Biomedical subjects

D L Riddle

Publications and source records attributed to D L Riddle.

At least 55 records · Page 3Linked to original sources

PubMed1994

Issues in determining treatment effectiveness of manual therapy.

The purpose of this article is to examine issues pertinent to the study of the clinical effectiveness of manual therapy. The need for complete operational definitions of treatment procedures, criteria for altering treatment, and criteria for subject selection is discussed. The need for studies that examine the relationship among impairment, functional limitations, and disability is also discussed. Considerations for selecting relevant outcome measures are presented. The use of a clinical decision-making model to direct the design of clinical studies on manual therapy is described. This article concludes with a discussion of alternative ways for clinicians to contribute to the manual therapy literature.

Manipulation, Orthopedic↗

PubMed1993

The daf-4 gene encodes a bone morphogenetic protein receptor controlling C. elegans dauer larva development.

The bone morphogenetic protein (BMP) family is a conserved group of signalling molecules within the transforming growth factor-beta (TGF-beta) superfamily. This group, including the Drosophila decapentaplegic (dpp) protein and the mammalian BMPs, mediates cellular interactions and tissue differentiation during development. Here we show that a homologue of human BMPs controls a developmental switch in the life cycle of the free-living soil nematode Caenorhabditis elegans. Starvation and overcrowding induce C. elegans to form a developmentally arrested, third-stage dauer larva. The daf-4 gene, which acts to inhibit dauer larva formation and promote growth, encodes a receptor protein kinase similar to the daf-1, activin and TGF-beta receptor serine/threonine kinases. When expressed in monkey COS cells, the daf-4 receptor binds human BMP-2 and BMP-4. The daf-4 receptor is the first to be identified for any growth factor in the BMP family.

Amino Acid Sequence↗

PubMed1993

Post-transcriptional regulation of RNA polymerase II levels in Caenorhabditis elegans.

To investigate the regulation of RNA polymerase II levels in Caenorhabditis elegans, we have constructed nematode strains having one, two, or three copies of ama-1, the gene for the largest subunit of RNA polymerase II. Steady-state levels of RNA polymerase II polypeptides and solubilized enzyme activity are invariant with gene dosage, indicating regulatory compensation. However, steady-state levels of ama-1 mRNA are directly proportional to gene dosage. These results imply that RNA polymerase II levels in C. elegans are regulated post-transcriptionally.

Animals↗

PubMed1993

Intertester reliability of McKenzie's classifications of the syndrome types present in patients with low back pain.

The McKenzie system for examining and treating patients with low back pain is frequently used by clinicians. The primary purpose of this multicenter study was to determine the intertester reliability of assessments of patients with low back pain when physical therapists used the McKenzie method. A second purpose was to determine if previous postgraduate training in the McKenzie system affects reliability. Some therapists had previously undertaken postgraduate training in the McKenzie system. All therapists were given written descriptions of the McKenzie method and the criteria used to classify patients. Classifications were made on 363 patients with low back pain by randomly paired physical therapists in eight clinics. The Kappa value on agreement of patient classification was 0.26, which suggests poor reliability. Therapists agreed on which syndrome was present 39% of the time. Previous postgraduate training did not improve reliability. The results suggest that assessments of the syndrome present in patients with low back pain appear to be unreliable when using the McKenzie system.

Adult↗

PubMed1992

Measurement of accessory motion: critical issues and related concepts.

The term "manual therapy" has traditionally been associated with physical therapists who examine and treat patients who have disorders related to the musculoskeletal system. In addition to using instruments to collect patient data, these therapists use a large variety of manually applied examination procedures. Range-of-motion tests, manual muscle tests, neurological tests, and palpation tests are just a few of the categories of tests these therapists use as part of the clinical decision-making process. The major sources of error that can affect the usefulness of manually obtained measurements are discussed. The literature that provides the theoretical and clinical bases for the assessment of joint surface movement is thoroughly reviewed. Conclusions are made about what is currently known about the usefulness of accessory motion tests. Suggestions are made for future research needs in order to clarify and enhance the usefulness of accessory motion tests and other examination procedures used by manual therapists.

Clinical Competence↗

PubMed1992

Intertester reliability of judgments of the presence of trigger points in patients with low back pain.

The purpose of this study was to determine the intertester reliability of assessments of the presence of trigger points in the region of the lumbar spine of patients with low back pain (LBP). A total of six trigger points described by Travell and Simons were studied. The trigger point examination procedures described by Travell and Simons were used by 12 physical therapists. Randomly paired therapists examined 50 patients for 197 trigger points. The Kappa coefficient, percent agreement, the observed proportion of positive agreement (Ppos), and the observed proportion of negative agreement (Pneg) were used to describe reliability. Kappa values ranged from .29 to .38. Percent agreement ranged from 76% to 79%. Ppos ranged from .43 to .52. The low Kappa and Ppos values suggest different therapists are unable to reliably determine when a trigger point is present in a patient with LBP. This study suggests the usefulness of examining for the presence of trigger points in patients with LBP should be questioned.

