Showing papers by "Saint Louis University published in 1982"

Evaluation of amplitude and frequency components of the surface EMG as an index of muscle fatigue.

Abstract: The frequency components and amplude of the surface electromyogram (EMG) were measured during both 3-s (tensions of 5-100% of the maximum voluntary contraction (MVC)) and fatiguing contractions at 25, 40 and 70% MVC in the handgrip, biceps, adductor pollicis and quadriceps muscles in six male subjects. For the handgrip and biceps muscles, the experiments were repeated at three different muscle lengths: the length at which the muscle was able to exert its maximum isometric strength, and the muscle length above and below that length which corresponded to a length at which the muscle could exert 80% of it maximum. The frequency components of the EMG were the same during brief fatiguing isometric contractions in any of the muscles examined here as long as the muscles contracted near their optimal length. Shortening the muscle length prior to contraction caused an increase in the power in the low frequencies of the EMG power spectra while stretching a muscle had the opposite effect during isometric contraction...

Multiple joint osteonecrosis following short-term steroid therapy. Case report.

Abstract: The general goals for treating an acetabular fracture are to restore congruity and stability of the hip joint. These goals are no different from those for the subset of fractures of the posterior wall. Nevertheless, posterior wall fractures present unique problems compared with other types of acetabular fractures. Successful treatment of these fractures depends on a multitude of factors. The physician must understand their distinctive radiologic features, in conjunction with patient factors, to determine the appropriate treatment. By knowing the important points of posterior surgical approaches to the hip, particularly the posterior wall, specific techniques can be used for fracture reduction and fixation in these often challenging fractures. In addition, it is important to develop a complete grasp of potential complications and their treatment. The evaluation and treatment protocols initially developed by Letournel and Judet continue to be important; however, the surgeon also should be aware of new information published and presented in the past decade.

Life forms and meaning structure

Abstract: Introductory Part. Part 1: Theory of Life Forms and Symbol Concept Life Forms and Meaning Structure Part 2: Theory of the Structure of the Objectification of Meaning Meaning Structures of Language. Meaning Structures of Literary Art Forms. Meaning Structures of Drama and Opera Part 3: Object and Method of the Social Sciences

Motilin in the Purkinje cell of the cerebellum

Abstract: None of the brain peptides has been demonstrated to be present in significant amounts in the cerebellum1,2. The only effector substance known in the Purkinje cell, whose axon carries the integrated output of the cerebellar cortex, is the decarboxylated residue of glutamic acid3–6. An antiserum raised against synthetic porcine gut motilin and directed at the midportion and carboxyl end of the 22-amino acid polypeptide7 shows, in anatomically intact rat, mouse and human cerebellum, that most Purkinje cells contain motilin or a closely related substance8. We report here that motilin-absorbable immunoreactivity is evident from the spines of tertiary dendrites, through the cell body and axon, to nerve endings terminating, as expected, in the deep cerebellar nuclei and, unexpectedly, on nerve cells of some brain stem nuclei. In addition to its obvious functional implications, motilin is thus an important marker with which to re-examine the organization and projections of Purkinje cells, their ontogeny and their response to injury.

Anatomical routes for cancer invasion of laryngeal cartilages.

Abstract: The larynx is separated into compartments bounded by connective tissue membranes and cartilages. The membranes and cartilages affect the localization and spread of cancer for a while, but invasion eventually occurs. Histological study of the cartilages in the earliest stages of invasion shows cancer cells growing between the collagen bundles where the connective tissue membranes attach to the cartilages. At these points, the collagen bundles pass obliquely through the perichondrium to anchor into the cartilage and bone like Sharpey's fibers. As the cancer cells multiply, they separate the collagen bundles, forming linear passageways through the perichon-drum. This appears to be the mechanism for cartilage invasion. Thus the sites of attachment of the strongest membranes are also the most frequent sites of invasion, i.e., the anterior commissure tendon and the cricothyroid membrane.

