A coupled Southwestern--DNase I footprinting assay.
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Base Sequence↗
Biomedical subjects
S E Smith
Publications and source records attributed to S E Smith.
The protein kinase C activators, phorbol 12-myristate,13-acetate and phorbol 12,13-dibutyrate, are convulsant in the pico-nanomolar range in mice.
Administration of phorbol 12-myristate,13-acetate (PMA, 10 fmol-10 nmol) or phorbol 12,13-dibutyrate (PDB, 0.2-495 nmol) (i.c.v.) to mice induced: hindlimb scratching, tremor, myoclonic jerks, hyperlocomotion, clonic seizure, followed by death or recovery. CD50 values for clonic seizures for PMA and PDB were 1.0 pmol and 1.2 nmol. 4-alpha-Phorbol (68-686 nmol) was inactive. The effects of PDB (24-247 nmol) were reduced by pretreatment with staurosporine (30 nmol, i.c.v.). Protein kinase C activators are potent convulsants in vivo.
Alkaloids↗
The glycine-site NMDA receptor antagonist, R-(+)-cis-beta-methyl-3-amino-1-hydroxypyrrolid-2-one, L-687,414 is anticonvulsant in baboons.
The glycine-site NMDA receptor antagonist, R-(+)cis-beta-methyl-3-amino-1-hydroxypyrrolid-2-one (L-687,414) was administered i.t. to photosensitive baboons. The anticonvulsant action of L-687,414 (5-45 mg kg-1) was dose-dependent and peaked between 15 min and 2 h after administration. Gross behavioural effects were not observed at the doses tested. L-687,414 is a potent systemically acting anticonvulsant apparently devoid of serious side effects.
Animals↗
Differential cardiovascular effects of propranolol, atenolol, and pindolol measured by impedance cardiography.
We have evaluated Sramek's method of impedance cardiography as a non-invasive way of detecting the cardiovascular effects of drugs. We made cardiovascular measurements using the method during passive tilting and exercise 2 h after the oral administration of atenolol (50 and 100 mg), propranolol (40 and 80 mg), pindolol (5 and 10 mg), and placebo in seven separate studies involving eight healthy male volunteers. Equivalent doses of the pure antagonists atenolol (beta 1) and propranolol (beta 1, beta 2) produced similar reductions in heart rate, systolic blood pressure, and cardiac index, and increases in stroke volume and total peripheral resistance, particularly during exercise. In contrast the partial agonist pindolol produced increases in heart rate and cardiac index, and reductions in peripheral resistance at rest. During passive tilting and exercise pindolol reduced heart rate, but cardiac output and total peripheral resistance were unchanged except at the highest levels of exercise. The similar cardiovascular effects of atenolol and propranolol, but differing effects of pindolol, are consistent with reports using other methods of measurement. This suggests that impedance cardiography may have a place in the non-invasive assessment of the cardiovascular effects of drugs.
Adult↗
Use of 99mtechnetium-dimercaptosuccinic acid to study patterns of renal damage associated with prenatally detected vesicoureteral reflux.
Static isotope imaging with 99mtechnetium-dimercaptosuccinic acid was performed at a mean age of 34 days in 32 children (50 kidneys) whose vesicoureteral reflux had been identified as a result of prenatal ultrasound scanning. Three patterns of isotope uptake were observed: 1) noninfected primary vesicoureteral reflux (15 children, 24 kidneys), 2) noninfected secondary (obstructed) vesicoureteral reflux (9 patients, 11 kidneys) and 3) infected primary reflux (8 infants, 15 kidneys). In 20 pattern 1 kidneys (83%) renal morphology and differential isotope were normal. In the 4 kidneys (17%) that showed evidence of impaired function this took the form of global parenchymal loss, that is small kidneys rather than focal scarring. In pattern 2 the combination of fetal vesicoureteral reflux and obstruction was a potent cause of renal damage with total or near total loss of function in 7 of 9 refluxing units associated with posterior urethral valves and in 2 kidneys with secondary ureteropelvic junction obstruction. Appearances of focal scarring were confined in pattern 3 and were found in 4 kidneys (27%). This overall incidence of detectable renal damage was lower than expected. Even when infection occurs, prenatal diagnosis may lessen the risk of scarring by enabling treatment to be instituted promptly. The findings suggest that uncomplicated primary vesicoureteral reflux is a relatively benign insult to the fetal kidney and that reflux nephropathy found in children presenting clinically is the result of infected vesicoureteral reflux in postnatal life. Any comparison of published studies will prove difficult until there is a more standardized approach to imaging technique and patient selection.
