Functional analysis of aberrant behavior maintained by automatic reinforcement: assessments of specific sensory reinforcers

The purpose of this study was to develop a systematic functional assessment package for aberrant behaviors maintained by nonsocial (automatic) reinforcement. The assessment package included four components: (1) functional analysis, (2) antecedent assessment of specific automatic reinforcement sources, (3) stimulus preference assessment, and (4) treatment evaluation. Functional analysis data indicated automatic reinforcement functions of the stereotypy exhibited by a 10-year-old male and the self-injury (SIB) exhibited by a 30-year-old male. Antecedent assessments of sensory classes indicated that auditory stimulation and tactile stimulation were associated with stereotypy and SIB, respectively. A multiple-stimulus-without-replacement procedure was conducted with each participant to identify the most- and least-preferred stimuli within the identified sensory classes. In an attempt to validate the assessment package for each participant, a DRO procedure was implemented using a reversal design with a multielement component. DRO procedures using stimuli within the targeted sensory classes were successful in eliminating the aberrant behaviors of both participants. The results are discussed in the context of improving the methodology for assessing and treating automatically reinforced behaviors.

Does literacy have an effect on stick construction tasks?

Since constructional apraxia is often concomitant with brain lesions, the study of constructional tasks in the non-brain-damaged population might be useful in helping to disentangle other causal factors. This paper explores the performance of illiterate individuals (N = 29) as compared to that of semiliterates (N = 21) and literates (N = 23) in order to see the effect of reading and writing abilities on constructional tasks. Each participant was asked to construct 4 figures based upon models having varying degrees of complexity. A global criterion of lack of fidelity and several analytic criteria (related to distortion, rotation, and disarticulation errors) were used to evaluate performance. Although illiterates generally made more errors than semiliterates and semiliterates more than literates, only some of these differences were statistically significant. Significant differences were found for lack of global fidelity and disarticulation errors when all 4 figures were considered together. Subtler data emerged with respect to single figures.

Beta-glucosidase from Chalara paradoxa CH32: purification and properties

The hyphomycete Chalara paradoxa CH32 produced an extracellular beta-glucosidase during the trophophase. The enzyme was purified to homogeneity by ion-exchange and size-exclusion chromatography. The purified enzyme had an estimated molecular mass of 170 kDa by size-exclusion chromatography and 167 kDa by SDS-PAGE. The enzyme had maximum activity at pH 4.0-5.0 and 45 degrees C. The enzyme was inactivated at 60 degrees C. At room temperature, it was unstable at acidic pH, but it was stable to alkaline pH. The purified enzyme was inhibited markedly by Hg(2+) and Ag(2+) and also to some extent by the detergents SDS, Tween 80, and Triton X-100 at 0.1%. Enzyme activity increased by 3-fold in the presence of 20% ethanol and to a lesser extent by other organic solvents. Purified beta-glucosidase was active against cellobiose and p-nitrophenyl-beta-D-glucopyranoside but did not hydrolyze lactose, maltose, sucrose, cellulosic substrates, or galactopyranoside, mannopyranoside, or xyloside derivatives of p-nitrophenol. The V(max) of the enzyme for p-NPG (K(m) = 0.52 mM) and cellobiose (K(m) = 0.58 mM) were 294 and 288.7 units/mg, respectively. Hydrolysis of pNPG was inhibited competitively by glucose (K(i) = 11.02 mM). Release of reducing sugars from carboxymethylcellulose by a purified endoglucanase produced by the same organism increased markedly in the presence of beta-glucosidase.

[Lewy body dementia: some contributions to the clinical knowledge]

INTRODUCTION

Dementia with Lewy bodies is the second commonest type of dementia. The latest criteria for its diagnosis have recently been established (1996).

PATIENTS AND METHODS

We report the clinical findings in 25 patients with probable dementia with Lewy bodies.

RESULTS

No sex predominance was seen, onset was after the age of 65 years in 60% of the cases and there was a past history of dementia in 48%. Onset was with cognitive disturbances in 32%, Parkinsonism in 32% and both in 32%. When there was an interval between Parkinsonism and dementia, this was of 3-19 months. The dementia included attention disorder, impaired recall and praxis alterations. Disorders of executive function, behaviour or language, were seen in two thirds of the patients and acalculia in over half. Around 50% showed signs of subcortical involvement different from Parkinsonism. Parkinsonism was basically hypokinetic (96%), with tremor in two thirds of the cases, at rest (29%) postural (12%) or combined (59%), and symmetrical in 41%. Rigidity was only seen in 52% and was slight in most cases. In 16% there was weakness of vertical gaze. In 40% urine or double incontinence occurred, mainly when the dementia was at an intermediate or advanced state.

CONCLUSIONS

Dementia with Lewy bodies is a dementia with fronto-temporo-parietal alterations, frequently associated with hypokinetic Parkinsonism (which always shows a lag period with respect to dementia of less than 24 months), hallucinations and a fluctuating course. Other findings supporting this diagnosis were seen in two out of every three patients.

