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Biomedical subjects

J Duke

Publications and source records attributed to J Duke.

34 records · Page 2Linked to original sources
PubMed1985

Effect of sleep state and position on the incidence of obstructive and central apnea in infants.

Sixty-four infants with a history of apnea were studied to determine the effects of sleeping position and sleep state (rapid eye movement [REM]) v (non-rapid eye movement [NREM]) on the occurrence of central and obstructive apneas. All-night polysomnographic studies were conducted on each infant, and the spontaneous occurrence of central and obstructive apneic events was determined in the prone, supine, and side positions. Sleeping position did not significantly affect the rate or duration of central or obstructive apneas. Furthermore, neither central nor obstructive apneic episodes were significantly altered by sleep state. These data suggest that, in spite of an ostensible predisposition to upper airway obstruction in the supine position and during rapid eye movement sleep, neither sleeping position nor sleep state appears to affect the rate of duration of apneic events.

Age Factors↗
PubMed1984

Interaction of anti-kojibiose antibody with the lipoteichoic acids from Streptococcus faecalis and Streptococcus faecium.

Antisera prepared in rabbits by immunization with p-aminophenyl beta-kojibioside conjugated to bovine serum albumin (antikojibiose sera), readily agglutinated whole cells of Streptococcus faecalis or Streptococcus faecium, and showed specific reactions with the lipoteichoic acids (LTAs) of these streptococci by passive hemagglutination, microscale enzyme-linked immunosorbent assay, and crossed immunoelectrophoresis. The interaction of the antikojibiose sera with the LTAs was inhibited best by kojibiose [alpha-D-glucopyranosyl-(1----2)-D-glucose], somewhat less by the dextran from which the kojibiose was prepared, and not measurably by maltose [alpha-D-glucopyranosyl-(1----4)-D-glucose]. The sera reacted only minimally in only the most sensitive assay (microscale enzyme-linked immunosorbent assay) with LTA from group A streptococci (this LTA contains a single kojibiosyl residue as part of the glycolipid moiety of the molecule and failed to react with the Lactobacillus fermentum LTA which is substituted with alpha-D-galactopyranosyl-(1----2)-D -glucosyl units.

Antibody Specificity↗
PubMed1984

Acceleration of fusion in mouse palates by in vitro exposure to excess G.

Palatal shelves from 13- and 14-day mouse embryos were excised and cultured in contiguous pairs. Experimental cultures were exposed to 2.6 G in a culture centrifuge; controls were in the same incubator. After 24 hours, palates were prepared for light or electron microscopy. Scoring of paraffin sections according to the stage of fusion seen in the medial epithelial edges (MEE) showed that palates exposed to excess G were in more advanced stages of fusion than were controls. Ultrastructurally, control MEE had tightly apposed cell membranes and numerous desmosomes; in centrifuged MEE, desmosomes had been removed and there was much intercellular space. Nuclear membranes were intact in control MEE, but showed marked deterioration in MEE of centrifuged palates. Few lysosomes and no necrosis were seen in control MEE; centrifuged MEE had numerous lysosomes as well as necrotic cells. Basal lamina were intact in controls, but interrupted in centrifuged palates. The results confirm the hypothesis that gravitational increases speed up the differentiative process.

Animals↗
PubMed1983

The role of lipopolysaccharide structure in the recipient cell during plasmid-mediated bacterial conjugation.

The role of the lipopolysaccharide (LPS) structure in the recipient cell during bacterial conjugation was studied using a series of well-defined LPS mutations in Salmonella minnesota. The plasmids Flac (IncFI) and R1drd19 (IncFII) transferred at a high frequency to the smooth S218 parent strain and the rough LPS mutants. However, R64drd1 1 (IncI alpha) transferred poorly to the LPS mutants compared with transfer to the smooth LPS parent strain. The decrease in R64drd1 1 transfer frequency correlated with the extent of the defect in LPS structure, suggesting that intact LPS on the recipient is a major requirement for R64drd1 1 mating. Transfer of the P-group plasmid, RK2, was not affected by changes in LPS structure. These results show that plasmids use different cell surface structures during conjugation, and that LPS is particularly important for R64drd1 1 transfer.

Cell Membrane↗
PubMed1981

Multiple dose extraamniotic prostaglandin gel for second trimester termination of pregnancy.

Multiple doses of PGF2 alpha gel were administered into the extraamniotic space in 30 patients to induce mid-trimester termination of pregnancy. In 18 of these patients, repeat doses of gel were given only in the absence of uterine contractions and in 12 patients the gel was administered every 4 hours, irrespective of uterine activity. The mean time to abortion in all patients was 13.9 hours; no benefit seemed to accrue from using routine 4-hourly doses and it is recommended that repeat doses are given only when contractions are absent. The latter technique compares favourably with the use of other natural prostaglandins and prostaglandin analogues.

Abortifacient Agents↗
PubMed1978

Cell adhesion and chondrogenesis in brachypod mouse limb mesenchyme: fragment fusion studies.

This study is a continuing investigation of the effect of the brachypod mouse mutation on cell interactions and chondrogenesis during early limb development. In this report, cell adhesiveness was assessed in fused fragments of brachypod and normal limb-bud mesenchyme. Examination of the interface of fused distal postaxial limb fragments show brachypod limb mesenchyme to be more adhesive than normal limb mesenchyme. Chondrogenesis within brachypod fragments is delayed and less extensive than in normal fragments. In addition, chondrogenesis within normal fragments is not affected by the juxtaposition of the brachypod fragment, and vice versa.

Animals↗
PubMed1976

Reciprocal reactivities of specific thiols when actin binds to myosin.

We report measurements of the reactivity (degree of labeling, as mole of ligand per mole of protein, at constant exposure time) of the reactive thiol, "SH1", of a subfragment of myosin (S-1), and of Cys-10 of F-actin under various conditions, using N-iodo-[3H]acetyl-N-(1-sulfo-5-naphthyl)ethylenediamine, a fluorescent radioactive iodoacetamide analog. When either ADP or adenyloyl imidodiphosphate (simulating unhydrolyzed ATP) is bound to the enzymatic site of S-1, the reactivity of "SH1" is slightly enhanced, but when active ATPase is going on, reactivity is reduced by about a third, presumably due to the species, (S-1) ADP,Pi. The reactivity of Cys-10 alone is very low. When the complex, (S-1)-F-actin, is formed, the reactivity of SH1 is strongly decreased, and the reactivity of Cys-10 is strongly increased. The foregoing results explain our further observation (on glycerol-treated rabbit psoas fibers) that when fibers labeled in relaxation solution are compared with fibers labeled in rigor solution, myosin is more reactive and actin is less reactive, in the former case; alpha-actinin and C-protein are also less reactive in the former case.

Actins↗
PubMedDate not supplied

Nurses' attitudes toward organ donation: an Australian perspective.

Australia's rate of organ donation, which has shown a continuing downward trend, is among the lowest in the developed world. Research has demonstrated that nurses' attitudes and behaviors are important functions in organ donation, particularly retrieval. This study investigated the attitudes and knowledge levels about organ donation of paediatric nurses in a large metropolitan children's hospital and nurses in two rural hospitals. The results highlight the role that critical care nurses and advanced practice nurses need to play in improving levels of organ donation.

Attitude of Health Personnel↗