PubMed Health⌕ Search

Biomedical subjects

L J Dunn

Publications and source records attributed to L J Dunn.

At least 19 recordsLinked to original sources
PubMed2001

Binding of dimeric aminoglycosides to the HIV-1 rev responsive element (RRE) RNA construct.

Through a series of elegant fluorescence measurements, particularly through stopped-flow kinetic measurements, it was recently demonstrated that aminoglycoside antibiotics are able to bind to the HIV-1 Rev responsive element (RRE) RNA construct in more than a 1:1 stoichiometry (Lacourciere, K. A.; Stivers, J. T.; Marino, J. P. Biocheminstry 2000, 39, 5630). Here, we present the binding study results of dimeric neomycin ligands through fluorescence anisotropy studies, to the HIV-1 RRE RNA construct. The dimeric neomycin molecules are observed to be able to bind the HIV-1 RRE RNA construct approximately 17-fold higher when compared to the monomeric neomycin, lending evidence that there are indeed two or more neomycin binding sites within the HIV-1 RRE construct.

Anti-Bacterial Agents↗
PubMed1998

Recent developments in medicine and law.

This article addresses important developments in the field of medicine and the law during the last year and highlights some of the significant areas of law affecting health care providers that should be considered. Actions against health care providers may include challenges to peer review immunity, allegations concerning the practice of medicine across state lines without a license, and even accusations of wrongfully assisting a patient to commit suicide. These areas are addressed in turn by this article. Finally, antitrust developments over the last year are briefly addressed as an emerging area of concern for providers forming complex practice networks in today's health care arena.

Antitrust Laws↗
PubMed1991

An integrated, hospital information system based obstetrical medical record and database.

Described in this paper is the implementation and integration of an obstetrical medical record and database into an existing hospital information system. A unique feature of this system was the integration of existing data captured by the established hospital information systems with the newly implemented obstetrical database to form a complete patient data profile. This complete database integrated data from hospital functions such as demographic data obtained at patient registration, outpatient visits and tests, inpatient admission historical data, tests and procedures, newborn data and miscellaneous data required for birth registration. An important second feature was the utilization of physicians and nurses to enter the obstetrical data. This permitted immediate access to patient data from any hospital information system terminal, immediate retrieval for generating reports, and subsequently, ad hoc queries, statistical analysis and the electronic transfer of birth registration data to the State Vital Statistics Registry.

Academic Medical Centers↗
PubMed1990

Isolation and sequencing of cDNA clones encoding ethylene-induced putative peroxidases from cucumber cotyledons.

A cDNA library from ethephon-treated cucumber cotyledons (Cucumis sativus L. cv. Poinsett 76) was constructed. Two cDNA clones encoding putative peroxidases were isolated by means of a synthetic probe based on a partial amino acid sequence of a 33 kDa cationic peroxidase that had been previously shown to be induced by ethylene. DNA sequencing indicates that the two clones were derived from two closely related RNA species that are related to published plant peroxidase sequences. Southern analysis indicates that there are 1-5 copies in a haploid genome of a gene homologous to the cDNA clones. The deduced amino acid sequences are homologous with a tobacco (55% sequence identity), a horseradish (53%), a turnip (45%), and a potato (41%) peroxidase. The cloned sequences do not encode the 33 kDa peroxidase from which the original synthetic probe was been derived, but rather other putative peroxidases. An increase in the level of mRNA is evident by 3 hours after ethephon or ethylene treatment and plateaus by 15 hours.

Amino Acid Sequence↗
PubMed1989

Hormonal Regulation, and Intracellular Localization of a 33-kD Cationic Peroxidase in Excised Cucumber Cotyledons.

Ethylene enhanced chlorosis and levels of 33-kilodalton cationic peroxidase (33-CPO) in excised cucumber (Cucumis sativus L. cv ;Poinsett 76') cotyledons. Compared to other hormones, such as kinetin, indoleacetic acid, gibberellic acid, and abscisic acid, ethylene was the only effective promoter of 33-CPO synthesis. The hypothesis that peroxidase plays a role in chlorophyll degradation was tested by comparing levels of 33-CPO in cotyledons treated with compounds thought to either retard (kinetin, indoleacetic acid and gibberellic acid), or promote (abscisic acid and methyl jasmonate [MJ]) senescence. It was concluded that 33-CPO did not play a role in senescence since no direct correlation between chlorophyll content and 33-CPO was observed. MJ was as effective as ethylene in inducing senescence. However, ethylene did not appear to be involved in the action of MJ. Using immunocytochemistry, 33-CPO was found to be located primarily around starch grains and near the plasmalemma. High levels of 33-CPO were also found in cells destined to be vascular tissue.

Journal Article↗
PubMed1989

Hormonal regulation and distribution of peroxidase isoenzymes in the Cucurbitaceae.

Ethylene enhanced the levels of peroxidases in the roots, stems, leaves, and cotyledons of 2-week-old cucumber Cucumis sativus cv Poinsett 76 seedlings. Antibodies to the isoelectric point (pl) 9 and pl 4 isoenzymes were used in a radial immuno-diffusion assay to demonstrate that ethylene induced similar peroxidases in other cultivars of C. sativus, other species of Cucumis and other genera of Cucurbitaceae. Examination of ethylene-induced peroxidases, using isoelectric focusing gels, demonstrated the presence of a series of other peroxidases, mostly slightly acidic, whose isoelectric focusing pH was approximately 6. These pl 6 peroxidases were partially purified on a cation exchange column. Ouchterlony double diffusion gels indicated that these proteins cross-reacted with antibodies to both the pl 9 and pl 4 peroxidase. The data presented here suggest that the induction of peroxidase isoenzymes during ethylene-induced senescence is a common response in this family of plants. In addition, antibody and isoelectric focusing studies indicate that both acidic and basic peroxidase are highly conserved in members of this family.