Phenol-oxidase (laccase) activity in strains of the hyphomycete Chalara paradoxa isolated from olive mill wastewater disposal ponds

Production of laccase activity by nine strains of Chalara paradoxa isolated from olive mill wastewater disposal ponds were studied. Enzyme extracts obtained from cultured broths by adsorption on hydroxyapatite showed a single band of laccase activity on ABTS after polyacrylamide gel electrophoresis (PAGE). They showed small mobility differences, with molecular masses of 67 to 68 kDa. Enzymes from the different strains oxidized a variety of phenolic and non-phenolic substances, and they could be divided into two groups according to their relative activities on substrates. All laccases showed a dual pH dependence of activity, with a maximum in the range of pH 3.0 to 4.5 for ABTS, o-dianisidine and 2,6-dimethoxyphenol, and pH 6.0 (Group 1) or pH 6.5 (Group 2) for syringaldazine and other substrates. Optimal temperatures were in the range of 10 to 28 degrees C for two strains (maximum at 10 degrees C) and 10 to 37 degrees C for the rest. The different enzymes were partially inactivated by heating at 60 degrees C and totally inactivated at 70 degrees C. Laccases were stable in a pH range of 3.0 to 9.0 (except for strain 36A, which was partially inactivated at pH 3.0), but became inactivated at pH 2.0. Altogether these data suggest that Ch. paradoxa strains produce different laccase isoenzymes.

Biochemical and functional characterization of the Tn-specific lectin from Salvia sclarea seeds

SSL, the lectin isolated from Salvia sclarea seeds, recognizes the Tn antigen (GalNAcalpha-O-Ser/Thr), a specific marker of many human carcinomas. Two-dimensional electrophoresis, amino-acid and amino-sugar analysis, and MALDI-TOF MS showed that SSL is an acidic (pI 5.5), 60-61-kDa dimeric glycoprotein composed of apparently identical subunits linked by a single disulfide bond. The apparent molecular mass of SSL in solution determined by equilibrium sedimentation analytical ultracentrifugation was 59 +/- 9 kDa. This value did not change in the pH range 2.5-8.5, indicating that SSL does not associate into higher order structures. Tandem mass spectrometry and methylation analysis of N-glycans released from SSL by hydrazinolysis indicated that SSL possesses 2-3 glycosylation sites occupied with the typical plant glycans Manalpha1-6[(Manalpha1-3)(Xylbeta1-2)]Manbeta1-4 -GlcNAcbeta1-4(Fucalp ha1-3)GlcNAc and [(Manalpha1-3/6)(Xylbeta1-2)]Manbeta1-4-GlcNAcbeta1 -4(Fucalpha1-3)Glc NAc. The influence of adjacent Tn structures on the binding of two Tn-specific lectins (SSL and the isolectin B4 from Vicia villosa) and an anti-Tn monoclonal antibody (mAb 83D4) was evaluated using synthetic Tn glycopeptides. The binding of both lectins to the synthetic Tn glycopeptides was independent of the density of Tn structures. On the other hand, mAb 83D4 only reacted with glycopeptides displaying two or three consecutive Tn structures.

[A controlled, double-blind, randomized pilot clinical trial of nicardipine as compared with a placebo in patients with moderate or severe head injury]

INTRODUCTION

One of the factors involved in the occurrence of ischemic cerebral lesions following head injury is cerebral vasospasm. We analyze the effect of intravenous nicardipine on the prevention and treatment of posttraumatic cerebral vasospasm.

PATIENTS AND METHODS

We made a placebo-controlled, randomised, double-blind pilot study of the effect of nicardipine (intravenously 5 mg/hour for one week) on patients with moderate or severe head injury who presented with cerebral vasospasm, defined as an average Doppler flow velocity (DFV) of 100 cm/second or more. The main variable assessed was the evolution of the DFV and the secondary criteria were the evolution of the arterial blood pressure, coma scales, the findings on the Glasgow Coma Scale and the safety of the drug.

RESULTS

Eleven patients were included in each homogeneous group. The DFV was found to have become normal on the first day of treatment with nicardipine and on the third day with the placebo (p = 0.023). During the first day of treatment the percentage of cerebral hemispheres diagnosed as having suspected spasm was 11.1% for nicardipine and 64.3% for the placebo (p = 0.02881). The average time for recovery (DFV < 100 cm/second) was 3.33 days with the placebo and 1.22 days with nicardipine (p = 0.0039). The patients treated with nicardipine had 8.89 times more chance of recovery from vasospasm. The incidence of adverse effects was greater with the placebo (p = 0.014).

CONCLUSION

Nicardipine is effective in the reversal and prevention of increased Doppler flow velocity in patients with moderate or severe head injury.

Economic evaluation of Viaflex with vial adapter in a unit-dose drug distribution system

The cost of parenteral admixtures has an important impact on the hospital budget. Recently, a Viaflex with vial adapter (named 'minibag plus' in some countries) has been commercialized in order to facilitate parenteral admixture preparation. In the present study a preparation using Viaflex with a vial adapter has been economically compared with a preparation with a traditional Viaflex (without adapter) in a centralized unit or in nursing wards in a unit-dose drug distribution system. A cost-analysis was conducted from the hospital point of view. Direct costs were considered: these included supplies and human resources. Differences in the whole process between the two types of Viaflex were analysed. The process included: purchasing, reception, storage, medical order record, preparation in the Pharmacy Service (PS), delivery from the PS to the nursing unit, preparation by the nurse, return of unused material to the PS. Human resource costs were estimated by time counting and multiplying by the average salary. To estimate wasted material, drug and supplies delivered from the PS and returned to the PS were counted during 26 days. With the new Viaflex costs are reduced by 30% in comparison with drug dilution using the traditional Viaflex in a centralized unit of the PS, and by 13.4% in comparison with preparation with the traditional Viaflex in the nursing ward. In addition it can be estimated that contamination risk with the new Viaflex is lower than preparation in the nursing ward with the traditional Viaflex. Therefore, owing to its lower cost we recommend the use of Viaflex with vial adapter for drug dilution for those vials that are compatible with the system.

