Papers by Ronald Campbell
Coronary Artery Disease, 1994
Biological Bulletin, 1981
Dic/idophora nezumiae sp. n. is described from the gills of the rat-tail fish Nezumia bairdii (Go... more Dic/idophora nezumiae sp. n. is described from the gills of the rat-tail fish Nezumia bairdii (Goode and Bean, 1877) taken from the environs of Hudson Submarine Canyon in the northwest Atlantic. The host-parasite relationships were studied in the host population. The new species is most similar to small species of Dic/idophora having short bodies that taper to maximum width at the level of the first pair of clamps. It may be differentiated from other species by the following: clamps wider than long, noticeably decreasing in size posteriorly; lamellate exten sion of sclerite b does not fuse with sclerite &; unsclerotized diaphragm; a relatively small clamp sucker; 10â€" 13 cirrus hooks; I 8â€"30intercecal, postovarian testes; Un lobed seminal receptacle; filamented eggs; and body dimensions. Of 378 N. bairdii specimens examined, 106 (28%) were infected with 1â€"21D. nezumiae per host.
Heart, 2001
OBJECTIVETo assess the efficacy and safety of intravenous dofetilide in preventing induction of a... more OBJECTIVETo assess the efficacy and safety of intravenous dofetilide in preventing induction of atrioventricular re-entrant tachycardia.DESIGNA multicentre, open, dose ranging trial. Fifty one patients with electrically inducible atrioventricular re-entrant tachycardia were allocated to one of five doses of dofetilide (1.5, 3, 6, 9, and 15 μg/kg), two thirds of the dofetilide dose being given over a 15 minute loading period
Current nomenclature for the atrioventricular (AV) junctions derives from a surgically distorted ... more Current nomenclature for the atrioventricular (AV) junctions derives from a surgically distorted view, placing the valvar rings and the triangle of Koch in a single plane with antero-posterior and right-left lateral coordinates. Within this convention, the aorta is considered to occupy an anterior position, although the mouth of the coronary sinus is shown as being posterior. Although this nomenclature has
Clinical cancer research : an official journal of the American Association for Cancer Research, Jan 15, 2014
In this study, we evaluated the analgesic potential of demethylating drugs on oral cancer pain. A... more In this study, we evaluated the analgesic potential of demethylating drugs on oral cancer pain. Although demethylating drugs could affect expression of many genes, we focused on the mu-opioid receptor (OPRM1) gene pathway, because of its role in pain processing. We determined the antinociceptive effect of OPRM1 re-expression in a mouse oral cancer model. Using a mouse oral cancer model, we determined whether demethylating drugs produced antinociception through re-expression of OPRM1. We then re-expressed OPRM1 with adenoviral transduction and determined if, and by what mechanism, OPRM1 re-expression produced antinociception. To determine the clinical significance of OPRM1 on cancer pain, we quantified OPRM1 methylation in painful cancer tissues and nonpainful contralateral normal tissues of patients with oral cancer, and nonpainful dysplastic tissues of patients with oral dysplasia. We demonstrated that OPRM1 was methylated in cancer tissue, but not normal tissue, of patients with o...
