Theory of uncertainty in illness in patients with cancer of unknown primary origin: Structure providers as antecedents of uncertainty in a population of cancer patients with an unknown primary diagnosis

Uncertainty has been found to be a major component of the cancer experience and can dramatically affect psychosocial adaptation and outcomes of a patient's disease state (McCormick, 2002). Patients with a diagnosis of Carcinoma of Unknown Primary (CUP) may experience higher levels of uncertainty due to the unpredictability of current and future symptoms, limited treatment options and an undetermined life expectancy. To date, only one study has touched upon uncertainty and its' effects on those with CUP but no information exists concerning the effects of uncertainty regarding diagnosis and treatment on the distress level and psychosocial adjustment of this population (Parker & Lenzi, 2003). ^ Mishel's Uncertainty in Illness Theory (1984) proposes that uncertainty is preceded by three variables, one of which being Structure Providers. Structure Providers include credible authority, the degree of trust and confidence the patient has with their doctor, education and social support. It was the goal of this study to examine the relationship between uncertainty and Structure Providers to support the following hypotheses: (1) There will be a negative association between credible authority and uncertainty, (2) There will be a negative association between education level and uncertainty, and (3) There will be a negative association between social support and uncertainty. ^ This cross-sectional analysis utilized data from 219 patients following their initial consultation with their oncologist. Data included the Mishel Uncertainty in Illness Scale (MUIS) which was used to determine patients' uncertainty levels, the Medical Outcomes Study-Social Support Scale (MOSS-SSS) to assess patients, levels of social support, the Patient Satisfaction Questionnaire (PSQ-18) and the Cancer Diagnostic Interview Scale (CDIS) to measure credible authority and general demographic information to assess age, education, marital status and ethnicity. ^ In this study we found that uncertainty levels were generally higher in this sample as compared to other types of cancer populations. And while our results seemed to support most of our hypothesis, we were only able to show significant associations between two. The analyses indicated that credible authority measured by both the CDIS and the PSQ was a significant predictor of uncertainty as was social support measured by the MOSS-SS. Education has shown to have an inconsistent pattern of effect in relation to uncertainty and in the current study there was not enough data to significantly support our hypothesis. ^ The results of this study generally support Mishel's Theory of Uncertainty in Illness and highlight the importance of taking into consideration patients, psychosocial factors as well as employing proper communication practices between physicians and their patients.^

The origin and development of hyperammonemia following exposure to hydrazine in rabbits

Hydrazine $\rm (N\sb2H\sb4),$ an important liquid propellant and derivative chemical for pharmaceuticals and pesticides, produces coma and convulsions sometimes resulting in death. Hyperammonia was found in rabbits exposed to 18 mg/Kg of hydrazine. Results of Part One of this study of rabbits emphasize the importance of acute ammonia toxicity during the first three hours following exposure to hydrazine. At no time during this post exposure period did a significant reduction of hydrazine to ammonia occur. Therefore, the elevated blood ammonia was apparently secondary to the effects of hydrazine on metabolic pathways. Further, the results support the theory of competitive inhibition of ammonia by hydrazine and emphasize the need to monitor plasma ammonia following toxic exposure to hydrazine.^ In Part Two, urea, ammonia, CO$\sb2,$ pH, glucose, sodium, potassium, chloride and creatinine were measured for up to 4 hours following injection of 18 mg/Kg of hydrazine in each of two groups of five rabbits. One group received normal saline and the other group received 5% dextrose and water/normal saline. Hyperammonemia, minimal metabolic acidosis and hyperglycemia without increased urea were found in the rabbits receiving normal saline intravenous infusion and hydrazine injection. Hence, hypoglycemia does not appear to play a role in the development of hyperammonemia. A significant difference in the elevated ammonia levels between the two groups receiving dextrose and water/normal saline and normal saline at 1 hour occurred. There was no significant difference in the elevated ammonia levels seen between the two groups receiving dextrose and water/normal saline and normal saline at 2.5 and 4 hours. Thus at 1 hour the group receiving dextrose was able to utilize excess glucose to detoxify ammonia, while at 2.5 and 4 hours there was no significant difference in the two groups' ability to detoxify ammonia.^ Findings support the theory that hydrazine inhibits the formation of urea resulting in hyperammonemia. Results suggest that hydrazine at 18 mg/Kg, a known hypoglycemic agent, causes serious hyperammonemia without increasing urea production during hyperglycemia. These experiments support a unified theory for the toxic mechanism of action of hydrazine, i.e., the intermediary metabolic effects of hydrazine are brought about by the formation of hydrazones which encumber ATP synthesis and vitamin B$\sb6$ enzymatic reactions. ^