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D E Riley

Publications and source records attributed to D E Riley.

At least 37 records · Page 2Linked to original sources
PubMed1997

Distribution and mobility of the tetracycline resistance determinant tetQ.

We tested 34 American Type Culture Collection (ATCC) and 168 clinical bacterial isolates, from the human urogenital and oral tracts and streptococci isolated from cows with mastitis, for the presence of the tetQ gene using a polymerase chain reaction (PCR) assay and DNA-DNA hybridization. The identities of PCR products were confirmed by Southern blot hybridization of whole-cell DNA. Eleven of the ATCC strains were positive for tetQ, including five Bacteroides spp., five Prevotella spp. and a single isolate of Mitsuokella multiacidus. Twenty-eight (29%) of the 95 clinical Gram-negative isolates carried the tetQ gene, while eight (11%) of the 73 clinical Gram-positive isolates carried the tetQ gene. This is the first description of tetQ in Gram-positive species. All isolates except one Peptostreptococcus sp. carried tetQ integrated into the chromosome. The tetQ gene could be transferred from Prevotella bivia, Bacteroides ovatus, Bacteroides fragilis, Bacteroides vulgatus and Bacteroides distasonis into an Enterococcus faecalis recipient at frequencies of 10(-7)-10(-9) per recipient. In contrast, tetQ failed to transfer from two isolates of Prevotella intermedia, two isolates of Porphyromonas gingivalis, one isolate of Mobiluncus curtisii and one isolate of Peptostreptococcus sp. The latter two are Gram-positive species. The PCR assay was used to screen 198 proteinase K-treated biopsies of prostate, periprostate and bladder from 84 men with prostatitis. Thirty-four (40%) of the patients had one or more positive samples, suggesting that the PCR assay could be of value in screening patient material directly for the presence of bacteria.

Animals↗
PubMed1996

Dynamic properties of horizontal and vertical eye movements in parkinsonian syndromes.

We studied dynamic properties of horizontal, vertical, and oblique eye movements in 23 patients with the following parkinsonian syndromes: idiopathic parkinsonism (PD), multiple system atrophy (MSA), pure akinesia (PA), progressive supranuclear palsy (PSP), and cortical-basal ganglionic degeneration (CBGD). Compared with age-matched controls, only PSP patients showed slowing of saccades. Patients in all groups showed saccadic hypometria that was most marked vertically. The trajectories of saccades made to diagonal target jumps were deviated toward the horizontal plane, due to the vertical hypometria; this was most marked in PA and PSP groups. Saccade latency was only increased in the CBGD group. Sinusoidal smooth pursuit did not differentiate between controls and patients; however, with step-ramp stimuli, pursuit eye acceleration was impaired in all patient groups compared with controls. The vestibulo-ocular reflex, with or without visual enhancement, was similar in patients and controls. These findings indicate that (1) in parkinsonian syndromes apart from PSP, the saccade-generating brainstem burst neurons are probably spared, but the signals that they receive, specifying the size and direction of saccades, are flawed; and (2) measurements of the gain and trajectory of oblique saccades, and initiation of smooth pursuit, may aid in diagnosing these different types of parkinsonism.

Aged↗
PubMed1996

Paroxysmal kinesigenic dystonia associated with a medullary lesion.

A 67-year-old man experienced the abrupt onset of intermittent spasms of tightening of his throat muscles and elevation of his tongue to the roof of his mouth. These were precipitated by initiating movements, either of his mouth (eating, drinking, speaking, yawning) or of his whole body (arising from bed or a chair, lifting heavy weights). Episodes occurred six to 20 times per day, lasted 10-30 s, then resolved spontaneously. Two years later, results of his general neurological examination, including speech, were normal. Several spasms were provoked by arising from a seated or supine position or by drinking. Objectively, there was a strained dysphonia accompanied by palpable hardening of the supralaryngeal muscles. Each episode resolved within 15 s. Magnetic resonance imaging (MRI) showed evidence of a remote hemorrhage in the medulla. No abnormal blood vessels were seen. Phenytoin 300 mg/day abolished the spasms within days. Decreasing the dose to 200 mg/day months later led to a partial return of symptoms. Relief has persisted for 3 years. This patient has paroxysmal kinesigenic dystonia (PKD) of structures (pharynx, larynx, tongue) innervated by lower cranial motor nerves and a medullary lesion on MRI. PKD has been associated with focal lesions at all levels of the central nervous system (CNS), although never before in the medulla. PKD seems to be a nonspecific phenomenon of the CNS in reaction to injury.

