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Biomedical subjects

J D Simmons

Publications and source records attributed to J D Simmons.

32 records · Page 2Linked to original sources
PubMed1988

Effect of environmental temperature and feeding regimen on quantity of digestive tract contents of broilers.

Carcass contamination from contents of the digestive tract during processing is a recurring problem for the broiler industry. Environment and feeding regimen are often implicated as causative factors. The effects of environmental temperature and meal feeding on passage of feed through the digestive tract of broilers were examined. Broilers were reared in environmental chambers in five experiments. In the first experiment, environmental temperatures were constant temperatures of 16 and 27 C and cycles of 16-24-16 and 24-35-24 C and rate of passage of feed through the digestive tract (ROP) was determined with ferric oxide. Temperature did not consistently affect ROP. In the other four experiments, various environmental temperatures were investigated and broilers were fed continuously or for 12 or 16 h/day. Contents of the crop, proventriculus plus gizzard, and small intestine were weighed 2, 4, 6, and 8 h after feeding withdrawal. Environmental temperature did not directly affect the movement of digesta but the feeding regimen affected the quantity of digesta in some segments of the tract. Environmental temperature may have indirectly affected the quantity of feed in the crop by affecting the quantity of feed consumed. Limiting the feeding period resulted in retention of digesta in the crop of some broilers for an extended period. This increased the variability in quantity of crop contents. A feeding regimen X temperature interaction resulted in increased small intestine weight for meal-fed broilers at 16 C.

Animals↗
PubMed1987

A longitudinal study of anteroposterior growth changes in the palatine rugae.

Palatine rugae have been used as internal dental cast reference points for quantification of tooth migration. Some, but not all, investigators have reported the medial rugal region to be stable or to show predictable change. The purpose of this study was to use the longitudinal data base of the Child Research Council of Denver to examine the anteroposterior stability of the medial rugal region. Dental casts of 20 females and 21 males with untreated normal Angle Class I occlusions were selected. Time intervals measured were: T1--primary teeth erupted, T2--earliest cast with permanent first molars erupted, T3--earliest cast with canines and pre-molars erupted, and T4--ages 16 to 22. Distinctive left and right anterior and posterior rugae which appeared on all four casts were identified, the medial ends marked, and the anteroposterior distances measured. The data were evaluated with the paired t test, repeated-measures ANOVA, and Tukey's multiple comparison procedure. From T1--T4, the medial rugal region increased 1.4 +/- 0.6 mm in females and 2.3 +/- 0.8 mm in males. Only two cases showed a trend toward stability. There were no significant differences by side. Significant increases in size occurred between T2 and T3 for females and males and between T3 and T4 for males. Analysis of these data indicates that the medial rugal region increases significantly in anteroposterior length, but not uniformly between the sexes across observation times. Such changes are characteristic of general craniofacial growth and suggest that the rugal region is responding to the differential growth of the underlying bone. Therefore, medial rugal landmarks appear not to be stable reference points for tooth migration research.

Adolescent↗
PubMed1987

Effect of beak trimming on body weight and feed intake of egg-type pullets fed pellets or mash.

Pelleted and mash feed were provided in each of two trials. In the first trial, it was noted that the pullets did not eat the feed that was offered in pellet form. Type of beak trimming appeared to be involved in lowering feed intake. The second trial demonstrated that pullets with either the top beak or both beaks trimmed (block cut) approximately 2 mm from the nostril when offered pellets or mash did not eat feed in pellet form as readily as that in mash form.

Animal Feed↗
PubMed1983

Computed tomography of ocular colobomas.

Typical ocular colobomas and associated orbital cysts are relatively common malformations that result from a defect in the fusion of the fetal optic fissure. Three cases studied with computed tomography (CT) are reported, and the spectrum of ocular colobomas, their associated findings, and CT differential diagnosis are reviewed. This experience indicates that the location and extent of colobomas can be determined with high-resolution CT.

Child↗
PubMed1983

The anterior junction anatomy.