Adult↗

PubMed1991

Reliability of goniometric measurements and visual estimates of knee range of motion obtained in a clinical setting.

The purpose of this study was to examine the intratester and intertester reliability for goniometric measurements of knee flexion and extension passive range of motion (PROM). In addition, parallel-forms reliability for PROM measurements of the knee obtained by use of a goniometer and by visual estimation was examined. The intertester reliability for visual estimates of the PROM of the knee was also examined. Repeated measurements were obtained on 43 patients in a clinical setting. The intraclass correlation coefficients (ICCs) for intratester reliability of measurements obtained with a goniometer were .99 for flexion and .98 for extension. Intertester reliability for measurements obtained with a goniometer was .90 for flexion and .86 for extension. The ICCs for parallel-forms reliability for measurements obtained with a goniometer and by visual estimation ranged from .82 to .94. The intertester reliability for measurements obtained by visual estimation was .83 for flexion and .82 for extension. Results suggest clinicians should use a goniometer to take repeated PROM measurements of a patient's knee to minimize the error associated with these measurements.

Adult↗

PubMed1990

daf-1, a C. elegans gene controlling dauer larva development, encodes a novel receptor protein kinase.

The dauer larva is a developmentally arrested, non-feeding dispersal stage normally formed in response to overcrowding and limited food. The daf-1 gene specifies an intermediate step in a hierarchy of genes thought to specify a pathway for neural transduction of environmental cues. Mutations in daf-1 result in constitutive formation of dauer larvae even in abundant food. This gene has been cloned by Tc1-transposon tagging, and it appears to encode a new class of serine/threonine kinase. A daf-1 probe detects a 2.5 kb mRNA of low abundance, and the DNA sequence indicates that the gene encodes a 669 amino acid protein, with a putative transmembrane domain and a C-terminal protein kinase domain most closely related to the cytosolic, raf proto-oncogene family. Hence, the daf-1 product appears to be a cell-surface receptor required for transduction of environmental signals into an appropriate developmental response.

Alleles↗

PubMed1990

Mutant Caenorhabditis elegans RNA polymerase II with a 20,000-fold reduced sensitivity to alpha-amanitin.

A doubly mutant ama-1(m118m526) gene results in an RNA polymerase (Rpo) II that is unusually resistant to alpha-amanitin. Rpo II activity in isolated Caenorhabditis elegans cell nuclei is inhibited 50% by alpha-amanitin at a concentration of 150 micrograms/ml, making this enzyme 150 times more resistant to the toxin than Rpo II from the singly mutant allele, ama-1(m118), 20,000 times more resistant than the wild-type Rpo II, and about six times more resistant to amanitin than is Rpo III. It was determined that the SL1 spliced leader precursor is transcribed by Rpo II, and this transcript was used to measure Rpo II activity. The Rpo II activity is unstable in vitro, and the mutant strain has a temperature-sensitive sterile phenotype. The highly resistant double mutant was selected among four million progeny of the mutagenized ama-1(m118) parent by its ability to grow and reproduce in 200 micrograms/ml amanitin in the presence of a permeabilizing agent, Triton X-100.

Amanitins↗

PubMed1990

Validity of derived measurements of leg-length differences obtained by use of a tape measure.

Determining the difference in the length of an individual's legs is often an important component of a musculoskeletal examination. Although measurements are easily obtained with a tape measure, the validity of these measurements is not known. The purpose of this study was to examine the validity of determinations of leg-length differences (LLDs) obtained by use of a specified tape measure method (TMM). Leg-length differences using the TMM and a radiographic technique were determined for 10 subjects who were candidates for clinical leg-length measurements and for 9 healthy control subjects. Validity of the TMM measurements was determined by assessing the degree of agreement between TMM-obtained LLDs and those obtained by the radiographic method. Validity estimates as determined by intraclass correlation coefficients (ICCs) were .770 for patients, .359 for healthy subjects, and .683 for all subjects. When the means of the two values obtained by use of the TMM were compared with the radiographic measurements, the ICCs were .852 for the patient group, .637 for the healthy subjects, and .793 for all subjects. This study suggests that TMM-derived LLD measurements are valid indicators of leg-length inequality and that the estimates of validity are improved by using the average of two determinations rather than a single determination.

Adult↗

PubMed1990

Reliability and validity of judgments of the integrity of the anterior cruciate ligament of the knee using the Lachman's test.