[Lewy bodies dementia: new data for the understanding of neuroimaging]

INTRODUCTION

The criteria for diagnosis of dementia with Lewy bodies (DLB) do not include neuroimaging, and few reports have been published on this.

OBJECTIVE

To report our observations of cerebral CAT and MR studies in 25 patients with probable DLB.

PATIENTS AND METHODS

Measurement of the surface of the cerebral lobes and the hippocampal region in two axial sections on CAT and MR and three coronal sections on MR. Our controls were 27 persons with probable Alzheimer's disease and 30 healthy persons of the same age group.

RESULTS

The size of the frontal, parietal and temporal lobes in DLB is intermediate between the values found in Alzheimer's disease and those found in asymptomatic persons, but without significant differences from these. Atrophy of the hippocampal region seen in DLB is significant as compared with healthy persons, but not when compared with those with Alzheimer's disease, in whom it was greater still. In the patients in whom DLB was still not an advanced stage, there was no atrophy of the occipital lobes, in spite of other observers having found hypoactivity of these lobes on SPECT and PET.

CONCLUSION

In the sample studied, structural imaging techniques were not useful in the diagnosis of DLB.

Interaction of a monoclonal antibody against hEGF with a receptor site for EGF

Epidermal growth factor (EGF) has been detected by radioimmunoassay (RIA) in different body fluids such as serum, amniotic fluid, and urine. Human tumor tissues with EGF receptors (EGF-Rc) may be saturated with EGF, which may be of prognostic value. An RIA was envisaged to measure human epidermal growth factor (hEGF) levels using EGF-Rc as capture agent and a monoclonal antibody anti-hEGF (MAb anti-hEGF) labeled with 125Iodine as a marker for this binding. The purpose of this work was to study the feasibility of MAb anti-hEGF to detect the receptor binding sites and to investigate the interaction between MAb anti-hEGF and the EGF-Rc. Various binding experiments were performed to study possible interference and interactions in the complex MAb anti-hEGF and the receptor. Affinity constants were determined by means of Scatchard plot analysis to interpret the complex stability challenged with other compounds for a better understanding of the interaction process. Binding constants were of the same order for all the ligands tested separately involving the EGF-Rc, but were significantly higher (t = 15.7, p < 0.05) for hEGF in its binding to MAb anti-hEGF. It was possible with equilibrium studies and competition experiments to evaluate the interaction of EGF and MAb anti-hEGF with the EGF receptor. This observation makes the MAb anti-hEGF a potential tracer for the quantitation of receptors in vitro, and possibly for the detection of membrane receptors on tumor cells in vivo.

Can accurate data on birthweight be obtained from health interview surveys?

BACKGROUND

Because hospital records rarely exist for a representative sample of the population in developing countries, researchers frequently rely on birthweight data from surveys. Yet, the quality of these data has rarely been evaluated. This study explores the accuracy of birthweight information in six demographic and health surveys in Latin America conducted in the early 1990s: two in Guatemala, and one each in Bolivia, Costa Rica, El Salvador and Peru.

METHODS

The quality of the birthweight reports is assessed by examining the plausibility of estimates of the proportion of newborns reported to have been weighed and estimates derived from the numerical weights, by characteristics of the delivery and maternal education.

RESULTS

The estimates suggest that a substantial proportion of women whose newborns were probably never weighed report a birthweight. For all of the surveys, with the possible exception of Costa Rica, the average birthweights appear to be too high, and the estimates of the prevalence of low birthweight too low. In addition, the data reveal anomalous patterns, such as higher birthweights for home as compared with hospital deliveries.

CONCLUSIONS

These findings suggest that estimates of low birthweight derived from surveys in developing countries are likely to portray an overly optimistic picture of children's and women's health status. More information about the underlying source of these data are needed not only to provide additional insight into the degree of error characterizing existing estimates, but also to improve data collection strategies in future health interview surveys.

The tropicamide test in patients with dementia of Alzheimer type and frontotemporal dementia

The tropicamide test was applied to 30 patients with probable Alzheimer's disease (pAD), 12 with frontotemporal dementia (FTD) and 46 healthy subjects. One drop of 0.01% tropicamide was instilled in one eye and one drop of saline solution in the other. The pupil diameter was measured with a Goldmann pupillometer in its basal condition and 10, 15, 20, 25, 30, 35, 45 and 55 minutes afterwards. The results do not show differences between pupil dilation observed in pAD and in FTD; in both groups, from the beginning of the test, the pupil dilated more than in healthy people. A high interindividual variability was observed. The best cutoff point is 38% of interpupillary difference at minute 25 (sensitivity = 63%, specificity = 80%). If we consider the prevalence of AD in a population over 40 years old to be 1.4%, the adjusted positive predictive value of the test would be 4.2%. According to these results, the test is not a true diagnostic marker of AD.

