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Abstract
Expression of c-fos-immunoreactivity (c-fos-ir) has been demonstrated in the dorsal horn of lumbar segments of an isolated spinal cord preparation from 3 week old rats. The method of preparation generated a low level of c-fos-ir activity which was not significantly altered by low intensity (1.5 times threshold) dorsal root stimulation, but was significantly increased by high intensity (20 times threshold) stimulation. Replacement of the calcium in the bathing medium by 2 mM manganese suppressed all detectable c-fos-ir, whereas inclusion of 0.5 microM capsaicin caused intense c-fos-ir expression in the absence of stimulation. The number of dorsal horn cells exhibiting c-fos-ir increased between 0.5 and 1 h after stimulation, reaching a maximum at 2 h, with no further increase at longer intervals. Few positive cells were found when the incubation temperature was reduced from 27 to 20 degrees C. The strongest increase in c-fos-ir was found in the dorsal horn ipsilateral to the stimulated dorsal root and a smaller, but significant, increase was also seen in the contralateral dorsal horn. Cords obtained from animals treated at 1 day old with capsaicin to destroy afferent C fibres showed a reduction in the number of c-fos-ir positive cells induced by high intensity dorsal root stimulation. This preparation will aid detailed investigation of the pharmacology of nociceptive pathways.
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Williams RG, Pitt WG. In vitro response of Escherichia coli to antibiotics and ultrasound at various insonation intensities. J Biomater Appl 1997; 12:20-30. [PMID: 9285328 DOI: 10.1177/088532829701200102] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Microbial infections on implanted medical devices are difficult to treat. Application of 70 kHz ultrasonic irradiation to gentamicin treatment greatly enhanced the action of the antibiotic in terms of reduced viable bacterial concentrations. Ultrasonic irradiation was carried out at various insonation intensities that were noninhibitory in the absence of antibiotic. Synergistic killing was observed to be a function of ultrasonic intensity. Greatest killing (approximately 5 log reduction in viable population) was realized at full intensity (4.5 W/cm2), and decreased with reductions in power density. At lowest intensity (10 mW/cm2), no significant acoustic enhanced killing was noted.
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Tekian A, Williams RG. Vital indicators of teaching and learning success (VITALS): stakeholders' perceptions of a course-improvement system. ACADEMIC MEDICINE : JOURNAL OF THE ASSOCIATION OF AMERICAN MEDICAL COLLEGES 1997; 72:412. [PMID: 10676326 DOI: 10.1097/00001888-199705000-00032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Cheitlin MD, Alpert JS, Armstrong WF, Aurigemma GP, Beller GA, Bierman FZ, Davidson TW, Davis JL, Douglas PS, Gillam LD, Lewis RP, Pearlman AS, Philbrick JT, Shah PM, Williams RG, Ritchie JL, Eagle KA, Gardner TJ, Garson A, Gibbons RJ, O'Rourke RA, Ryan TJ. ACC/AHA guidelines for the clinical application of echocardiography: executive summary. A report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (Committee on Clinical Application of Echocardiography). Developed in collaboration with the American Society of Echocardiography. J Am Coll Cardiol 1997; 29:862-79. [PMID: 9091535 DOI: 10.1016/s0735-1097(96)90000-5] [Citation(s) in RCA: 157] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Stanfa LC, Singh L, Williams RG, Dickenson AH. Gabapentin, ineffective in normal rats, markedly reduces C-fibre evoked responses after inflammation. Neuroreport 1997; 8:587-90. [PMID: 9106728 DOI: 10.1097/00001756-199702100-00002] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Gabapentin (Neurontin) is a novel anticonvulsant with an as yet unknown mechanism of action. This electrophysiological study investigated the potential antinociceptive actions of systemically administered gabapentin in normal animals and after inflammation induced by the injection of carrageenan. Gabapentin facilitated the noxious evoked responses of dorsal horn neurones recorded in normal animals. In complete contrast, gabapentin strongly and dose-dependently inhibited the C-fibre evoked response and post-discharge, but not the A beta-fibre evoked response, of neurones recorded in animals 3 h after the injection of carrageenan. This unique and selective profile of gabapentin may provide a novel treatment for clinical inflammatory pain states.
