No abstract

We have investigated the effects of prolonged systemic injections of nerve growth factor (NGF) and its antiserum on the survival and morphology of sympathetic ganglion cells in adult mice. Using intracellular injections of Lucifer yellow in lightly fixed superior cervical ganglia, we show that total dendritic lengths of ganglion cells are increased 29% after 2 weeks of NGF treatment. The increased dendritic length is characterized by increased branching within the dendritic arborization and not by the addition of new primary dendrites. In addition, cell soma cross-sectional area was increased 45%. Conversely, administration of NGF antiserum for 1 month decreased total dendritic length by 33%, decreased ganglion cell body size by 26%, and reduced the number of neurons in the ganglion by 25%. After 3 months of NGF antiserum treatment, the number of neurons in the ganglion was reduced a total of 41%. NGF antiserum treatment for 1 month in aged (22 months old) animals reduced ganglion cell body size by 21% and cell number by 22%, decreases that are comparable to those observed in young adult animals. Our results indicate that, even in maturity, sympathetic ganglion cells remain dependent on NGF for survival and maintenance of dendritic geometry, and this dependence continues into old age.

No abstract

The reaction of dorsal root ganglia (DRG) neurons to axotomy and its alteration by locally supplied nerve growth factor (NGF) were examined in adult rats. Surgically implanted silicone chambers attached to the severed tip of the sciatic nerve acted as reservoirs capable of providing prolonged access of NGF to the site of injury. The time course of NGF activity within the chambers was determined by using the standard NGF chick DRG bioassay. The fluid from chambers filled with the NGF-saline solution maintained NGF activity for periods up to 6 weeks after implantation. By 9 weeks, however, the fluid from most chambers failed to show any NGF activity in the bioassay. Experiments were designed to compare the response in adult rats to injury of DRG neurons receiving chambers filled with either NGF-saline or with only saline. The total neuronal counts in the lumbar fourth and fifth DRG at 3 weeks and 6 weeks after sciatic nerve section showed 22% and 16% cell death, respectively, in those injured neurons receiving saline-filled chamber implants. The animals that received chamber implants which contained an NGF-saline solution showed no cell death in the ipsilateral DRG at either 3 or 6 weeks after injury. Morphometric analysis of injured DRG neurons showed evidence of atrophy in the injured neurons which did not receive NGF. The degree of atrophy among all cell sizes was significantly decreased in those injured neurons receiving NGF. At 3 weeks after section the mean volume of injured neurons not treated with NGF was decreased by 28% as compared with only a 13% decrease in neurons treated with NGF.(ABSTRACT TRUNCATED AT 250 WORDS)

Dimensions of nurse caring were elicited through nurse and patient responses on the revised Caring Behaviors Inventory (CBI), a 43-item instrument. Subjects included 278 nurses and 263 patients and former patients. An exploratory factor analysis using the principal components method with varimax rotation was used to identify CBI dimensions; a five factor solution resulted. The five dimensions of nurse caring were respectful deference to others, assurance of human presence, positive connectedness, professional knowledge and skill, and attentiveness to the other's experience.