The symptomatic treatment of multiple system atrophy

Multiple system atrophy (MSA) is a neurodegenerative disease of undetermined aetiology that occurs sporadically and manifests itself as a combination of parkinsonian, autonomic, cerebellar and pyramidal signs. Despite the lack of any effective therapy to reverse this condition, some of the symptoms may be, at least temporarily, improved with adequate symptomatic therapies. Medical treatment is largely aimed at mitigating the parkinsonian and autonomic features. The therapeutic results of levodopa therapy in cases of MSA are difficult to interpret because of their variability. Nevertheless, the statement that patients with MSA are non or poorly levodopa-responsive is misleading. Clinical and pathologically proven series document about 40-60% levodopa efficacy in patients with MSA presenting with predominant parkinsonian features. Unfortunately, other antiparkinsonian compounds (dopamine agonists, amantadine) are not more effective than levodopa. Orthostatic hypotension (OH) can be suspected from the patient's history and subsequently documented in the clinic by measuring lying and standing blood pressure. The diagnosis ideally should be confirmed in the laboratory with additional tests to determine the cause and evaluate the functional deficit, so as to aid treatment. A variety of pharmacological agents with different mechanisms of action have been used in MSA to reduce OH when this is symptomatic. OH can also be alleviated by avoiding aggravating factors, such as the effects of food, micturition, exposure to a warm environment and physiological diurnal changes and by using other non-pharmacological strategies. The treatment of the very common genito-urinary symptoms (incontinence, retention, impotence) should also be considered in order to improve the quality of life of these patients.     

Anxiety in patients undergoing MR imaging

To determine and quantify the major sources of anxiety for patients undergoing magnetic resonance (MR) imaging and to suggest means by which to eliminate or diminish their negative effects, the authors studied anxiety in 46 subjects. Of these, 20 randomly selected subjects who successfully completed the examination participated in exit interviews. Six subjects who terminated the examination before completion also completed exit interviews. Pre-imaging and postimaging questionnaires (state-trait anxiety inventory) were administered to measure anxiety in the 20 other subjects. Anxiety was associated with the constrictive dimensions of the magnet bore, examination duration, coil noise, and temperature within the bore. Preparation at the point of referral was consistently absent, incomplete, or misleading. Patients used identifiable strategies to cope with the examination: blinding, breathing relaxation techniques, visualization of pleasant images, and performance of mental exercises.     

Cerebrospinal fluid rhinorrhea: depiction with MR cisternography in dogs

Canine cerebrospinal fluid rhinorrhea, which occurs frequently in purebred beagles, was demonstrated in two dogs on magnetic resonance images after cisternal introduction of gadolinium-DTPA dimeglumine.     

核、膜蛋白的基因能抑制禽类流感病毒及其重组株的繁殖

对人流感病毒A/Udorn/72(H_3N_2)株与禽类流感病毒A/Mallard/NY/78/(H_2N_2)重组后的重组株分析表明,仅含禽类病毒的核蛋白(NP)或膜蛋白(M)的RNA片段的重组株,在松鼠猴的呼吸道繁殖是受限制的。另外。仅有禽类的RNAl和NS基因的重组株(Clone 12)在松鼠猴的气管内的繁殖也明显受限制,而只具有其中一个基因的Clone 9, Clone 2, 则限制就不明显。由此表明,禽类流感病毒的NP和M基因在宿主范围的繁殖限制中起主要作用,而RNAI和SN基因的结合,同样起着繁殖受限制作用。     

