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1.
Oncogene ; 40(18): 3260-3272, 2021 05.
Article En | MEDLINE | ID: mdl-33846571

The molecular mechanisms of luminal cell differentiation are not understood well enough to determine how differentiation goes awry during oncogenesis. Using RNA-Seq analysis, we discovered that CREB1 plays a central role in maintaining new luminal cell survival and that oncogenesis dramatically changes the CREB1-induced transcriptome. CREB1 is active in luminal cells, but not basal cells. We identified ING4 and its E3 ligase, JFK, as CREB1 transcriptional targets in luminal cells. During luminal cell differentiation, transient induction of ING4 expression is followed by a peak in CREB1 activity, while JFK increases concomitantly with CREB1 activation. Transient expression of ING4 is required for luminal cell induction; however, failure to properly down-regulate ING4 leads to luminal cell death. Consequently, blocking CREB1 increased ING4 expression, suppressed JFK, and led to luminal cell death. Thus, CREB1 is responsible for the suppression of ING4 required for luminal cell survival and maintenance. Oncogenic transformation by suppressing PTEN resulted in constitutive activation of CREB1. However, the tumor cells could no longer fully differentiate into luminal cells, failed to express ING4, and displayed a unique CREB1 transcriptome. Blocking CREB1 in tumorigenic cells suppressed tumor growth in vivo, rescued ING4 expression, and restored luminal cell formation, but ultimately induced luminal cell death. IHC of primary prostate tumors demonstrated a strong correlation between loss of ING4 and loss of PTEN. This is the first study to define a molecular mechanism whereby oncogenic loss of PTEN, leading to aberrant CREB1 activation, suppresses ING4 expression causing disruption of luminal cell differentiation.


Prostate , Prostatic Neoplasms , Cell Cycle Proteins , Cell Differentiation , Humans , Male , PTEN Phosphohydrolase
2.
Top Catal ; 61(3): 213-224, 2018.
Article En | MEDLINE | ID: mdl-30956506

Sequential treatment of a previously-calcined solid oxide support (i.e. SiO2, γ-Al2O3, or mixed SiO2-Al2O3) with solutions of Cr{N(SiMe3)2}3 (0.71 wt% Cr) and a Lewis acidic alkyl aluminium-based co-catalyst (15 molar equivalents) affords initiator systems active for the oligomerisation and/or polymerisation of ethylene. The influence of the oxide support, calcination temperature, co-catalyst, and reaction diluent on both the productivity and selectivity of the immobilised chromium initiator systems have been investigated, with the best performing combination (SiO2-600, modified methyl aluminoxane-12 {MMAO-12}, heptane) producing a mixture of hexenes (61 wt%; 79% 1-hexene), and polyethylene (16 wt%) with an activity of 2403 g gCr -1 h-1. The observed product distribution is rationalised by two competing processes: trimerisation via a supported metallacycle-based mechanism and polymerisation through a classical Cossee-Arlman chain-growth pathway. This is supported by the indirect observation of two distinct chromium environments at the surface of the oxide support by a solid-state 29Si NMR spectroscopic study of the Cr{N(SiMe3)2}x/SiO2-600 pro-initiator.