Aged↗
PubMed1996

Non-Parkinson akinetic-rigid syndromes.

We review developments in the study of akinetic-rigid syndromes other than Parkinson's disease within three main categories: recording of new etiologies, advancing knowledge on previously known causes, and studies of Parkinson's disease imitators and clinical and investigational means of accurately distinguishing them from Parkinson's disease.

Diagnosis, Differential↗
PubMed1996

Prokaryotic DNA sequences in patients with chronic idiopathic prostatitis.

Half of all men experience symptoms of prostatitis at some time in their lives, but the etiology is unknown for more than 90% of patients. Optimal clinical and culture methods were used to select 135 men with chronic prostatitis refractory to multiple previous courses of antimicrobial therapy. The subjects had no evidence of structural or functional lower genitourinary tract abnormalities of bacteriuria or bacterial prostatitis by traditional clinical tests, or of urethritis or urethral pathogens by culture. Specific PCR assays detected Mycoplasma genitalium, Chlamydia trachomatis, or Trichomonas vaginalis in 10 patients (8%). Broad-spectrum PCR tests detected tetracycline resistance-encoding genes, tetM-tetO-tetS, in 25% of patients and 16S rRNA in 77% of subjects. The tetM-tetO-tetS-positive cases constituted a subset of the 16S rRNA-positive cases. Patients with 16S rRNA were more likely to have > or = 1,000 leukocytes per mm3 in their expressed prostatic secretion than men whose prostate biopsy specimens were negative for 16S rRNA (P < 0.001). Based on direct sequencing and repetitive cloning, multiple sources of 16S rRNA were observed in individual patients. Sequences of 29 cloned PCR products revealed 16S rRNAs distinct from those of common skin and gut flora. These findings suggest that the prostate can harbor microorganisms that are not detectable by traditional approaches. These organisms may be associated with inflammation in the expressed prostatic secretions. Molecular methods hold great promise for identifying culture-resistant microorganisms in patients with chronic prostatitis.

Adult↗
PubMed1995

Molecular and phylogenetic analysis of PCR-amplified cyclin-dependent kinase (CDK) family sequences from representatives of the earliest available lineages of eukaryotes.

Cyclin-dependent kinase (CDK) and cell division control (CDC2) sequences are strongly conserved among eukaryotes and may complement the use of other sequence families in eukaryotic phylogenetic inference. We synthesized degenerate PCR primers to amplify the catalytic region of CDK homologs in representatives of the earliest available lineages of eukaryotes. CDK family sequence-based, maximum-likelihood distance measurements with neighbor-joining, and Fitch-Margoliash least-squares analyses produced unrooted dendrograms that included protists, yeasts, and higher eukaryotes. Bootstrap confidence estimates supported CDK-based phylogenetic groupings among the protists, fungi, and vertebrates although resolution within these groups was often insignificant. However, Trichomonas vaginalis and Giardia lamblia exhibited two of the most divergent CDK-like sequences consistent with rRNA-phylogenetic inference of early divergence of these eukaryotic lineages. In the evolution from unicellular to multicellular organisms, a constellation of amino acid residues aligning with the human, CDK N-terminal beta sheet may have undergone abrupt replacement.

Amino Acid Sequence↗
PubMed1995

PCR-based study of conserved and variable DNA sequences of Tritrichomonas foetus isolates from Saskatchewan, Canada.

