Anorexia nervosa as a compulsive behaviour disease.

A number of anorexic young women develop bulimia, a condition in which binge eating is driven so intensely they cannot resist it. Although this drive has the character of a compulsion the patients do not as a rule suffer from obsessional-compulsive neurosis. A questionnaire was developed and used to determine whether similar compulsive drives manifest themselves in restricting anorexics and whether there are compulsive features resembling patients with compulsive personality disorder (as described in DSM-III) in eating disorders. A total of 162 patients were studied, comprising 42 controls, 30 depressed patients, 34 non-bingeing anorexics, 28 bingeing anorexics and 28 compulsive patients. The questionnaire was shown to be a stable instrument and, on the compulsion scale, the anorexics, bulimics and compulsive patients all scored very highly (mean +/- S.E.; 32.1 +/- 1.9, 35.8 +/- 1.9, 28.0 +/- 2.2, respectively) compared to the controls (13.1 +/- 1.1, p < 0.005). The compulsive patients did not have anorexia-type eating disorders. It was concluded that many of the factors which underlie compulsive personality disorder are present in primary eating disorders and the compulsive nature of anorexia could not be ignored when treatment was considered. The difference between compulsive behaviour and addiction is discussed in the light of the failure of long-term naloxone infusion to cure severe anorexia, even though some patients had dramatic weight gains associated with the antilipolytic action of naloxone.     

General Ultrasound in the Critically Ill. D. A. Lichenstein. Published by Springer-Verlag, Berlin. Pp. 199; indexed; illustrated. Price {pound}77.00. ISBN 3-540-20882-4

Bedside ultrasound with ‘point of care machines’is now a reality for any critical care department. Often thesemachines are primarily used by visiting radiologists to preventwear and tear on less portable equipment. However, there ispotential benefit to be gained by the critical care physicians     

Role of group II and group III metabotropic glutamate receptors in spinal cord injury.

Spinal cord injury (SCI) produces an increase in extracellular excitatory amino acid (EAA) concentrations that results in glutamate receptor-mediated excitotoxic events. An important class of these receptors is the metabotropic glutamate receptors (mGluRs). mGluRs can activate a number of intracellular pathways that increase neuronal excitability and modulate neurotransmission. Group I mGluRs are known to modulate EAA release and the development of chronic central pain (CCP) following SCI; however, the role of group II and III mGluRs remains unclear. To begin evaluating group II and III mGluRs in SCI, we administered the specific agonists for group II, APDC, or group III, L-AP4, by interspinal injection immediately following SCI. Contusion injury was produced at spinal segment T10 with a New York University impactor (12.5-mm drop, 10-g rod 2 mm in diameter) in 30 adult male Sprague-Dawley rats (175-200 g). Evoked and spontaneous behavioral measures of CCP, locomotor recovery, changes in mGluR expression, and amount of spared tissue were examined. Neither APDC nor L-AP4 affected locomotor recovery or the development of thermal hyperalgesia; however, L-AP4 and APDC attenuated changes in mechanical thresholds and changes in exploratory behavior indicative of CCP. APDC- and L-AP4-treated groups had higher expression levels of mGluR2/3 at the epicenter of injury on post contusion day 28; however, there was no difference in the amount of spared tissue between treatment groups. These results demonstrate that treatment with agonists to group II and III mGluRs following SCI affects mechanical responses, exploratory behavior, and mGluR2/3 expression without affecting the amount of tissue spared, suggesting that the level of mGluR expression after SCI may modulate nociceptive responses.     

Renin correlates with blood pressure reactivity to stressors

This study examines the relationship between renin levels and physiologic reactivity to stressors. Seventy-five normotensive and mildly hypertensive men were studied on a high salt diet (200 mEq/day Na) and on a low salt diet (10 mEq/day Na). Renin, plasma catecholamines, heart rate, and blood pressure were examined at rest, after standing in place for 8 minutes, and after a brief mathematics task. Renin levels increased in response to the stressor tasks, particularly on the low salt diet. The change in diastolic pressure in response to the stressor tasks was correlated with the change in renin (r = 0.45, p less than 0.001) but not with the change in norepinephrine. The combination of change in renin and norepinephrine levels accounted for 21% of the variance in predicting diastolic pressure reactivity (p less than 0.0015).     