3.
Biol Lett ; 13(11)2017 Nov.
Article En | MEDLINE | ID: mdl-29118240

The major histocompatibility complex (MHC) plays a key role in vertebrate immunity, and pathogen-mediated selection often favours certain allelic combinations. Assessing potential mates' MHC profiles may provide receivers with genetic benefits (identifying MHC-compatible mates and producing optimally diverse offspring) and/or material benefits (identifying optimally diverse mates capable of high parental investment). Oscine songbirds learn songs during early life, such that song repertoire content can reflect population of origin while song complexity can reflect early life condition. Thus birdsong may advertise the singer's genetic dissimilarity to others in the population (and, presumably, compatibility with potential mates), or individual genetic diversity (and thus condition-dependent material benefits). We tested whether song repertoire content and/or complexity signal MHC class IIß dissimilarity and/or diversity in male song sparrows (Melospiza melodia). Pairwise dissimilarity in repertoire content did not predict MHC dissimilarity between males, suggesting that locally rare songs do not signal rare MHC profiles. Thus, geographical variation in song may not facilitate MHC-mediated inbreeding or outbreeding. Larger repertoires were associated with intermediate MHC diversity, suggesting intermediate rather than maximal MHC diversity is optimal. This could reflect trade-offs between resisting infection and autoimmune disorders. Song complexity may advertise optimal MHC diversity, a trait affecting disease resistance and capacity for parental care.


Major Histocompatibility Complex/genetics , Sparrows/physiology , Vocalization, Animal , Animals , Genetic Variation , Male , Sparrows/genetics
4.
Proc Biol Sci ; 283(1842)2016 Nov 16.
Article En | MEDLINE | ID: mdl-27807264

In jawed vertebrates, genes of the major histocompatibility complex (MHC) play a key role in immunity by encoding cell-surface proteins that recognize and bind non-self antigens. High variability at MHC suggests that these loci may also function in social signalling such as mate choice and kin recognition. This requires that MHC genotype covaries with some perceptible phenotypic trait. In mammals and fish, MHC is signalled chemically through volatile and non-volatile peptide odour cues, facilitating MHC-dependent mate choice and other behaviours. In birds, despite evidence for MHC-dependent mating, candidate mechanisms for MHC signalling remain largely unexplored. However, feather preen wax has recently been implicated as a potential source of odour cues. We examined whether the chemical composition of preen wax correlates with MHC class IIß genotypes of wild song sparrows (Melospiza melodia). Pairwise chemical distance reflected amino acid distance at MHC for male-female dyads, although not for same-sex dyads. Chemical diversity did not reflect MHC diversity. We used gas chromatography-mass spectrometry (GC-MS) to characterize preen wax compounds, and identified four wax esters that best reflect MHC similarity. Provided songbirds can detect variation in preen wax composition, this cue may allow individuals to assess MHC compatibility of potential mates.


Feathers/chemistry , Major Histocompatibility Complex , Songbirds/genetics , Waxes/chemistry , Animals , Female , Gas Chromatography-Mass Spectrometry , Genotype , Male , Odorants
6.
Disabil Rehabil ; 37(13): 1178-85, 2015.
Article En | MEDLINE | ID: mdl-25204841

PURPOSE: People with multiple sclerosis (MS) commonly experience muscle weakness which limits their ability to stand. Supported standing may minimise the secondary complications of prolonged sitting but evidence for this is scarce. This study investigated the effects of regular standing in an Oswestry frame on some secondary complications of immobility and explored the lived experience of standing. METHODS: Nine people with MS participated in a mixed-methods study over 48 weeks. Single-case experiments were used. Outcomes included: Amended Motor Club Assessment, Canadian Occupational Performance Measure, Penn Spasm Scale, bowel frequency and a numerical pain-scale. The qualitative strand used a case-study approach with a phenomenological perspective. RESULTS: Significant improvements (p < 0.05) were demonstrated for individuals in strength, ADL and spasms but not in bowel frequency or pain. Subjective improvements occurred in continence, clonus and fall-rate. Being upright or strengthened by standing enabled participants to re-engage with activities and re-establish themselves within relationship roles. This engendered a sense of achievement and increased optimism. CONCLUSION: This study provides preliminary evidence of the effectiveness of regular frame-standing in improving strength, function, spasms, continence and fall-rate in people with severe MS. Standing reinstated a sense of belonging and optimism by restoring important life-roles and feelings of normality as participants regained previously valued activities. Implications for Rehabilitation Regular standing in an Oswestry frame may improve functional ability in people with severe MS. Regular frame standing may have a positive psychological effect on people with severe MS. Self-management of a standing regime may be feasible.