The protozoan parasite Tritrichomonas foetus causes infertility and spontaneous abortion in cattle. In Saskatchewan, Canada, the culture prevalence of trichomonads was 65 of 1,048 (6%) among 1,048 bulls tested within a 1-year period ending in April 1994. Saskatchewan was previously thought to be free of the parasite. To confirm the culture results, possible T. foetus DNA presence was determined by the PCR. All of the 16 culture-positive isolates tested were PCR positive by a single-band test, but one PCR product was weak. DNA fingerprinting by both T17 PCR and randomly amplified polymorphic DNA PCR revealed genetic variation or polymorphism among the T. foetus isolates. T17 PCR also revealed conserved loci that distinguished these T. foetus isolates from Trichomonas vaginalis, from a variety of other protozoa, and from prokaryotes. TCO-1 PCR, a PCR test designed to sample DNA sequence homologous to the 5' flank of a highly conserved cell division control gene, detected genetic polymorphism at low stringency and a conserved, single locus at higher stringency. These findings suggested that T. foetus isolates exhibit both conserved genetic loci and polymorphic loci detectable by independent PCR methods. Both conserved and polymorphic genetic loci may prove useful for improved clinical diagnosis of T. foetus. The polymorphic loci detected by PCR suggested either a long history of infection or multiple lines of T. foetus infection in Saskatchewan. Polymorphic loci detected by PCR may provide data for epidemiologic studies of T. foetus.

Abortion, Veterinary↗
PubMed1994

The syndrome of 'pure akinesia' and its relationship to progressive supranuclear palsy.

Five patients developed a stereotyped syndrome of progressive akinesia of gait, speech, and hand-writing without rigidity, tremor, or dementia. The symptoms did not improve with levodopa. These clinical findings conform to a syndrome described repeatedly in Japan since 1974 as "pure akinesia." Evidence has indicated that pure akinesia often represents a pre-ocular motor, and in some cases an ocular motor-sparing, form of progressive supranuclear palsy (PSP). Although we found disorders of eyelid movements, none of the patients demonstrated a gaze palsy on clinical examination. Four patients underwent eye movement recordings. The two patients with the longest disease duration had slow or small vertical saccades. These findings support the notion that patients with pure akinesia may develop a vertical gaze palsy, similar to that in PSP, late in their course. Our patients show that pure akinesia occurs in North America as well as in Japan. Recognition of the syndrome of pure akinesia may suggest the diagnosis of PSP before the development of abnormalities of ocular movement.

Dementia↗
PubMed1993

What's in a name?

Explore the source record for details and available documents.

Community-Institutional Relations↗
PubMed1993

Detection of Tet M and Tet O tetracycline resistance genes by polymerase chain reaction.

Degenerate oligonucleotide primers were used in polymerase chain reaction assays to detect tetracycline resistance genes, Tet M and Tet O. Each of 44 clinical isolates and eight laboratory strains, representing 20 different species carrying either Tet M or Tet O determinants, gave appropriate PCR products with the two primer sets. The PCR products hybridized with radiolabelled Tet M or Tet O probes. The PCR assay was then used to evaluate vaginal swab specimens from women with vaginitis and semen specimens from men with prostatis. Seven of eight vaginal samples and five of eight semen samples exhibited PCR products that hybridized with the radiolabelled probes, suggesting the presence of Tet M and/or Tet O genes. PCR-based detection of Tet M and/or Tet O genes holds promise for evaluation of urogenital specimens.

Bacteria↗
PubMed1993

DNA and RNA amplification in urology: the polymerase chain reaction.

Polymerase chain reaction (PCR) technology is a promising molecular approach for diagnosis of genitourinary tract infections, inherited disorders, tumor-associated genetic alterations and tumor markers. Because it is based on exponential amplification, the technology is capable of ultimate theoretical sensitivity. Although not entirely free of technical limitations, PCR holds advantages over other diagnostic tests, including exquisite sensitivity, specificity, interchangeability and speed.

Base Sequence↗
PubMed1993

Trichomonas vaginalis and early evolving DNA and protein sequences of the CDC2/28 protein kinase family.

The human sexually transmitted parasite Trichomonas vaginalis is a representative of one of the three earliest evolving eukaryotic lineages. We investigated whether T. vaginalis has DNA sequences and peptides related to cell division control molecules universal among yeasts and higher eukaryotes. A T. vaginalis cell division control (CDC2/28) homologue was amplified by the polymerase chain reaction and sequenced. The absolute similarity with other CDC2/28 genes was 47%, with conservative replacement similarity of 67%. Western blots demonstrated a single T. vaginalis peptide reactive with antiserum to the PSTAIRE peptide, an expressed component of CDC2/28 genes in higher eukaryotes. Although eukaryotic, T. vaginalis has properties similar to those of bacteria and is the earliest evolving eukaryote reported to possess CDC2/28 DNA and peptide homologues. These observations suggest that the molecular origins of cell division control in eukaryotes preceded mitochondria, 28S ribosomes and regulated glycolysis.

