pulmonary artery. The flow area of each vessel was calculated from the vessel diameter, measured from a 2-dimensional ultrasound image. Differences in the site and method of measuring the vessel diameter altered the estimation of cardiac output by the Doppler method. Cardiac output was modified by the i.v. infusion of 4 micrograms/kg bwt/min dopamine and 4 micrograms/kg bwt/min dobutamine and by the i.v. administration of 10 micrograms/kg bwt detomidine and 20 micrograms/kg bwt butorphanol. Doppler measurements of cardiac output correlated closely with measurement by thermodilution. Measurements from the aortic outflow correlated more closely with thermodilution, than those from the pulmonary artery (r = 0.89 and r = 0.77, respectively). Doppler measurements when the mean flow velocity was recorded from the aorta and the flow area was measured from the ascending aorta using the leading edge method. There was no significant bias between the 2 techniques when Doppler flow velocities were recorded by this method and the limits of agreement were narrow (+/- 12.26 l/min). The differences between the 2 methods increased with increasing cardiac output. Doppler echocardiography is a safe noninvasive method of measuring cardiac output in horses. The agreement between Doppler echocardiography and thermodilution in this study is similar to that reported in man and is similar to that reported between thermodilution and other techniques in man.

Analgesics↗
PubMed1997

Reducing stereotyped behaviour: a comparison of two methods of programming differential reinforcement.

Differential Reinforcement of Other behaviours (DRO) has proven to be successful in reducing challenging behaviour, although the need for staff vigilance can limit its applicability in applied settings. The present study compared the effectiveness of whole-interval DRO with momentary DRO, a less intensive schedule. In a multiple-baseline design, two participants who exhibited high-rate stereotyped behaviours were presented with the two schedules. Momentary DRO was more effective than whole-interval DRO in reducing the targeted stereotypies of one participant, and as effective with the second. Momentary DRO was also more effective in reducing a second (non-consequated) stereotyped behaviour.

Adult↗
PubMed1996

Tonic facilitation of glutamate release by presynaptic N-methyl-D-aspartate autoreceptors in the entorhinal cortex.

N-Methyl-D-aspartate receptors are fundamental for neuronal plasticity and development in the CNS. Most studies have examined postsynaptic roles of this receptor, but there are also indications for a presynaptic location and function. Here, we provide electrophysiological evidence for the existence of presynaptic N-methyl-D-aspartate receptors which can tonically facilitate glutamate release in the CNS. The N-methyl-D-aspartate receptor antagonist 2-amino-5-phosphonopentanoate reduced the frequency, but not amplitude, of glutamate-mediated spontaneous excitatory postsynaptic currents in layer II neurons of the rat entorhinal cortex. This effect was also observed in the presence of tetrodotoxin and when postsynaptic N-methyl-D-aspartate receptors were blocked by dialysis with dizocilpine maleate. When extracellular calcium was replaced with strontium, 2-amino-5-phosphonopentanoate reduced the "tail" of spontaneous excitatory postsynaptic currents that followed an evoked excitatory postsynaptic current. Finally, there was a tendency for paired-pulse facilitation of excitatory postsynaptic currents evoked at short (50 ms) intervals with postsynaptic N-methyl-D-aspartate receptors blocked) to be reduced by 2-amino-5-phosphonopentanoate, although this did not reach significance. These data strongly support the presence of presynaptic N-methyl-D-aspartate autoreceptors which may facilitate glutamate release in layer II of the entorhinal cortex.

2-Amino-5-phosphonovalerate↗
PubMed1996

Donor lazaroid pretreatment improves viability of livers harvested from non-heart-beating rats.

BACKGROUND: Lazaroids are potent inhibitors of lipid peroxidation. Whether the compounds can benefit the liver procured from non-heart-beating donors (NHBDs) is unknown. METHODS: Donor rats were pretreated with lazaroid U74006F (4.5 mg/kg) 1 hour before cardiac arrest, and transplantation was performed in the rats with donor cardiac arrest from 0 to 60, 100, 120, 140, and 160 minutes as lazaroid pretreated groups. The same number of liver transplantations were done in each paired control group without donor lazaroid pretreatment. Recipient survival rates, bile secretion, serum enzymes, and a lidocaine metabolism test were analyzed. RESULTS: Donor lazaroid pretreatment significantly increased recipient 3-day survival rates in groups with 60, 100, and 120 minutes of warm ischemia and 7-day survival with 60 minutes of warm ischemia. Also, the pretreatment increased bile secretion and reduced serum aspartate aminotransferase and lactate dehydrogenase levels in the lazaroid-pretreated groups. CONCLUSIONS: Donor U74006F pretreatment improves viability of livers procured from NHBDs.