Disabled Persons/rehabilitation , Multiple Sclerosis/rehabilitation , Posture , Self-Help Devices , Activities of Daily Living , Adult , Aged , Canada , Female , Humans , Male , Middle Aged , Mobility Limitation , Pilot Projects , Recovery of Function , Self Care , Treatment Outcome
8.
Am J Transplant ; 14(9): 2072-80, 2014 Sep.
Article En | MEDLINE | ID: mdl-25040819

Under the "sickest first" Model for End-Stage Liver Disease (MELD) allocation, livers amenable to splitting are most often allocated to patients unsuitable for split liver transplantation (SLT). Our experience with SLT using hemilivers was reviewed. From April 2004 to June 2012, we used 25 lobar grafts (10 left lobes and 15 right lobes) for adult-sized recipients. Twelve recipients were transplanted with primary offers, and 13 were transplanted with leftover grafts. Six grafts were shared with other centers. The data were compared with matched whole liver grafts (n = 121). In 92% of donors, the livers were split in situ. Hemiliver recipients with severe portal hypertension had a greater graft-to-recipient weight ratio than those without severe portal hypertension (1.96% vs. 1.40%, p < 0.05). Hemiliver recipients experienced biliary complications more frequently (32.0% vs. 10.7%, p = 0.01); however, the 5-year graft survival for hemilivers was comparable to whole livers (80.0% vs. 81.5%, p = 0.43). The secondary recipients with leftover grafts did not have increased incidences of graft failure (p = 0.99) or surgical complications (p = 0.43) compared to the primary recipients. In conclusion, while routine application is still controversial due to various challenges, hemiliver SLT can achieve excellent outcomes under the MELD allocation.


End Stage Liver Disease/surgery , Liver Transplantation/methods , Adolescent , Adult , Child , Female , Humans , Male , Retrospective Studies , United States , Young Adult
9.
Anaesthesia ; 69(7): 683-6, 2014 Jul.
Article En | MEDLINE | ID: mdl-24862655

Hip fracture is the most common orthopaedic emergency. We investigated the concentration of 30 ml levobupivacaine that provided analgesia to 50% and 95% of patients with a hip fracture when injected around the femoral nerve under ultrasound guidance. We defined analgesia as a ≥ 20-point decrease on a 100-point pain scale with reduced cold sensation in the middle third of the anterior thigh 30 min after the nerve block. We increased the concentration of levobupivacaine if the preceding dose had been ineffective and decreased it if the preceding dose had been effective. Probit regression modelling estimated the effective (95% CI) concentration of 30 ml levobupivacaine in 50% and 95% of patients with a fractured hip to be 0.026 (0.023-0.028)% w/v and 0.036 (0.027-0.047)% w/v, respectively.


Femoral Nerve/drug effects , Hip Fractures/complications , Nerve Block/methods , Pain Management/methods , Pain/drug therapy , Pain/etiology , Aged , Aged, 80 and over , Dose-Response Relationship, Drug , Female , Humans , Male , Pain Measurement/methods
10.
Anaesthesia ; 69(6): 604-12, 2014 Jun.
Article En | MEDLINE | ID: mdl-24749931

Assessment tools must be investigated for reliability, validity and feasibility before being implemented. In 2013, the Australian and New Zealand College of Anaesthetists introduced workplace-based assessments, including a direct observation of a procedural skills assessment tool. The objective of this study was to evaluate the psychometric properties of this assessment tool for ultrasound-guided regional anaesthesia. Six experts assessed 30 video-recorded trainee performances of ultrasound-guided regional anaesthesia. Inter-rater reliability, assessed using absolute agreement intraclass correlation coefficients, varied from 0.10 to 0.49 for the nine individual nine-point scale items, and was 0.25 for a 'total score' of all items. Internal consistency was measured by correlation between 'total score' and 'overall performance' scale item (r = 0.68, p < 0.001). Construct validity was demonstrated by the 'total score' correlating with trainee experience (r = 0.51, p = 0.004). The mean time taken to complete assessments was 6 min 35 s.


