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Biomedical subjects

P Morrissey

Publications and source records attributed to P Morrissey.

At least 19 recordsLinked to original sources
PubMed1997

Determination of drug exposure using hair: application to child protective cases.

The use of hair as a specimen for the determination of drug use remains controversial. Scientists disagree upon whether environmental drug contamination (e.g. smoke) can be differentiated from actual drug use. Children whose parents use drugs (particularly crack) at home are considered to be at risk. Using the hair of the children to determine exposure gives extra credibility to the child protective services and allows them to remove children from dangerous households. Children are tested when there are credible reasons for suspecting drug exposure. In Blackhawk Country, Iowa, this program was implemented in late 1994, and since then many children have tested positively for drugs, the majority of the hair containing cocaine or methamphetamine. In some cases, cocaethylene and benzoylecgonine were also found in the hair of the children. While the presence of benzoylecgonine can be explained by exposure to crack smoke, the presence of cocaethylene suggests ingestion of cocaine and alcohol. Blackhawk Country Juvenile Court have found the program to be so useful in helping children, that they have extended hair testing from Child Protective allegation investigations to ongoing court cases and even delinquency hearings.

Adolescent↗
PubMed1990

Cephalosporins to carbapenems: 1-oxygenated carbapenems and carbapenams.

The photo "Wolff" rearrangement of readily available 2-diazoceph-3-em oxides (1) directly affords carbapen-2-ems, allowing a facile entry into a ring system previously accessible only by total synthesis, lengthly semisynthesis or fermentation. The chirality of the cephalosporin is accurately translated into the corresponding carbapenem. The resulting 1-oxocarbapenems (2) were selectively transformed through reduction into 1-oxygenated carbapenems and carbapenams (3 and 4, respectively). On microbiological screening, a carbapenem (3c) was found to possess a broad spectrum of activity. An interesting antibacterial profile was discovered for a carbapenam (26).

Anti-Bacterial Agents↗
PubMed1989

Molecular cloning and characterization of protective outer membrane protein P.69 from Bordetella pertussis.

Protein P.69 is localized on the outer membrane of Bordetella pertussis and is one of the virulence factors believed to contribute to the disease state of whooping cough. We demonstrate that protein synthesis of P.69 is under genetic control of the vir locus. Using oligonucleotide probes derived from the protein sequence of a cyanogen bromide fragment, we have cloned the gene for P.69 from B. pertussis CN2992. Analysis of the DNA sequence reveals a G + C-rich gene capable of encoding a protein of 910 amino acids with a Mr of 93,478, suggesting that P.69 is a processed form of a larger precursor. In common with some of the genes in the pertussis toxin operon, the sequence CCTGG was found 5' to the ATG initiation codon. At the 3' end, 29 bases after the TAA stop codon, the sequence GTTTTTCCT was found and may have some function in transcription termination. A full-length clone of the gene for P.69 carried by the cosmid pBPI69 was unable to direct the expression of P.69 protein in an Escherichia coli host. The generation of P.69-fusion products allowed the detection of P.69-specific protein products synthesized in E. coli.

Amino Acid Sequence↗
PubMed1988

The influence of IL-1 treatment on the reconstitution of the hemopoietic and immune systems after sublethal radiation.

The influence of IL-1 administration on the recovery of the hemopoietic and immune systems from sublethal irradiation was assessed. Mice were irradiated (750 R) and injected twice daily with purified recombinant derived IL-1 beta (200 ng/injection). At various times after irradiation, the functional capacity of the hemopoietic and immune systems was determined. It was found that IL-1 therapy resulted in a significantly greater number of granulocyte-macrophage-CSF responsive colony-forming cells in the bone marrow of the irradiated mice on days 5 and 11 postirradiation but not at later times. In addition the radiation induced neutropenia recovered quicker in the IL-1-treated mice with significantly greater numbers of peripheral blood granulocytes being seen on days 15 and 20 after irradiation. The influence of IL-1 therapy on the recovery of the immune system was also assessed. Of note was the observation that mice receiving IL-1 therapy had chronically hypoplastic thymi. Although thymic cellularity increased with time after irradiation in the control mice, there was no such increase in the IL-1-treated mice. Similarly, the number of pre-B cells in the marrow of these mice was also diminished. Thus, in the IL-1-treated mice the regeneration of the peripheral immune function was retarded, characterized by a general lymphopenia and decreased splenic responses to mitogenic stimuli.

Animals↗
PubMed1988

Retropharyngeal hematomas.

Hyperextension of the cervical spine in the elderly can cause retropharyngeal hematomas. We report this unusual cause of retropharyngeal hematoma in a 77-year-old women. The airway must be thoroughly evaluated in any such patient in whom this lesion is suspected.

Aged↗
PubMed1988

Cloning and nucleotide sequence of the aroA gene of Bordetella pertussis.

The aroA locus of Bordetella pertussis, encoding 5-enolpyruvylshikimate 3-phosphate synthase, has been cloned into Escherichia coli by using a cosmid vector. The gene is expressed in E. coli and complemented an E. coli aroA mutant. The nucleotide sequence of the B. pertussis aroA gene was determined and contains an open reading frame encoding 442 amino acids, with a calculated molecular weight for 5-enolpyruvylshikimate 3-phosphate synthase of 46,688. The amino acid sequence derived from the nucleotide sequence shows homology with the published amino acid sequences of aroA gene products of other microorganisms.