It is useful to consider the anterior junction anatomy in terms of three components: the superior recesses, the line, and the inferior recesses. Each component localizes to a specific area retrosternally: the superior recesses--behind the manubrium; the line--behind the upper two thirds of the sternal body; and the inferior recesses--behind the lower third of the sternal body and below where the cardiac mass abuts the anterior chest wall. Since the anterior chest wall curves backward from bottom to top (Figure 61), the coronal plane of the superior recesses is behind that of the anterior junction line, the coronal plane of the inferior recesses being in front of that of the anterior junction line. Accordingly, then, anteroposterior conventional tomograms will usually demonstrate the inferior recesses on the most anterior levels, the line a centimeter or so behind the inferior recesses, the superior recesses a centimeter or so behind the line. Understanding the anterior junction anatomy in terms of three components has widespread use, as shown above, by many examples obtained from everyday film reading. The presence, absence, and location of disease may be diagnosed. As well, mistaken diagnoses may be avoided. Since the anterior junction lung relates to the anterior pleural space, pleural space processes may alter the anterior junction anatomy. It must be realized that although visualization of the normal anterior junction anatomy components may help to exclude the presence of retrosternal abnormality, they are not infallible. It is possible for a small lesion to be entirely contained within the anterior mediastinum and, thus, not alter the normal anterior junction components. A deep retrosternal space, where normally the anterior junction line is formed, may allow an anterior mediastinal mass to be present and a normal anterior junction line to be seen if the mass does not occupy the entire depth of the space. Furthermore, in patients with markedly hyperexpanded lungs, it is conceivable that the cardiac mass may abut the chest wall at the level of the inferior recesses to a lesser degree than usual, or not at all. Marked lung hyperexpansion may also conceivably cause the superior recesses to extend above the manubrium.

Heart↗
PubMed1983

The posterior junction anatomy.

The anatomy of the posterior junction is more than just the well-recognized posterior junction line. It is helpful to consider this anatomy in terms of three components, each corresponding to a specific area. (a) The Line--Contact of the parietal and visceral pleural surfaces of the right and left lungs, usually anterior to thoracic vertebral bodies 3-5; (b) The Superior Recesses--Edges of lung contact with the mediastinum, usually anterior to thoracic vertebral bodies 1 and 2, which edges marginate a "V" shaped area above the posterior junction line; (c) The Inferior Recesses--Edges of lung contact with the mediastinum over the posterior azygos and aortic arches and in the vicinity of the superior intercostal veins, which edges marginate an inverted "V" shaped area.

Aorta, Thoracic↗
PubMedDate not supplied

The effect of biological isolation and a molt-inducing regimen on the recovery of Mycoplasma gallisepticum from commercial Leghorn hens.

Two trials were conducted to determine the effect of induced molt on the reisolation of Mycoplasma gallisepticum (MG) from commercial leghorn hens that had been eyedrop-inoculated with MG at 10 weeks of age. Chickens were maintained in a conventional floored chicken house on dry litter through 100 weeks of age. At age 64 weeks, 4 days (Trial 1), and at 100 weeks (Trial 2), hens were swabbed and cultured for MG and then molted in biological isolation units. Swabs were again taken at the end of each molt. No difference was observed in the number of MG isolations between molted hens and controls that did not undergo molting. However, a significant decrease in MG isolations was observed in both trials from swabs obtained when hens were housed on dry litter floors as compared with swabs taken from the same hens after 18 days (Trial 1) or 21 days (Trial 2) of confinement in isolation units.

Age Factors↗
PubMedDate not supplied

Influence of F strain Mycoplasma gallisepticum infection on response of commercial layers to heat exposure.

Commercial layers were inoculated with F strain Mycoplasma gallisepticum (MG) and housed in either conventional chicken houses or the lower-stress environment of biological isolation units. At the end of 2 weeks, all treatment groups were placed in environmental chambers and subjected to 4 hr of heat stress (40 C with a dew point of 21 C). Rectal temperature, an indicator of response to high heat, was monitored. Rectal temperatures of F strain MG-inoculated hens housed in the conventional chicken house environment were significantly higher than those of uninoculated controls, whereas rectal temperatures of hens held in isolation units were comparable to those of their uninoculated controls.

Animals↗
PubMedDate not supplied

Preoperative demonstration of postinflammatory syringomyelia.

Syringomyelia secondary to arachnoiditis is a rarely reported entity, which has not been described in the radiographic literature. A series of eight patients who had either postinfectious, posthemorrhagic, iatrogenic, or idiopathic arachnoiditis was examined recently with metrizamide computed tomography (CT). These patients presented with progressive neurologic deficits that could not be attributed to the level of arachnoid changes on myelography. On immediate and/or delayed CT scans, metrizamide accumulation within the central part of the cord was identified, both at and above the level of the arachnoiditis. In some patients, the cord diameter was normal. Syrinx cavities were demonstrated and shunted at surgery with subsequent partial relief or arrest of the symptoms. The mechanism of development of postinflammatory syringomyelia is discussed.

Adult↗