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Biomedical subjects

K Dawson

Publications and source records attributed to K Dawson.

86 records · Page 5Linked to original sources
PubMed1987

Chemical mutagenesis of human interferon-beta: construction, expression in E. coli, and biological activity of sodium bisulfite-induced mutations.

A series of modified human interferon-beta (IFN-beta) genes was produced by sodium bisulfite treatment of the IFN-beta gene cloned in M13. A library of mutated sequences was generated from which subgenomic fragments containing one or a small number of coding alterations were isolated and substituted into the IFN-beta gene in an E. coli expression vector. A number of modified genes and their expression products were evaluated. In several instances levels of expression and biological activity profiles are altered compared to the parental gene product. A number of key amino acids can be identified, whose substitutions have marked effects on biological activity of IFN-beta.

Amino Acid Sequence↗
PubMed1987

Fertilisation and moral status: a scientific perspective.

The debate about the moral status of the embryo has gained new impetus because of the advances in reproductive technology that have made early human embryo experimentation a possibility, and because of the public concern that this arouses. Several philosophical arguments claiming that fertilisation is the event that accords moral status to the embryo were initially formulated in the context of the abortion debate. Were they formulated with sufficient precision to account for the scientific facts as we now understand them? Or do these arguments need modification? Aspects of three arguments for moral status being acquired at fertilisation are examined in relation to current scientific knowledge, highlighting the reasons why such arguments, at present, seem to provide an inadequate basis for the determination of moral status.

Beginning of Human Life↗
PubMed1986

Novel modified beta-interferons: gene cloning, expression, and biological activity in bacterial extracts.

A series of novel, modified interferons based on the structure of human beta-interferon have been expressed in Escherichia coli. Modified interferon genes were constructed from sequences derived from the natural beta-interferon gene, a synthetic beta-interferon gene, or a specific combination of the two. A total of 23 out of the 25 novel interferons exhibited antiviral (AV) and antiproliferative (AP) activity which varied from 3 to 230% and 8 to 490% of the values for beta-interferon, respectively. None of the novel interferons had only AV or AP activity, although one had a much reduced ratio of AV/AP activity compared with beta-interferon. Substitution of beta-interferon amino acids 2-7 or 28-46 resulted in interferons with significantly increased AP activity on Daudi lymphoblastoid cells (four- to fivefold). All the novel interferons except two with modifications in the 82-105 region reacted with a neutralizing beta-interferon monoclonal antibody.

Amino Acid Sequence↗
PubMed1984

Specific syndromes and associated communication disorders: a review.

The purpose of this review is to provide speech-language pathologists and special educators with an awareness of genetics and specific syndromes that involve a speech, language, or hearing component. Both genetic and environmental etiologies are discussed. A description is provided for some of the physical anomalies associated with selected syndromes that also include speech and language deficits. These are presented to provide a rationale for the speech-language pathologist as well as special educators to become more active team members in the identification of syndromes, promote early remedial intervention, and increase interaction with other disciplines in dealing with the multihandicapped child.

Child↗
PubMed1975

Potentiation by cocaine of relaxations of the guinea-pig colon caused by noradrenaline and by stimulation of adrenergic nerves.

The distal colon of the guinea-pig is relaxed by noradrenaline, by isoprenaline and by the stimulation of fibres running with the colonic nerves or intramurally. The relaxations in response to stimulation of the colonic nerves have a guanethidine-sensitive (adrenergic) and a guanethidine-insensitive (non-adrenergic) component. Cocaine causes a three-fold sensitization of the muscle to noradrenaline but no sensitization to isoprenaline. Cocaine increases the duration, but does not affect the amplitude, of the relaxation observed when adrenergic nerves are stimulated, and affects neither duration nor amplitude of the non-adrenergic response. The adrenergic nerve terminals lie in Auerbach's plexus, not in the longitudinal muscle. It is concluded that the sensitization to noradrenaline and the increases in durations of responses to adrenergic nerve stimulation are due to inhibition of catecholamine uptake into adrenergic nerves by cocaine. It appears that, even where the neuromuscular separation is large as it is in the colon, the concentration of exogenous noradrenaline at the receptors can be decreased by neuronal uptake, and the uptake mechanism can modify responses to nerve stimulation in vitro.

Animals↗
PubMedDate not supplied

Frequency of anesthetic cardiac arrests in infants: effect of pediatric anesthesiologists.

