The manpower crisis facing radiation oncology

Data from several sources document that the number of radiation oncologists being trained is substantially above the number projected as recently as 1983. This paper addresses the manpower crisis facing radiation oncology and includes information on the supply of and need for specialists, as well as possible courses of action given current circumstances.     

Elevated choline levels in brain. A non-cholinergic component of organophosphate toxicity

The role of cholinergic and non-cholinergic mechanisms in mediating organophosphate cholinesterase (ChE) inhibitor-induced elevations in choline levels in brain was investigated. The nerve agents soman and sarin, when administered to rats at doses greater than the IC50 for acetylChE inhibition, significantly increased the levels of choline and acetylcholine in both the striatum and hippocampus. The elevation in choline levels was evident 1 hr after injection with a maximal increase at 2 hr. Levels of choline returned to control by 4 hr. In contrast, the administration of diisopropyl phosphorofluoridate at doses greater than the IC50 for acetylChE inhibition increased the levels of acetylcholine, but did not alter the concentration of choline during the first 3 hr. Between 4 and 24 hr after injection, however, a significant decrease in choline levels was apparent. This effect persisted for 48 hr. When rats were pretreated with the anticonvulsant diazepam, the sarin- and soman-induced increases in choline levels were attenuated significantly. Results indicate that the organophosphates differentially alter the levels of choline in brain and suggest that the effect of soman and sarin to elevate choline levels is not a reflection of excessive cholinergic activity, but rather may be a consequence of the excitotoxic actions of these compounds.     

Evolving techniques in the treatment of macular detachment caused by optic nerve pits

Fourteen patients with macular detachments caused by optic nerve pits were treated for progressive visual loss, cystoid macular changes, or atrophy of the macular retinal pigment epithelium. Photocoagulation of the temporal disc border alone was unsuccessful in two cases but promptly reattached the macula of two patients immobilized after laser surgery. Vitrectomy and gas tamponade improved vision and flattened the macula of three patients over various periods. The detachment recurred in one patient. Prompt and sustained macular reattachment with improved vision was noted after photocoagulation, vitrectomy, and gas tamponade in eight patients, although four required second operations. The prompt reattachment and visual recovery noted in these eight patients surpasses the reported 25% rate of spontaneous resolution.     

Phenylalanine kinetics are associated with tardive dyskinesia in men but not in women

Rationale: An association between tardive dyskinesia (TD) and severely impaired metabolism of the large neutral amino acid (LNAA), phenylalanine (Phe) was defined in a group of mentally retarded patients. Subsequently, an altered kinetics of Phe was associated with TD in men with schizophrenia based on plasma analyses subsequent to the ingestion of a protein meal. Methods: In the present study, a standardized oral challenge of pure Phe (100 mg/kg in 170 ml orange juice) was administered to psychiatric patients of both sexes (n = 312), with and without TD after an overnight fast. Plasma LNAA levels were assayed both fasting and 2 h subsequent to the ingestion of the challenge. The extent of the increase in plasma Phe levels 2 h following a standardized challenge is determined by the sum of the kinetic processes of plasma absorption, tissue distribution, metabolism and elimination. Results: The study hypothesis, that TD would be associated with significantly higher post-challenge plasma Phe indices of an absolute plasma Phe level and plasma Phe/LNAA ratio (a brain availability measure), was verified for the study men (n = 209), but not for the study women (n = 103). Conclusions: The demonstrated altered kinetics of Phe in men with TD indicates a greater availability of Phe to the brain in these men. We suggest that the disorder may be related to the effects of this greater availability. Such effects could be the direct neurotoxic effects of Phe and its metabolites and/or the modulating effects of these compounds on the synthesis of the monoamine neurotransmitters. The fact that TD (Yes/No) group differences in post-challenge plasma Phe indices were not seen for the study women suggests the possibility of a sex difference in the biology of TD that we propose may be reflective of the young age of the study sample. Received: 28 January 1998/Final version: 14 December 1998     

Preventing and treating childhood overweight and obesity in children up to 5 years old: A systematic review by intervention setting

The prevalence of childhood obesity is increasing worldwide with long‐term health consequences. Effective strategies to stem the rising childhood obesity rates are needed but systematic reviews of interventions have reported inconsistent effects. Evaluation of interventions could provide more practically relevant information when considered in the context of the setting in which the intervention was delivered. This systematic review has evaluated diet and physical activity interventions aimed at reducing obesity in children, from birth to 5 years old, by intervention setting. A systematic review of the literature, consistent with Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines, was performed. Three electronic databases were searched from 2010 up to December 2020 for randomised controlled trials aiming to prevent or treat childhood obesity in children up to 5 years old. The studies were stratified according to the setting in which the intervention was conducted. Twenty‐eight studies were identified and included interventions in childcare/school (n = 11), home (n = 5), community (n = 5), hospital (n = 4), e‐health (n = 2) and mixed (n = 1) settings. Thirteen (46%) interventions led to improvements in childhood obesity measures, including body mass index z‐score and body fat percentage, 12 of which included both parental/family‐based interventions in conjunction with modifying the child''s diet and physical activity behaviours. Home‐based interventions were identified as the most effective setting as four out of five studies reported significant changes in the child''s weight outcomes. Interventions conducted in the home setting and those which included parents/families were effective in preventing childhood obesity. These findings should be considered when developing optimal strategies for the prevention of childhood obesity.     

Visual hallucinations in sensory deprivation

Summary The case of a 72-year-old blind woman with visual hallucinations of unusually long duration was reported. The related literature was reviewed, and the mechanism, or pathogenesis, was discussed in the light of the psychoanalytic theory of hallucinations.From the Neuropsychiatric Institute of the University of California at Los Angeles.     

Clinical syndrome of potassium intoxication

Potassium intoxication in man results in widespread impairment of neuromuscular function. Potassium produces a characteristic sequence of electrocardiographic changes, impaired contraction of the heart recognizable by auscultation, and final arrest of the heart in diastole. Flaccid paralysis may also be present, involving the extremities and to a lesser degree the trunk but sparing the cranial nerves for the most part.Two cases with elevation of serum potassium manifesting this clinical syndrome are described. Following administration of sodium chloride, both paralysis and electrocardiographic changes reverted toward normal.The genesis of potassium intoxication, the typical sequence of electrocardiographic changes, the nature of the paralysis and the therapeutic approach are discussed.     

An assessment of the construct validity of the CHU9D in the Australian adolescent general population

Purpose  

To assess the construct validity of the CHU9D in an adolescent general population sample. The CHU9D is a new generic preference-based measure of health-related quality of life developed specifically for application in the economic evaluation of health care treatments and interventions for young people.