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Biomedical subjects

K P Quinn

Publications and source records attributed to K P Quinn.

9 recordsLinked to original sources
PubMed2001

Functional gamma-secretase inhibitors reduce beta-amyloid peptide levels in brain.

Converging lines of evidence implicate the beta-amyloid peptide (Ass) as causative in Alzheimer's disease. We describe a novel class of compounds that reduce A beta production by functionally inhibiting gamma-secretase, the activity responsible for the carboxy-terminal cleavage required for A beta production. These molecules are active in both 293 HEK cells and neuronal cultures, and exert their effect upon A beta production without affecting protein secretion, most notably in the secreted forms of the amyloid precursor protein (APP). Oral administration of one of these compounds, N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester, to mice transgenic for human APP(V717F) reduces brain levels of Ass in a dose-dependent manner within 3 h. These studies represent the first demonstration of a reduction of brain A beta in vivo. Development of such novel functional gamma-secretase inhibitors will enable a clinical examination of the A beta hypothesis that Ass peptide drives the neuropathology observed in Alzheimer's disease.

Administration, Oral↗
PubMed2000

Method in Catholic bioethics.

Method in Catholic bioethics is distinguished by a specific philosophical and theological anthropology. Human beings are not to be considered simply as selves, but as selves in relation to God and each other. This essay reflects on that claim by reviewing four areas of concern from Catholic social teaching: common good, human dignity, option for the poor, and stewardship.

Bioethics↗
PubMed1997

Assisted suicide and equal protection: in defense of the distinction between killing and letting die.

The author argues that the distinction between intentionally killing oneself and intentionally letting oneself die is both coherent "as a matter of principle" and morally relevant. This principled distinction then provides a benchmark for courts considering equal protection arguments to distinguish one patient seeking to commit suicide from another wishing to free herself of unwanted life-sustaining medical treatment, and to conclude that these two individuals are not similarly situated for purposes of the Equal Protection Clause. These two situations are morally distinct--the deaths are caused by different means and those involved have different intentions. The intention of the doctor and patient to hasten the patient's death is material, and the intention relates to understanding what it means to treat people equally. Doctors who participate in assisted suicide intend their patients to die by their own acts, i.e., intentional killing. The author concludes that those who ask their doctors to commit assisted suicide and those who forego treatment are not similarly situated for purposes of the Equal Protection Clause. The afterward comments on the Supreme Court's recent assisted suicide decision. It affirms the author's analysis.

Double Effect Principle↗
PubMed1994

The structure of lipooligosaccharide produced by Neisseria gonorrhoeae, strain 15253, isolated from a patient with disseminated infection. Evidence for a new glycosylation pathway of the gonococcal lipooligosaccharide.

We studied the structure of the lipooligosaccharide (LOS) that is produced by Neisseria gonorrhoeae, strain 15253. This strain, recovered from a patient with disseminated infection, produces predominantly a single LOS component, and its oligosaccharide (OS) structure is different from those of previously studied LOSs. Definition of this OS structure provides additional information on the LOS biosynthesis. We determined that the 15253 OS has an unusual structure: 2 lactosyl residues at its nonreducing ends shown below, [formula: see text] where KDO is 2-keto-3-deoxy-mannooctulosonic acid and Hep is heptose. Comparison of this OS structure with those determined previously indicates the presence of a new glycosylation pathway for gonococcal OS biosynthesis: elongation of a GlcNAc-linked heptose, in contrast to elongation of the other heptose by sequential addition of glycoses which results in the antigenic similarity with human glycolipids. The current study provides not only additional structural information on LOS expressed during different clinical states of infection but also evidence for the diversity of gonococcal LOS biosynthesis. This evidence may be helpful in understanding the pathogenesis involving gonococcal LOS.

Acetylglucosamine↗