Female↗
Cerebroprotective effect of a non-N-methyl-D-aspartate antagonist, GYKI 52466, after focal ischemia in the rat.
BACKGROUND AND PURPOSE: Cerebroprotection after the administration of N-methyl-D-aspartate antagonists has been well documented. The present study sought to determine whether a cerebroprotective effect could be achieved with the administration of a non-N-methyl-D-aspartate antagonist, GYKI 52466 (1-(4-aminophenyl)-4-methyl-7,8-methylene-dioxy-5H-2,3-benzodiazep ine hydrochloride; molecular weight, 330) after middle cerebral artery occlusion in the rat. METHODS: Neurological deficit and infarct volume 24 hours after permanent left middle cerebral artery occlusion in Fischer rats (n = 7-13 per group per dose) were studied. Cerebral infarcts was visualized by the lack of reduction of 2,3,5-triphenyltetrazolium chloride. RESULTS: GYKI 52466 (10 mg.kg-1 i.p. at 0, 2, 4 hours) after middle cerebral artery occlusion had no effect on infarct volume. GYKI 52466 (10 mg.kg-1 i.v. for 5 minutes followed by 15 mg.kg-1.hr-1 i.v. for 2 hours immediately after middle cerebral artery occlusion reduced cortical infarct volume by 68% (from 69 mm3 in vehicle-treated to 22 mm3 in GYKI 52466-treated animals; p less than 0.05). A 1-hour delay before initiation of drug infusion resulted in a 48% reduction in cortical infarct volume (from 60 mm3 vehicle-treated rats to 31 mm3 in GYKI 52466-treated rats; p less than 0.05). A 2-hour delay before initiation of drug infusion had no effect on cortical infarct volume. Neurological deficits (with blinded assessment after 24 hours) were improved after immediate treatment and after delayed treatment (1 or 2 hours). CONCLUSIONS: The cerebroprotective effect of GYKI 52466 in the rat suggests a possible therapeutic role for non-N-methyl-D-aspartate antagonists given shortly after the onset of stroke.
Animals↗
Liver transplantation.
Nationwide, healthcare professionals are more involved with liver transplantation. Although providing a new lease on life is very rewarding within itself, it can also be stressful for all involved. Through a better understanding of the actual procedure, healthcare professionals can alleviate some of their own stress as well as understand the anxiety of the recipient.
Academic Medical Centers↗
The effects of AMPA receptor antagonists on kindled seizures and on reflex epilepsy in rodents and primates.
Two potent glutamate antagonists, NBQX and GYKI 52466, that act selectively on non-NMDA receptors, have been tested for anticonvulsant activity in 3 models of reflex epilepsy (sound-induced seizures in DBA/2 mice and in genetically epilepsy-prone rats and photically-induced myoclonus in Papio papio) and in amygdala kindled rats. Both compounds potently but transiently suppress reflexly-induced epileptic responses. GYKI 52466 also reduces behavioral seizures and afterdischarge duration in amygdala kindled rats, but with a lower potency than it suppresses reflex epilepsy. These data are similar to earlier results with antagonists acting selectively on NMDA receptors; they do not support a specific involvement of enhanced AMPA receptor sensitivity as a major factor in the expression of kindled seizures.
Acoustic Stimulation↗
Functional dissection of AP-1 transcription factors using the Gal4 adaptor assay.
In the Gal4 adaptor assay, leucine zipper-containing proteins are tethered indirectly to the promoters of Gal4-responsive reporter genes via synthetic protein chimeras consisting of a Gal4 DNA-binding domain with an attached leucine zipper. Ternary complexes composed of the DNA binding site, the adaptor protein, and a leucine zipper factor can stimulate reporter gene activity, provided that the latter component possesses a transcriptional activation domain. This system is used to assay the transcriptional function and the interactions between various AP-1 factors.
Amino Acid Sequence↗
Heritable paternal cytoplasmic organelles in alfalfa sperm cells: ultrastructural reconstruction and quantitative cytology.