Journal Article↗
PubMed1988

Induction of 33-kD and 60-kD Peroxidases during Ethylene-Induced Senescence of Cucumber Cotyledons.

Ethylene enhanced the senescence of cucumber (Cucumis sativus L. cv ;Poinsett 76') cotyledons. The effect of 10 microliters per liter ethylene was inhibited by 1 millimolar silver thiosulfate, an inhibitor of ethylene action. An increase in proteins with molecular weights of 33 to 30 kilodaltons and lower molecular weights (25, 23, 20, 16, 12, and 10 kilodaltons) were observed in sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels after ethylene enhanced senescence. The measurement of DNase and RNase activity in gels indicated that these new proteins were not nucleases. Two proteins from ethylene-treated cotyledons were purified on the basis of their association with a red chromaphore and subsequently were identified as peroxidases. The molecular weights and isoelectric points (pI) of two of these peroxidases were 33 kilodaltons (cationic, pI = 8.9) and 60 kilodaltons (anionic, pI = 4.0). The observation that [(35)S]Na(2)SO(4) was incorporated into these proteins during ethylene-enhanced senescence suggests that these peroxidases represent newly synthesized proteins. Antibodies to the 33-kilodalton peroxidase precipitated two in vitro translation products from RNA isolated from ethylene-treated but not from control cucumber seedlings. This indicates that the increase in 33-kilodalton peroxidase activity represents de novo protein synthesis. Both forms of peroxidase degraded chlorophyll in vitro, which is consistent with the hypothesis that peroxidases have catabolic or scavenging functions in senescent tissues.

Journal Article↗
PubMed1986

Urethral axis and sphincteric function.

Position and mobility of the urethral axis are considered factors influencing urethral competence. Specific correlation between the urethral axis and its sphincteric function is lacking. Eighty-four patients with the symptom of stress urinary incontinence and 31 patients with sensory symptomatology but not urinary incontinence underwent clinical and urodynamic evaluation. This included objective assessment of urethral axial positions and mobility with use of a specially designed protractor. Comparative analysis of urethral axial data was done between 70 incontinent women with objective evidence of sphincteric incompetence and 24 continent women without it. The urethral axis at rest, during bearing down, and in its total excursion were found to be not significantly different and distributed similarly between both groups. Assessment of the urethral axis was found to be not predictive of urethral function.

Cough↗
PubMed1985

Plasma volume determination in normal and preeclamptic pregnancies.

To determine the clinical usefulness of plasma volume determinations, we measured plasma volume serially throughout pregnancy with the use of the Evans blue dye-dilution technique in 20 subjects with normal pregnancies. In comparison, four preeclamptic subjects were studied. In preeclamptic subjects compared to normal subjects, plasma volume was reduced (1763 +/- 216 versus 2345 +/- 198 ml/m2, p less than 0.001). Two normotensive subjects who subsequently developed preeclampsia had reduced plasma volumes prior to the onset of hypertension as compared to volumes in those who remained normotensive (1918 +/- 86 versus 2345 +/- 198 ml/m2, p less than 0.01). Those subjects who were delivered of infants who were small for gestational age had significantly reduced plasma volumes compared to volumes of those who were delivered of infants who were appropriate for gestational age (1950 +/- 333 versus 2237 +/- 259 ml/m2, p less than 0.05), but this was true only among gravid women with pregnancies complicated by preeclampsia. We conclude that failure of plasma volume expansion is associated with the development of preeclampsia and also intrauterine fetal growth retardation in preeclamptic subjects.

Birth Weight↗
PubMed1985

Incisional bladder hernia and urinary incontinence: report of three cases.

Herniation of the bladder has been primarily described in association with inguinal and femoral hernias. Review of the literature yielded only one case report of incisional bladder hernia. The authors report three cases of herniation of the bladder through a postoperative fascial defect. All patients presented with nonspecific sensory lower urinary tract symptoms, pelvic discomfort, and urinary incontinence. Involuntary urine loss as related to bladder hernia has been mentioned only circumstantially. Although urodynamic evaluations were performed, the mechanism of urinary incontinence could not be clarified. Cystography was essential in arriving at a definitive diagnosis.

Adult↗
PubMed1984

Presidential panel. The gynecologic oncologist in academic departments.

Now that the subspecialty of gynecologic oncology is well established within the specialty of obstetrics and gynecology, it seems timely to evaluate the pros and cons, the strengths and weaknesses of such a program as it interrelates with other programs in an academic department. A survey is presented which reflects the beliefs of both members and candidate members of the Society of Gynecologic Oncologists on such issues as gynecologic oncologists as chairmen of departments; teaching demands; time commitments to patient care and research in an academic institution; and surgical privileges for gastro-intestinal and urologic procedures in various hospitals. Financial and budgetary items are also discussed. Perspectives from three different points of view are presented as a discussion of the report of the survey.

Academic Medical Centers↗