Axoplasmic transport in vagal afferent fibres in normal and alloxan-diabetic rabbits

Fast and slow components of anterograde axoplasmic transport have been studied in the sensory fibres of the vagus nerve of alloxan-diabetic rabbits and age-matched controls by incorporation of tritiated leucine into nodose ganglion cells. The diabetic rabbits were maintained for 2 months with blood glucose levels in the range 20--40 mmol/l. They showed growth retardation and one third developed cataracts. No alteration of either fast or slow axoplasmic transport was detected in the diabetic animals. These results are discussed in the light of the present understanding of the role of axoplasmic transport, of the findings in other axoplasmic transport studies, and of other data available on the pathogenesis of human and experimental diabetic neuropathy.     

(Na+ + K+)-ATPase in subcellular fractions of rat skeletal muscle.

Sodium and potassium-stimulated, magnesium-dependent, ouabain-sensitive ATPase has been used as an enzymic marker for muscle membrane (sarcolemma). However, the precise localization of this enzyme is still unknown. The enzyme activity was determined in muscle homogenates, sarcolemma, mitochondria, myosin B, and fragmented sarcoplasmic reticulum fractions isolated from frozen rat skeletal muscle. NaI-extracted fragmented sarcoplasmic reticulum isolated from frozen muscle (NaI-extracted high-speed fraction) contained a much higher specific (Na⁺ + K⁺)-ATPase activity (102 nmoles P₁/mg/min) than did a similar fraction isolated from fresh skeletal muscle (34 nmoles P₁/mg/min). NaI-treated muscle homogenate, sarcolemma, myosin B, and mitochondria had lower (Na⁺ + K⁺)-ATPase specific activity than the NaI-extracted high-speed fraction. The fragmented sarcoplasmic reticulum prepared from fresh or frozen muscle had the same calcium accumulating capacity; this capacity was almost abolished in the fragmented sarcoplasmic reticulum of both fresh and frozen muscle treated with NaI. The methods described may be useful in the study of muscle from humans or experimental animals where the amount of tissue available is limited. The results reemphasize the possible hazard in determining precise subcellular localization of enzyme activities in frozen tissues, as is a necessarily routine procedure in histochemistry.     

Mandies are not dandy: Another adverse drug interaction with methaqualone

There has been a steady increase in methaqualone abuse throughout the world. Phrases used to describe the drug or its effect include “mandies, Sopors, and luding out.” Dependence, attempted suicide, adverse interaction with alcohol, suicide, acute toxic states, and withdrawal epileptic seizures have all been well documented.¹ Epistaxis, menstrual disturbance, dry mouth, and depersonalization have occurred² with phenothiazine and or tricyclic antidepressants in combination with the hypnotic. A recent editorial³ suggests that methaqualone may cause neuropathy. Drug abusers have reported an elation with ataxia and paraesthesia of the extremities, lips, and tongue.⁴This report describes the side effects following a methaqualone-fluphenazine-nortriptyline combination.     

The influence of D.D.A.V.P. on the survival of factor VIII in severe haemophiliacs

The effect of D.D.A.V.P. (desamino-cys'-D-arg8-Vaso-pressin) on the survival characteristics of transfused VIII concentrate was studied in six severe, adolescent, haemophiliacs (VIII:C 1 iu/dl). D.D.A.V.P. was administered at a concentration of 0.3 ug/kg immediately following or 24 hours post infusion. No significant alteration in the half disappearance (1/2 d) or biological half-life (t 1/2) was detected for either VIII procoagulant (VIII:C) or its antigenic counterpart VIII:C Ag. As anticipated there was a significant (if sub-optimal) increase in VIII:R Ag within 2-4 hours of D.D.A.V.P. administration.     

Declining diazepam desensitization therapy

The use of high and gradually diminishing doses of diazepam in the in vivo desensitization of a severe travel phobia is described and discussed.     

Experimental ischemic myopathy: Effects of aortic ligation and serotonin

Support for the hypothesis that biogenic amines are involved in the production of muscle diseases comes from a report that rat muscle is damaged by combining distal aortic ligation with serotonin injection. Our studies explore the role of serotonin in the production of the myopathic changes in the aortic ligation-serotonin model. Twenty-six young Sprague-Dawley rats were subjected either to aortic ligation alone, aortic ligation followed by injection of serotonin (40 mg/kg, i.p.), or injection of serotonin alone. Following sacrifice 7–14 days later, 10 μm frozen sections of the soleus muscle were stained by trichrome, NADH-TR, and ATPase methods. Focal necrosis and phagocytosis or focal regeneration were seen after aortic ligation with, or without, subsequent serotonin injection. Serotonin alone produced only occasional mild changes in muscle. Therefore, we conclude that the significant damage to muscle in the ligation-serotonin model is provided by the aortic ligation, not the serotonin injection.     

The development of the right ear advantage in dichotic listening with focused attention

The influence of selective attention on cerebral asymmetry in 6, 8 and 10 year old children was studied using pre-cued dichotic recall of 1 to 4 pairs of digits. A constant right ear advantage for correct recall from the attended ear and intrusions from the unattended ear was found in all three age groups. The ear difference increased with set size and across serial position with a set size of 4 digit pairs. Thus the number of items in acoustic memory determined the degree of lateral asymmetry. The ability to focus attention on the left ear improved between 6 and 8 years. It was concluded that control of directed attention, which improves with development, and left hemisphere specialization for speech processing, which remains constant, both determine performance in dichotic verbal listening.     

