Descriptive and comparative analysis of geometrical properties of neuronal tree structures

The morphology of neurons is an important factor for the identification and the study of the changes that occur in the nervous system during development or as a result of disease or an experimental treatment. A number of methods to describe the topological aspects of neuronal morphology is discussed. Furthermore it is illustrated how different groups of neurons can be compared. Although both topological and metrical aspects are considered in the comparative sections emphasis is put on counting instead of measuring. Our intention is to present quick and easy methods that are applicable to camera lucida drawings.     

Factors relating to the sensory acuity of limbs with peripheral vascular insufficiency

We examined several possible causes for the high incidence of poor sensory acuity in the limbs of 176 patients with moderate to severe peripheral vascular insufficiency. We investigated the relationships of diabetes, alcoholism, and smoking, as well as the severity of peripheral vascular disease, to the integrity of basic sensory modalities such as two-point discrimination and perception of light touch. The presence or absence of diabetes exerted the strongest effect on peripheral sensation. In patients who did not have diabetes, sensation in the limbs was most strongly affected by whether the patient was an alcoholic. Smoking did not have a significant effect on limb sensation. Among nondiabetic, nonalcoholic patients, there was a weak residual effect related to the severity of the peripheral vascular insufficiency. Even among these patients, however, systemic factors predominated in determining the loss of sensation. We also examined the extent to which loss of sensation might be related to the development of ulcers. Among patients who were not diabetic, there was a highly significant relationship between loss of sensation and the presence of limb ulceration. Surprisingly, however, there was no discernable relationship between the presence of ulcers in diabetic patients and the degree of loss of peripheral sensation. This result suggests that a large percentage of ulcers seen in diabetic patients are not of neurogenic origin.     

Work therapy and return to work

In summary, data were selected for 1 year on patients treated in the Work Tolerance Program at the Hand Rehabilitation Center in Philadelphia. The type of information obtained has been used to obtain a profile of the patient population in the Work Tolerance Program. Statistical analysis was used, not only to formulate patient demographics, but also to evaluate the length of treatment of patients in the Work Tolerance Program. This period averaged 6 weeks. The statistical analysis also revealed there was significant interaction between the type of injury and the patient's diagnosis, and the rate of return to work. The patients with injuries to bone and nerve required longer periods of treatment until they returned to work than did patients with injuries to soft tissue or combination injuries. Our statistical analysis revealed that in 1982, 75 per cent of the patients in the Work Tolerance Program returned to work to regular or modified jobs. The length of time from injury to return to work was 63 per cent longer for patients with Workers' Compensation coverage than for patients with private insurance coverage. Because the statistical analysis that 60 per cent of the patients treated in the Work Tolerance Program were Workers' Compensation insured, and 80 per cent of the patients treated in the Work Tolerance Program were secondarily referred, it should be recognized that all patients with severe hand injuries would benefit from an immediate referral to a Hand Rehabilitation Center of excellence to facilitate their therapeutic management and expedite their recovery from time of injury to return to work. This study was restricted to the analysis of length of treatment and rate of return to work. Future studies should study the effect of early referral and the application of specific treatments.     

Using sobriety tests to increase awareness of alcohol impairment

There is a need to investigate methods by which drinkers canbe made aware of their level of alcohol impairment prior todriving. In the current research, 195 students at various bloodalcohol concentration (BAC) levels participated in an evaluationof three simple sobriety tests: a ruler drop/reaction time task,a balance test and a verbal task. Although self-reported measuresof impairment were the best predictors of BAC, both the rulerdrop and body balance tests accounted for significant portionsof BAC variance. These tasks were also perceived by the studentsas reflecting substantial driving ability. Unfortunately, asBAC increased, poor test performance was less likely to resultin a decision not to drive. These results are discussed in termsof the need to continue studying ways to educate drinkers abouttheir level of alcohol impairment so that they can make informeddrinking/driving decisions.     

High power, low frequency components of cardiac, renal, splenic and vertebral sympathetic nerve activities are uniformly reduced by spinal cord transection

Others have reported that spinal cord transection non-uniformly affects the activities of the cardiac, renal and splenic nerves. We were unable to confirm this finding while recording the wide band (1-1000 Hz) discharges of these sympathetic nerves in baroreceptor-denervated, chloralose-anesthetized cats. Most of the power in nerve discharges was below 6 Hz. There was high coherence between the low frequency discharges of different nerves, and power below 15 Hz was essentially eliminated by spinal transection. Evidence is presented that the disparities between this and past studies are, in part, due to the use of a 30-Hz high-pass filter in the earlier studies.     

Carnitine deficiency associated with ornithine transcarbamylase deficiency

An infant with X-linked recessive ornithine transcarbamylase deficiency is described who also had severe deficiency of plasma and liver carnitine during normoammonemic periods. Treatment with L-carnitine (100 mg/kg/day) for 12 months decreased the frequency of hospitalizations for hyperammonemia, although it did not alter his neurologic status. This report demonstrates that persistent carnitine deficiency may be present in patients with ornithine transcarbamylase deficiency even when plasma ammonia is normal. Carnitine evaluation and supplementation may be important in the treatment of patients with this metabolic disorder.     

Improving organizational performance. Administrative nurse specialist

The Executive Nurse Council was challenged to develop strategies designed to empower staff nurses and nurse managers and create opportunities for professional growth. Implementation of these strategies resulted in broad-sweeping changes in roles and functions of groups and individuals at all levels of the organization. The authors describe a support role, administrative nurse specialist, designed to support staff and managers striving to actualize changes in a shared governance framework.