Substrate inhibition of adenosine phosphorylation in adenosine deaminase deficiency and adenosine-mediated inhibition of PP-ribose-P dependent nucleotide synthesis in hypoxanthine phosphoribosyltransferase deficient erythrocytes

Summary The metabolism of adenosine and its effects on phosphoribosylpyrophosphate, PP-ribose-P, dependent nucleotide synthesis were studied using erythrocytes from patients with adenosine deaminase and hypoxanthine phosphoribosyltransferase deficiency as models. The phosphorylation of adenosine was progressively inhibited by concentrations of adenosine greater than 1 µmol L^–1 for control and ADA deficient erythrocytes. There was essentially no initial rate of phosphorylation at 30 µmol L^–1 adenosine. Adenosine, 1 µmol L^–1, also caused a 60% reduction in PP-ribose-P concentration in ADA deficient erythrocytes. For HPRT deficient erythrocytes in which ADA activity was blocked by coformycin, 10 µmol L^–1 inosine stimulated PP-ribose-P dependent nucleotide synthesis from adenine, whereas, 10 µmol L^–1 adenosine inhibited nucleotide synthesis. These observations suggest that adenosine phosphorylation and PP-ribose-P dependent nucleotide synthesis are inhibited under conditions in which adenosine accumulates, such as in hereditary or pharmacologically induced ADA deficiency.     

On the dual structure of the auditory brainstem response in dogs.

OBJECTIVE: To use the over-complete discrete wavelet transform (OCDWT) to further examine the dual structure of auditory brainstem response (ABR) in the dog. METHODS: ABR waveforms recorded from 20 adult dogs at supra-threshold (90 and 70dBnHL) and threshold (0-15dBSL) levels were decomposed using a six level OCDWT and reconstructed at individual scales (frequency ranges) A6 (0-391Hz), D6 (391-781Hz), and D5 (781-1563Hz). RESULTS: At supra-threshold stimulus levels, the A6 scale (0-391Hz) showed a large amplitude waveform with its prominent wave corresponding in latency with ABR waves II/III; the D6 scale (391-781Hz) showed a small amplitude waveform with its first four waves corresponding in latency to ABR waves I, II/III, V, and VI; and the D5 scale (781-1563Hz) showed a large amplitude, multiple peaked waveform with its first six waves corresponding in latency to ABR waves I, II, III, IV, V, and VI. At threshold stimulus levels (0-15dBSL), the A6 scale (0-391Hz) continued to show a relatively large amplitude waveform, but both the D6 and D5 scales (391-781 and 781-1563Hz, respectively) now showed relatively small amplitude waveforms. CONCLUSIONS: A dual structure exists within the ABR of the dog, but its relative structure changes with stimulus level. SIGNIFICANCE: The ABR in the dog differs from that in the human both in the relative contributions made by its different frequency components, and the way these components change with stimulus level.     

