Effect of dehydration on stimulation of ADH release by heterologous renin infusions in conscious dogs

The effect of acute administration of morphine on cerebral excitability was investigated in rats with two convulsant drugs: flurothyl (hexafluorodiethyl ether) and pentylenetetrazol (PTZ). In the flurothyl study, adult male Sprague-Dawley (S-D) rats were injected subcutaneously with morphine sulfate in doses ranging from 0.5 to 256 mg/kg. At 15, 30, 60 and 120 minutes after morphine injection, flurothyl was administered by inhalation and the seizure thresholds were determined. In the PTZ study, 64 mg/kg of morphine sulfate were injected subcutaneously into both S-D and CFN (Wistar-derived) rats. Thresholds to PTZ seizures were measured after administering the convulsant either by the intraperitoneal or intravenous route. The data revealed an anticonvulsant action of morphine on both flurothyl and PTZ. Peak time for this effect on flurothyl seizures was 30 minutes after subcutaneous administration of the opiate, with the maximal anticonvulsant activity appearing at the 64-mg/kg dose. The increase in seizure threshold in S-D rats at this dose was 36% with flurothyl, 94% with intravenous PTZ and 352% with i.p. PTZ. Morphine had a less dramatic influence on raising the latter seizure threshold in the CFN than in the S-D strain. The graded dose-related anticonvulsant action is independent of the respiratory depression associated with morphine administration and appears to be a reflection of an altered central nervous system excitability produced by the narcotic in rats.     

Net Present Value from Complex Cash Flow Streams by Simulation

In models previously developed for the purpose of obtaining net present value from a stream of discounted cash flow increments, it is difficult to introduce complex economic, market and behavioral considerations without rendering the problem intractable computationally. Monte Carlo simulation with a digital computer, particularly in a simulation language, offers an attractive and feasible solution to the flexibility problem. This article illustrates the use of simulation techniques to find the net present value of a proposed project, together with its statistical distribution, when three types of phenomena are incorporated in the model: (1) long-term exponential market growth, (2) “non-instantaneous” response by the firm to price/elasticity fluctuations, and (3) imposition of arbitrary, yet reasonable, constraints on product output.     

Dihydrofolate reductase and thymidylate synthetase activities in the liver of rabbit foetuses during the haemapoietic period

Dihydrofolate reductase activity did not change with variations of mitotic rate in foetal rabbit haemopoietic tissue, whereas the activity of thymidylate synthetase declined with decrease in cell divisions. Both the activities were normal in the brachydactylia strain, in which a failure in folate metabolism was previously assumed.     

Comparison of mortality of patients with heart attacks admitted to a coronary care unit and an ordinary medical ward

During a 32-month period 2047 patients suspected of having heart attacks were admitted to hospital and were followed up prospectively. Out of 1480 eventually found to have definite or probable myocardial infarction, 483 had initially been admitted to an ordinary medical ward because of the shortage of coronary care unit (CCU) beds. More patients aged over 65 had been admitted to a ward than to a CCU, and more patients aged 65 or less had been admitted initially to a CCU. Within each age group, however, patients admitted initially to a CCU were clinically similar to those admitted initially to a ward. There was a higher proportion of successful resuscitations among patients admitted to a CCU, but there was no significant difference in mortality in either age group between patients admitted to a CCU and a ward.     

Fiberoptic transillumination: a new tool for the pediatric surgeon

Transillumination (TI) is a safe and reliable technique for evaluating masses or the presence of free air in the thorax or abdomen. TI can also be of help in the accurate placement of catheters or needles in the chest, abdomen, bladder, or vessels. Its use in several hundred cases has been documented by this report.