Anesthesia, Conduction , Clinical Competence , Ultrasonography, Interventional , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Psychometrics
11.
Transplant Proc ; 40(10): 3339-41, 2008 Dec.
Article En | MEDLINE | ID: mdl-19100385

BACKGROUND: Ischemia/reperfusion injury (IRI) is a major problem in intestinal transplantation. Toll-like receptor 4 (TLR4) has been implicated as a possible link between the innate and adaptive immune systems, however little data exists regarding TLR4 in intestinal IRI. The goal of this study is to evaluate the involvement of TLR4 in intestinal IRI and to assess the effect on T cell related chemokine programs. METHODS: C57BL6 mice underwent 100 minutes of warm intestinal ischemia by SMA clamping. Control WT mice underwent laparotomy without vascular occlusion. Separate survival and analysis groups were performed, and intestinal tissue was harvested at 1 hour, 2 hours, 4 hours, and 24 hours post-reperfusion. Analysis included histology, CD3 immunostaining, myeloperoxidase activity, Western blot, and PCR. RESULTS: Survival was significantly worse in the IRI group vs control (50% vs. 100%). IRI caused severe histopathological injury including mucosal erosions and villous congestion and hemorrhage. Myeloperoxidase activity increased in a time-dependent manner after IRI (2.71 0.25 at 1 hour, 2.92 0.25 at 2 hours, 4 0.16 at 4 hours, 5.1 0.25 at 24 hours vs 0.47 0.11 controls, P < .05). Protein expression of TLR4 followed by NF-kappaB was increased after IRI. Additionally, mRNA production of IP-10, MIP-2, MCP-1, and RANTES was increased at all time-points, as was mRNA for ICAM-1 and E-selectin. CONCLUSION: This study is the first to demonstrate increased expression of TLR4 and NF-kappaB after warm intestinal IRI. This detrimental cascade may be initiated by TLR4 via NF-kappaB signaling pathways, implicating TLR4 as a potential therapeutic target for the prevention of intestinal IRI.


Chemokines/physiology , Intestines/physiopathology , Reperfusion Injury/physiopathology , Toll-Like Receptor 4/physiology , Actins/genetics , Animals , DNA Primers , Immunohistochemistry , Intestinal Mucosa/pathology , Intestines/blood supply , Intestines/pathology , Male , Mice , Mice, Inbred C57BL , Muscle, Smooth/pathology , Peroxidase/metabolism , RNA/genetics , RNA/isolation & purification , RNA, Messenger/genetics , Reperfusion Injury/pathology , Reverse Transcriptase Polymerase Chain Reaction , Survivors
12.
Phys Rev E Stat Nonlin Soft Matter Phys ; 69(3 Pt 1): 031906, 2004 Mar.
Article En | MEDLINE | ID: mdl-15089321

Using neutron diffraction and a specially constructed high pressure cell suitable for aligned multibilayer systems, we have studied, as a function of pressure, the much observed anomalous swelling regime in dimyristoyl- and dilauroyl-phosphatidylcholine bilayers, DMPC and DLPC, respectively. We have also reanalyzed data from a number of previously published experiments and have arrived at the following conclusions. (a). The power law behavior describing anomalous swelling is preserved in all PC bilayers up to a hydrostatic pressure of 240 MPa. (b). As a function of increasing pressure there is a concomitant decrease in the anomalous swelling of DMPC bilayers. (c). For PC lipids with hydrocarbon chains >or=13 carbons the theoretical unbinding transition temperature T small star, filled is coupled to the main gel-to-liquid crystalline transition temperature T(M). (d). DLPC is intrinsically different from the other lipids studied in that its T small star, filled is not coupled to T(M). (e). For DLPC bilayers we predict a hydrostatic pressure (>290 MPa) where unbinding may occur.