[A study of bilingual Galician-Castillian aphasic patients]

INTRODUCTION

Aphasia in bilingual persons has some striking peculiarities. Most studies have been carried out in mono-lingual societies, where the second language has usually been learnt after immigration. In Galicia, linguistic closeness and simultaneous learning of Galician and Castilian languages permits the testing of neuropsychological theories conceived in other circumstances.

OBJECTIVE

In aphasic bilingual Galician-Castilian patients we studied how this affected denomination, designation and translation, different modes of recovery, variables associated with differential affectation, the presence and influence of specific phenomena of aphasia in bilingual persons on changes in dominance and mixing of the languages. Material and methods. We selected 49 patients, 29 men and 20 women aged between 32 and 85 years old. We analyzed the variables associated with differential affectation: types of aphasia, size and site of the lesion, aetiology, age, educational level, and the presence and influence of phenomena specific to aphasia in bilingual persons.

RESULTS

The test most affected was translation, to a lesser extent denomination, and finally designation. Capacity for recovery is greater in the dominant language. Translation recovers better than denomination and this better than designation. We found no changes in dominance, no selective loss of either language but have seen some interference in the non-dominant language.

CONCLUSIONS

The two languages are seen to be recovered equally, as were other languages previously studied in aphasiology.

[Progressive degenerative aphasia: clinical and neuroradiological observations in 18 cases]

INTRODUCTION

In some types of degenerative dementia aphasia is the main disorder. In primary progressive aphasia. (PPA) atrophy is limited to the dominant peri-sylvan region. We present 18 cases of progressive aphasia of degenerative origin, with or without dementia.

MATERIAL AND METHODS

We describe the clinical and neuro-radiological findings in 3 patients with 'aphasic dementia and motor neuron disease (ADMND)', 7 with 'semantic dementia' (DS), and 4 with 'fronto-temporal dementia' with 'marked non-fluent aphasia' (AFTD). Criteria published in recent years were used.

RESULTS

In patients with ADMND non-fluent aphasia progressed to global aphasia, with dementia occurring after 2-9 months, and death after an average of 17 months. In cases with SD, initial anomic aphasia progressed to transcortical sensory or global aphasia, and in patients with AFTD, Broca's aphasia or motor transcortical aphasia progressed to global aphasia. Seven of these patients had been initially diagnosed as having PPA and became demented after two years or more. In most of the cases the cognitive disorder had the characteristics of fronto-temporal dementia. All cases had cortical atrophy or asymmetrical cortical or cortico-subcortical atrophy. The 4 cases of non-fluent PPA were not demented after 21 months-6 years of illness, and showed perisylvan and left fronto-temporopolar atrophy.

CONCLUSIONS

The PPA may correspond to the initial form of at least three varieties of dementia, usually the fronto-temporal type. Dementia occurs after two years or more, except in patients with motor neurone disease, when there is a latent period of less than one year.

A randomized double-blind clinical trial of two antivenoms in patients bitten by Bothrops atrox in Colombia. The Regional Group on Antivenom Therapy Research (REGATHER)

A randomized double-blind clinical trial in 39 patients envenomed by Bothrops atrox in Antioquia and Chocó, Colombia, was performed to compare the efficacy and safety of 2 equine-derived antivenoms prepared at Instituto Clodomiro Picado, University of Costa Rica. Twenty patients received a monovalent anti-B. atrox antivenom (group A) and 19 patients were treated with a polyvalent (Crotalinae) antivenom (group B). Both antivenoms were equally efficient in the neutralization of the most relevant signs of envenoming (haemorrhage and blood clotting time alteration). Fourteen patients (36%) presented early adverse reactions to antivenoms and no significant difference between the 2 groups was observed. Urticaria (18%) was the most frequent early adverse reaction and there was no life-threatening anaphylactic reaction. Based on clinical criteria and serum venom levels, estimated by an enzyme immunoassay, 15 patients were classified into 2 groups: mild and moderate/severe envenoming. With the antivenom doses used in this study (3, 6 and 9 vials for mild, moderate and severe envenoming, respectively), both antivenoms were equally efficient in clearing serum venom levels within the first hour of treatment, and the levels remained below the lower limit of venom detection for 24 h. Antivenom concentration in serum remained high for up to 24 h after antivenom infusion, suggesting that an excess of antibody in relation to circulating antigen had been administered.

Successful oral desensitization to trimethoprim-sulfamethoxazole in acquired immune deficiency syndrome

OBJECTIVE

To study the outcome of a modified oral desensitization protocol for trimethoprim-sulfamethoxazole in human immunodeficiency virus infected patients with Pneumocystis carinii pneumonia and acquired immune deficiency syndrome.

DESIGN

A prospective study.

SETTING

Tertiary care referral center.

PATIENTS

Thirteen human immunodeficiency virus infected patients with Pneumocystis carinii pneumonia and allergy to sulfonamides who failed alternative therapy.

INTERVENTION

Oral desensitization to trimethoprim-sulfamethoxazole.

MEASUREMENTS

Nature of allergic reactions, toxicity of alternate medications, indication as well as outcome of trimethoprim-sulfamethoxazole desensitization and routine laboratory determinations.