Sperm cells within pollen grains and pollen tubes of alfalfa (Medicago sativa L.) were observed at the ultrastructural level, and their plastid DNA was detected by DAPI (4,6-diamidino-2-phenylindole) staining. One sperm pair within the pollen grain and three sperm pairs within pollen tubes were reconstructed in three-dimensions from serial ultrathin sections. The two sperm cells are linked by cytoplasmic bridges in both pollen grains and tubes, and the vegetative nucleus is closely associated with the sperm cells within the pollen tube. The number of plastids and plastid nucleoids (DNA aggregates) in the sperm cell pair, collectively, is not significantly different from that in the generative cell; however, over 60% of the sperm cell plastids contain no DNA detectable with DAPI. The mean number of mitochondria in sperm cells is reduced from that in the generative cell (from 54 to 17), which suggests that paternal mitochondrial inheritance probably does not occur in the genotype investigated. Sperm cells of a pair may vary in their shape within the pollen grain and tube, but the number of plastids and mitochondria is not significantly different between the sperm cells. Therefore, heterospermy is not a factor determining cytoplasmic inheritance patterns in this species.
Cytoplasm↗
Effects of exercise stress on various immune functions in horses.
Chemotactic locomotion and luminol-dependent chemiluminescence of neutrophils, mitogen-induced lymphocyte blastogenesis, serum cortisol concentration, immunoglobulin quantification, and leukocyte counts were determined to evaluate the effect of a single strenuous exercise in horses. Increased serum cortisol concentration (P less than 0.01) and an increased neutrophil-to-lymphocyte ratio (P less than 0.05) indicated that horses had been stressed. The chemotactic index and peak chemiluminescence production decreased significantly (P less than 0.05 and P less than 0.01, respectively) 1 day after exercise. Mitogen-induced blastogenesis of lymphocytes and serum immunoglobulin values remained unchanged in response to exercise. Results of this study indicated that a single bout of exercise may transiently impair neutrophil antimicrobial functions and nonspecific defense mechanisms, but not specific immunity in horses.
Animals↗
The non-N-methyl-D-aspartate receptor antagonists, GYKI 52466 and NBQX are anticonvulsant in two animal models of reflex epilepsy.
The effect of i.p. or i.v. administration of the non-N-methyl-D-aspartate antagonists, GYKI 52466 (1-(4-aminophenyl)-4-methyl-7,8-methylendioxy-5H-2,3-benzodiazepin e.HCl, molecular weight 330) and NBQX (2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(F)-quinoxaline, molecular weight 342) on sound-induced seizures in rats and photically induced myoclonus in baboons was studied. In both species an anticonvulsant effect occurred 15-60 min after administration of GYKI 52466 or NBQX. The ED50 value for clonic seizure suppression for GYKI 52466 at 30 min was 39 (rats, i.p.) and at 15 min was 13 (Papio papio, i.v.) mumol kg-1 and for NBQX at 30 min was 40 (rats, i.p.) and at 15 min approximately 10 (Papio papio, i.v.) mumol kg-1. Side effects were not observed in rats; apparent side effects in baboons probably arose from drug formulation. The anticonvulsant actions of GYKI 52466 and NBQX suggest a possible role for non-NMDA antagonists in the therapy of epilepsy.
Acoustic Stimulation↗
Factors influencing the ocular pulse--the heart rate.
Using pneumotonometry combined with a Langham ocular blood-flow system, measurements of pulsatile ocular blood flow (POBF) were performed in eight ocular normotensive patients with implanted cardiac pacemakers, with the subjects assuming both the erect and the supine postures. Sequential measurements of POBF were made at pre-set values of heart rate over the physiological range between 60 and 120 beats/min at intervals of 10 beats/min. With patients in the supine position, measurements of cardiac output and stroke volume indices were also recorded by impedance cardiography. The mean pulse amplitude of the intraocular pressure (the ocular pulse) decreased as heart rate increased, and this change was statistically significant in both postures according to repeated-measures analysis of variance (erect: f = 18.7, P less than 0.0001; supine: f = 18.8, P less than 0.0001). As measured in supine patients following an increase in heart rate, the pulse amplitude decreased in parallel with a decline in stroke volume index (f = 18.8, P less than 0.0001). Up to a level of 90 beats/min, the mean POBF increased with heart rate, but it declined above this rate in both erect and supine postures. At all heart rates, intraocular pressure was higher when subjects were supine than when they stood erect (f = 4.3, P less than 0.001). At lower heart rates of 70 and 80 beats/min, ocular pulse volume and POBF were significantly lower in supine patients than in erect subjects (70 beats/min: t = 3.89, P less than 0.01 vs; t = 3.87, P less than 0.01; 80 beats/min: t = 2.85, P less than 0.05 vs; t = 2.87, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Aged↗
The anticonvulsant effect of the non-NMDA antagonists, NBQX and GYKI 52466, in mice.
