Age-dependent decrease in the negative inotropic effect of carbachol on isolated human right atrium

On isolated, electrically driven human right atrial strips, carbachol (10(-8)-10(-3) M) concentration-dependently decreased force of contraction prestimulated with 1 microM forskolin; maximal negative inotropic effects of carbachol (10(-6)-3 x 10(-6) M), however, were in atria from patients aged < 25 years (mean age: 16.8 +/- 2.0 years, n = 9) significantly larger than in patients aged 50-69 years (mean age: 62.5 +/- 0.7 years, n = 33) and were further decreased in patients aged > 70 years (mean age: 73.8 +/- 0.6 years, n = 11). We conclude that, in human right atrium, the recently described age-dependent decrease in muscarinic M2 receptor density is accompanied by a decrease in negative inotropic effects.     

A method of predicting failure or life for stochastic systems by using autoregressive models

This paper discusses on-line detection and prediction problems of the failure or life of stochastic systems by using autoregression (AR) models. We regard the change of the equipment from an ordinary state to failure as a variation of the characteristics of a time aeries signal. An AR model is fitted to the time aeries signal and the change is detected by variations of the model. Using four types of performance index of the variations, we detect the failure of a cutting tool of a lathe and predict the width of flank wear.     

The similarity and differences in the circadian fluctuations in the central nervous system reaction of animals to acute gamma radiation and alcohol exposures

24-h fluctuations in the response of CNS (occurrence of the complex of neurological disorders) were studied in white rat males which were exposed to gamma radiation (Co-50, 62.5 Gy, craniocaudally) or injected alcohol (2.25 g/kg, 15% solution, i.p.). After alcohol administration, the above fluctuations were at first almost similar to those in response to the radiation. Later, the curve of the CNS sensitivity to alcohol was leveling, rhythm phases shifted without the rhythm inversion. Neurological symptoms induced by alcohol and radiation were very much alike suggesting the existence of common mechanisms of nonspecific regulation evident early after exposure to these two factors.     

Binding of phosphoorganic cholinesterase inhibitors in rat brain tissue

Hydrophobity (coefficient in distribution in the hexane water system) and the content of cholinesterase organophosphorous inhibitors (OPI) of the structure Ro (CH3) P (O) SC2H4 SC2H5 were studied in the rat brain. When the O-alkyl radical is increased hydrophobity rises and the relative content of free OPI in the brain extracted by chloroform decreases. With an increase in R from the ethyl to butyl one the ability to the additional inhibition of the brain own cholinesterase lowers due to incubation of homogenate at 37 degrees C, that evidences for an essential drop in the studied series of the free OPI fraction relative to the free OPI extracted by chloroform.     

Elevated alpha-fetoprotein secondary to Hodgkin's lymphoma

We describe the case of a 26-year-old man with an elevated level of alpha-fetoprotein who had no evidence of intragonadal or extragonadal germ cell tumor. The patient was found to have Hodgkin's lymphoma within an anterior mediastinal mass. We review the significance of elevated alpha-fetoprotein levels and discuss the clinical relevance of this unusual presentation of a possible primary Hodgkin's lymphoma.     

Laboratory support of the State Sanitary and Epidemiologic Service under the new socioeconomic conditions

The results of experimental investigations to evaluate the adverse effects of metal-containing industrial waste on warm-blooded animals are presented. Acute experiments assessing the toxicity of industrial waste were not shown to be informative. Long-term exposure to different industrial wastes was found to have varying toxicity at the cell, organ, and body levels.