3-Phosphoshikimate 1-Carboxyvinyltransferase↗
PubMed1985

Molecular analysis of the virulence determinants of enterotoxigenic Escherichia coli isolated from domestic animals: applications for vaccine development.

Enterotoxigenic strains of Escherichia coli are an important cause of diarrhoeal disease in young farm animals. Several virulence determinants have been shown to play a major role in the pathogenicity of these strains. The molecular structure of some of these determinants including adhesion fimbriae, heat-labile toxins and heat-stable toxins have been elucidated. This knowledge has made possible the development of novel vaccines effective against enterotoxigenic strains. In this short review, the structure of these virulence factors will be described and the implications for the development of future vaccines will be discussed.

Adhesiveness↗
PubMed1985

Intrinsic laryngeal muscle activity in a spastic dysphonia patient.

EMG activity from four intrinsic laryngeal muscles (thyroarytenoid, posterior cricoarytenoid, interarytenoid, and cricothyroid) was obtained from one female spastic dysphonia patient while she performed a variety of speech and nonspeech tasks. These tasks were performed before and during a period of temporary unilateral laryngeal muscle paralysis. In the nonparalyzed condition, adductory muscle activity showed intermittent sudden increases that coincided with momentary voice arrests. These muscle patterns and accompanying voice interruptions were not present either when speech was produced in falsetto register or at anytime during the paralysis condition. The data suggest that individuals with this type of spastic dysphonia have normal morphology of recurrent laryngeal nerves and intrinsic laryngeal muscles, which means that the triggering mechanism(s) for spastic dysphonia symptoms must be located at some point neurologically upstream from the larynx.

Combined Modality Therapy↗
PubMed1985

Cloning and expression of two Streptococcus mutans glucosyltransferases in Escherichia coli K-12.

Chromosomal DNA from Streptococcus mutans strain MFe28 (serotype h) was cloned in the bacteriophage vector lambda L47.1. Two classes of recombinants were found which expressed glucosyltransferase activity in phage plaques: (i) gtfS, which expressed a glucosyltransferase synthesizing a water-soluble, dextranase-sensitive glucan, and (ii) gtfI, which expressed a primer-dependent glucosyltransferase synthesizing an insoluble glucan.

Bacteriophage lambda↗
PubMed1985

Impact of recombinant DNA technology on studies of bacterial pathogenicity.

Gene manipulation techniques along with other molecular approaches have aided studies on bacterial pathogenicity in a number of ways. Potential virulence determinants have been isolated from a wide variety of pathogenic bacteria and some of these have been characterized in order to determine their genetic organization and identify specific gene products. Proteins such as toxins, adhesins, extracellular enzymes and surface antigens have been analysed. Once a potential virulence determinant has been characterized opportunity exists for further manipulations to be undertaken. For example, natural toxoid producing strains have been constructed including organisms expressing high levels of E. coli heat-labile toxin B-subunit and cholera B-subunits. Gene fragments can be used as hybridization probes to screen for silent or related virulence genes. Mutated genes can be re-introduced into parental pathogenic bacteria, following manipulations in E. coli, to construct specific mutants. Examples of some of these approaches will be discussed.

Bacteria↗
PubMed1984

Physiologic stages of vocal reaction time.

A simple vocal reaction time (RT) task was performed by 10 male subjects while measures from intrinsic laryngeal muscles and subglottal air pressure were obtained simultaneously. Based only on each subject's fastest time among 15 trials, RT values were similar to the latencies previously observed in normal subjects. The mean of the subjects' fastest trials was 185 ms (range: 160-250 ms). Shortest latency values obtained for each measure were interarytenoid muscle, 50 ms; thyroarytenoid muscle, 60 ms; posterior cricoarytenoid muscle, 80 ms; subglottal air pressure rise, 125 ms. From these data estimates were made of 115 ms for the shortest respiratory system latency and 25 ms for the minimal central processing time. These data suggest that fastest vocal RTs are determined principally by the temporal constraints involved in activating pulmonary rather than laryngeal structures.

Adult↗
PubMed1980

Selenium-independent glutathione peroxidase activity in rabbit liver.

The reduction of linoleic acid hydroperoxide catalyzed by rat liver cytosol was previously shown to be catalyzed by a selenium-dependent glutathione peroxidase. In contrast, the activity in rabbit liver cytosol could also be attributed to a selenium-dependent peroxidase. The selenium-independent peroxidase copurified with glutathione transferase B and was completely inhibited by antitransferase B antiserum and transferase substrates. These results suggest that glutathione transferase B in rabbit liver cytosol is involved in the intracellular decomposition of lipid peroxide and could explain the lower selenium requirement of rabbits in comparison with other species.

Animals↗
PubMed1979

Predicting vocal frequency from selected physiologic measures.

Simultaneous physiologic measures were obtained on four young adult male subjects as they sustained phonation at seven frequencies within their modal-to-falsetto voice range. Data were analyzed using a multiple regression program to determine the contribution of each measure singly and in combination with other measures to the prediction of the resultant voice frequency. Results showed that by far the best predictor was cricothyroid muscle activity for both the pooled data model, and for each individual subject. The contribution of subglottal air pressure and thyroarytenoid muscle activity increased the variance explained by only 4% while the measure of vertical laryngeal position was a significant factor in only one subject's predictive model. Partial models from the pooled data explained from 67% to 73% of the variance; whereas the obtained measures for individual subjects explained from 90% to 94% of the variance.

Adult↗