Arnold W. Pratt

Automatic indexing of pathology data

A procedure for automated indexing of pathology diagnostic reports at the National Institutes of Health is described. Diagnostic statements in medical English are encoded by computer into the Systematized Nomenclature of Pathology (SNOP). SNOP is a structured indexing language constructed by pathologists for manual indexing. It is of interest that effective automatic encoding can be based upon an existing vocabulary and code designed for manual methods. Morphosyntactic analysis, a simple syntax analysis, matching of dictionary entries consisting of several words, and synonym substitutions are techniques utilized.

Computer-assisted characterization of oligoribonucleotides by their ultraviolet absorption

Abstract Spectrophotometric constants at pH 1, 7, and 12 were obtained for 34 di-, tri-, and tetranucleotides by computer-assisted examination of ultraviolet absorption spectra. The values given consist of absorption ratios at 6 wavelengths, the position of maxima and minima, hyperchromicity ratios, and an estimate of the purity of the compounds so examined.

Automated processing of medical English

In this paper the development of a system for automated processing of medical English is investigated. The parsing algorithms for morphological, syntactic and semantic analysis of medical diagnoses are described. The immediate objective of this research is the automatic encoding of pathology data. The long-range goal of the system is its expansion and application to general medical text.

Automated Morphosyntactic Analysis of Medical Language.

Abstract This paper describes an automated procedure for morphosyntactic analysis of medical English based on the recognition of terminal suffixes as syntactic markers. In addition, certain suffixes convey semantic information about a semantic category to which a word may belong. The output of the morphosyntactic analysis provides the input for subsequent syntactic and semantic analysis on the sentence level.

The function of semantics in automated language processing

This paper is a survey of some of the major semantic models that have been developed for automated semantic analysis of natural language. Current approaches to semantic analysis and logical inference are based mainly on models of human cognitive processes such as Quillians semantic memory, Simmons Protosynthex III and others. All existing systems and/or models, more or less experimental, were applied to a small subset of English. They are highly tentative because the definitions of semantic processes and semantically structured lexicons are not formulated rigorously. This is due mainly to the fact that it is unknown whether a unique, consistent hierarchization of the semantic features of language is possible.However, the models described are significant contributions to an unexplored field called semantics. The progressive development of a sophisticated, semantically based system for automated processing of natural language is a realistic goal. It should not be neglected, despite the fact that it is difficult to predict when this goal will be achieved.

A Microtome Specimen Holder Advanced by Thermal Expansion

A microtome specimen holder which advances the specimen by thermal expansion is described. The holder was heated by an electrical current, the value of which could be regulated to give any desired rate of heating and expansion. A quantitative comparison was made between the heating and expansion rates of the Newman, Borysko and Swerdlow CO2 precooled instrument and the electrically heated instrument. It was found that the electrically heated specimen holder fulfilled the requirements of flexibility, reproducibility, sensitivity and linearity.

COMPUTER ASSISTED ANALYSIS OF OLIGONUCLEOTIDES

Current biochemical theory accepts the concept that the cell nucleic acids control protein synthesis (Wilkins, 1957; Ochoa, 1963). Many properties of the ribonucleic acid code and protein synthesis system have been clarified by the repeated demonstration in cell-free preparations that oligoribonucleotides of specific composition direct the preferential incorporation of amino acids into polypeptide molecules (Nirenberg and Leder, 1964; Leder and Nirenberg, 1964). In these studies the applicability of computational methods in the analysis of the composition and structure of oligonucleotide fragments of naturally occurring ribonucleic acid using spectrophotometric data solely is being examined (Pratt et al., 1964). This approach is feasible because of (1) improved enzymatic hydrolysis and chromatographic separation procedures for oligoribonucleotide preparation, (2) almost all recognized purine and pyrimidine bases found in synthetic and naturally occurring polynucleotides absorb ultraviolet (UV) light, (3) an adequate instrument complement exists for the collection of quantitative spectrophotometric data and (4) the availability of computers. General Background. Ribonucleic acid (RNA) is a linear polymer in which the monomers, known as mononucleotides, are composed of purine or pyrimidine bases linked to a phosphate sugar; the mononucleotides are strung together via phosphodiester linkages (FIGURE 1). Ribonucleic acid contains the pentose sugar, ribose, and generally, four different purine or pyrimidine bases. The four common bases of RNA are adenine, cytosine, guanine and uracil which when linked to the sugar phosphate form respectively, adenylic acid, cytidylic acid, guanylic acid and uridylic acid.* The purine and pyrimidine bases are the major variable constituents in the RNA molecules and i t is presumed that it is their linear order which contain the information essential for the control of protein (enzyme) synthesis.

An Application of Mass Spectrometer Analysis to the Study of Respiratory Metabolism

An application of the mass spectrometer to the study of the respiratory metabolism is described. In this application an unmodified mass spectrometer is used for high precision measurements of both the normal and abnormal components in the collected samples. From these data the oxygen consumption rate, the carbon dioxide formation rate, and the respiratory quotient are calculated for physiological interpretation.

Food and water intakes and Walker tumor growth in rats with hypothalamic lesions

Abstract By the 15th day post transplant of the Walker tumor into Sprague-Dawley rats, food intake showed a depression which continued with subsequent tumor growth. A less severe depression of water intake occurred later, indicating dissociation of food and water intake in the tumor bearer. Electrolytic lesions in the lateral area of the hypothalamus of animals at 13 days post transplant produced true aphagia and adipsia; thus the controlling mechanism of the latera area is functional in the tumor bearer at 15 days. Tumor bearers with sham operations in the lateral area at 15 days showed an initial depression in food and water intakes. Focd intake eventually equaled that of nonoperated tumor bearers, but water intake remained depressed, again indicating dissociation of food and water intakes. The Walker tumor was transplanted into rats previously made hyperphagic by lesions in the ventromedial hypothalamus. Food intake began to decline by 15 days, eventually reaching very low levels; thus depression of food intake in the intact tumor-bearing host is not mediated via the ventromedial hypothalamus.

Electron Microscopy of Crystalline Plates in Rabbit Papilloma

Summary The finding of crystalline platelets in the water extracts of papillomatous lesions of the wild and domestic rabbit is noted. A few of the elementary properties of the crystals are discussed.