RESULTS

The most common reaction to trimethoprim-sulfamethoxazole was generalized, pruritic maculopapular rash (n = 10, 76.9%) followed by urticaria/angioedema in two patients (15.38%). Two patients had generalized pruritus without rash. All patients (n = 13) tolerated oral desensitization to trimethoprim-sulfamethoxazole without any adverse reactions including three patients who were critically ill and on mechanical ventilation. Thus the success rate of our protocol was 100%. No patient had received antihistamines prior to or during the protocol. Four patients (5, 6, 7, and 9) were receiving prednisone for severe Pneumocystis carinii pneumonia. Total followup has ranged from 4 to 84 weeks. Two patients died during followup due to causes unrelated to desensitization. All other patients are tolerating trimethoprim-sulfamethoxazole without any allergic reactions.

CONCLUSIONS

Oral desensitization to trimethoprim-sulfamethoxazole, as per this protocol is safe, in that there were no systemic or cutaneous reactions during desensitization as well as followup. It is well tolerated in all patients, including the three critically ill patients. As judged by the outcome and ability to tolerate trimethoprim-sulfamethoxazole after desensitization, the procedure is successful in all patients in this study. Equipped with this protocol one can evaluate possible mechanisms of desensitization such as oral tolerance or mediator depletion in a controlled fashion.

Laparoscopic cholecystectomy in the third trimester of pregnancy

Laparoscopic cholecystectomy has become the method of choice for symptomatic cholelithiasis. Laparoscopic cholecystectomy during pregnancy is also becoming more accepted, as illustrated by several recent publications on this subject. In the third trimester, however, laparoscopic cholecystectomy has been less commonly attempted, with only a few case reports. We present a series of four patients who underwent laparoscopic cholecystectomy during the third trimester of pregnancy without complication. We describe a safe and effective technique for this procedure, and review the literature on this topic.

[The hostility complex and myocardial infarct]

Several studies have associated the hostility complex (part of type A personality) to the development of coronary atherosclerosis. The complex is composed by aggressive behavior, frequent rage outbursts, intolerance to waiting lines and sense of urgency. To investigate the occurrence of this behavioral trait, 50 post-myocardial infarction men were compared against 50 normal male subjects of the same age. In all of them sphygmomanometric blood pressure was obtained, total blood cholesterol was measured and hostility was quantified by means of the Cook and Medley's questionnaire and an arbitrary ad hoc scale. Diastolic blood pressure was significatively higher in post-infarction patients (82 +/- 10 vs 77 +/- 9, p < 0.001), as well as the cholesterol level (231 +/- 55 vs 197 +/- 43, p < 0.001). Also, hostility score was higher in the post-infarcted men (16 +/- 4 vs 13 +/- 5, p < 0.001). The hostility score showed correlation with the occurrence of myocardial infarction (p < 0.02). These results establish that post-myocardial infarction patients express more hostility than control subjects. It was not possible to establish the true nature of the relationship among hostility and diastolic blood pressure, total cholesterol and the occurrence of coronary events. Nevertheless, this study confirms that the hostility complex is frequently present in atherosclerotic patients.

[A preliminary study of low dosage zuclopenthixol depot in Alzheimer's disease]

Persistent psychomotor agitation and psychotic ideation in patients with Alzheimer's disease are normally treated orally with antipsychotic drugs and are occasionally treated with other drugs. Neuroleptics administered intramuscularly at very low doses are an alternative, especially when the patient rejects medicine as a results of his or her anosognosia or of paranoid manifestations. We present the results we obtained after observing the effects of depot zuclopenthixol in six patients with probable Alzheimer's disease (based upon NINCDS-ADRDA criteria). Psychic abnormalities were assessed as per the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Positive Symptoms (SAPS) and the Scale for the Assessment of Negative Symptoms (SANS). Possible extrapyramidal side effects were evaluated by means of the Abnormal Involuntary Movement Scale (AIMS). Initially 60 mg (0.3 ml) were administered intramuscularly and successive doses could be modified by +/-20 mg (0.1 ml) according to results seen on the various scales. During the first six weeks of treatment progressive improvement was noted on all three psychic functions scales in all patients. Between the sixth and twelfth weeks improvement continued although without significant change. The AIMS did not show significant changes in the twelve weeks of follow-up. We consider depot zuclopenthixol at low doses as efficacious in treating persistent psychomotor agitation and/or psychotic manifestations of Alzheimer's disease. No undesired side effects were observed in our group after a twelve week follow-up.

[Experience with pupil tropicamide test in Alzheimer's disease]

Scinto et al (Science 1994; 266: 1051-4) observed that a single drop of 0.01% tropicamide elicited more than a 13% pupil dilatation in 19 individuals with probable or possible Alzheimer's disease (AD) and 3 cognitive abnormal elderly without dementia, but not in 30 out of 32 normal elderly and 3 out of 4 patients suffering from other dementias. It could be an easy and bloodless test to help in diagnosing AD. We have administered the same test to 10 patients with probable AD (NINCDS-ADRDA criteria) and twenty 40-90 year-old control subjects (10 of whom were sons or daughters of AD patients and 10 without a family history of dementia). The researcher does not know which group the subject belongs to. He administers a single drop of 0.01% tropicamide in eye and one drop of 0.45% normal saline solution in the other (without knowing the contents of either vial) and measures the pupil diameter by means of a Goldmann pupilometer in basal condition and 10, 15, 25, 30, 35, 45, and 55 minutes after. The results show that it is necessary to measure the pupils at least between the minutes 25 and 55 to detect tha maximum pupil dilation in every case. The cutoff point to consider the result positive must be located between 43 and 50%. If we establish the cutoff point in 50% of pupil dilation, 90% of AD patients and 35% of control subjects show a positive response. There was not a statistically significant difference between both control groups. Our results from this test show a sensitivity of 90% and a specificity of 65%. The positive responses of some control subjects may express a weak specificity, or perhaps they mean that we have a marker of the pre-clinical stage of the disease before us.