Characterization of two new plasmid DNAs found in mitochondria of wild-type Neurospora intermedia strains

Abstract: Mitochondria from two Neurospora intermedia strains (P4O5-Labelle and Fiji N6-6) were found to contain plasmid DNAs in addition to the standard mitochondrial DNA species. The plasmid DNAs consist of monomeric circles (4.1-4.3 kbp and 5.2-5.3 kbp for Labelle and Fiji, respectively) and oligomers in which monomers are organized as head-to-tail repeats. DNA-DNA hybridization experiments showed that the plasmids have no substantial sequence homology to mtDNA, to each other, or to a previously characterized mitochondrial plasmid from N. crassa strain Mauriceville-lc (Collins et al. Cell 24, 443-452, 1981). The intramitochondrial location of the plasmids was established by cell fractionation and nuclease protection experiments. In sexual crosses, the plasmids showed strict maternal inheritance, the same as Neurospora mitochondrial DNA. The plasmids may represent a novel class of mitochondrial genetic elements.

Avian Retrovirus pp32 DNA-Binding Protein I. Recognition of Specific Sequences on Retrovirus DNA Terminal Repeats

Abstract: The avian retrovirus pp32 protein possesses a DNA-nicking activity which prefers supercoiled DNA as substrate. We have investigated the binding of pp32 to avian retrovirus long terminal repeat (LTR) DNA present in both supercoiled and linear forms. The cloned viral DNA was derived from unintegrated Schmidt-Ruppin A (SRA) DNA. A subclone of the viral DNA in pBR322 (termed pPvuII-DG) contains some src sequences, tandem copies of LTR sequences, and partial gag sequences in the order src-U(3) U(5):U(3) U(5)-gag. Binding of pp32 to supercoiled pPvuII-DG DNA followed by digestion of this complex with a multicut restriction enzyme (28 fragments total) permitted pp32 to preferentially retain on nitrocellulose filters two viral DNA fragments containing only LTR DNA sequences. In addition, pp32 also preferentially retained four plasmid DNA fragments containing either potential promoters or Tn3 "left-end" inverted repeat sequences. Mapping of the pp32 binding sites on viral LTR DNA was accomplished by using the DNase I footprinting technique. The pp32 protein, but not the avian retrovirus alphabeta DNA polymerase, is able to form a unique protein-DNA complex with selected regions of either SRA or Prague A LTR DNAs. Partial DNase I digestion of a 275-base pair SRA DNA fragment complexed with pp32 gives upon electrophoresis in denaturing gels a unique ladder pattern, with regions of diminished DNase I susceptibility from 6 to 10 nucleotides in length, in comparison with control digests in the absence of protein. The binding of pp32 to this fragment also yields enhanced DNase I-susceptible sites that are spaced between the areas protected from DNase I digestion. The protected region of this unique complex was a stretch of 170 +/- 10 nucleotides that encompasses the presumed viral promoter site in U(3), which is adjacent to the src region, extends through U(5), and proceeds past the joint into U(3) for about 34 base pairs. No specific protection or DNase I enhancement by pp32 was observed in experiments with a 435-base pair SRA DNA fragment derived from a part of U(3) and the adjacent src region or a 55-base pair DNA fragment derived from another part of U(3). The DNA sequence of Prague A DNA at the fused LTRs differs from that of SRA DNA. The alteration in the sequence at the juncture of the LTRs prevented pp32 from forming a stable complex in this region of the LTR. Our results are relevant to two aspects of the interaction between pp32 and LTR DNA. First, the pp32 protein in the presence of selected viral DNA restriction fragments possibly forms a higher order oligomer analogous to Escherichia coli DNA gyrase-DNA complexes or eucaryotic nucleosome structures. Second, the specificity of the binding suggests a role for pp32 and the protected DNA sequences in the retrovirus life cycle. The preferred sequences to which pp32 binds include two adjacent 15-base pair inverted terminal repeats at the joint between U(5) and U(3) in SRA DNA. This region is involved in circularization of linear DNA and is perhaps the site that directs integration into cellular DNA.