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Williams RG, Kavanagh KM, Teo KK. Pathophysiology and treatment of cocaine toxicity: implications for the heart and cardiovascular system. Can J Cardiol 1996; 12:1295-301. [PMID: 8987970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
OBJECTIVE To review the data on pharmacology, pathophysiology and treatment of cocaine toxicity, with particular relevance to the heart and cardiovascular system. DATA SOURCE AND STUDY SELECTION Published epidemiology, laboratory and clinical studies on the pharmacology, electrophysiology and pathophysiology of cocaine toxicity and its treatment. MAIN RESULTS Cocaine toxicity-related morbidity and mortality are frequent due to the potent pharmacological effects of the drug as an indirect-acting sympathomimetic agent and its class I antiarrhythmic property paradoxically inducing pro-arrhythmia. The cardiac and cardiovascular toxic effects of cocaine include various degrees of myocardial ischemia, cardiac arrhythmias, cardiotoxicity, hypertensive effects, cerebrovascular effects and a hypercoagulable state. Treatment of cocaine toxicity must be based on the multiple factors leading to the toxicity. Sodium bicarbonate appears to have an important role in the acute setting with conduction abnormalities, seizures or acidosis. Unopposed alpha-stimulation provided by beta-blockade should be avoided. Central nervous system hyperexcitability should be treated with diazepam. The use of calcium antagonists appears logical. CONCLUSION Cocaine is an alkaloid with widespread illicit use. The rationale for treating acute cocaine intoxication has become clearer and more logical with increased knowledge of its mechanisms of action.
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Williams RG. Compensation of lawyers and doctors. N Engl J Med 1996; 335:1691. [PMID: 8965875 DOI: 10.1056/nejm199611283352220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Singh L, Field MJ, Ferris P, Hunter JC, Oles RJ, Williams RG, Woodruff GN. The antiepileptic agent gabapentin (Neurontin) possesses anxiolytic-like and antinociceptive actions that are reversed by D-serine. Psychopharmacology (Berl) 1996; 127:1-9. [PMID: 8880937 DOI: 10.1007/bf02805968] [Citation(s) in RCA: 169] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
This report describes the activity of the antiepileptic agent gabapentin (Neurontin) in animal models predictive of anxiolysis and analgesia. Gabapentin displayed anxiolytic-like action in the rat conflict test, the mouse light/dark box and the rat elevated X-maze with respective minimum effective doses (MEDs) of 3, 10 and 30 mg/kg. Furthermore, gabapentin also induced behavioural changes suggestive of anxiolysis in the marmoset human threat test with a MED of 30 mg/kg. In the rat formalin test of tonic nociception, gabapentin dose-dependently (30-300 mg/kg) and selectively blocked the late phase with a MED of 100 mg/kg. However, it failed to block carrageenan-induced paw oedema. The intracerebroventricular (ICV) administration of the glycine/NMDA receptor agonist D-Serine, dose-dependently (10-100 micrograms/animal) reversed the antinociceptive action of gabapentin (200 mg/kg, SC). D-Serine (30 micrograms/animal, ICV) also reversed the anxiolytic-like effects (in the light/dark box and the rat elevated X-maze) of gabapentin (30 mg/kg). In contrast, L-Serine (100 micrograms, ICV) failed to block the antinociceptive action of gabapentin. The antinociceptive action of (+)-HA-966 (25 mg/kg, SC), a partial agonist at the glycine/NMDA receptor, was reversed by D-Serine (100 micrograms/animal, ICV). However, D-Serine (100 micrograms/animal, ICV) failed to affect the antinociceptive action of a competitive NMDA receptor antagonist CGS 19755 (3 mg/kg, SC). Gabapentin has negligible affinity for the strychnine insensitive [3H]glycine binding site. This indicates that the interaction between gabapentin and D-Serine may not involve the NMDA receptor complex. Gabapentin may represent a novel type of anxiolytic and analgesic agent.