The excitatory amino acid antagonists, NBQX (2,3-dihydroxy-6-nitro-7-sulfamoylbenzo(F)quinoxaline) and GYKI 52466 (1-(4-aminophenyl)-4-methyl-7,8-methylenedioxy-5H-2,3-benzodiazepine) that act on non-NMDA receptors, provide potent anticonvulsant protection against AMPA [RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid)-induced seizures in Swiss mice and against sound-induced seizures in seizure-susceptible DBA/2 mice. Maximal anticonvulsant protection is observed 5-30 min after the i.p. administration of NBQX and 5-15 min after the i.p. administration of GYKI 52466 in DBA/2 mice. The ED50 values for the protection against AMPA-induced seizures by NBQX (30 min, i.p.) and GYKI 52466 (15 min, i.p.) are 23.6 (11.6-48.0) and 18.5 (11.5-29.5) mumol/kg, respectively. The ED50 values at 15 min for the protection against sound-induced seizures in DBA/2 mice are 31.3 (24.9-39.4) mumol/kg (NBQX, i.p.), 37.8 (21.2-67.4) mumol/kg (NBQX, i.v.) and 13.7 (11.5-16.5) mumol/kg (GYKI 52466, i.p.). In DBA/2 mice the therapeutic index (ratio of ED50 values for impaired rotarod performance and anticonvulsant action) is 6.6 for NBQX (15 and 30 min, i.p.) and 2.0 for GYKI 52466 (15 min, i.p.).
Acoustic Stimulation↗
Ocular responses in healthy subjects to topical bunazosin 0.3%--an alpha 1-adrenoceptor antagonist.
The ocular effects of the alpha-adrenoceptor blocking drug bunazosin, administered as eyedrops, have been measured in a placebo-controlled double-blind single-dose study in 15 healthy volunteers. The drug significantly reduced intraocular pressure over 10 hours, and there was no associated change in pulsatile ocular blood flow. Characteristic effects of alpha-adrenoceptor blockade were observed--miosis, ptosis, and conjunctival hyperaemia. The miosis alone persisted for more than 24 hours in nine out of 15 subjects.
Adrenergic alpha-Antagonists↗
Phagocytosis of protein coated colloidal-gold-agarose-gelatin microbeads by cultured uterine glandular epithelial and stromal cells.
A procedure for fixing and immunostaining whole cells from primary cultures of ovine and bovine uterine gland fragments was used to identify keratin in intermediate filaments of epithelial cells to distinguish them from stromal cells. Colloidal gold encapsulated agarose-gelatin microbeads were coated with different proteins and used to investigate uptake by epithelial and stromal cells in culture. Microbeads were taken up by stromal cells and by epithelial cells on the outskirts of colonies. These cells formed ridges where they contacted and grew above stromal cells. Electron microscopy demonstrated that the microbeads had been internalized and appeared to be nontoxic. Individual cells could harbor more than 90 microbeads within their cytoplasm for at least seven to ten days with no apparent harm. Some cells with microbeads were seen to divide.
Animals↗
Isolation of large numbers of chromosome 3-specific cosmids containing clusters of rare restriction-endonuclease sites.
We tested 519 chromosome 3-specific cosmids for the presence of rare restriction-endonuclease sites in a search for cosmids containing HTF islands. We have identified 49 cosmids (9% of those tested) that contain multiple rare restriction-endonuclease sites. The cosmids were digested with several common cutting restriction endonucleases to liberate small fragments which were tested as unique-sequence chromosome 3-specific hybridization probes and for evolutionary sequence conservation. Unique-sequence hybridization probes isolated from the cosmids were hybridized to a somatic cell hybrid deletion mapping panel to subchromosomally localize the cosmids. Fragments from many of these cosmids demonstrated conservation of sequence through evolution, and these fragments hybridize to distinct transcripts. These cosmids should therefore prove a useful resource for the identification of many chromosome 3-specific genes, in addition to having potential use as linking clones for pulsed-field gel mapping studies.
Biological Evolution↗