Frequency Analysis of Ventricular Fibrillation and Resuscitation Success

SUMMARY In 56 patients, frequency analysis of the electrocardiogramof ventricular fibrillation exhibited power spectra with a distinctdominant frequency. The greatest success for resuscitation fromventricular fibrillation is recorded when ventricular fibrillationdevelops after the patient comes under coronary care. Of the41 patients in whom the onset and first 8 s of ventricular fibrillationwere artefact-free the mean dominant frequency of primary ventricularfibrillation (no cardiogenic shock or cardiac failure) in 21patients was 6.2±0.2 Hz, significantly higher than themean dominant frequency of the first 8 s of secondary ventricularfibrillation (cardiogenic shock or heart failure) (4.0±0.2Hz, 20 patients, p =0.0001). In these patients the peak-to-troughamplitude (ECG) of the first 8 s of ventricular fibrillationwas similar in both primary and secondary ventricular fibrillationas was the mean duration of ventricular fibrillation prior tothe first DC shock. There was a significantly lower successrate for resuscitation from secondary ventricular fibrillation(6 of 20 patients) compared with resuscitation from primaryventricular fibrillation (18 of 21 patients, x² 17.8, p=0.001).Of the remaining 15 patients who were collapsed between 3 and20 min before the arrival of the mobile coronary care unit,the dominant frequency of the first 8 s of ventricular fibrillationfell with increased duration of collapse (from 5.5 Hz at 3 minto a mean of 2.1 Hz at 20 min). Four of these 15 patients whosurvived the initial arrest had a mean dominant frequency of5.2±0.3 Hz, which was significantly higher than the meandominant frequency (3.1±0.3 Hz, p<0.01) of the 11patients who were not resuscitated. This study shows that low frequency ventricular fibrillationis indicative of a poor chance of successful resuscitation.Alteration of the frequency may increase resuscitation success.     

Impact of an infection consultation service for bacteraemia on clinical management and use of resources

Since 1993, the infection consultation service for bacteraemia has seen 310 patients in the Medical and Surgical Directorates at Ninewells Hospital and Kings Cross Hospital. A random sample of 100 was audited. Case-notes were incomplete for five patients, leaving 95 fully-audited patients. Clinical outcome measures were death from infection, and readmission within 2 weeks of discharge. Initial treatment was inconsistent with antibiotic policy in 46 patients (48%). Antibiotic treatment was changed in 37 (80%) of these patients: increased in intensity in 19 (41%) and decreased in 18 (39%). Changes were also made in 30 (61%) of the 49 patients whose initial treatment was consistent with sepsis policy-increased in seven (14%) and decreased in 23 (47%). Median daily antibiotic costs were lowered in patients whose initial treatment was consistent with sepsis policy (pounds 10.10 vs. pounds 7.28, p = 0.0274). However, in the other patients, savings were balanced by increases (p = 0.7696). Consultation required one consultant session per week (3.5 h) and the audit required an additional 16 consultant sessions. Seven patients died, but only one death was directly related to infection. Six patients were readmitted to hospital within 2 weeks, in three due to recurrence of infection. Changes to treatment were recommended in the majority of patients, regardless of whether initial treatment complied with the sepsis policy. The service primarily redistributed resources rather than reducing costs. A fully audited service requires considerable consultant time, but we believe such time is well spent.      

How much would the safety of blood transfusion be improved by including p24 antigen in the battery of tests?

BACKGROUND: Because p24 antigen may be detectable during seroconversion, before antibodies, some of the infected blood undetected by antibody screening could be identified through antigen screening. STUDY DESIGN AND METHODS: The potential benefit of antigen screening was evaluated in a simulation model incorporating present knowledge of the time sequence from antigen exposure to antibody development during seroconversion and the incidence of seroconversion among repeat donors. The model was designed so that the results were consistent with the observed rate of antibody-positive blood donations and the CIs of surveys that did not find any antibody-negative/antigen- positive donated blood. RESULTS: In the United States in 1990, the number of expected, undetected, contaminated blood components was estimated at 68; of these 8 to 17 could have been identified by antigen screening, depending on the hypothesis explored. (In 1992, 20 undetected, contaminated blood components were expected according to this model, of which 2 to 5 could have been identified by antigen screening.) In France, the comparable figures were 1 to 4 of 13 in 1990 and 1 to 2 of 7 in 1992. CONCLUSION: The projected benefit must be weighted against possible negative consequences, including 1) an increase in recently infected persons seeking p24 antigen screening at blood banks (assuming this test is not incorporated into screening in non-blood bank settings) and 2) the need for additional quality assurance procedures to avoid operational flaws associated with the increase in the donor screening test battery. In any case, the best way of increasing the safety of blood is improvement in the selection of donors, which can diminish the residual risk of transmission of any viruses.