Affect and vigilance performance in depressive illness

The relationships between the affective states of depression and anxiety on the one hand, and vigilance performance on the other, were examined for 10 neurotic depressive patients, 10 psychotic depressive patients and 10 normal controls. Affect did not consistently and systematically influence vigilance performance for individual subject groups.Combination of all 3 groups did however produce some significant relationships in the hypothesized directions. A significant negative relationship between severity of depressive affect and signal detection performance and a significant curvilinear (inverted U) relationship between anxiety and signal detection performance allowed confirmation of the hypotheses.The results were discussed in terms of a cognitive deficit among patients with depressive illness.     

Secondary depression in alcoholism: Implications for future research

While an association between excessive consumption of alcohol and depression has long been suspected it has only recently been demonstrated. This is probably due to the fact that only during the last 15 years have research diagnostic criteria for both alcoholism and depression been developed. The relationship between alcoholism and depression appears to be unidirectional in that the presence of an affective disorder does not seem to predispose to alcoholism (except perhaps in women), whereas the presence of alcoholism does appear to lead to subsequent development of depressive symptomatology. Unfortunately, there is a very wide range in the reported frequency of depression among alcoholics. We will examine the literature on secondary depression in alcoholism in an attempt to clarify the parameters which may account for this.     

The classification of psychiatric disorder

Altogether 26 psychiatrists and other mental health workers, from Colombia, Brazil, Sudan, Egypt, India and the Philippines tried to reach agreement on the classification of 10 case histories, using the International Classification of Diseases (8th revision). The exercise was part of the WHO Collaborative Study on Strategies for Extending Mental Health Care. Conventions, mistakes, differences of opinion and a lack of rules are discussed as causes for disagreement.     

The use of ECT within the veterans administration hospital system

Survey data describing present patterns of ECT use within the VA hospital system is presented, with particular focus on ECT technique. Seventy-four percent of the VA psychiatric services possessing an ECT capability responded. The results show that during 1977, most VA hospitals with inpatient psychiatric services (56%) still utilized ECT, with an estimated 3.1% of depressed psychiatric inpatients treated with this modality, versus 0.21% for schizophrenics. As of the summer of 1978, one-third of ECT treatment series were being given with unilateral electrode placement, and there is growing acceptance of ECT equipment that utilizes low-energy brief pulse stimuli and other technical refinements. All respondents reported the use of muscle relaxation and general anesthesia.     

Hemisphere differences in the recognition of closed and open class words

The distinction between closed and open class words—of interest in the first instance because of claims about the support of structural analysis during comprehension—has its reflection in word recognition. For normal speakers, performances over these types give evidence of the operation of separate recognition devices, while for agrammatic speakers, performance indicates no such separation. A study of recognition accuracy with tachistoscopic presentation lateralized to the visual hemifields suggests some parallel between left and right hemisphere processing and the contrast of normal and agrammatic speakers: with direct input restricted to the left hemisphere, the vocabulary types show different levels of accuracy; no such differences are evident with presentations to the right.     

Should the term “thought disorder” be revised?

The term “thought disorder” is widely used in American and British psychiatry to describe the cognitive and linguistic abnormalities which occur in schizophrenia. Both the term itself and the emphasis on its importance in the diagnosis of schizophrenia derive from Bleuler, who regarded it as pathognomonic.¹ During more recent years some investigators have questioned both its value and its specificity.^2–6 Diagnostic systems have been developed which emphasize the importance of other symptoms, such as specific types of delusions and hallucinations or poor premorbid personality and social adjustment.^7–10 Further, various types of thought disorder have also been observed in other illnesses, such as mania or depression.^11–13Yet another objection to the term thought disorder, perhaps even more salient and compelling than those mentioned, is that the term has come to be used so broadly and imprecisely that it has become nearly meaningless. Wittgenstein has warned us that we cannot assume that because there is only one word, there is only one thing. The single term thought disorder has grown pregnant with a variety of meanings over the years. If the language of medicine and science relied on connotative richness and ambiguity, the value of the term would be thereby increased. Since science and medicine instead demand denotative sparseness and precision, the term has in fact become prostituted. Current usage of the term “thought disorder” varies so widely that it may mean anything from delusional thinking to memory impairment to a cognitive set predisposing to low self-esteem. A reevaluation of the terminology used to describe the psychopathology of cognition and self-espression is long overdue.     

Laterality and recency effects in working memory

Following a previous finding that visual field advantage in recognition memory for letters is contingent on recency [1], four experiments were conducted to replicate and explain the effect. In all four experiments subjects were exposed to a series of potential target stimuli in central vision followed by simultaneous bilateral probes in the visual fields. The results demonstrated that the interaction is determined during retrieval rather than initial encoding, and that it is restricted to verbal processing conditions. The implications of the results for the determination of lateralization, individual differences in hemispheric function, and models of hemispheric processes in continuous information processing tasks are discussed.     

Central monoamine metabolism in depressions. II. Catecholamines and related compounds

CA research in depressions is reviewed. The present situation can be outlined as follows:Vital depressive patients may show central CA disorders that point in the direction of CA deficiency. In principle, this deficiency can be a primary phenomenon or a secondary development: the result of hypersensitivity of postsynaptic CA receptors. The former possibility is considered more plausible than the latter.The DA disorder seems to be related to motor retardation and loss of initiative and probably plays a role in their pathogenesis. There is no reason to assume that this disorder is a predisposing factor.The NA disorder is not related to motor symptoms. Its causative significance is still uncertain.An important byproduct of CA research in depressions is the momentum it gives to attempts to “translate” behavior disorders in terms of disturbed psychological functions. Such a functional psychopathology could be an important supplement to the traditional, more syndromal, and nosological classification of psychiatric conditions.