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Williams RG, Chang S, Comaratta MR, Simoni G. Does the presence of heparin and dexamethasone in the vitrectomy infusate reduce reproliferation in proliferative vitreoretinopathy? Graefes Arch Clin Exp Ophthalmol 1996; 234:496-503. [PMID: 8858355 DOI: 10.1007/bf00184858] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Reproliferation following vitrectomy for proliferative vitreoretinopathy (PVR) causes redetachment in up to 55% of cases. Heparin and corticosteroids have each been shown to inhibit the development of proliferative vitreoretinopathy (PVR) in experimental models. However, little information is available on the use of these agents in humans. METHODS In this pilot study, 62 eyes of 62 patients with severe PVR requiring vitrectomy were prospectively randomized to receive either BSS Plus (control) or BSS Plus with heparin and dexamethasone (HD) in the infusate. RESULTS After one operation, the retina was reattached in 42 (71%) of 59 eyes: 22 (65%) of 34 eyes in the control group and 20 (80%) of 25 eyes in the HD group (P = 0.16). Reproliferation developed in 26.5% of the control group (9 of 34 eyes) and 16% of the HD group (4 of 25 eyes; P = 0.26). Postoperative hemorrhage was significantly more frequent in the HD group (P = 0.02) but did not influence final visual or anatomic outcome. Hypotony was less frequent in the HD group but the difference was not significant (P = 0.063). CONCLUSION The trend from this randomized pilot study suggests that HD supplementation of the vitrectomy infusate may reduce the reproliferation rate in PVR and possibly reduce the rate of hypotony. Postoperative hemorrhage was more frequent with HD but did not cause redetachment or alter visual outcome. A multicenter trial involving more patients would be required to better evaluate the efficacy of HD as a pharmacologic adjunct to PVR surgery.
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Jensen RA, Williams RG, Laks H, Drinkwater D, Kaplan S. Usefulness of banding of the pulmonary trunk with single ventricle physiology at risk for subaortic obstruction. Am J Cardiol 1996; 77:1089-93. [PMID: 8644663 DOI: 10.1016/s0002-9149(96)00138-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
This study addresses the effects of early banding of the pulmonary trunk and subsequent management of subaortic obstruction on the attainment of acceptable pre-Fontan hemodynamics in patients with a single left ventricle and aorta arising from an outflow chamber. We report our experience with 26 patients seen at our institution between January 1984 and December 1994 with a diagnosis of double-inlet left ventricle or tricuspid atresia and transposed great arteries, who were initially managed with pulmonary artery banding in the first 6 months of life. Pulmonary artery band placement was performed at an age of 2.1 +/- 1.8 months (mean +/- SD). Associated aortic arch abnormalities were present in 8 patients (31%). There were 19 patients (73%) who underwent treatment with a Damus-Kaye-Stansel procedure or ventricular septal defect (VSD) enlargement for a significant subaortic gradient or morphologically small VSD, alone or in conjunction with a Glenn or Fontan procedure. Eighteen of 26 patients (69%) underwent cardiac catheterization to assess their candidacy for the Fontan operation. Of this group, 16 were classified as low to moderate risk and 2 as high-risk Fontan candidates, based on hemodynamic criteria. The cumulative mortality for the entire cohort was 19%. Our results suggest that this high-risk group of patients can undergo effective pulmonary artery banding as an initial palliative step, with subsequent intervention for subaortic ob- struction when it is documented or highly suspected, and that acceptable pre-Fontan hemodynamic parameters can be achieved.
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Bascal ZA, Montgomery A, Holden-Dye L, Williams RG, Thorndyke MC, Walker RJ. NADPH diaphorase activity in peptidergic neurones of the parasitic nematode, Ascaris suum. Parasitology 1996; 112 ( Pt 1):125-34. [PMID: 8587795 DOI: 10.1017/s0031182000065161] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The histochemical marker for nitric oxide synthase, NADPH diaphorase, is known to co-localize in mammalian neurones with various classical neurotransmitters and neuropeptides. The nervous system of the parasitic nematode Ascaris suum has previously been shown to contain both NADPH diaphorase activity and neuropeptide immunoreactivity. This study examined the possibility that NADPH diaphorase and neuropeptide immunoreactivity may co-exist in the same neurones. Two antisera were used, one raised to KYSALMFamide, a C-terminal synthetic analogue of SALMFamide 1 (GFNSALMFamide), and another that recognizes calcitonin-gene-related peptide (CGRP). We provide evidence that in a distinct subset of neurones in the ventral, dorsal and lateral ganglia NADPH diaphorase staining and SALMFamide-like immunoreactivity are co-localized, suggesting a possible role for nitric oxide in modulating neuropeptide activity in these regions. CGRP-like immunoreactivity was less widely distributed, and was not consistently co-localized with NADPH diaphorase.
