A cross-sectional survey of bowel habit has been carried out on 201 elderly patients living at home. Although symptoms of constipation were common, reported bowel frequency was similar to younger ...people. Constipation was most clearly associated with poor mobility and depression. Digital rectal examination was generally unreliable as an indicator of constipation. Using the abdominal radiograph as the final arbiter, true constipation was present in less than half of those complaining of constipation.
Epidermal growth factor (EGF) has been shown to stimulate bone resorption in mouse calvaria in organ culture by a prostaglandin-mediated mechanism. In this report we demonstrate and characterize ...specific receptors for EGF in mouse bone. Binding of tracer quantities of 125Iiodo-EGF reached a maximum after 2 h of incubation at 37 C and began to decrease only after 8 h of continuous exposure to EGF. Scatchard analysis of equilibrium binding data showed a single class of binding sites with a Kd = 2 X 10(-9) M present at a concentration of 3.8 X 10(10) sites/calvarium. The association (ki = 4.4 X 10(6) M-1 min-1) and dissociation (k2 = 0.015 min-1) rate constants for the approach to equilibrium were calculated, and there was no evidence of cooperativity between binding sites. Pretreatment of bones with EGF for 12 h produced a decrease in EGF binding of about 20%, and a maximum decrease to 50-60% of control binding after 48 h of treatment. Decreased binding was due solely to a decrease in the number of receptors rather than to a change in receptor affinity. This down-modulation of receptors occurred even when the bone resorption-stimulating action of EGF was blocked completely by indomethacin, and thus seemed to be triggered only by occupancy of receptors by EGF. Treatment of calvaria with parathyroid hormone, 1,25-dihydroxyvitamin D3, calcitonin, and prostaglandin E2 produced no net change in the number or affinity of EGF receptors in bone. EGF also produced no change in the total DNA content of mouse calvaria. We conclude that mouse bone contains specific high affinity receptors for EGF, and that this experimental system is useful for investigations on EGF receptor modulation and the biological actions of EGF on bone.
A patient with Prader-Willi syndrome showed an elongated proximal 15q, and thus was initially considered to be negative for a proximal 15q deletion. However, repeated high resolution chromosome study ...demonstrating the DNA-replication banding patterns revealed an obvious deletion/deficiency of the 15q12 equivalent band on that elongated chromosome 15. This deletion was further verified by comparison with the parental chromosomes 15 and the deleted chromosome 15 was of paternal origin. The elongation was due to a long variant of 15q11.2 band, which has previously been shown to be polymorphic/variable. This variable proximal 15q site could potentially mask a deletion if it is too long, or mimic a deletion if it is too short. The use of the DNA-replication banding technique instead of the more widely used trypsin banding technique could alleviate this possible pitfall.
Pulmonary and renal excretion of isoflurane and its metabolites was studied in nine surgical patients following administration of known quantitities of isoflurane. Uptake and pulmonary washout were ...predictable by a mathematical model for inert vapors. The agreement between predicted and experimental data supports the view that isoflurane is subject to little or no biotransformation. The average recovery in exhaled air was 95 per cent, SE 7 per cent. The postoperative increase of urinary excretion of fluoride and organic fluorine accounted for less than 0.2 per cent of fluorine administered as isoflurane. This small extent of biotransformation is probably biologically insignificant, but only after extensive clinical experience can the hazard of delayed toxic response be conclusively evaluated.
Large volume and small discrete sources of Tc-99m were used to study the spatial resolution, sensitivity, linearity and reproducibility of the radionuclide brain images. The spatial resolution is ...constant both within and perpendicular to the section. For uniform distributions of activity the response is uniform over the field of view, and the mean pixel count rate is a linear function of the radioactive concentration and is independent of the diameter of the source. However, for discrete sources, the sensitivity was found to vary with the position of the source, and the potential of the system for quantitative assessment of the uptake of radioactivity in organs and tumors was limited initially. Later studies, with modified software, show that this undesirable effect has been reduced.