Animals↗
PubMed1996

Measurement of cardiac output by transoesophageal Doppler echocardiography in anaesthetized horses: comparison with thermodilution.

In order to determine if transoesophageal Doppler echocardiography could be used to estimate cardiac output in anaesthetized horses, we have compared the technique with estimations of cardiac output by thermodilution in eight healthy adult thoroughbreds. Measurements of aortic blood flow velocity were made by high pulse repetition frequency (HPRF) and continuous wave (CW) Doppler echocardiography from a 3.5-MHz transoesophageal probe. Cardiac output was increased during the study by administration of dobutamine, providing a range of cardiac output measurements by thermodilution from 15.0 to 64.4 liter min-1. Estimations derived from CW Doppler overestimated cardiac output compared with thermodilution (bias = 4.0 litre min-1). Estimations from HPRF Doppler echocardiography more closely reflected measurements obtained by thermodilution (bias = 0.7 litre min-1). Limits of agreement between the techniques were similar for both modes of insonation (HPRF = -7.7 to 9.1 litre min-1, CW = -4.9 to 12.8 litre min-1). There were significant differences in bias between both Doppler techniques and thermodilution for individual horses. As a result, for any individual horse, limits of agreement between the techniques were closer (HPRF = +/- 6.4 litre min-1, CW = +/- 7.6 litre min-1). We conclude that transoesophageal echocardiography provided an alternative, effective and non-invasive method for measurement of cardiac output in anaesthetized horses.

Anesthesia, General↗
PubMed1996

The therapeutic effect of reactive self-monitoring on the reduction of inappropriate social and stereotypic behaviours.

The effect of self-monitoring on the reduction of inappropriate social and stereotypic behaviour was investigated. Participants were three men and two women with mild to moderate learning disabilities. A multiple baseline design across participants was used. Participants were taught to monitor and record the frequency of their inappropriate behaviours. No extrinsic reinforcement was used throughout the study. Assessments of language ability and functional significance of behaviours were made. Significant reductions in target behaviours for all participants were observed. The findings suggest that individuals with learning disabilities have the potential to use self-regulatory procedures to control their behaviour with a minimum of external intervention. The implications of language development and functional covariation of behaviours are discussed.

Adult↗
PubMed1996

A comparison of spontaneous EPSCs in layer II and layer IV-V neurons of the rat entorhinal cortex in vitro.

1. We have compared the characteristics of spontaneous excitatory postsynaptic currents (sEPSCs) in neurons of layer IV-V and layer II of the rat entorhinal cortex (EC) using whole cell voltage-clamp recordings in a slice preparation. 2. The frequency of sEPSCs was similar in the two layers, but the events in layer IV-V had a larger mean amplitude, faster rise time, and were faster to decay. The difference in amplitude could be attributed to the presence of a population of larger events in the layer IV-V neurons that were not present in layer II. 3. Electrotonic length was greater in layer II neurons, suggesting that the difference in kinetics of the sEPSCs may be explained partly by electrotonic attenuation. 4. The frequency of sEPSCs in both layers was reduced by tetrodotoxin (TTX) to a similar extent (15-20%). However, the amplitude distribution was unchanged in layer II, whereas in layer IV-V TTX abolished most of the larger amplitude sEPSCs. 5. 6-cyano-7-nitroquinoxaline-2,3-dione or 6-nitro-7-sulphamoylbenzo (f)-quinoxaline-2,3-dione, abolished most of the sEPSCs in neurons of both layers. However, even at negative holding potentials, a population of slower time-course sEPSCs remained in the presence of these antagonists. 6. The slow sEPSCs were more frequent in layer IV-V but had similar characteristics in both layers, being increased in amplitude at more positive holding potentials or in Mg2+-free medium, and blocked by 2-amino-5-phosphonovalerate (AP5). 7. AP5 alone (i.e., without addition of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid antagonists) reduced the peak amplitude and decay phase of sEPSCs in layer IV-V neurons but appeared to have little effect on amplitude and only a weak effect on decay phase in layer II. 8. Thus both layer IV-V and layer II neurons of the EC suffer continuous spontaneous excitation. However, layer IV-V neurons exhibit larger amplitude sEPSCs, probably mediated by release of multiple quanta of neurotransmitter. In addition, although both types of neurons display spontaneous excitation mediated by N-methyl-D-aspartate receptors, this component appears more pronounced in the deeper layers.

Animals↗