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At least 55 records · Page 3Linked to original sources
PubMed1975

Computer method for the analysis of evoked motor unit potentials. 2. Duchenne, limb-girdle, facioscapulohumeral and myotonic muscular dystrophies.

Single motor unit potentials recorded from surface electrodes over the extensor digitorum brevis muscle and evoked by stimulation of the anterior tibial nerve at the ankle were obtained by a computer subtraction method. Their latencies, durations, amplitudes, and areas were measured in control subjects and patients with Duchenne, limb-girdle, facioscapulohumeral, and myotonic muscular dystrophy. Lateral popliteal motor nerve conduction velocities were also recorded. In the muscular dystrophies there was a significant increase in both the latencies and durations of motor unit potentials, the latter in notable contrast with the findings of conventional needle electromyography. Fastest motor conduction velocities were significantly reduced in the limb-girdle, facioscapulohumeral, and myotonic muscular dystrophy patients, while the shortest distal motor latencies were significantly prolonged in these patients and those with Duchenne muscular dystrophy. The results support the presence of a definitive neurogenic influence in the muscular dystrophies.

Adolescent↗
PubMed1975

[Study of interventricular septal defects with equal aortic and pulmonary artery pressures. Classification by clinical and computer methods of 70 cases].

Application of various methods of classification to a group of 70 cases of ventricular septal defect with high pulmonary artery hypertension allowed a comparative study between the various methods aiming at distinguishing the forms with low from high pulmonary artery resistance. The reference clinical classification provides supplementary informations derived from the natural or post-operative course and eventually from the microscopic examination. The first automatic classification relies on the study of a single criterion: the pulmonary arteriolar resistance and the systemic resistance ratio. A second classification is based on the attribution of points to some clinical or haemodynamic signs resulting in a score orienting the classification of every individual. Multifactorial analysis methods deal with all the available informations for the overall group, and suppose the use of a computer. The informatic methods make it possible to study the classifying value of every sign. Correlations were established between these various techniques and the medical classification.

Adolescent↗
PubMed1978

Simple computer method for equivalent square therapy field determination.

A simple BASIC computer program allows rapid determination of the equivalent squares of irregular radiation therapy fields. A port film or scale drawing of the irregular field is outlined manually on a spark tablet digitizer, and the side length of the square of equivalent area to perimeter ratio is rapidly calculated and returned by the computer.

Computers↗
PubMed2025

Prediction and Evaluation of Protein Aggregation with Computational Methods.

Protein and peptide aggregation has recently become one of the most studied biomedical problems due to its central role in several neurodegenerative disorders and of biotechnological importance. Multiple in silico methods, databases, tools, and algorithms have been developed to predict aggregation of proteins and peptides to better understand fundamental mechanisms of various aggregation diseases. Here, we attempt to provide a brief overview of bioinformatic methods and tools to better understand molecular mechanisms of aggregation disorders. Furthermore, through a better understanding of protein aggregation mechanisms, it might be possible to design novel therapeutic agents to treat and hopefully prevent protein aggregation diseases.

Computational Biology↗
PubMed1988

An improved secondary structure computation method and its application to intervening sequence in the human alpha-like globin mRNA precursors.

Current secondary structure prediction computations have a serious drawback. The calculated thermodynamically most stable structure often differs from that observed in solution or in crystal form. In this paper we suggest a way to partially over-come some of these limitations by simulating the RNA folding process and calculating the frequencies of occurrence of the various substructures obtained. The frequently recurring substructures are then selected to construct the secondary structure of the whole RNA. 142 tRNA molecules and an E. coli 16S rRNA molecule have been examined by this method. The percentage of successful prediction of the correct helices are significantly higher than those calculated previously. The secondary structures of intervening sequences (IVSs) excised from human alpha-like globin pre-mRNAs are also computed. Thus, in this method the secondary structures obtained are composed of the statistically more significant substructures. This has also been demonstrated by using randomly shuffled sequences. The secondary structures of each of the randomized sequences are computed and their mean and standard deviations are used in evaluating the significance of the substructures obtained in the folding of the biological sequence. Some potentially appealing structural features aligning adjacent exons for ligation have been found.

Base Sequence↗
PubMed1985

A computer method for scanning and analysis of dot blots.

A system is described for computer analysis of autoradiograms produced from dot blots. The autoradiograms are first digitized on a rotating drum densitometer. The system automatically locates, integrates, and corrects the intensity of each spot for background. A linear range of exposures for each series of dilutions on the dot blot is calculated, and the amount of specific RNA is reported relative to other samples or to an internal standard. Without operator intervention, the system can directly scan and analyze all possible spots produced by the commercial filtration devices which use the geometry of a 96-well microtiter plate.