European Journal of Biochemistry, 1986
The proteolytic specificities of two zinc hemorrhagic toxins (Ht-c and Ht-d), isolated from Crota... more The proteolytic specificities of two zinc hemorrhagic toxins (Ht-c and Ht-d), isolated from Crotalus atrox venom, were investigated by using the oxidized B chain of bovine insulin and synthetic peptide substrates. The enzymes cleaved the Ala14-Leu15 bond of the insulin B chain most rapidly and the Tyr16-Leu17 slightly more slowly. The His5-Leu6, His10-Leu11, and Gly23-Phe24 bonds were also cleaved but at considerably slower rates. In order to assess the substrate length preferences of the enzymes, peptide analogs of the B chain about the Ala14-Leu15 bond were synthesized ranging in length from four to seven residues. The heptapeptide NH2-Leu-Val-Glu-Ala-Leu-Tyr-Leu-COOH was the best peptide substrate tested with the other peptides having decreasing kcat/Km values with decreasing length. The tetrapeptide NH2-Ala-Leu-Tyr-Leu-COOH was not cleaved by the enzymes. Furthermore, this peptide was shown to serve as a competitive inhibitor of the toxins. The N-acetylated pentapeptides and hexapeptides, synthesized to probe the active site environment of the enzymes, were significantly better substrates than their unacetylated counterparts. The toxins had the highest kcat/Km values for the acetylated peptide Ac-Val-Ala-Leu-Leu-Ala-COOH. The data suggest that the toxins may indeed have extended substrate-binding sites, which may accommodate at least six amino acid residues. The best substrate examined thus far for the toxins is the fluorogenic peptide analog 2-aminobenzoyl-Ala-Gly-Leu-Ala-4-nitrobenzylamide, suggestive of similarities between the toxins and mammalian collagenases as well as thermolysin. Mechanisms for inhibition of the enzymes were investigated using amino acid hydroxamates, chloromethyl esters, phosphoramidon and the peptide NH2-Ala-Leu-Tyr-Leu-COOH. All of these inhibitors had Ki values in the 10(-4) M range.
Systematic Parasitology, 1999
A preliminary cladistic analysis was carried out on the 49 currently recognised genera of the ord... more A preliminary cladistic analysis was carried out on the 49 currently recognised genera of the order Trypanorhyncha. Forty-four characters were analysed; a functional outgroup was used for scolex and strobilar characters, while Nybelinia was utilised to polarise characters related to the rhyncheal system. Eight well-resolved clades were evident in the resultant cladogram, which is compared with existing phenetic classifications. An analysis of families resulted in a similar clustering of taxa to that observed in the case of the genera. The results suggest that two key characters used in existing classifications, namely the presence of sensory fossettes on the bothridia and the development of atypical heteroacanth and poeciloacanth armatures from typical heteroacanth armatures, have occurred on several occasions. Some clades provide support for the arrangements used in current classifications. Suggestions are made for future avenues of research which might provide more robust phylogenetic data for the Trypanorhyncha.
Systematic Parasitology, 1999
Evolutionary relationships of the Eucestoda have received intense but sporadic attention over the... more Evolutionary relationships of the Eucestoda have received intense but sporadic attention over the past century. Since 1996, the landscape has dramatically changed with respect to our knowledge of the phylogenetic relationships among the tapeworms. The 2nd International Workshop for Tapeworm Systematics (IWTS) held in Lincoln, Nebraska in October of that year provided the catalyst for development of novel hypotheses for inter- and intraordinal phylogeny. The working-group structure of the 2nd IWTS and results of phylogenetic studies are briefly introduced in the present manuscript. Higher-level phylogenies derived from parsimony analysis of independent data bases representing comparative morphology or molecular sequences were largely congruent and supported monophyly for the Eucestoda. The Caryophyllidea are basal; difossate forms such as the Pseudophyllidea are primitive; tetrafossates including the Tetraphyllidea, Proteocephalidea, Nippotaeniidea, Tetrabothriidea and Cyclophyllidea are derived; and hypotheses differed in the placement of the Trypanorhyncha and the Diphyllidea. These studies may provide a foundation for resolution of inter- and intra-ordinal relationships for the tapeworms. Additionally, the first comprehensive phylogenetic hypotheses for the Pseudophyllidea, Diphyllidea, Trypanorhyncha, the paraphyletic Tetraphyllidea + Lecanicephalidea, Proteocephalidea and Cyclophyllidea were developed during and subsequent to the 2nd IWTS. The stage is now set for continued and rapid advances in our understanding of the eucestodes. These studies have also served to re-emphasise the rich genealogical diversity of tapeworms and the temporally deep history for their origin. A co-evolutionary history and radiation of eucestodes may involve deep co-speciation with vertebrate host taxa, accompanied by some level of colonisation and extinction, extending into the Palaeozoic, minimally 350-420 million years ago.