This study assessed the intratester and intertester reliability and the validity of judgments of the integrity of the anterior cruciate ligament (ACL) based on the use of the Lachman's test. End-feel and tibial translation judgments made during the Lachman's test were also assessed. Patients with unilateral knee problems (N = 32), 13 of whom had documented ACL damage, were examined by two physical therapists and two orthopedic surgeons. Intratester Kappa values for whether the test was positive or negative were .44 for physical therapists, .60 for orthopedic surgeons, and .51 for all examiners. Intertester Kappa values were .69 for the therapists, .61 for the surgeons, and .42 for all examiners. The predictive value of a positive test was 47% for all examiners, whereas the predictive value of a negative test was 70%. Results indicate that Lachman's test judgments have limited reliability and may be more useful for predicting that a patient does not have an ACL injury than for predicting that the ACL is injured. [Cooperman JM, Riddle, DL, Rothstein JM: Reliability and validity of judgments of the integrity of the anterior cruciate ligament of the knee using the Lachman's test.

Adolescent↗

PubMed1990

Reliability of clinical measurements of forward bending using the modified fingertip-to-floor method.

The purpose of this study was to examine the intratherapist and intertherapist reliability of measurements obtained with a modified version of the fingertip-to-floor method of assessing forward bending. With the modified fingertip-to-floor (MFTF) method, patients stand on a stool and forward bend so that measurements can be taken on patients who are able to touch the floor or reach beyond the level of the floor. Randomly paired physical therapists took repeated MFTF measurements on 73 patients with low back pain. Intraclass correlation coefficients (ICCs) were calculated for intratherapist and intertherapist reliability. The ICC value for intratherapist reliability was .98, and the ICC value for intertherapist reliability was .95. The results of this study suggest that measurements of forward bending obtained on patients with low back pain using the MFTF method are highly reliable.

Adolescent↗

PubMed1989

Developmental regulation of energy metabolism in Caenorhabditis elegans.

Changes in energy metabolism during larval development in Caenorhabditis elegans have been investigated using phosphorus nuclear magnetic resonance (31P NMR). The relative concentrations of ATP, ADP, AMP, sugar phosphates, and other metabolites were observed to change during larval development, producing stage-specific spectra. These spectra are consistent with enzyme assays for isocitrate dehydrogenase and isocitrate lyase, indicating that high activity of the glyoxylate pathway during embryonic development decreases during the first larval (L1) stage, and respiration during the L2, L3, and L4 stages occurs preferentially through the TCA cycle. Metabolic strategies were further studied using mutants that are predisposed to enter the dauer stage, a developmentally arrested third-stage larva formed under conditions of overcrowding and limited food. After the L1 molt, energy metabolism in animals destined to become dauer larvae diverges from that of animals committed to growth. Relative to the L1, the L2 larvae committed to growth exhibit increased isocitrate dehydrogenase activity as well as increases in ATP and other high-energy phosphates, but predauer (L2d) larvae exhibit declining enzyme activities and declining levels of high-energy phosphates. The predominant phosphorus NMR signal in dauer larva extracts corresponds to inorganic phosphate. We conclude that metabolism is regulated during C. elegans larval development, with a major transition apparent after the L1 stage. This transition does not occur in larvae destined to form dauer larvae.

Adenine Nucleotides↗

PubMed1989

Intrasession and intersession reliability of hand-held dynamometer measurements taken on brain-damaged patients.

Recent reports have characterized force measurements obtained with hand-held dynamometers from brain-damaged patients as being highly reliable. The purposes of this two-part study were to replicate essential parts of those studies and to further examine the reliability of these measurements in a clinical context. Repeated force measurements were taken from the nonparetic and paretic limbs of brain-damaged patients during the same testing session (Part 1) and during two testing sessions separated by two days (Part 2). The intratester intraclass correlation coefficients (ICCs) for all measurements taken during a single session ranged from .88 to .98. The ICCs for repeated measurements taken two days apart from the paretic limbs ranged from .90 to .98. The ICCs for repeated measurements taken two days apart from the nonparetic limbs ranged from .31 to .93. The ICCs for repeated measurements taken two days apart from the combined data for all limbs ranged from .79 to .97. Hand-held dynamometer measurements taken on brain-damaged patients appear to be highly reliable when taken during the same testing session. When repeated measurements are separated by a longer time interval, the measurements taken from the paretic limbs continue to be highly reliable, whereas most measurements taken on the nonparetic limbs exhibit poor reliability.

Adult↗

PubMed1989

Intertester reliability of clinical judgments of medial knee ligament integrity.

The purpose of this study was to determine the intertester reliability of judgments based on tibiofemoral joint abduction (TFJA) tests of the medial collateral ligament (MCL). The TFJA tests were performed by three physical therapists on 50 patients with unilateral knee problems. The therapists used the techniques they normally use in clinical practice and tested TFJA with the knee in both 0 and 30 degrees of flexion. Three variables were evaluated: the amount of TFJA, pain elicited during the test, and the type of end-feel. When the test was performed with the subjects' knees in 0 degrees of flexion, the weighted Kappa value for judgments of motion was .06, the Kappa value for judgments of whether pain was elicited was .40, and the Kappa value for end-feel was .00. For the 30-degree test position, the weighted Kappa value for judgments of the amount of TFJA was .16, and the Kappa values for judgments of pain and end-feel were .33 and .38, respectively. The results suggest that judgments based on TFJA tests may not be reliable when taken in a clinical setting by physical therapists.

