Opiate antagonists and long-term analgesic reaction induced by inescapable shock in rats

Five experiments examined the influence of opiate antagonists on both the short-term analgesic reaction resulting 30 min after exposure to inescapable shock and the long-term analgesic reaction resulting after reexposure to shock 24 hr after inescapable shock exposure. Experiment 1 showed that the long-term analgesic reaction could be reduced by administration of naltrexone prior to exposure to inescapable tail shock. Experiment 2 showed that the reduction in the long-term analgesic reaction produced by naltrexone was dose-dependent. Experiment 3 showed that the long-term analgesic reaction could also be reduced by administration of naltrexone prior to reexposure to shock. Experiment 4 showed that the long-term analgesic reaction could be reduced by administration of large dose of naloxone prior to reexposure to shock. Experiment 5 showed that the short-term analgesic reaction was reduced by naltrexone administered prior to inescapable shock. Some implications of these results for the biochemical substrates of both learned helplessness and stress-induced analgesia are discussed.

Life-threatening cold and exercise-induced asthma potentiated by administration of propranolol

We present two patients with acute respiratory failure secondary to cold and exercise-induced asthma. Neither patient had a prior history of asthma, and both had recently been placed on therapy with propranolol for treatment of hypertension. We discuss the postulated mechanism of bronchospasm in these patients. In addition, we urge aggressive searching for any change in respiratory symptoms in patients receiving propranolol.

Frequency dependence of dynamic compliance in patients with rheumatoid arthritis

An investigation of lung function was carried out in 99 randomly selected patients with calssic or definite rheumatoid arthritis and in 60 control subjects matched for age, sex, and smoking habits. Mean FEV1 and mean VC were both significantly lower in the rheumatoid patients due to significant differences for women but mean FEV/VC ratio was 73.0% in the rheumatoid group and 72.1% in the control. Steady-state transfer factor was significantly greater in the normal men than in the comparable rheumatoid group, but there was no difference for women. After excluding patients with FEV1 less than 80% predicted normal and patients with low compliance, 72 rheumatoid patients and 45 controls provided series of tracings that could be assessed for a fall in Cdyn of 20% between 20 cycles and 60 cycles a minute. Dynamic compliance was not significantly different in any group at any rate of respiration. Fourteen of 72 rheumatoid patients and three of 45 controls showed frequency dependence (FDC). After the age of 50 the prevalence in the rheumatoid groupwas 11/38 and in the control group 2/27. This difference was significant (P less than 0.05). FDC was not consistently related to other abnormalities of lung function or to the duration, severity, or treatment of the rheumatoid arthritis. In various categories of smoking habits, dust exposure, or allergic tendency, the prevalence was always greater in the rheumatoid group. This provides evidence of patchy involvement of small airways, or alveoli and connective tissue, by the rheumatoid process.

Acute respiratory failure following severe arsenic poisoning

A 47-year-old man had an episode of severe respiratory failure after acute intoxication with arsenic. Features of the initial clinical presentation included nausea, vomiting, and diarrhea, acute psychosis, diffuse skin rash, and marked pancytopenia. A peripheral neuropathy then developed which resulted in severe weakness of all muscles of the limbs, the shoulder and pelvis girdles, and the trunk. The neuropathy continued to progress despite treatment with dimercaprol (BAL in oil). Five weeks after the initial exposure, the patient was no longer able to maintain adquate ventilation and required mechanical ventilatory support. Improvement in the patient's neuromuscular status permitted successful weaning from the ventilator after one month of mechanical ventilation. Long-term follow-up revealed no further respiratory difficulty and slow improvement in the strength of the peripheral muscles.

In Vitro Secondary MLR

We have examined the kinetics and specificity of secondary in vitro mixed lymphocyte reactions (MLR). With limited numbers of primed responder cells (PRC) in the presence of “excess antigen” it was possible to obtain proliferative responses that were proportional to the number of PRC initially placed in culture. The responding cells, after an initial lag period, seem to grow exponentially until day 3 of culture. The responses of PRC (with the strain combinations and culture conditions described in this report) seemed to be directed toward stimulator cell determinants whose expression was determined by genes in the I region of the MHC. In one case, the relevant incompatibilities could be further restricted to the I-A region. Although PRC responded best to stimulator cells sharing the I region with the priming stimulator cell, apparent cross-reactivity could be observed by restimulating PRC with stimulator cells that did not carry the MHC haplotype of the priming stimulator cell. The rate of proliferation (measured as 3H-thymidine incorporation) in these apparent cross-reactions was reproducible and comparable to the rate observed in response to the priming stimulator cell. It was possible, therefore, to estimate the proportion of PRC that reacted in the presence of third party stimulator cells compared to the response of these PRC to the priming stimulator cells. We have estimated that the response of A (B6) PRC against H-2d and H-28 haplotype stimulator cells is about half of the response of these PRC to H-2b, the priming stimulator cell.