Systematic Parasitology, 2007
Members of the trypanorhynch cestode genus Grillotia Guiart, 1927 belonging to the Grillotia erin... more Members of the trypanorhynch cestode genus Grillotia Guiart, 1927 belonging to the Grillotia erinaceus (van Beneden, 1858) species complex are redescribed. The type-species of the genus, G. erinaceus, is redescribed from Raja spp. in the eastern and western north Atlantic and the Mediterranean. The redescription establishes the presence of: an hermaphroditic sac; internal and external seminal vesicles (but absence of an accessory seminal vesicle); a uterine pore; and the attachment of the retractor muscle in the mid-region of the tentacular bulb. G. pseuderinaceus Dollfus, 1969 and G. recurvispinis Dollfus, 1969 from Raja spp. in the Mediterranean are considered to be synonyms of G. erinaceus, following Palm (2004). G. dollfusi Carvajal, 1971 from R. chilensis Guichenot off Chile is redescribed from the paratypes and features of the terminal genitalia, consistent with those of G. erinaceus, are described for the first time. G. musculara (Hart, 1936) is redescribed from new material collected from the type-host, R. rhina (Jordan & Gilbert), off Nanaimo on the western coast of Canada. The features of the terminal genitalia of G. musculara are similar to those of the G. erinaceus group. The morphological features of G. borealis Keeney & Campbell, 2001 from Bathyraja spp. in the Bering Sea and the Sea of Okhotsk are summarised and illustrations of this species provided. G. brayi n. sp. is described from Amblyraja radiata from the coasts of Iceland and Britain. The new species differs from other members of the complex in lacking modified hooks 1 and 1' at the base of the tentacle (differentiating it from G. erinaceus), a long pars vaginalis (differentiating it from G. dollfusi) and uncinate hooks in the band on the external surface of the tentacle (differentiating it from G. musculara). Brief descriptions are provided of two apparently new species of Grillotia currently represented in collections by single specimens.
Journal of Organizational and End User Computing, 2000
ABSTRACT Opportunities for Internet use in the political process are constantly emerging. The use... more ABSTRACT Opportunities for Internet use in the political process are constantly emerging. The use of the Internet to obtain political news and share political information is gaining momentum. Remote Internet voting initiatives are also growing in popularity. This study presents a model of Internet voting adoption that explores the predictors of the perceived usefulness of Internet voting systems. To test the model a survey is administered to 372 citizens. The results of structural equation modeling indicate that accessibility, convenience, disposition to trust, and Internet trust all have a significant impact on the perceived usefulness of Internet Voting. Implications for research and practice are discussed.
International Journal of Electronic Government Research, 2000
Folia Parasitologica, 2013
Three new genera of eutetrarhynchid trypanorhynch cestodes are described from Mobula spp. (Mobuli... more Three new genera of eutetrarhynchid trypanorhynch cestodes are described from Mobula spp. (Mobulidae) from the Gulf of California, Mexico. Fellicocestus mobulae gen. et sp. n. from the gall bladder of Mobula japonica (Miller et Henle) is distinguished by elongate bothria, a pars bothrialis equal in length to the pars vaginalis, masses of gland cells in the pars vaginalis and an heteromorphous armature in which hook rows arise from a central file of hooks on the bothrial surface of the tentacle and terminate in a central file on the antibothrial surface. Species of Mobulocestus gen. n. occur in the nephridial system and cloaca of rays and are characterized by two bothria, an heteroacanthous armature with hook rows beginning on the bothrial surface and terminating on the antibothrial surface, and by hooks at the beginnings of rows with an apical cavity. M. nephritidis sp. n. and M. lepidoscolex sp. n., both from the nephridial system of Mobula thurstoni (Lloyd) are differentiated by testis number and by the presence of scale-like microtriches on the tegument of the scolex of M. lepidoscolex. M. mollis sp. n., from the cloaca of Mobula thurstoni is distinguished by testis number (97-111 in M. lepidoscolex, 20-22 in M. nephriticus and 48-70 in M. mollis). Hemionchos gen. n. from the spiral valve of Mobula spp. has two bothria, an heteroacanthous armature, hook rows arising on the bothrial surface and terminating on the antibothrial surface and hooks at the beginning of rows with an apical cavity. It differs from Mobulocestus in having a distinctive basal armature and both hook files 1 and 1' on the bothrial surface, but has an additional, small, satellite hook adjacent to each hook 1'. H. striatus sp. n. from the spiral valve of Mobula thurstoni and M. japonica is differentiated by having a basal armature of closely packed arrays of small, uncinate hooks. H. mobulae sp. n. from the spiral valve of Mobula japonica and M. munkiana Notarbartolo di Sciari, differs in testis number and in having large, flattened hooks in the basal armature. H. maior sp. n., from the spiral valve of M. japonica, is larger, differing in both the number of testes and in the basal armature.