Adolescent↗

PubMed1989

Molecular cloning and sequencing of ama-1, the gene encoding the largest subunit of Caenorhabditis elegans RNA polymerase II.

Two genomic sequences that share homology with Rp11215, the gene encoding the largest subunit of RNA polymerase II in Drosophila melanogaster, have been isolated from the nematode Caenorhabditis elegans. One of these sequences was physically mapped on chromosome IV within a region deleted by the deficiency mDf4, 25 kilobases (kb) from the left deficiency breakpoint. This position corresponds to ama-1 (resistance to alpha-amanitin), a gene shown previously to encode a subunit of RNA polymerase II. Northern (RNA) blotting and DNA sequencing revealed that ama-1 spans 10 kb, is punctuated by 11 introns, and encodes a 5.9-kb mRNA. A cDNA clone was isolated and partially sequenced to confirm the 3' end and several splice junctions. Analysis of the inferred 1,859-residue ama-1 product showed considerable identity with the largest subunit of RNAP II from other organisms, including the presence of a zinc finger motif near the amino terminus, and a carboxyl-terminal domain of 42 tandemly reiterated heptamers with the consensus Tyr Ser Pro Thr Ser Pro Ser. The latter domain was found to be encoded by four exons. In addition, the sequence oriented ama-1 transcription with respect to the genetic map. The second C. elegans sequence detected with the Drosophila probe, named rpc-1, was found to encode a 4.8-kb transcript and hybridized strongly to the gene encoding the largest subunit of RNA polymerase III from yeast, implicating rpc-1 as encoding the analogous peptide in the nematode. By contrast with ama-1, rpc-1 was not deleted by mDf4 or larger deficiencies examined, indicating that these genes are no closer than 150 kb. Genes flanking ama-1, including two collagen genes, also have been identified.

Amino Acid Sequence↗

PubMed1988

dpy-13: a nematode collagen gene that affects body shape.

Mutations in the Caenorhabditis elegans dpy-13 (dumpy) gene result in a short, chunky body shape. This gene was tagged by insertion of the Tc1 transposon, and the wild-type gene was cloned by chromosomal walking 11 kb from ama-1, a cloned gene encoding the large subunit of RNA polymerase II. Three transposon insertion sites in dpy-13 are located near the 5' end of a 1.2 kb transcribed region. The EMS-induced reference allele, dpy-13(e184), carries a small deletion near the middle of this gene. The DNA sequence reveals that dpy-13 is a member of the collagen multi-gene family, and it could encode a polypeptide of 302 amino acids. A 146 base pair sequence, encoding amino acids 56-103, is unique in the C. elegans genome, and it hybridizes to a 1 kb mRNA of moderate abundance.

Alleles↗

PubMed1988

Mutants of Caenorhabditis elegans that form dauer-like larvae.

The development, ultrastructure, and genetics of two mutants that form dauer-like larvae have been characterized. Dauer larva morphogenesis is initiated regardless of environmental stimuli, and it is incomplete or abnormal. The resistance to detergent characteristic of normal dauer larvae is not fully achieved, and the mutants are unable to exit from the dauer-like state of developmental arrest. Mutant life span is not extended beyond the three weeks characteristic of the nondauer life cycle, whereas normal dauer larvae can live for several months. Growth of daf-15(m81)IV, the less dauer-like of the two, is nearly arrested at the second (dauer-specific) molt, but feeding is not completely suppressed. Head shape, cuticle, and intestinal ultrastructure are nondauer, whereas sensory structures (amphid and deirid) and excretory gland morphology are intermediate between that of dauer and nondauer stages. The daf-9(e1406)X mutant is dauer-like in head shape, cuticle, and deirid ultrastructure, intermediate in amphid and inner labial neuron morphology, and nondauer or abnormal in the intestine. Also, the daf-9 mutant exhibits abnormalities in the pharyngeal arcade cell processes and pharyngeal g1 gland. Double mutants carrying both daf-9 and daf-15 are more resistant to detergent than either single mutant. Like the single mutants, they cannot complete morphogenesis, and they are unable to exit from the dauer-like stage. Both daf-9 and daf-15 mutations are epistatic to previously described dauer-defective mutations, indicating that these two genes act late in the pathway leading to the dauer larva. The genetic tests and the mutant ultrastructure suggest that the two genes may affect parallel pathways of morphogenesis.

Animals↗