The activities of brain dopamine-β-hydroxylase and catechol-O-methyl transferase in schizophrenics and controls

It has been suggested that deterioration of central noradrenergic pathways may be responsible for the production of certain schizophrenic symptoms, and that such a degeneration might be reflected in lowered dopamine--hydroxylase (DBH) activity in the brains of schizophrenics. The present study revealed that in rats lowered DBH activity was a sensitive index of noradrenergic degeneration. In the postmortem brains of 12 controls and 12 schizophrenics, however, no significant difference in DBH activity between controls and schizophrenics was found. DBH activity was relatively unstable postmortem and adversely affected by neuroleptic drugs, and these factors may have contributed to the previous finding of lowered DBH activity in the brains of schizophrenics. The activity of catechol-O-methyl transferase, which has also been previously reported as low in the brains of schizophrenics, was found to be no different in the controls of the present study.     

Avoidance behavior in rats selectively bred for differential alcohol sensitivity

Most affected (MA) and least affected (LA) rats, bred for extremes in motor impairment following an alcohol challenge, differed in their performance on two active avoidance tasks. In two-way shuttle avoidance, the MA line performed significantly better than the LA group, both in terms of response latencies and percent avoidances. The inferior performance of the LA line persisted across the 15 days of testing, and appeared to reflect an difference in asymptotic performance levels. In one-way avoidance, the MA line showed significantly better acquisition than the LA group; however, this difference dissipated across the 3 days of training. When tested following alcohol administration in either the one-or two-way avoidance paradigm, the MA rats showed a greater performance deficit than LA animals. These data were interpreted as indicating the generality of alcoholrelated line differences to a situation motivated by aversive consequences. Moreover, the line difference in avoidance acquisition represents one of the few non-drug-related phenotypic differences that have been found in these lines. In previous generations, disparate base rates of wheel running have been reported, and the data presented here confirm and extend this finding.     

A century of editors

They are unalike and far apart, these 13 past editors of The Journal. Between Nathan S. Davis's first issue and William R. Barclay's retirement, there was almost a century of change in medicine, society, the American Medical Association, prose style, and editorial needs. During these years, the editors ranged from the brilliant organizers John B. Hamilton and George H. Simmons to the diligent John H. Hollister and the devoted Johnson F. Hammond. There were editors with the hot determination of James C. Culbertson, John H. Talbott, and Robert H. Moser, and there were those with the cool precision of Austin Smith and Hugh H. Hussey. They varied from Morris Fishbein, who wrote and spoke "with the grade of an eagle in its unhindered soar," to Truman W. Miller, who wrote scarcely a word. Here, briefly, they are together.     

Observer variation in detecting the radiologic features associated with bronchiolitis

Chest radiographs are commonly obtained to assess children for bronchiolitis, both to corroborate the diagnosis and to exclude other diagnostic possibilities. Their utility in this setting has not previously been examined. Using a blinded, randomized study design, we examined the interobserver and intraobserver variation in the detection of the radiologic features of bronchiolitis from the chest radiograph using "weighted kappa" statistics. This observer variation was compared with that found by other authors for other diagnoses. We also determined the reported presence of these radiologic features in radiographs from patients with bronchiolitis as compared with normal controls. Our study showed acceptable interobserver (kappa = 0.40-0.66) and intraobserver agreement (kappa = 0.50-0.78) on the radiologic features of bronchiolitis relative to other diagnoses. We demonstrated a higher reported presence of these accepted radiologic features in patients with bronchiolitis as compared to controls. Although kappa statistics are widely used in studies of observer variation, "weighted kappa" has received little attention in the radiologic literature. This statistical analysis allows observers to equivocate on the presence or absence of a feature and therefore allows the format of observer variation studies to simulate more closely the normal clinical setting.     

U.S. initiatives and approaches for outcomes and effectiveness research

This paper provides an overview of the new Federal initiative underway to promote research in outcomes and effectiveness of services provided in the U.S. It discusses the factors that stimulated the U.S. government ot undertake this initiative and summarizes past research and current efforts to advance knowledge about utilization and outcomes of care. A focal point of this initiative is to take advantage of information in large, administrative data bases to monitor the use, costs and outcomes of medical services. As part of this initiative, the Federal Government for the first time assembled detailed data, by geographic area and by demographic groups, on the hospitalization, mortality and rehospitalization experience of the entire Medicare population. The paper describes this project and illustrates uses of these data.     

Myoclonus and the electroencephalogram, a review.

Myoclonus is a phenomenon which cuts through a considerable number of neurological conditions. It occurs in a variety of epileptic conditions (Primary generalized epilepsy, hypsarrhythmia, Lennox-Gastaut syndrome, also known as "petit mal variant"), in inborn errors of metabolism (Tay-Sachs disease, forms of ceroid lipofuscinosis), in neurobiochemically still poorly understood forms of degenerative processes such as Essential hereditary myoclonus epilepsy (Lafora-Unverricht-Lundborg), in benign heredo-degenerative disorders (Hartung's syndrome), in CNS infections (SSPE, Jakob-Creutzfeldt disease), in metabolic encephalopathies (renal failure, hypoglycemia), in CNS poisoning, in acute cerebral anoxia and in post-anoxic states. The EEG plays a crucial role in the differential diagnosis of these conditions by the demonstration of a) presence or absence of typical inter-ictal abnormalities, and b) various correlates of the myoclonic ictal event.     

The effect of neuromuscular blockade on pedicle screw stimulation thresholds

STUDY DESIGN: Nerve root stimulation thresholds were studied relative to the level of neuromuscular blockade in patients undergoing lumbar decompression surgery. OBJECTIVES: To determine what levels of intraoperative neuromuscular blockade can be used during pedicle screw stimulation. BACKGROUND DATA: Previous studies of intraoperative pedicle screw stimulation thresholds have failed to determine the effect of neuromuscular blockade on the stimulation threshold. METHODS: Twenty-one roots in 10 patients undergoing lumbar decompression surgery were studied at different levels of neuromuscular blockade. Ninety-five nerve root thresholds were determined relative to level of blockade. RESULTS: Neuromuscular blockade below 80% provides nerve root thresholds similar to thresholds without blockade. CONCLUSIONS: Neuromuscular blockade should be less than 80% when using pedicle screw electrical stimulation testing.