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Drant SE, Klitzner TS, Shannon KM, Wetzel GT, Williams RG. Guidance of radiofrequency catheter ablation by transesophageal echocardiography in children with palliated single ventricle. Am J Cardiol 1995; 76:1311-2. [PMID: 7503018 DOI: 10.1016/s0002-9149(99)80364-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Vetrovec GW, Gardin JM, Gregory JJ, Herrmann HC, Rutherford BD, Weiner BH, Williams RG, Collishaw K, Ganslaw LS. Adult Cardiovascular Physician Resources and Needs Assessment. Report of the 1992 and 1993 American College of Cardiology Surveys on Physician Training and Resource Requirements. Physician Workforce Advisory Committee. J Am Coll Cardiol 1995; 26:1125-32. [PMID: 7594022 DOI: 10.1016/0735-1097(95)00323-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Cotton JL, Williams RG. Noonan syndrome and neuroblastoma. ARCHIVES OF PEDIATRICS & ADOLESCENT MEDICINE 1995; 149:1280-1. [PMID: 7581766 DOI: 10.1001/archpedi.1995.02170240098019] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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40
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Keating CD, Holden-Dye L, Thorndyke MC, Williams RG, Mallett A, Walker RJ. The FMRFamide-like neuropeptide AF2 is present in the parasitic nematode Haemonchus contortus. Parasitology 1995; 111 ( Pt 4):515-21. [PMID: 11023415 DOI: 10.1017/s0031182000066026] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Peptides belonging to the FMRFamide family are widely distributed amongst invertebrates. We report here on the isolation of the FMRFamide neuropeptide AF2 (Lys-His-Glu-Tyr-Leu-Arg-Phe-NH2) from the parasitic nematode Haemonchus contortus. Immunocytochemical techniques showed that FMRFamide-like material was distributed in several regions of these organisms including nerve cords and cell bodies of the central nervous system. AF2 was isolated using a method that employed 6 steps of reverse-phase HPLC. The concentration of AF2 in this organism was approximately 30 pmol/g of nematode.
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Dodo H, Alejos JC, Perloff JK, Laks H, Drinkwater DC, Williams RG. Anomalous origin of the left main pulmonary artery from the ascending aorta associated with DiGeorge syndrome. Am J Cardiol 1995; 75:1294-5. [PMID: 7778565 DOI: 10.1016/s0002-9149(99)80788-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We place on record 2 infants with the DiGeorge syndrome and anomalous origin of the left pulmonary artery from the ascending aorta. We postulate that: (1) embryogenesis of anomalous origin of the left pulmonary artery from the ascending aorta might be due to the persistent fifth aortic arch connecting both arterial systems; (2) an anomalous pulmonary artery arising from the ascending aorta is part of the aortic arch abnormality accompanied by normal conotruncal septation; and (3) in the DiGeorge syndrome, cardiac anomalies that originate from the conotruncus or aortic arch, or both, may have the same embryologic mechanisms.
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Bascal ZA, Montgomery A, Holden-Dye L, Williams RG, Walker RJ. Histochemical mapping of NADPH diaphorase in the nervous system of the parasitic nematode Ascaris suum. Parasitology 1995; 110 ( Pt 5):625-37. [PMID: 7596645 DOI: 10.1017/s0031182000065343] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
NADPH diaphorase has recently been discovered to be responsible for neuronal nitric oxide (NO) synthase activity in mammals. It thus serves as a histochemical marker for the localization of NO synthase in the nervous system. The histochemical technique was used to map out potential NO-producing neurones in the nervous system of the parasitic nematode, Ascaris suum. Positive staining for NADPH diaphorase was present in various parts of the central nervous system, in particular within selective cell bodies and fibres in the ventral ganglion, the retrovesicular ganglion, ventral and dorsal cords and sublateral lines. Intense staining was also present in the motorneurone commissures, indicating a potential role for NO as a neurotransmitter at the neuromuscular junction. NADPH disphorase-positive neurones were not confined to the central nervous system. Selective staining was also present in the enteric nervous system, in particular the pharynx and in the peripheral nervous system innervating the sensory organs.