Amino Acid Sequence↗
PubMed1992

Comparison of predictable smooth ocular and combined eye-head tracking behaviour in patients with lesions affecting the brainstem and cerebellum.

We compared the ability of eight normal subjects and 15 patients with brainstem or cerebellar disease to follow a moving visual stimulus smoothly with either the eyes alone or with combined eye-head tracking. The visual stimulus was either a laser spot (horizontal and vertical planes) or a large rotating disc (torsional plane), which moved at one sinusoidal frequency for each subject. The visually enhanced vestibulo-ocular reflex (VOR) was also measured in each plane. In the horizontal and vertical planes, we found that if tracking gain (gaze velocity/target velocity) for smooth pursuit was close to 1, the gain of combined eye-hand tracking was similar. If the tracking gain during smooth pursuit was less than about 0.7, combined eye-head tracking was usually superior. Most patients, irrespective of diagnosis, showed combined eye-head tracking that was superior to smooth pursuit; only two patients showed the converse. In the torsional plane, in which optokinetic responses were weak, combined eye-head tracking was much superior, and this was the case in both subjects and patients. We found that a linear model, in which an internal ocular tracking signal cancelled the VOR, could account for our findings in most normal subjects in the horizontal and vertical planes, but not in the torsional plane. The model failed to account for tracking behaviour in most patients in any plane, and suggested that the brain may use additional mechanisms to reduce the internal gain of the VOR during combined eye-head tracking. Our results confirm that certain patients who show impairment of smooth-pursuit eye movements preserve their ability to smoothly track a moving target with combined eye-head tracking.

Adult↗
PubMed1992

Tizanidine in cranial dystonia.

Recent electrophysiological studies in patients with cranial dystonia (CD) have demonstrated evidence for hyperactivity of brainstem interneurons. Tizanidine (Tz), a centrally acting skeletal muscle relaxant, is thought to act by antagonizing the activity of excitatory interneurons which mediate hypertonic processes (e.g. spasticity). Theoretically this agent may be effective in patients with CD. Ten patients were enrolled in an open-label study with a single-blind placebo wash-in. Eight patients tolerated doses of between 28-36 mg per day. For the most part tizanidine was ineffective for the symptoms of CD. This failure suggests that the reported brainstem interneuronal disturbances may not be altered by Tz. Further studies using concomitant electrophysiological assessment would be necessary to assess this possibility. Alternatively, these disturbances may not be a principle cause of the dystonic movements. The finding of similar changes in other basal ganglia diseases lacking CD (e.g. Parkinson's disease) favours this latter explanation.

Brain Stem↗
PubMed1992

Development of a polymerase chain reaction-based diagnosis of Trichomonas vaginalis.

We developed a polymerase chain reaction (PCR)-based test for detecting the protozoan parasite Trichomonas vaginalis. Genomic libraries were constructed from two independent clinical isolates of T. vaginalis. From these libraries, 12 genomic clones were purified, sequenced, and then screened for uniqueness by computer-assisted sequence comparisons. PCR reactions were performed to evaluate eight PCR-primer pairs, including a primer pair that targeted the T. vaginalis ferredoxin gene. All eight primer pairs yielded PCR products of the expected sizes. However, six of the primer pairs amplified their respective target sequences in limited numbers of clinical T. vaginalis isolates, suggesting the presence of significant genomic variability among isolates. An exception was a primer pair, termed TVA5-TVA6, that amplified a 102-bp genomic sequence, termed A6p, in all of 24 clinical isolates. The A6p sequence was not detected by PCR in human DNA or in a wide variety of flagellates, ciliates, or bacteria tested. The A6p sequence appears highly selective for a broad range of T. vaginalis isolates and holds promise for PCR-based diagnosis of the parasite.

Animals↗