[125I]IgM (KAU) human monoclonal cold agglutinin: labelling and studies on its biological activity

In order to study the interaction between an IgM cold agglutinin and the erythrocyte I antigen, the former antibody was labelled with 125I using the Chloramine-T, IODOGEN and Bolton-Hunter methods. High incorporation and adequate stability of the labelled IgM were obtained with all procedures. However, suitable biological activity was maintained only with the Bolton-Hunter method. Further studies suggest that tyrosine iodination affects antigen recognition by this IgM, whereas iodination of amino groups does not. The reagent thus prepared allowed the determination of the number of I sites per erythrocyte as well as the antibody affinity constant.

[Paramedian bithalamic infarct syndrome: report of five new cases]

Five patients were examined suffering from bilateral paramedian thalamic infarction, caused by occlusion of the posterior paramedian thalamo-subthalamic arteries, when they begin from one single pedicle. All cases began with obnubilation or transitory coma, followed by hypersomnia. Four patients showed vertical gaze paralysis, and the fifth vertical nystagmus. In three cases, nuclear lesion of the III cranial nerve was observed along with alteration of the photomotor reflexes, and there was miosis in one case. All were suffering from weakness in one or another limb or facial paresis and generalised acute hypotonia: only one patient had hemihypostesia. All five had dysarthria, ataxy and dysmetria, one had asterixis and two spasmodic crying. Between 5 and 12 months later, one had akinetic mutism and vertical gaze paralysis as the most noteworthy signs. The neuroradiological images show a bilateral ischemic lesion in the paramedian thalamic region, which extends in some cases to the anterior nucleus and in one case to the pulvinars; the lesion continues through the subthalamic regions and the medial part of the mesencephalic tegmentum, with a clear extension to the medial region of the cerebral peduncles in three cases and to the tectum in one case.

[Clinical diagnosis of dementia associated with cortical Lewy bodies]

8 cases of dementia associated with cortical Lewy bodies are dealt with, that were diagnosed in 1993 in examinations for dementia, using the Nottingham's clinical criteria. They make up 15.4% of primary degenerative dementias diagnosed in this examination. All developed a predominantly cortical dementia with variable bradiphrenia and a parkinsonian syndrome which was predominantly of the rigid-bradikinetic type. The dementia established itself rapidly -between 1 and 3 weeks- in 3 cases (37.5%). 50% of patients (4 cases) showed marked psychiatric symptoms. In 2 cases stiffness was predominantly axial and another had supranuclear paralysis of vertical gaze. 3 patients had no tremor, and 2 of the 5 remaining patients showed postural tremor. CT and axial MR images of the encephalon were similar to those observed in dementia of the Alzheimer type. The coronal MR carried out on 3 patients revealed less atrophy of the hypocampus than is normally observed in patients with dementia of the Alzheimer type who are at the same stage of development.

Comparison of biphasic and monophasic waveforms in epicardial atrial defibrillation

OBJECTIVES

Because biphasic waveforms have previously been shown to be more efficient than monophasic waveforms in defibrillation of the ventricle, we compared the efficiency of the two waveforms in defibrillation of the atria.

BACKGROUND

The development of an implantable atrial defibrillator would offer significant advantages over current approaches to the management of atrial fibrillation. Patient tolerance of atrial shocks from such a device, however, would depend critically on the deployment of an efficient waveform.

METHODS

Both the monophasic and biphasic shocks were of 8-ms duration, and the biphasic was a dual-capacitor waveform with equal first- and second-phase duration and leading-edge voltage. One hundred randomized atrial shocks were evaluated in 21 patients during cardiopulmonary bypass. Atrial fibrillation was induced by the application of alternating current. Atrial shocks were delivered through customized, contoured epicardial paddles applied to the posterior left atrial wall (surface area 11 cm2) and to the anterior right atrial wall (surface area 26 cm2).

RESULTS

For the monophasic waveform the delivered energy (joules) associated with 50% success (E50) was 1.44 J (95% confidence interval [CI] 0 to 11.2) and with 80% (E80) success 3.9 J (95% CI 2.42 to 109.8); for the biphasic waveform 50% success was achieved with 0.37 J (95% CI 0.36 to 0.38) (p = NS) and 80% success with 0.57 J (95% CI 0.56 to 0.58) (p < 0.05).

CONCLUSIONS

A biphasic waveform is more efficient than a monophasic waveform in atrial defibrillation. This may have implications for the development of an implantable atrial defibrillator for paroxysmal atrial fibrillation in addition to improvement of elective transthoracic and endocardial cardioversion of chronic atrial fibrillation.