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Alejos JC, Williams RG, Jarmakani JM, Galindo AJ, Isabel-Jones JB, Drinkwater D, Laks H, Kaplan S. Factors influencing survival in patients undergoing the bidirectional Glenn anastomosis. Am J Cardiol 1995; 75:1048-50. [PMID: 7747687 DOI: 10.1016/s0002-9149(99)80722-x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The bidirectional Glenn anastomosis (BGA) has long been used as a surgical intervention for patients with single ventricle physiology. Initially, this procedure was the final stage in palliation and was performed in older children. Eventually, as the Fontan procedure came to be used as a method to separate circulations, the Glenn procedure was performed as an intermediate step. Over time, the BGA was performed as an alternative for patients who were considered to be at high risk with the Fontan procedure. Between January 1, 1988, and January 1, 1994, 129 patients underwent BGA at the University of California-Los Angeles. These patients were reviewed retrospectively, including clinic visits, catheterization, and echocardiographic information. The overall survival rate was 87% (112 of 129 patients). The average length of follow-up was 27 months. This information was then analyzed by univariate and multivariate analysis. Several factors were related to failure in patients who underwent BGA including pulmonary artery pressure, systemic right ventricle, and presence of anomolous pulmonary venous drainage and heterotaxy syndrome.
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Holden-Dye L, Franks CJ, Williams RG, Walker RJ. The effect of the nematode peptides SDPNFLRFamide (PF1) and SADPNFLRFamide (PF2) on synaptic transmission in the parasitic nematode Ascaris suum. Parasitology 1995; 110 ( Pt 4):449-55. [PMID: 7753584 DOI: 10.1017/s0031182000064787] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The action of two peptides isolated from the nematode Panagrellus redivivus, PF1 (SDPNFLRFamide) and PF2 (SADPNFLRFamide) have been studied on synaptic transmission in the motornervous system of the parasitic nematode Ascaris suum. Intracellular recordings were made from Ascaris somatic muscle cells and excitatory junction potentials (EJPs) elicited by stimulation of the ventral nerve cord. The EJPs were cholinergic as they were blocked by the Ascaris nicotinic receptor antagonist, benzoquinonium. PF1 caused a slow hyperpolarization, similar to the action of this peptide first reported by Bowman, Geary & Thompson (1990) and further characterized by Franks et al. (1994). The hyperpolarization was accompanied by a marked decrease in the amplitude of the EJPs with an EC50 of 311 +/- 30 nM (n = 5). This inhibition is unlikely to be due to a post-synaptic site of action of the peptide as the muscle cell input conductance was not significantly altered by PF1 and furthermore the response to bath-applied acetylcholine was not inhibited by PF1 at concentrations up to 10 microM (n = 6). PF2 also inhibited the EJPs in a similar manner to PF1. These studies indicate that both of the peptides isolated from the free-living nematode Panagrellus redivivus have biological activity in the parasitic nematode Ascaris suum. PF1 and PF2 have inhibitory actions in contrast to the predominantly excitatory actions of the Ascaris endogenous peptides AF1 (KNEFIRFamide) and AF2 (KHEYLRFamide). The potent actions of the Panagrellus neuropeptides PF1 and PF2 in Ascaris suggest that peptides with a similar or identical sequence may also occur in Ascaris and have an inhibitory role in the motornervous system.