Dimyristoylphosphatidylcholine/chemistry , Lipid Bilayers/chemistry , Membrane Fluidity , Neutron Diffraction/methods , Phosphatidylcholines/chemistry , Binding Sites , Gels/chemistry , Hydrostatic Pressure , Membranes, Artificial , Molecular Conformation , Phase Transition , Phospholipids/chemistry , Solutions , Transition Temperature
13.
Br J Anaesth ; 90(4): 509-11, 2003 Apr.
Article En | MEDLINE | ID: mdl-12644427

BACKGROUND: Insertion of a needle into the lumbar subarachnoid space may cause damage to the spinal cord. Current techniques to identify a safe interspace have limitations. Ultrasound was investigated as a means to improve anatomical accuracy. METHODS: Seventeen patients attending for elective magnetic resonance imaging (MRI) of the spine were studied. Ultrasonic identification of the L3-4 interspace was attempted by an anaesthetist and a marker was placed. A radiologist identified the anatomical location of the marker on the MRI scan. RESULTS: Thirteen out of 17 markers were at the L3-4 interspace; four were at the L2-3 interspace. CONCLUSIONS: These results suggest that ultrasonography may be a useful adjunct to safe subarachnoid anaesthesia.


Anesthesia, Spinal/methods , Lumbar Vertebrae/diagnostic imaging , Adult , Aged , Anesthesia, Spinal/adverse effects , Female , Humans , Injections, Spinal/adverse effects , Injections, Spinal/methods , Lumbar Vertebrae/anatomy & histology , Magnetic Resonance Imaging , Male , Middle Aged , Spinal Cord Injuries/etiology , Spinal Cord Injuries/prevention & control , Subarachnoid Space/anatomy & histology , Subarachnoid Space/diagnostic imaging , Ultrasonography
15.
Man Ther ; 5(4): 234-42, 2000 Nov.
Article En | MEDLINE | ID: mdl-11052903

A number of studies indicate poor intra-therapist and inter-therapist reliability in the performance of graded, passive oscillatory movements to the lumbar spine. However, it has been suggested that therapists can be trained to be more consistent in their performance of these techniques if given reliable quantitative feedback. The intention of this study was to develop equipment, analogous to the lumbar spine that could be used for both teaching and research purposes. Equipment has been updated and connected to a personal IBM compatible computer. Custom designed software allows concurrent and accurate feedback to students on their performance and in a form suitable for advanced data analysis using statistical packages. The uses and implications of this equipment are discussed.


Lumbar Vertebrae/physiology , Physical Therapy Modalities/instrumentation , Calibration , Computer-Assisted Instruction , Equipment Design , Feedback , Humans , Physical Therapy Modalities/education , Reproducibility of Results , Signal Processing, Computer-Assisted , Software
16.
Clin Rehabil ; 14(4): 408-16, 2000 Aug.
Article En | MEDLINE | ID: mdl-10945425

OBJECTIVE: To develop a behavioural assessment based on observations of patients recovering after severe head injury whereby data could be collected by observation and by testing everyday tasks. DESIGN: A prospective observational study of a cohort of 88 consecutive hospital admissions with severe head injury. SETTING: Two district general hospitals in the UK. PATIENTS: Eighty-eight consecutive admissions with severe traumatic head injury. Ages ranged from 14 to 67 years, mean coma duration was 14 days and mean duration of post traumatic amnesia (PTA) was 56 days. RESULTS: Fifty-eight items of behaviour were identified. Paired preference analysis was used to identify a sequence of recovery of these behaviours. The sequence began with arousal and led on to behaviours signalling recovery of social interaction and communication. Subsequent behaviours indicated increasing cognitive organization and return of orientation and memory. The behaviours on the scale are hierarchical and range from coma to emergence from PTA. CONCLUSIONS: A scale to assess patients and monitor cognitive recovery after severe head injury has been developed. While individual patients will show some departures from the sequence identified, the scale helps to make explicit the earliest stages of natural recovery patterns after head injury.