Computers↗
PubMed2026

Development of a multi-copy integration platform in Kluyveromyces marxianus enabled by a computational method for genome-wide identification of multi-copy integration loci.

Multi-copy integration is a core strategy for redirecting metabolic flux toward target compounds. However, its application has been hampered by the absence of methods for systematically identifying native multi-copy genomic loci. To overcome this, we developed a computational procedure for genome-wide identification of such loci. Theoretically, this method is potentially applicable to any genome-sequenced species as it only requires the genomic assembly of the target species as input. Applying the procedure to Kluyveromyces marxianus, we identified four groups of loci (KmCS1-4). Combining these loci-KmCS1-4 and the traditional 26S rDNA-with 14 markers with graded selection strengths, we established a versatile multi-copy integration toolkit comprising 70 plasmids. Each plasmid exhibits a unique integration pattern, collectively forming an integration profile. This profile serves as a manual, enabling users to select appropriate tools tailored to the expression requirements of rate-limiting enzymes in their pathways. Applying representative plasmids exhibiting low-, medium-, and high-copy integration patterns to lycopene biosynthesis modules resulted in lycopene titers of 3.5, 6.8 and 40.5 mg/L, corresponding to 2, 6 and 9 genomic copies, respectively, demonstrating a positive correlation between lycopene titers, genomic copy numbers and integration patterns, which highlights the versatility of the toolkit and its supporting manual. Our study not only provides a broadly applicable methodology for genome-wide identification of multi-copy loci, but also an efficient integration platform for K. marxianus.

Kluyveromyces marxianus↗
PubMed1988

A versatile computational method for the determination of areas under the curve and moment curve following multidose drug administration.

The accurate determination of area under the biologic fluid concentration-time curve (AUC) and area under the first moment curve (AUMC) are important in the calculation of a compound's pharmacokinetic parameter estimates. Although numerous mathematical methods exist for the calculation of both AUC and AUMC under varying conditions, some permit direct computation of areas, whereas others only approximate the true areas. In this study, we describe an alternative mathematical method which allows the direct calculation of either the AUC or AUMC after any dose of drug administered by any route. Simulated data with known areas were used to assess the accuracy of the proposed method and compared to area calculations obtained from widely used published methods. Experiments were also performed under conditions of varying elimination half-lives and reduced numbers of concentration-time values. Under any experimental condition, the newly proposed method was the most accurate in determining both the AUC and AUMC. Percent deviations from exact area values were less than or equal to 0.11% with the proposed method, whereas as much as 30% deviation was observed using other methods of calculation. These findings support the accuracy of the proposed method in calculating the AUC or AUMC and its utility in data analysis.

Infusions, Intravenous↗
PubMed1992

Computer methods in child language research: four principles for the use of archived data.

With the increasing use of computers in language research, there is a need for caution concerning several new issues of data accountability. This paper presents four principles for archive-based language research: Maximum Readability and Minimum Bias; Consistent Encoding for exhaustive computer search; Systematic Contrastiveness; and Data Comparability in elicitation, transcription and coding. These and related principles are illustrated by examples from existing computer archives, and strategies are suggested for minimizing detrimental effects of violations. Finally, the paper describes some implications of the principles for properties of a field-wide and international standard of transcription of language data.

Archives↗
PubMed1991

Computational method for the design of enzymes with altered substrate specificity.

A combination of enzyme kinetics and X-ray crystallographic analysis of site-specific mutants has been used to probe the determinants of substrate specificity for the enzyme alpha-lytic protease. We now present a generalized model for understanding the effects of mutagenesis on enzyme substrate specificity. This algorithm uses a library of side-chain rotamers to sample conformation space within the binding site for the enzyme-substrate complex. The free energy of each conformation is evaluated with a standard molecular mechanics force field, modified to include a solvation energy term. This rapid energy calculation based on coarse conformation sampling quite accurately predicts the relative catalytic efficiency of over 40 different alpha-lytic protease-substrate combinations. Unlike other computational approaches, with this method it is feasible to evaluate all possible mutations within the binding site. Using this algorithm, we have successfully designed a protease that is both highly active and selective for a non-natural substrate. These encouraging results indicate that it is possible to design altered enzymes solely on the basis of empirical energy calculations.

Algorithms↗
PubMed1989

A least-squares computer method for the determination of the molecular ratio of conjugates between two different proteins from the results of the amino acid analysis.

A method for the determination of the composition of a conjugate between two different proteins by amino acid analysis followed by least-squares evaluation of the concentration ratio of the two components is presented. The method is based solely on calculations and avoids the use of labeled residues. A computer program, written in BASIC, is also presented to perform the calculations.

Amino Acids↗