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Pang FY, Mason J, Holden-Dye L, Franks CJ, Williams RG, Walker RJ. The effects of the nematode peptide, KHEYLRFamide (AF2), on the somatic musculature of the parasitic nematode Ascaris suum. Parasitology 1995; 110 ( Pt 3):353-62. [PMID: 7724243 DOI: 10.1017/s003118200008094x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
AF2 is an endogenous RFamide-like peptide from the parasitic nematode Ascaris suum. The potent stimulatory effects of this peptide on the somatic musculature of Ascaris strongly suggest that it may have an important role in the motornervous system. Here we have investigated the possibility that AF2 may elicit a stimulatory action on Ascaris muscle by potentiating the actions of the excitatory cholinergic motonervous system either pre-synaptically, post-synaptically or both. In in vitro pharmacological experiments AF2 produced a dose-dependent increase in the frequency and amplitude of spontaneous contractions of Ascaris muscle strip which lasted for more than 1 h after a 3 min application of AF2 (10 nM-10 microM; N = 7). In addition, AF2 (100 nM) potentiated the contraction elicited by ACh by 43 +/- 9% (P < 0.01; N = 8). In electrophysiological recordings from muscle cells, AF2 (10-100 nM; N = 10) potentiated the amplitude of EJPs (excitatory junction potentials). For 100 nM AF2, the potentiation of the EJP was 218 +/- 48% (N = 7; P < 0.01). This effect reversed after a wash of 10 min. AF2 did not potentiate the depolarization of the muscle cell elicited by bath applied ACh. These latter two observations are consistent with a presynpatic action of AF2. AF2 (10-100 nM) generated spontaneous muscle cell action potentials in previously quiescent cells. This effect took more than 1 h to wash out. These observations are discussed in terms of the paralysis of Ascaris that is elicited by AF2.
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Mills RG, Douglas-Jones T, Williams RG. 'Ceruminoma'--a defunct diagnosis. J Laryngol Otol 1995; 109:180-8. [PMID: 7745330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The clinical and pathological features of glandular tumours of the external auditory meatus are presented. Their heterogenous clinical and pathological features make the collective term 'ceruminoma' ambiguous and misleading. The spectrum of pathological behaviour and histological features demonstrated by these interesting tumours necessitate a broader classification system. In our hospital 32 patients presented with tumours of the external auditory meatus over a 30-year period, of which seven were glandular in origin. A review of the histology of these glandular tumours enabled us to reclassify them as adenoma, cylindroma, adenoid cystic carcinoma or ceruminous adenocarcinoma. Together with the less common mucoepidermoid carcinoma and pleomorphic adenoma this subdivision forms a basis for a more meaningful classification system with prognostic and therapeutic implications specific to each tumour type. The term 'ceruminoma' should no longer be used unqualified.
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Abstract
The resurgence of tuberculosis world-wide and its association with HIV infection means a greater likelihood of otolaryngologists encountering the disease in one form or another. In this review the features of primary and secondary tuberculosis in various head and neck sites are described, and recent advances in diagnosis are discussed. For the otolaryngologists other important aspects such as infections with atypical mycobacteria, the differential diagnosis of cervical lymphadenopathy in HIV-infected patients, recently recognized problems in drug treatment, and the role of surgery in head and neck tuberculosis are also discussed.
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Kao JM, Alejos JC, Grant PW, Williams RG, Shannon KM, Laks H. Conversion of atriopulmonary to cavopulmonary anastomosis in management of late arrhythmias and atrial thrombosis. Ann Thorac Surg 1994; 58:1510-4. [PMID: 7979684 DOI: 10.1016/0003-4975(94)91945-3] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The original atriopulmonary connection or "classic" Fontan operation is associated with several late complications such as arrhythmias, right atrial dilatation, and thromboembolism. This report describes our experience with 3 patients who presented with the acute onset of atrial arrhythmias and upon further evaluation were found to have significant hemodynamic lesions. After failing medical management, all 3 patients were treated successfully with surgical conversion of their atriopulmonary connection to a lateral tunnel cavopulmonary Fontan. The postoperative course of these patients was uneventful. However, long-term evaluation is needed to assess the efficacy of this technique in the prevention of postoperative morbidity.
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Allgood NL, Alejos J, Drinkwater DC, Laks H, Williams RG. Effectiveness of the bidirectional Glenn shunt procedure for volume unloading in the single ventricle patient. Am J Cardiol 1994; 74:834-6. [PMID: 7942565 DOI: 10.1016/0002-9149(94)90450-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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50
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Ritchie JL, Cheitlin MD, Hlatky MA, Ryan TJ, Williams RG. Task Force 5: Profile of the cardiovascular specialist: trends in needs and supply and implications for the future. J Am Coll Cardiol 1994; 24:313-21. [PMID: 8034862 DOI: 10.1016/0735-1097(94)90282-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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