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Biomedical subjects

K Rankin

Publications and source records attributed to K Rankin.

8 recordsLinked to original sources
PubMed1996

Evaluating the 'Labeled Magnitude Scale' for measuring sensations of taste and smell.

The Labeled Magnitude Scale (LMS) is a semantic scale of perceptual intensity characterized by a quasi-logarithmic spacing of its verbal labels. The LMS had previously been shown to yield psychophysical functions equivalent to magnitude estimation (ME) when gustatory, thermal and nociceptive stimuli were presented and rated together, and the upper bound of the LMS was defined as the 'strongest imaginable oral sensation'. The present study compared the LMS to ME within the more limited contexts of taste and smell. In Experiment 1, subjects used both methods to rate either taste intensity produced by sucrose and NaC1 or odor intensity produced by acetic acid and phenyl ethyl alcohol, with the upper bound of the LMS defined as either the 'strongest imaginable taste' or the 'strongest imaginable odor'. The LMS produced psychophysical functions equivalent to those produced by ME. In, Experiment 2 a new group of subjects used both methods to rate the intensity of three different taste qualities, with the upper bound of the LMS defined as the 'strongest imaginable [sweetness, saltiness, or bitterness]'. In all three cases the LMS produced steeper functions than did ME. Experiment 3 tested the hypothesis that the LMS yields data comparable to ME only when the perceptual domain under study includes painful sensations. This hypothesis was supported when the LMS again produced steeper functions that ME after subjects had been explicitly instructed to omit painful sensations (e.g. the 'burn' of hot peppers) from the concept of 'strongest imaginable taste'. We conclude that the LMS can be used to scale sensations of taste and smell when they are broadly defined, but that it should be modified for use in scaling specific taste (and probably odor) qualities. The implications of these results for theoretical issues related to ME, category-ratio scales and the size of the perceptual range in different sensory modalities are discussed.

Acetic Acid↗
PubMed1995

The timing of SIDS deaths in premature infants in an urban population.

Previous reports have demonstrated that premature infants are at greatly increased risk for sudden infant death syndrome (SIDS). Although only 9% of infants are born at less than 36 weeks' gestation, 20% of SIDS victims are former premature infants. The objective of this study was to characterize the time course of SIDS in premature infants and to determine why SIDS occurs at such a high rate in this patient population. A database of all cases of SIDS in Philadelphia from 1987 through 1991 was used to establish the time course for SIDS deaths in term and preterm infants. Gestational age was established by Dubowitz exam. To evaluate distinctly different age groups, infants from 32-36 weeks were excluded from analysis. Age at death and postconceptional age of death were compared for both groups. Data are described in weeks (mean +/- SEM), and analyzed using unpaired t-test and log-rank test to compare survival rate between term and preterm infants. A significant difference (P < 0.01) was noted in age at death of term versus preterm infants. No difference was found in postconceptional age of death. The survival rates were also different (P < 0.001). Preterm infants showed a much wider distribution in age of death from SIDS. The term infants followed the classic SIDS curve. By 32 weeks' postnatal age, 95% of all SIDS had taken place in the term group, but only 75% in the preterm group. The age at death for SIDS differs in the preterm infant.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1995

Infant sleep position following new AAP guidelines. American Academy of Pediatrics.

OBJECTIVE: This report examines the response of families to the American Academy of Pediatrics June 1992 recommendation that healthy term infants be put to sleep on their back or side to decrease the risk of sudden infant death syndrome. Parents at two clinics and private practices were interviewed to ascertain sleep position practices. METHODS: Parents of infants from 1 to 6 months of age who were in the waiting room for a well-child visit were eligible for study. A total of 760 interviews were conducted using a closed-ended questionnaire. Parents were asked about sleep position, positional changes during sleep, and factors that influenced their decision to position their infant prone, side, or supine. Interviews were conducted from September 1993 through April 1994. This interval was divided into two equal, 4-month time intervals. Sleep practices were compared during the first and second time periods. Differences between practice and clinic groups were measured. Groups were compared using the chi-square test, with results considered significant at P < .05. RESULTS: The number of infants placed side or supine for sleep increased significantly since the inception of the study, from 38.1% to 59.1%. Despite this increase, parents reported that the impetus for changing position came from family or the media, rather than from health professionals. Initially, the proportion of infants in private practices placed side or supine was greater than that of clinic patients. That difference disappeared by the end of the study. Prone positioning continued to be more prevalent in the 3- to 6-month-old infants than in the 1- to 3-month-old group. The majority of infants at all ages awoke in the same position that they were put to sleep. CONCLUSIONS: Side and supine positioning for sleep increased in all socioeconomic groups. A small number of infants placed side or supine for sleep are found prone on awakening. Health professionals need to increase their role in providing sleep position guidance. As the proportion of the population positioning their infants side or supine for sleep increases, it should be possible to examine the effect on the sudden infant death syndrome rate.

Cross-Sectional Studies↗
PubMed1989

Differentiation-linked expression of the plasminogen activator inhibitor type-2 gene in the human HL-60 promyelocytic cell line.

HL-60 is a human promyelocytic cell line which was found to be capable of differentiating toward a macrophage-like or granulocyte-like phenotype. Histochemical analysis demonstrated that incubation of cells in the presence of phorbol myristate acetate (PMA) or 1,25-dihydroxyvitamin D3 induced varying degrees of monocytic differentiation, while incubation in the presence of retinoic acid (RA) or dimethyl sulfoxide (DMSO) induced granulocytic differentiation. The differentiation induced by PMA, RA, and to a lesser extent DMSO, was accompanied by the induction of plasminogen activator inhibitor expression. mRNA analysis of control and PMA-induced cultures revealed the induction of a 2-kb message in treated cells which hybridized with a PAI-2-specific oligonucleotide probe. This is consistent with the literature concerning the expression of PAI by macrophages and granulocytes. No hybridization was detected with a PAI-1 specific probe. Expression of PAI by cells of hematopoietic origin appears to be associated with differentiation or stimulation of committed cells. Furthermore, PAI-2 expression by HL-60 cells is not restricted to one specific hematopoietic lineage. Since other cells of hematopoietic origin such as platelets express PAI-1, future studies using pluripotential cell lines could provide information on the initial events of lineage commitment and gene expression.

Cell Differentiation↗