Effects of low-dose isoflurane on saccadic eye movement generation

The effects of 0.15% quasi-steady-state end-tidal isoflurane on two saccadic eye-movement tests were examined in five volunteers using a newly devised computer-based recording system. The tests were saccadic latency and a countermanding task, the latter being an indicator of the highest levels of conscious performance. A moving light-emitting diode target was displayed on a screen and in the saccadic-latency task the latency of eye movement to the target was measured. In all five subjects the latency increased with anaesthetic by an amount which varied from 8 to 45 ms. This result was significantly different (p < 0.05) from subjects without anaesthetic. In the countermanding task, the subject had to voluntarily inhibit movement to the target. Again anaesthetic increased the latency of response, which varied from 6 to 33 ms. This result was significantly different (p < 0.05) from subjects without anaesthetic. In these studies it appeared that two tasks, one a simple latency test and the other, the countermanding task, requiring higher cortical processing were equally impaired at subanaesthetic concentrations of isoflurane.     

Severity of illness and profitability: a patient level analysis.

Crafting a payment mechanism for hospitals that provides for the legitimate operating needs of efficient institutions is an enduring health policy dilemma. The Prospective Payment System used by Medicare and some other payers in the US has been criticized for not adjusting for differences in severity of illness within diagnosis-related groups (DRGs). Previous studies have examined the relationship between profitability and severity of illness at the hospital level. This study examines the relationships between severity of illness and cost, revenue, and profit at the patient level. Two measures of severity (disease stage and number of unrelated diseases) were significant predictors of cost per case, and often had better predictive power than DRGs. In most instances, payers did not compensate adequately for severity so that higher values for the severity variables resulted in financial losses for the hospital.     

Aerosol deposition modeling using ACSL

An aerosol deposition model has been written for inclusion into physiologically based pharmacokinetic (PBPK) models, allowing PBPK model based risk assessments to be performed for aerosolized materials. Previously, PBPK models could only treat inhaled gases and vapors. The deposition model employs a semi-empirical equation to describe extrathoracic deposition and employs data concerning the geometry of the thoracic conducting airways as well as that of the gas exchange regions of the lung to compute the deposited aerosol mass based on aerosol diffusion, sedimentation, and impaction. Provisions are made to allow calculations for polydisperse aerosols whose size distribution and mass vary with time. Variations in the model subject's respiration can be accommodated through selection of respiratory parameters at model startup as well as through consideration of carbon dioxide stimulation of respiration. The model is compared with other similar calculations and experimental data to validate the calculations. An example model application is presented in the form of a comparison of two inhalation atmospheres, one from an inhalation toxicity study and one from a similar atmosphere produced for fire extinguishing agent testing.     

Long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency—diagnosis,plasma carnitine fractions and management in a further patient

Long-chain 3-hydroxyacyl-coenzyme A dehydrogenase (LCHAD), the third enzyme of the mitochondrial -oxidation pathway, carries out the dehydrogenation of 3-hydroxyacyl-CoA compounds of 12–18 carbon length. To date only nine cases of LCHAD deficiency have been documented. We report a further patient who as a neonate developed non-specific gastro-intestinal symptoms and at 5 months of age cardiomyopathy, recurrent hypoketotic hypoglycaemia and gross alterations of plasma carnitine fractions. Dietary management with medium chain triglycerides led rapidly to clinical improvement. There was a close correlation between the clinical condition, plasma carnitine fractions and cardiac function. At 2 years of age she is developing normally.     

Residual radiation damage in the mouse foot after exposure to heavy particles

Mice receiving a first treatment with graded doses of various heavy charged particles (protons and heavy ions) to one of their hind legs were re-exposed to a fixed dose of x rays eight months later to study the "memory" of residual damage from the first treatment. No significant memory of the first radiation exposure was observed for acute skin rection. However, there is an indication of memory for foot deformity. The results do not seem to indicate any significant differences in memory after exposure to 60Co gamma rays compared with protons or heavy ions, if biological effectiveness of the doses is taken into consideration.     

Early intervention, time-limited, targeted pharmacotherapy of schizophrenia

A growing appreciation of the risks of long-term, continuous neuroleptic use in the aftercare of schizophrenic patients has led to a search for alternative strategies. The authors report their experiences with the clinical strategy of "targeted" medication, in which patients are followed drug free until prodromal signs of impending relapse appear. Medication is then initiated to abort the impending episode and discontinued when patients restabilize clinically. Preliminary experience suggests that control of schizophrenic symptomatology comparable to that obtained with maintenance drugs can be achieved with a marked reduction in medication use when the targeted strategy is applied in the context of a broad-based program of psychosocial intervention based on a comprehensive medical model.     

Atelosteogenesis I and boomerang dysplasia: a question of nosology

We report a patient whose clinical, radiologic and histopathologic findings are compatible with severe atelosteogenesis (AT-I). The patient is compared with previously reported cases of AT-I, as well as with patients reported as having "boomerang" dysplasia. We conclude that it is reasonable to consider AT-I and boomerang dysplasia as part of a spectrum, probably reflecting a common etiology. More and detailed clinical, radiologic and histopathologic reports are needed to further clarify the relationship of AT-II and AT-III in this family of skeletal dysplasias.     

The available niacin values of foods for rats and their relation to analytical values

A bioassay for niacin was developed using weight gain or "gain/food eaten" of young rats as the response measure. The best basal diet contained casein 70 and gelatin 65.5 g/kg together with supplementary tryptophan to a total of 0.97 g/kg and other amino acids to meet requirements. After a 4-day depletion period, rats gained ca. 1 g/day over the next 20 days on the basal diet alone, or ca. 7 g/day and 12 mg/kg added nicotinic acid. Test foods were added at two levels with diets adjusted to keep constant amino acid composition. The results were compared with chemical analyses for total niacin (i.e., in extracts prepared from samples digested with alkali) and for free niacin (using extracts made at neutral pH) with separation of nicotinic acid and nicotinamide on thin-layer chromatograms or Sephadex columns. Eight samples of mature cooked cereals, with their niacin largely in bound forms, gave rat assay values equivalent to ca. 35% of their total niacin content. Alkali-cooked tortilas, steamed sweet corn, beans and liver, with their niacin all in free form, gave assay values close to their total niacin content. Baked potatoes and peanut flour were intermediate in both respects.