Early ischaemia after severe head injury. Preliminary results in patients with diffuse brain injuries

Ischaemic brain lesions still have a high prevalence in fatally head injured patients and are the single most important cause of secondary brain damage. The present study was undertaken to explore the acute phase of severely head injured patients in order to detect early ischaemia using Robertson's approach of estimating cerebral blood flow (CBF) from calculated arterio-jugular differences of oxygen (AVDO2), lactates (AVDL), and the lactate-oxygen index (LOI). Twenty-eight cases with severe head injury were included (Glasgow Coma Scale Score below or equal to 8). All patients but one had a non-missile head injury. All the patients had a diffuse brain injury according to the admission CT scan. ICP measured at the time of admission was below 20 mmHg in 17 cases (61%). All patients were evaluated with the ischaemia score (IS) devised in our center to evaluate risk factors for developing ischaemia. Mean time from injury to the first AVDO2/AVDL study was 23.9 +/- 9.9 hours. According to Robertson's criteria, 13 patients (46%) had a calculated LOI (-AVDL/AVDO2) value above or equal to 0.08 and therefore an ischaemia/infarction pattern in the first 24 hours after the accident. Of the 15 patients without the ischaemia/infarction pattern, in three cases the CBF was below the metabolic demands and therefore in a situation of compensated hypoperfusion. No patient in our series had hyperaemia. Comparing different variables in ischaemic and non-ischaemic patients, only arterial haemoglobin and ischaemia score (IS) was significantly different in both groups. The ischaemia score had mean of 4.3 +/- 1.7 in the ischaemic group and 2.7 +/- 1.4 in non-ischaemic patients (p = 0.01). It is concluded that ischaemia is highly prevalent in the early period after severe head injury. Factors potentially responsible of early ischaemia are discussed.

Turbidity of hyperimmune equine antivenom: the role of phenol and serum lipoproteins

Twenty batches of polyvalent antivenom produced at the Instituto Clodomiro Picado were analyzed for turbidity, both before and after freezing-thawing and lyophilization. Eight batches became turbid upon freezing-thawing, and this change correlated with high levels of cholesterol, triglycerides and lipoproteins, especially beta-lipoprotein. Since normal horse serum does not become turbid after freezing-thawing, despite the fact that it has high lipoprotein levels, the possibility was raised that phenol, used as a preservative during serum fractionation, might affect lipoproteins, inducing the appearance of turbidity after freezing-thawing. This hypothesis was tested by fractionating a sample of hyperimmune serum either without phenol or using two different phenol concentrations (0.1 g/dl and 0.25 g/dl). Results showed that, although the three samples had the same cholesterol and triglyceride levels before fractionation, only the one having 0.25 g/dl phenol became turbid upon freezing-thawing, containing a diffuse lipoprotein band on electrophoresis. This finding suggests that turbidity in equine antivenoms depends on the interaction of at least three factors: (a) freezing, (b) high initial cholesterol and lipoprotein concentration in the serum, and (c) addition of phenol during fractionation of serum.

[Hematologic values and serum enzymes in horses inoculated with snake venoms for the production of antivenins in Costa Rica]

Blood components were studied in six horses immunized with snake venoms for the production of polyvalent antivenom in Costa Rica. No significant changes in hemoglobin or hematocrit throughout the immunization period were observed, whereas a significant increment in total serum proteins occurred in the second half of the immunization process, probably due to an increased synthesis of immunoglobulins. There were no significant changes in creatine kinase, but a slight increment was detected in both transaminases, although they did not exceed normal limits. These findings suggest the absence of relevant tissue damage in skeletal muscle, cardiac muscle and liver. In agreement with these results, horses did not develop signs of systemic poisoning, presenting only minor alterations at the site of venom injection, such as oedema, abscesses and fistulas. The development of anti-phospholipase A2 antibody response showed a prominent individual variability, as previously described.

Interference with sawfly (Arge pullata) poisoning in Fasciola hepatica-infected lambs

Lambs harbouring an 8-week-old infection with Fasciola hepatica, together with fluke-free animals, were dosed orally with 2 g per kg body weight of sawfly larvae (Arge pullata). Fluke-free, non-dosed lambs and lambs infected only with F. hepatica served as controls. Clinico-pathological observations on sawfly-dosed, fluke-free lambs revealed the characteristic picture of sawfly poisoning. Four of six animals had to be killed in extremis. In contrast, sawfly-dosed, fluke-infected lambs exhibited only moderate clinico-pathological signs of sawfly poisoning and no deaths occurred. A reduction in the sawfly-induced liver pathology as a consequence of the concurrent F. hepatica infection was also noted. Possible factors responsible for the antagonistic effect of F. hepatica infection on sawfly poisoning in lambs are discussed.

[Pneumatocele as a form of presentation of Pneumocystis carinii pneumonia]

Pulmonary infection by Pneumocystis carinii in patients with acquired immunodeficiency syndrome (AIDS) can result in different radiological patterns with an ever expanding spectrum. A 40-year-old male, infected with the human immunodeficiency virus (HIV), presented with toxic symptoms and multiple pulmonary cystic lesions in the context of a Pneumocystis carinii pneumonia. The rarity of this radiological presentation is discussed and literature is reviewed. In addition, the possible pathogenetic mechanisms are discussed, and emphasis is made on the need for higher suspicion index in similar presentations in patients at risk of HIV infection.