European Heart Journal, 1998
Birth, 2007
Bedrest has long been recommended for high-risk pregnancies, but recent studies question its effe... more Bedrest has long been recommended for high-risk pregnancies, but recent studies question its effectiveness in improving pregnancy outcomes. To be effective, the women for whom bedrest is recommended must practice it. This study examined degree of compliance and reason for noncompliance in women for whom bedrest was recommended, and outcomes of pregnancy among high-risk women who complied compared with those who did not. The subjects were 326 high-risk pregnant women who were prescribed bedrest for preterm labor, blood pressure problems, or bleeding problems. Of that group, one-third did not comply with the bedrest recommendation. These women had more children, were not currently married, had more stress, did not attend prenatal classes, continued drinking alcohol during pregnancy, and were not trying to get pregnant compared with women who complied. Reasons for noncompliance included the need to care for children, not feeling sick, household demands, lack of partner or family support, need to work, and discomfort. The pregnancy outcomes for the women who complied were similar to those of the women who did not comply. These findings support the importance of more research on the practice of prescribing bedrest to improve pregnancy outcomes.
The American Journal of Cardiology, 1995
There is increasing evidence that class III antiarrhythmic agents may be superior to class I agen... more There is increasing evidence that class III antiarrhythmic agents may be superior to class I agents for the long-term treatment of life-threatening ventricular tachyarrhythmias. This open study evaluated the acute electrophysiologic effects, antiarrhythmic efficacy, and safety of different doses of intravenous dofetilide, a new class III drug, in 50 patients with sustained monomorphic ventricular tachycardia inducible by programmed electrical stimulation who had previously been unsuccessfully treated with 0 to 7 (median 3) other drugs. Intravenous dofetilide was administered over 60 minutes at the following dose levels: 1.5, 3.0, 6.0, 9.0, and 15.0 micrograms/kg. Significant class III activity was apparent at doses of 3.0 to 15.0 micrograms/kg, as evidenced by dose-related prolongation of the QTc interval by 13.4% to 14.2%, ventricular effective refractory period by 7.9% to 20.6%, and ventricular functional refractory period by 7.3% to 25.0%. The corresponding mean +/- SD plasma dofetilide concentrations ranged from 1.45 +/- 0.52 to 6.48 +/- 1.31 ng/ml. There was no evidence of reverse use-dependence. At these electrophysiologically active dose levels, intravenous dofetilide suppressed (complete response) or slowed (partial response) inducible ventricular tachycardia in 17 of 41 patients (41%) compared with 0 of 9 patients receiving only 1.5 micrograms/kg. The response rate was fairly uniform among the groups receiving 3.0, 6.0, 9.0, and 15.0 micrograms/kg. Intravenous dofetilide was hemodynamically well tolerated. Torsades de pointes (which was self-limiting) developed in only 1 patient, who was allocated to receive 15.0 micrograms/kg. There were no other proarrhythmic episodes or serious adverse effects. Further evaluation of the therapeutic potential of dofetilide in the management of life-threatening ventricular arrhythmias is justified.
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Papers by Ronald Campbell