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Biomedical subjects

W Ireland

Publications and source records attributed to W Ireland.

7 recordsLinked to original sources
PubMed1997

Porcine lingual taste buds: a quantitative study.

BACKGROUND: Taste buds on the pig tongue have been neither studied in detail nor quantified. We have counted the numbers of fungiform and vallate papillae, estimated their taste bud densities, and computed numbers of taste buds per volume of papilla on porcine tongue. Pig was chosen for this work because it is an omnivorous animal, and is one of the better models for study of nutrition-related problems in omnivorous human beings. METHODS: Tongues from three adult pigs were obtained from the local abattoir, fixed in 10% neutral buffered formalin, and mapped for the fungiform and vallate papillae. Serial 15 microns sections were prepared from blocks containing the papillae, and were stained by H & E. Density and volume of the taste buds were estimated using a Bioquant system. RESULTS: Eight hundred fifty and 826 fungiform papillae were observed on tongue I and II, respectively; numerically vallate papillae were 1, 2, and 2 for tongue I, II and III, respectively. Number of taste buds per fungiform papilla was considerably less on the dorsal surface of the tongue (3.88/papilla) than on the lateral side (22.11/papilla). Vallate papillae contained significantly more taste buds, a mean of 732.67 per papilla (t = 14.27; df = 6; P = < 0.05), than in the fungiform papillae. Density of the buds per volume of fungiform papilla was notably less on the dorsum (13.69) than on the lateral border (30.08). The density of vallate papillae taste buds per volume of the papilla was significantly greater than the lateral and dorsal papillae taste bud density (t = 4.28; df = 6; P < or = 0.05). CONCLUSIONS: The present results are relevant to studies on variations of taste sensitivity among regions of the tongue.

Animals↗
PubMed1995

Morphological changes in the small intestine of the fetal pig after prenatal stimulation of the sow with ACTH.

Twelve pregnant primiparous sows were catheterized on day 102 of gestation and randomly allocated to receive ACTH (days 112-113 of gestation [2d], days 105-parturition [10d]) or saline. At parturition the 3rd, 4th, 6th and 7th piglet born alive were sacrificed either at birth or at 6 h. The later group was fed bovine colostrum through a stomach tube at 30 min, 2 and 4 h of life. Following sacrifice, the small intestine of each piglet was excised, extended and measured. Piglets from sows in the 2d group tended to be heavier with longer small intestines than either the control or 10d groups. When the small intestine length was expressed as a function of body weight, the 10d group had the greatest ratio, suggesting that the pre-parturition maintenance of elevated cortisol levels either enhanced small intestine growth or attenuated overall weight gain. Two types of enterocyte granules were described at the level of the electron microscope: granular and opaque. Opaque granules from piglets born to sows in the 2d treatment group had both a lower volume fraction and were fewer per unit area when compared to those of either the saline or 10d treatments. The process of macromolecule uptake from the intestinal lumen appeared to have been interfered with as a result of an acute prenatal stimulation with ACTH. The above results suggest that in piglets, the level of circulating cortisol differentially controls the processes of IgG absorption, enterocyte replacement and small intestine growth through separate mechanisms. Further, these processes can be manipulated in the prenatal piglet.

Adrenocorticotropic Hormone↗
PubMed1991

Development of the small intestine of piglets in response to prenatal elevation of glucocorticoids.

The effects of prenatal adrenal stimulation and synthetic glucocorticoid supplementation on development of the gastro-intestinal tract of the piglet were investigated. Twelve pregnant sows were treated with either ACTH infusion, Isoflupredone injection or Saline between days 105 and 112 of gestation. Neonatal pigs were weighed, bled and sacrificed at 0 or at 6 h. Piglets sacrificed at 6 h were fed bovine colostrum. Transverse sections were prepared from the duodenum, jejunum and ileum for measurement of the villus amplification factor (VAF) and basal membrane circumference. Sows in the ACTH group showed an elevation in cortisol in response to infusion; this decreased after infusion and then rose again at parturition. Piglets from both the ACTH and Saline groups had more villus surface area per unit of body weight (BW) than those born to Isoflupredone-treated animals. The BW of the ACTH piglets was lower (P less than 0.05) than those of piglets in the other groups. When the weight of the stomach and the Small Intestine (SI) was expressed as a function of the body weight, the stomach and SI:BW ratio was larger (p less than 0.05) in pigs born to ACTH-treated sows. The circumference of the ileum was larger at 6 h than at 0 h. Control pigs had a higher concentration of bovine IgG at 4 and 6 h (P less than 0.05). Observations of the light microscopic preparations indicated a less organized epithelium in both ACTH and isoflupredone pigs sacrificed at 0 h. Light and EM preparations of ileum from ACTH pigs sacrificed at 6 h, showed an abundance of dark-stained vacuoles, characteristic of IgG-containing structures. These became less evident in piglets from the Isoflupredone group and even less so in the control groups. The consequences of these phenomena in terms of absorptive capacity are discussed.

Adrenocorticotropic Hormone↗
PubMed1990

World Health Organization--basic radiographic system (WHO-BRS) unit: experimental clinical evaluation.

The basic radiographic system (BRS) is a simplified version of a standard radiographic unit designed by the World Health Organization and the Pan American Health Organization. The design of the BRS includes the requirement that it should be able to perform routine radiographic examinations with a minimum of operator training. This report describes the performance of a BRS manufactured by Siemens. The physical parameters of this BRS were very good and operation should require a minimum of training. A small number of BRS films were compared with films obtained using the standard equipment in the department. The BRS films were generally regarded as satisfactory. Radiation exposure to patients is equal to, and in some cases less than, exposures with conventional X-ray units.

Developing Countries↗
PubMed1985

A mathematical model for the growth of dendritic trees.

A theoretical model for calculating the total length of dendritic trees is presented. Predictions of velocity of dendritic growth, time when branching begins and mean maximal extent of dendritic tree derived from the model for apical dendrites in entorhinal cortex of the rat are presented.

Animals↗
PubMedDate not supplied

A small-scale outdoor plant growth chamber with modulated enhancement of solar UV-B radiation.

An outdoor, solar illuminated growth chamber with modulated UV-B enhancement, is described and its performance characterized. The chamber was clad with Teflon film that transmitted both UV-A and UV-B with little absorption and whose transmission did not change significantly over 1 yr. An array of UV-B emitting fluorescent tubes with cellulose diacetate filters provided additional UV-B radiation inside the chamber with little additional UV-A, while a similar chamber with unenergized tubes provided an ambient control. Ambient and enhanced UV-B levels were measured using a pair of integrating broad band radiometers, and it was found that frequency modulation allowed control of lamp intensity over a range in excess of 100:1. Within the UV-B chamber, enhanced levels of integrated UV-B could be maintained at a constant ratio over ambient throughout the day. However, it was not sufficient simply to maintain a constant ratio of radiometer output voltages: the angular responses of the two radiometers had to be well matched. The shape of the UV-B portion of the enhanced spectrum closely followed that expected under ozone depleted skies, while the enhancement of UV-A was insignificant. The spectral profile obtained in the UV-B depended on the thickness of the cellulose diacetate filters used to block short wavelength UV radiation emitted by the fluorescent tubes. The number (thickness) of cellulose diacetate filters required to achieve this match varied with season. Although the filters did degrade with exposure to UV-B it was not necessary to replace them for several months. This was due to: (i) low rate of filter degradation because the lamps were rarely required to be run at full brilliance except at midsummer midday; and (ii) increased tube intensity compensated for reduced filter transmission.

Environment, Controlled↗