Involvement of lipid mediators in the pathogenesis of experimental nephrosis in rats: its pharmacological modulation

The administration of a single-injection of Adriamycin (ADR) to rats results in marked proteinuria and glomerular morphological changes that are similar to minimal change disease in humans. We have hypothesized that Adriamycin, by itself or through the release of some mediators from resident glomerular cells, could provoke a damage to epithelial glomerular cells. Sprague-Dawley rats received a single injection of Adriamycin, 7.5 mg/kg bw, allocated randomly in several groups and treated throughout 2 weeks of follow-up. All control nontreated animals developed important nephrotic syndrome and degenerative lesions of epithelial glomerular cells. Isolated glomeruli from animals injected with adriamycin 14 days before synthesized thromboxane (TxB2) and platelet activating factor (PAF) in amounts above the rates of control glomeruli. Animals treated with three structurally different PAF receptor antagonists did not present proteinuria or only to a very low extent (p less than 0.0005). In these rats no alterations in epithelial cells were noted. Furthermore, no significant changes in the TxB2 production were noted in rats treated with BN 52021, a PAF receptor antagonist. Leukotrienes also seem to participate since treatment with a 5-lipoxygenase inhibitor partially corrected proteinuria. Moreover, glomeruli from animals with nephrosis and treated with this compound presented only a discrete reduction in the PAF synthesis. On the whole, these data suggest a key role for PAF in the pathogenesis of adriamycin nephropathy. Other lipid meditors, released in cascade simultaneously or thereafter, could perpetuate the renal damage.

Operative findings after percutaneous pulmonary balloon dilatation of the right ventricular outflow tract in tetralogy of Fallot

Since 1983 percutaneous balloon dilatation of the right ventricular outflow tract has been performed as an alternative to surgical palliation in selected cases of tetralogy of Fallot at the Royal Liverpool Children's Hospital. From 31 December 1984 to 31 December 1988, 27 of these patients underwent subsequent surgical correction. Age at operation ranged from 7 to 58 months (median 2.7 years). The mean interval between balloon dilatation and correction was 15.6 months (range 3-39 months). Two patients had a systemic pulmonary shunt operation performed before dilatation and a further five required one afterwards. Overall 20 (74%) patients had some anatomical alteration as the result of balloon dilatation, while in seven (26%) there was no discernible change in the right ventricular outflow tract. There was no consistent relation between the ratio of balloon size to pulmonary annulus diameter and the morphological findings. Balloon dilatation may obviate the need for systemic-pulmonary shunt at the expense of some structural damage, particularly to the posterior cusp. The present data suggest that dilatation does not bring about growth of the annulus to such an extent that transannular patch is no longer needed at intracardiac repair.

Left ventricular fibroma: echocardiographic diagnosis and successful surgical excision in three cases

The management of three patients with left ventricular fibromas is outlined. All were asymptomatic children. Routine chest radiography suggested cardiac masses. M-mode and two-dimensional echocardiography were valuable adjuncts to conventional angiography in assessing these children. Electrocardiographic changes, present in all cases, were shown to regress postoperatively. We stress the importance of these noninvasive aids in the initial investigation and outline our operative methods of reconstruction.

[Acute ischemia of lower limb and long-term treatment with epidural bupivacaine]

We report the treatment of an ischemic lower limb (arterial obstruction shown by angiography at popliteal level, proximal to common tibioperoneal artery) with 0.125% and 0.20% epidural bupivacaine, which was continuously administered by pump during 30 days. Simultaneously, 8 mg morphine chloride was administered every 24 hours by epidural route, anticoagulation with heparin was started, and transcutaneous electrical stimulation was used. The favorable outcome, with sufficient peripheral revascularization, permitted to preserve the limb. During therapy no sign of cardiac toxicity attributable to bupivacaine was detected.

[The development of the anti-phospholipase A2 antibody response in horses inoculated with venom for the production of polyvalent antisnake serum in Costa Rica]

The development of antibody response against phospholipase A2 activity of Bothrops asper venom was studied in a group of adult and healthy horses used in the production of the polyvalent antivenom at the Instituto Clodomiro Picado. Simultaneously, the general condition of the animals during the immunization schedule was also studied. There was a great individual variability in the immune response, although most of the horses studied reached the highest neutralizing titer after injection of doses of venom of 30 mg and 50 mg. On the other hand, in horses that had been previously immunized and were infected for a second immunization, the highest antibody titer was observed 16-22 days after inoculation. There were only mild alterations in the general condition of the horses as a consequence of venom inoculation. However, local abscesses, fistulae and fibrosis were observed at the site of venom injection. On the basis of the conspicuous individual variability observed, it is proposed that the immune response in horses used in the production of antivenom must be evaluated on individual basis, instead of working with pools of serum samples.

Truncus arteriosus with interrupted aortic arch: successful correction in a neonate

Truncus arteriosus (type II) with interrupted aortic arch (type B) was successfully repaired at 11 days of age using anterior translocation of the pulmonary arteries, resection of the ductus arteriosus, and direct anastomosis between the descending aorta and truncus. This technique permitted wide reconstruction of the aortic arch and minimized the number of suture lines. It also positioned the right ventricle-pulmonary artery conduit anteriorly, which may simplify its subsequent replacement.