Craniocerebral Trauma/diagnosis , Trauma Severity Indices , Adolescent , Adult , Aged , Amnesia/diagnosis , Coma/diagnosis , Craniocerebral Trauma/physiopathology , Craniocerebral Trauma/psychology , Humans , Middle Aged , Neurobehavioral Manifestations , Observation , Prognosis , Prospective Studies , Recovery of Function , Reproducibility of Results
17.
Int Surg ; 85(3): 270-1, 2000.
Article En | MEDLINE | ID: mdl-11325009

We report the misleading sonographic appearance of Surgicel in the diagnosis of renal vein thrombosis in a case of kidney transplant and a review of the literature. Removal of the Surgicel before closure is advisable to avoid misdiagnosis.


Cellulose, Oxidized , Kidney Transplantation , Renal Veins , Venous Thrombosis/diagnostic imaging , Diagnostic Errors , Humans , Male , Middle Aged , Ultrasonography
18.
Br J Pharmacol ; 123(3): 505-17, 1998 Feb.
Article En | MEDLINE | ID: mdl-9504392

1. The nature of the membrane channels underlying the membrane conductance changes induced by the nitric oxide (NO) donors, S-nitroso-L-cysteine (NOCys) and sodium nitroprusside (SNP) were investigated in single myocytes isolated from the circular muscle layer of the guinea-pig proximal colon, by use of standard whole-cell and single channel recording techniques. 2. Under voltage clamp, depolarizing steps from -60 mV elicited a rapidly-developing, little-inactivating outward K+ current (IK) at potentials positive to -40 mV (at 20-25 degrees C). The steady-state level (ISS) of this K current increased in amplitude as the step potential was made to more positive potentials. If the depolarizing steps were made from a holding potential of -80 mV an additional rapidly activating and inactivating outward K+ current was also elicited, superimposed on IK. 3. At 20-25 degrees C, NOCys (2.5 microM), SNP (100 microM) and 8-bromo-cyclic GMP (500 microM) increased the amplitude of ISS of IK elicited from a holding potential of -60 mV. In contrast, NOCys (2-5 microM) had little effect on ISS at 35 degrees C. Higher concentrations (> or = 5 microM at 20-25 degrees C and > or = 10 microM at 35 degrees C) of NOCys decreased the peak amplitude (I[Peak]) and ISS of IK in a concentration-dependent manner. This blockade of IK with NOCys was always associated with an increase of the holding current (IHold), due to the activation of a membrane conductance with a reversal potential between 0 and + 30 mV and which was reduced approximately 50% upon the addition of Cd2+ (1 mM). 4. NOCys (2.5 to 10 microM) or SNP (100 microM) increased the activity of large conductance Ca2+-activated (BK) K' channels in both cell-attached and excised inside-out patches, bathed in either a symmetrical high K+ (130 mM) or an asymmetrically K+ (6 mMout: 130 mMin) physiological saline. Increases in BK channel activity in NOCys (10 microM) or SNP (100 microM) were associated with an increase in the probability of BK channel opening (N.Po), and with a negative shift of the plots of ln(N.Po) against the patch potential, with little change in the slopes of these plots. In cell-attached patches, the increase in N.Po with NOCys was often associated with a decrease in the BK single channel conductance. 5. In both cell-attached and excised patches, NOCys (2.5 to 10 microM) also activated an additional population of channels which allowed inward current flow at potentials positive to EK. In excised inside-out patches bathed in asymmetrical K+ physiological saline, these single channel currents were 2-3 pA in amplitude at -30 mV and reversed in direction near + 10 mV, even if the NaCl (126 mM) concentration in the pipette solution had been replaced with an equimolar concentration of Na gluconate. 6. Under current clamp, NOCys (2.5 microM) and SNP (100 microM) had variable effects on the membrane potential of colonic myocytes, inducing either a small membrane hyperpolarization of <5 mV, or a slowly-developing membrane depolarization of about 5 mV. In contrast, NOCys (5 microM) produced a transient membrane hyperpolarization which was followed by a large depolarization of the membrane potential to positive potentials. The electrotonic potentials elicited in response to an injection of constant hyperpolarizing current (10 pA for 400 ms) were little changed during the NOCys (5 PM)-induced membrane hyperpolarization, but significantly reduced (to 61% of control) during the periods of membrane depolarization. 7. It was concluded that NOCys and SNP, directly increased the number of active BK channels in the membrane of colonic myocytes which leads to a small rapidly oscillating membrane hyperpolarization. The following rebound depolarization in NOCys arises from both the direct opening of a population of cationic channels and the blockade of voltage- and Ca-activated K+ conductances. Finally, the apamin-sensitive K+channels underlying the initial transient hyperpolarization recorded in the intact proximal colon, in response to nerve-released or directly-applied NO, have yet to be identified at the single channel or whole-cell current level.


