Idiopathic multifocal osteopathy in four Scottish terriers (1991-1996).

This case series describes four Scottish terriers with an osteopathic condition, characterized by multifocal absence of bone in the skull, cervical spine, and proximal radii, ulnae, and femora. All dogs were affected clinically; two dogs were euthanized due to progression of the disease, one died acutely, and one was euthanized for an oral melanoma. Histopathology in one case was characterized by osteoclastic osteolysis and replacement of bone with fibrous tissue. This disease has some characteristics of human osteolysis syndromes. Three of the dogs were related through pedigree analysis, and the pedigree of the other dog was not available. The name, idiopathic multifocal osteopathy, is used to describe a new disease in dogs, found particularly in Scottish terriers.

Enhanced apomorphine-induced hypothermia in alloxan-treated rats.

Previous studies have indicated that drug-induced experimental diabetes is associated with increased receptor binding in the rat brain. The purpose of this study was to determine whether the dopamine receptor agonist apomorphine (APO) might produce an accentuated hypothermic response in rats rendered diabetic by alloxan (ALX) treatment. In a previous study, however, the only controls used were ALX-treated rats that failed to develop glycosuria. Therefore, in this study, APO (0.5 mg/kg IP) was administered to ALX-diabetic and non-diabetic as well as saline-treated control rats to ascertain whether the APO responsiveness of ALX-non-diabetic rats was comparable to that of saline control animals. ALX-diabetic rats experienced significantly greater hypothermic response to APO than did the saline control animals. Although ALX-non-diabetic rats were similar to the saline control animals in body weight and blood glucose levels, they too were hyperresponsive to APO. These findings indicate that pancreatic injury from ALX, while not always sufficiently severe to produce overt diabetes, does appear to induce an hyperresponsiveness to APO-induced hypothermia in a manner similar to that observed in severely diabetic animals.

Sulfate incorporation by mouse synovial cells in vivo.

Mouse synovium was examined autoradiographically at various postinjection to determine the pattern of 35S utilization. Synovial cells incorporated 35S in a manner consistent with synthesis and secretion of sulfated macromolecules. Ultrastructural examination demonstrated two cell populations, one with a structure indicative of phagocytic function, the other with a structure typical of secretory activity.

Incorporation of leucine by mouse synovial cells in vivo.

Following 3H-leucine administration, mouse synovium was examined autoradiographically at various postinjection times to determine whether the pattern of 3H-leucine utilization in vivo is comparable to that previously reported in vitro. Synovial cells incorporated 3H-leucine in significantly greater amounts than other cells examined. The pattern suggested intracellular incorporation, followed by secretion.

Effect of initial developmental stage on morphology of transplanted embryonic chick pancreas.

It has been reported that only certain types of pancreatic parenchymal cells survive transplantation. This study examines whether the extent of differentiation of the pancreas at the time of transplantation affects the resulting morphology or viability of its components. Segments of chick pancreas or its primordia from stages preceding formation of dorsal bud (60 h) through hatching (day 21) were implanted in the abdominal region of three-day chick embryos. After various periods of growth, grafts were examined by light- and electron microscopy. In all transplants, individual endocrine cells (A, B, D, PP) and islet structure were identical to those of normal embryos of comparable age. The exocrine portion also appeared normal in implants from embryos younger than seven days. In grafts from older donors, however, normal acini and ducts were replaced by dilated, irregularly shaped tubules from which new islets appeared to develop. These results suggest that transplantation causes structural modification of exocrine tissue, which may reflect its initial functional capabilities. These observations are compared with similar structural alterations that occur following experimental obstruction of ducts and in human pancreatic pathology.

Effects of two antecedent conditions on vocalization frequency of severely retarded children.

Rather than concentrating exclusively on consequences in early vocal instruction, the manipulation of antecedent conditions has been recommended. Few empirical data have been collected on the effect of different antecedent events. Therefore, a series of three experiments was conducted with three severely retarded children to investigate the vocalization-producing potential of two antecedent conditions: adult talk, a commonly cited antecedent, and adult silence. The conditions were evaluated using a modified alternating treatments design. In Experiment 1, 5 min of continuous adult talk was alternated with 5 min of adult silence; the results indicated that adult silence occasioned more vocalizations than did adult talk. In Experiment 2, a mixed (alternating 30-s periods of silence and talk) condition was compared to a silence condition; again the results indicated a higher frequency of vocalization during the silence condition. In Experiment 3, a modified talk (a question or comment presented every 10 s) condition was compared to a silence condition; the results indicated that the two conditions occasioned similar vocalization frequencies for two children, and the questions/comments condition occasioned more vocalizations for one child. In addition to studying optimal conditions for adult talk, the present investigation provides a methodology for deriving empirical data on the effects of differing antecedent conditions on vocalization frequencies.