STUDY OBJECTIVE: To determine whether the presence of pediatric anesthesiologists decreases the frequency of anesthetic-related cardiac arrests in infants (children who are 1 year of age or younger). DESIGN: A comparative retrospective study of anesthetics and cardiac arrests during a 7-year period. SETTING: The main operating room (OR) suite of a large university hospital. PATIENTS: All patients age 1 year or less undergoing surgical anesthesia from July 1983 through March 1990. INTERVENTIONS: Computerized anesthetic and operative patients records were queried for patient age, ASA physical status, body weight, surgical procedure, intraoperative complications, and the identity of the attending anesthesiologist. In each case, it was determined whether a pediatric anesthesiologist was in attendance and whether a cardiac arrest due to anesthesia occurred. Pediatric anesthesiologists were identified as those with pediatric fellowship training or the equivalent. The study population was divided into two groups: (1) the pediatric anesthesiologist group, with 2,310 patients whose anesthetics were supervised by pediatric anesthesiologists; (2) the nonpediatric anesthesiologist group, with 2,033 patients. MEASUREMENTS AND MAIN RESULTS: Mean age and weight were comparable in the two groups, and the distribution of physical status did not differ. No anesthesia-related cardiac arrests occurred in the pediatric anesthesiologist group; four anesthetic cardiac arrests occurred in the nonpediatric anesthesiologist group, for a frequency of 19.7 per 10,000 anesthetics. This difference between provider groups is significant (Fisher's exact probability test, p = 0.048). CONCLUSIONS: The results suggest that the use of pediatric anesthesiologists for all infants 1 year of age or younger might decrease anesthetic morbidity in this age-group.

Anesthesia↗
PubMedDate not supplied

Family functioning of perinatal substance abusers in treatment.

This prospective study examined family characteristics of perinatal substance abusers enrolled in an intensive outpatient treatment program both during and after treatment. Data is provided on family functioning in three areas: current family, family of origin, and love/partner relationship, and at six time points up to 24 months postdischarge. Standard family assessment measures, including the Self-Report Family Inventory (SFI) and Family-of-Origin Scale (FOS) were utilized to measure current family functioning and family of origin health, respectively. A new instrument, the Relationship Assessment Form (RAF), was used to measure the level of unhealthy, codependent behaviors in the subject's love/partner relationship. A mixed models repeated measures ANOVA was used to determine if subjects' family functioning changed over time. Multivariate and univariate methods examined differences between the subjects in the current study and previously reported means for the SFI and FOS. Results were that perinatal substance abusers' perception of the overall health of their families of origin remained stable over time. Subjects rated their families of origin as more pathological than community adults, but similarly to adults presenting for psychotherapy. Although current family functioning was relatively stable, SFI scores that changed worsened over time after treatment. Perinatal substance abusers scored more pathologically at intake than normal, nonclinic families, but were similar to families presenting for family therapy on the SFI. In contrast, enduring changes of greater magnitude occurred in the subjects' self-reported codependent behavior over time. All RAF scores that changed moved in the direction of healthier, more autonomous functioning. Change and stability in aspects of family functioning may be due to specific factors of the treatment program, which are discussed. Standard family measures may need further refinement for use in this population. Recommendations for clinical programs and future research are provided.

Adolescent↗
PubMedDate not supplied

DetSel 1.0: a computer program to detect markers responding to selection.

Estimating population parameters from polymorphism frequency data requires neutral genetic markers. Any departure from neutrality may invalidate the inferences drawn from such analyses. We recently discussed the possibility of identifying markers that show deviation from neutral expectations in pairwise comparisons of diverging populations. We are now releasing a user-friendly software package that implements all the necessary steps to identify the signature of selection among molecular markers in a set of polymorphism data. This software can be downloaded free of charge at http://www.univ-montp2.fr/~genetix/detsel/detsel.html.

Data Interpretation, Statistical↗
PubMedDate not supplied

[Base plate as a logical controller, matching receptor and other functions of bacteriophage T4].

It has been shown that the complex functioning of the baseplate of the bacteriophage T4 is based on the high level hierarchy in the structure organization and on the interaction of protein components forming the hub and the "channels" of short and long fibers. The presence of structure proteins with stabilizing and destabilizing functions has been revealed. It has been shown that the process of binding of long tail fibers with cell receptors is a cooperative process. In general the baseplate can be considered as a logic module providing the transition from the adsorbtion to the nonreversible reorganization in the bacteriophage functioning.

Bacteriophage T4↗