Colon/drug effects , Cysteine/analogs & derivatives , Muscle, Smooth/drug effects , Nitric Oxide/metabolism , Nitroprusside/pharmacology , Nitroso Compounds/pharmacology , Potassium Channels/drug effects , S-Nitrosothiols , Animals , Cadmium/pharmacology , Colon/cytology , Colon/metabolism , Cysteine/pharmacology , Guinea Pigs , In Vitro Techniques , Membrane Potentials/drug effects , Muscle, Smooth/cytology , Muscle, Smooth/metabolism , Potassium Channels/metabolism
20.
Neuropsychopharmacology ; 15(3): 217-30, 1996 Sep.
Article En | MEDLINE | ID: mdl-8873105

11192U90 was submitted to receptor binding and monoamine uptake assays. It bound potently at serotonin 5-HT2, dopaminergic D2, serotonin 5-HT1A, and adrenergic alpha 1 and alpha 2 receptors. It also bound to dopaminergic D1, serotonin 5-HT3, serotonin 5-HT4, and sigma sites, albeit with lower affinity. It was essentially inactive at 22 other sites, including those for cholinergic M1 and M2. It weakly inhibited uptake of 3H-norepinephrine, 3H-serotonin and 3H-dopamine. Acute doses of 1192U90 (5 and 20 mg/kg P.O.) increased whole-brain levels of dopamine metabolites but did not affect levels of norepinephrine, dopamine, and serotonin. Subcutaneous injection of 1192U90 (0.8 mg/kg/day) and clozapine (20 mg/kg/day) for 28 days preferentially decreased the number of spontaneously active dopamine cells in the ventral tegmental area (VTA) but not the substantia nigra (SN) of rats, as measured by population sampling. This outcome is characteristics of atypical antipsychotics like clozapine. Acute injections of 1192U90 reversed the rate-inhibiting effects of microiontophoretically applied dopamine and intravenously injected apomorphine and d-amphetamine on dopamine cell firing. Intravenous injection or iontophoretic application of 1192U90 or the 5-HT1A agonist (+/-)8-OH-DPAT inhibited the firing rates of dorsal raphe nucleus (DRN) neurons in rats, and the effects of both compounds were blocked by iontophoretically applied S(-) propranolol, a 5-HT1A antagonist. The results suggest that 1192U90 is a preferential dopamine D2 antagonist as well as a 5-HT1A agonist that may prove to be an atypical antipsychotic.


Antipsychotic Agents/metabolism , Piperazines/metabolism , Thiazoles/metabolism , Amphetamine/pharmacology , Animals , Apomorphine/pharmacology , Biogenic Amines/metabolism , Brain/drug effects , Brain/physiology , Clozapine/metabolism , Clozapine/pharmacology , Male , Neurons/drug effects , Neurons/physiology , Piperazines/pharmacology , Radioligand Assay , Rats , Thiazoles/pharmacology
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