Narcotic reversal in hypercapnic dogs: comparison of naloxone and nalbuphine

Reversal of opioid effects by naloxone (NX) can lead to significant cardiovascular problems. We have reported previously that hypercapnic dogs develop greater increases in blood pressure and plasma catecholamine (CA) levels than hypocapnic ones when reversed with naloxone. We have also demonstrated differences between NX and nalbuphine (NBPH) in producing excitatory adrenergic responses when administered during normocapnia. The present study was designed to investigate possible dissimilarities in cardiovascular and sympathetic events after administration of either NX or NBPH in dogs made hypercapnic following fentanyl administration. After induction of anaesthesia with thiopentone and intubation, two groups of dogs were maintained with controlled ventilation on enflurane in oxygen anaesthesia and given 50 micrograms.kg-1 fentanyl IV. This caused a significant decrease in heart rate (HR) (P less than 0.001), mean arterial blood pressure (MAP) (P less than 0.001), and plasma concentrations of norepinephrine (NE) (P less than 0.002). Then, ventilation was decreased to produce a PaCO2 of 60 mmHg; this was accompanied by a significant elevation in plasma level of both epinephrine (EPI) (P less than 0.02) and NE (P less than 0.001). Administration of 20 micrograms.kg-1 NX to six dogs resulted in immediate increases in HR (P less than 0.01) and MAP (P less than 0.01), and a further rise in CA levels to greater than pre-fentanyl baseline values. In six other dogs, NBPH (0.3 mg.kg-1) caused increases in HR (P less than 0.001) and MAP (P less than 0.001) only, and the MAP rise was significantly less than that seen in the NX group (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Technology anxiety as a potential mediating factor in response to medical technology

Technology anxiety, defined as a fear of working with medical equipment, was measured via the use of the Technology Response Questionnaire. Nurses (N=414) working on nine types of nursing units at two hospitals participated in the study. Nurses working on psychiatric units were found to be most anxious about working with medical equipment, while nurses working on surgical and adult intensive care units were least anxious. A comparison of the nurses who were highest and lowest on technology anxiety indicated that those who were most anxious about technology were less positive toward computers, felt more stressed by their work, were lower on job satisfaction, less positive toward the physicians they worked with, lower on personality scales of autonomy and adaptability, were less likely to do care planning regularly or to use nursing diagnoses, and tended to be older than less anxious nurses.     

Apparent lack of synergism between heparin and dihydroergotamine in prevention of deep vein thrombosis after elective hip replacement: a randomised double-blind trial reported in conjunction with an overview of previous results.

We report the results of a double-blind, randomised trial of venous thrombosis (VT) prevention in 117 patients having elective hip replacement where low dose heparin alone (5,000 IU sodium heparin given subcutaneously [sc] 8 hourly until the seventh postoperative day) was compared with low dose heparin plus dihydroergotamine (DHE; 0.5 mg, given 8 hourly by sc injection). The trial end point consisted of VT discovered through bilateral ascending venography done routinely on the seventh postoperative day. VT developed in 34% of patients given heparin/DHE (95% confidence interval = 22% - 47%) compared with 24% in those given low dose heparin alone (95% confidence interval = 14% - 37%; p = 0.34), difference = 10% (95% confidence interval = -7% to +26%). Corresponding figures for the incidence of proximal (above-knee) thrombosis were 17% and 14% (95% confidence intervals = 8% - 29% and 6% - 25% respectively). These results are discussed in the context of a detailed overview of published evidence concerning VT prevention with heparin/DHE after hip replacement and we conclude it is unlikely that heparin/DHE is markedly superior to low dose heparin alone in this clinical setting.     

Expression of Helenium virus S coat protein in Escherichia coli, in vitro in rabbit reticulocyte lysate and transgenic tobacco.

The coat protein open reading frame (ORF) sequence of Helenium virus S (HelVS) was cloned and expressed in E. coli, rabbit reticulocyte and transgenic tobacco. In E. coli the size of the protein was identical to that obtained for the coat protein from purified virus particles and less than that predicted for the fusion protein. This may be due to ribosome binding at a potential ribosome binding site present on the viral sequence, approximately 45 nucleotides upstream from the initiating methionine of the coat protein ORF. This region of HelVS, equivalent to the 1.5 kb subgenomic RNA, also produced high levels of protein when transcribed and translated in vitro. When introduced into Nicotiana tabacum by leaf disk transformation via Agrobacterium tumefaciens, high levels of stable coat protein were detected which were identical in molecular weight to that of HelVS coat protein and constituted approximately 0.1-0.5% of the total extracted protein.