Self-association of rabbit muscle phosphofructokinase: Effects of ligands

Abstract: The effects of ligands on the self-association of rabbit muscle phosphofructokinase (PFK) were investigated by velocity sedimentation at pH 7.0 and 23 degrees C. The concentration dependence of the weight-average sedimentation coefficient was monitored in the presence of these ligands. The mode of association and equilibrium constants characterizing each association step were determined by theoretical fitting of the sedimentation data. The simplest mode of association for the PFK system is M in equilibrium M2 equilibrium M4 in equilibrium M16. Ligands and temperature would perturb the various equilibrium constants without altering the mode of association. The apparent equilibrium constants for the formation of tetramer, K4app, are increased in the presence of 0.1 mM ATP and 1.0 mM fructose 6-phosphate. The value of the sedimentation coefficient for the tetramer, S4 degrees, that would best fit the data is 12.4 S instead of 13.5 S determined in the absence of substrates, thus implying a structural change in the tetramer induced by substrates. Only an insignificant amount of dimer is present under the experimental conditions. The presence of activators, ADP or phosphate, enhances the formation of tetramers, and S4 degrees assumes a value of 13.5 S. Similar results are obtained with decreasing concentrations of proton. The presence of the inhibitor, citrate, however, favors the formation of dimers. The equilibrium constants determined as a function of ADP concentration were further analyzed by the linked-function theory derived by Wyman [Wyman, J. (1964) Adv. Protein Chem. 19, 224--285], leading to the conclusion that the formation of a tetramer involves the binding of two additional molecules of ADP per monomer. Similar analysis results in a conclusion that the formation of a dimer involves the binding of one additional molecule of citrate per phosphofructokinase subunit.

Forecasting Applications of an Adaptive Multiple Exponential Smoothing Model

Abstract: This paper introduces a class of multiple exponential smoothing models useful in automated or minimal intervention industrial forecasting systems. These models are an alternative to simple univariate exponential smoothing and Trigg and Leach type adaptive models, which treat time series as unrelated and so cannot explicitly accommodate interrelationships that may exist between two or more time series. Moreover, the multiple models are adaptive in that the smoothing matrix, which is a generalization of the smoothing constant of univariate models, changes from period to period. Maximum likelihood estimates of the model parameters, including the full variance-covariance structure as well as the smoothing matrix, are provided, thus freeing the model user from the need for making ad hoc estimates of parameter values, a feature of simple univariate exponential smoothing. The forecast performance of this multiple time series model is compared with that of other univariate models using automobile sales data and some promising results are obtained.

Carotid Atherosclerosis: High-Resolution Real-Time Sonography Correlated with Angiography

Abstract: The merits of high-resolution real-time sonography in detection of plaque and estimation of stenoses were compared with angiography in 97 carotid bifurcations from 50 consecutive patients. For flow-reducing lesions, that is, stenosis ≥50% or complete occlusion, sonographic accuracy was 86% and the mean difference in percentage narrowing was 17% (SO, 21.6%). For detection of normal or non–flow-reducing lesions, that is,

Takayasu's disease with aneurysm of right common iliac artery and iliocaval fistula in a young infant: case report and review of the literature.

Abstract: Takayasu9s arteritis or nonspecific arteritis is a term used to designate a primary arteritis of unknown etiology involving the aorta and its major branches at any level. Generally, the lesions are obliterative; however, aneurysms and saccular dilations have also been described. The arteritis was originally believed to be limited to the aortic arch; however, involvement of the descending thoracic and abdominal aorta has been reported. In fact, the majority of cases of Takayasu9s disease in children involve the descending thoracic and abdominal aorta. A case of Takayasu9s disease in a 7-month-old black male infant involving the right common iliac artery with development of a large aneurysm and an iliocaval fistula is reported. This child is the youngest to be affected by the disease as reported in the literature. Although Takayasu9s disease is rare, it should be considered in the differential diagnosis of children with an abdominal mass.