In vitro secondary MLR. I. Kinetics of proliferation and specificity of in vitro primed responder cells

We have examined the kinetics and specificity of secondary in vitro mixed lymphocyte reactions (MLR). With limited numbers of primed responder cells (PRC) in the presence of "excess antigen" it was possible to obtain proliferative responses that were proportional to the number of PRC initially placed in culture. The responding cells, after an initial lag period, seem to grow exponentially until day 3 of culture. The responses of PRC (with the strain combinations and culture conditions described in this report) seemed to be directed toward stimulator cell determinants whose expression was determined by genes in the I region of the MHC. In one case, the relevant incompatibilities could be further restricted to the I-A region. Although PRC responded best to stimulator cells sharing the I region with the priming stimulator cell, apparent cross-reactivity could be observed by restimulating PRC with stimulator cells that did not carry the MHC haplotype of the priming stimulator cell. The rate of proliferation (measured as 3H-thymidine incorporation) in these apparent cross-reactions was reproducible and comparable to the rate observed in response to the priming stimulator cell. It was possible, therefore, to estimate the proportion of PRC that reacted in the presence of third party stimulator cells compared to the response of these PRC to the priming stimulator cells. We have estimated that the response of A (B6) PRC against H-2d and H-2s haplotype stimulator cells is about half of the response of these PRC to H-2b, the priming stimulator cell.

Salmefamol and Salbutamol in exercise-induced asthma in children

A double-blind controlled study is reported of salmefamol 200 mug and salbutamol 200 mug administered by aerosol before exercise tests in asthmatic children. Both drugs prevented exercise-induced asthma. There was no significant difference between them.

Plasma erythropoietin assay in patients with chronic renal failure

Using the post-hypoxic mouse method of assay, values for erythropoietin in the plasma of patients with chronic renal failure were equal to, or greater than, normal values. Results suggest that the source of erythropoietin may be primarily extrarenal. Normal renal tissue, provided in the assay by the intact mouse, is required for activation of the hormone. There still remains to be explained the enhanced erythropoietic response to haemorrhage or hypoxia that can occur in anephric man.

Comparison of peak flow gauge and peak flow meter

A comparison has been made of the new peak flow gauge and the Wright peak flow meter. Close correlation was found between measurements made with the two instruments both in normal subjects and in patients. The peak flow gauge is as consistent as the peak flow meter but is cheaper and more portable. It should be useful in survey work in general practice and for loan from hospital outpatient departments where serial measurements are used to monitor patients' progress.

Forgetting as a function of sleep at different times of day

The experiment studied the separate effects of sleep and time period of retention interval on forgetting. A free recall task was given to independent groups of subjects either at night or in the morning, and a second recall demanded 5 h later, after an intervening period of sleeping or waking activity. Oral body temperatures (BT) were measured at each session. The data were analysed in terms of (a) immediate recall at test 1, and (b) amount forgotten from test 1 to test 2. Immediate recall was higher for morning groups, in agreement with previous findings, serial position analysis indicating that the effect is confined to enhancement of the primary memory component. Long-term retention was higher over the night interval, irrespective of sleeping conditions, though having slept at night produced better retention than having stayed awake. Sleep during the morning was not effective in reducing forgetting. BT showed a marked drop for both night groups and rise for day groups over the retention interval. Alternative explanations for the classical sleep/memory findings are suggested in terms of (a) differential effects of sleep stages on memory, and (b) the underlying diurnal variation in BT and other processes.

Purification and properties of L(+)-lactate dehydrogenase from potato tubers

1. A purification of l(+)-lactate dehydrogenase is described. 2. The final preparation is active with NADH and NADPH and with a number of keto acids, but evidence is presented to support the view that a single enzyme is involved. 3. NAD(+) showed product inhibition, but at slightly acid pH values there was evidence of co-operative binding. 4. At acid pH values ATP was a potent inhibitor and appears to be an allosteric effector. At neutral or alkaline pH values ATP behaved as a weak competitive inhibitor. 5. The physiological significance of inhibition by ATP is discussed.

Linear growth of a Torulopsis sp. on n-alkanes

Slide cultures showed that growth of a hydrocarbon-utilizing Torulopsis sp. occurred only when the cells were in physical contact with the n-alkane droplets. Growth in batch culture was found to be linear and dependent on the surface area of substrate available to the cells. The hydrocarbon may enter the cell without first being converted to a more water-soluble intermediate.

Environmental radiation surveillance at a nuclear fuel reprocessing plant

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A specific factor in extracts of the choroid plexus influencing the permeability of the myelencephalic roof

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The Morphology and Permeability of the Roof of the Fourth Ventricle in some Mammalian Embryos

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The Development of the Cerebrospinal Fluid Spaces and Choroid Plexuses in the Chick

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