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Biomedical subjects

J Monforte

Publications and source records attributed to J Monforte.

6 recordsLinked to original sources

Mutagenesis of the hairpin ribozyme.

Extensive in vitro mutagenesis studies have been performed on the hairpin ribozyme and substrate in an effort to refine the overall secondary structure of the molecule and provide further insight into what elements are essential for activity. A secondary structure consisting of four helices and five loop regions remains the basic model as originally proposed. Two helices, helix 1 and 2, form between the substrate and ribozyme while helices 3 and 4 are within the ribozyme itself. Our results suggest that helices 3 and 4 are smaller than previously proposed, consisting of four base pairs and three base pairs respectively. Helix 4 can be extended without loss of activity and loop 3 at the closed end of the hairpin model can be varied in sequence with retention of activity. There is an unpaired nucleotide between helices 2 and 3 consisting of a single A base, suggesting the opportunity for flexibility within the tertiary structure at this point. Comparisons are made between the new data and previously published mutagenesis and phylogenetic data. Substrate targeting rules require base pairing between helices 1 and 2 with cleavage (*) occurring in a preferred 5'(g/c/u)n*guc3' sequence of the substrate.

Base Composition↗

Cocaine in Wayne County Medical Examiner's cases.

We determined the incidence of detection of cocaine or its metabolites in Wayne County (Michigan) Medical Examiner's cases from 1984 to 1987. Over this four-year period there was a significant (P less than 0.01) increase each year in evidence of recent cocaine use in this population, reaching 38.3% of all tested cases in 1987. Much of this increase was accounted for by homicide victims, especially those in their third or fourth decade of life, of whom 58.6 and 56.3%, respectively, tested positive in 1987. There was a large increase in recent cocaine use in teenage homicide victims in 1987, having previously changed little from 1984 to 1986. In victims of drug abuse, recent cocaine use also increased significantly (p less than 0.01) each year, reaching 47.6% in 1987, generally in combination with heroin. Although deaths attributed solely to cocaine were not as common, they also increased significantly each year from 4 in 1984 to 25 in 1987. Compared with the general population, those who use cocaine in Wayne County are more likely than those who do not to die prematurely, often as a result of violence.

Adolescent↗

Fatality from illicit phendimetrazine use.

Phendimetrazine is an anorectic agent which recently has been detected in three medical examiner's cases. In one instance death was attributed to this drug. Methods of detecting and identifying this drug in urine and blood are discussed. In the one instance where death was attributed to this substance, the blood concentration was 300 ng/ml.

Adult↗

Fatal thyrotoxic crisis.

Graves' disease is a form of hyperthyroidism. A rare complication of Graves' disease is thyrotoxic crisis. Although the crisis is frequently fatal, it is a distinctly unusual cause of sudden death. We investigated the case of a young woman with Graves' disease who died suddenly. Radioimmunoassay tests of thyroid function were used to establish the diagnosis.

Adult↗

Immunohistochemical demonstration of homicidal insulin injection site.

Deliberate fatal injection of insulin is apparently a rare event. Its investigation generally requires demonstration of an exogenous insulin injection site and high blood or tissue levels. Interpretation of such results in postmortem samples can be difficult, and the demonstration of an insulin injection site has previously usually involved a tedious extraction procedure. We report a case of infanticide in which insulin was demonstrated immunohistochemically at the fatal injection site and discuss some aspects of interpretation of postmortem insulin levels.

Autopsy↗