A confidence interval analysis of three studies using the Alzheimer's disease knowledge test

It has been suggested that community awareness of Alzheimer's disease (AD) has increased over recent years. This claim has been difficult to evaluate given the lack of systematic research in this area however, despite some recent attempts at monitoring changes in knowledge about AD. To address the question of change in awareness about AD, the present study compared results from three studies that have investigated the level of AD knowledge among undergraduate students, using confidence intervals. Consistent with previous findings, the results of this study suggest that more recent cohorts of undergraduate students are more knowledgeable about some aspects of AD, although to an extent that is much less marked than previously thought. Importantly, there are also a number of areas in which there appears to have been little or no change in community awareness about AD, and these are highlighted as issues that may need to be specifically addressed as part of future career education programs.

Examining the influence of biological and psychological factors on cognitive performance in chronic fatigue syndrome: a randomized, double-blind, placebo-controlled, crossover study

The pathophysiology of chronic fatigue syndrome (CFS) remains unclear; however, both biological and psychological factors have been implicated in establishing or maintaining this condition. People with CFS report significant and disabling cognitive difficulties such as impaired concentration that in some cases are exacerbated by exposure to chemical triggers. The aim of this study was to determine if neuropsychological deficits in CFS are triggered by exposure to chemicals, or perceptions about the properties of these substances. Participants were 36 people with a primary diagnosis of CFS, defined according to Centers for Disease Control (CDC) criteria. A randomized, double-blind, placebo-controlled, crossover design was used, with objective assessment of neuropsychological function and participant rating of substance type, before and after exposure to placebo or chemical trigger. Results showed decrements in neuropsychological tests scores on three out of four outcome measures when participants rated the substance they had been exposed to as "chemical." No change in performance was found based on actual substance type. These results suggest that cognitive attributions about exposure substances in people with CFS may be associated with worse performance on neuropsychological tasks. In addition, these findings suggest that psychological interventions aimed at modifying substance-related cognitions may reduce some symptoms of CFS.

Malingering on subjective complaint tasks: an exploration of the deterrent effects of warning

Assessing patient's subjective experience of illness is an important component of neuropsychological assessment. This information can be assessed using standardized self-reported complaint (SRC) checklists and may have specific applications in the assessment of malingering. Previous research suggests that subjective complaints can be faked under some circumstances, however, the extent to which this occurs when assessments are made using standardized SRC measures is less well understood. In addition, if complaints can be faked, this raises the question: What might reduce the likelihood of faked symptom reports? In this study, we randomly allocated 60 first-year undergraduate subjects to one of the three conditions: malingering, malinger-with-warning, and control. Using a repeated-measures analogue design, we assessed differences between groups on selected SRC measures. The measures used were the Neuropsychological Symptoms Checklist (NSC), the General Health Questionnaire-30 (GHQ-30), and the Depression, Anxiety, and Stress Scales (DASS). We expected to find that SRC measures would be vulnerable to faking, but also that warning malingerers about the possibility of detection would reduce faking behavior. Further, control group scores on SRC measures were calculated to produce preliminary complaint base rate data for these tests. Our results showed that SRC measures were vulnerable to faking. In addition, contrary to expectations, we found that warnings did not significantly deter malingering, although we observed that a trend in the expected direction and future studies with a larger sample size or a modified warning may be needed to further investigate warning efficacy. Broader implications of these findings are discussed in light of deterrence theory and recent debate over the use of SRC measures in the assessment of malingering.

Malingering on the RAVLT: Part II. Detection strategies

In this study two potential indices of malingering derived from the Rey Auditory Verbal Learning Test (RAVLT) were evaluated as a means of detecting malingering. These were indices based on discrepancies between recognition-recall scores and differences in the serial position effect (SPE). Sixty undergraduate students were randomly assigned to one of four conditions: malingerers, malingerers-with-warning, warning-only, and control. Incentives were offered to participants in all conditions to encourage faking in a believable manner (malingering conditions), or to encourage optimal performance (nonmalingering conditions). Two predictions were made. First, it was predicted that the serial position curve for subjects in malingering conditions would show suppression of primacy effects relative to nonmalingerers. Second, it was predicted that recall would be better than recognition for subjects in malingering conditions compared to nonmalingering conditions. The utility of these indices was also explored in the context of providing subjects' with warnings regarding use of methods to detect malingering. Results indicated that both indices failed to reliably differentiate between malingerers and nonmalingerers, and warnings failed to modify participants' behaviour.

Oxygen-mediated regulation of porphobilinogen formation in Rhodobacter capsulatus

A Rhodobacter capsulatus hemC mutant has been isolated and used to show that oxygen regulates the intracellular levels of porphobilinogen. Experiments using a hemB-cat gene fusion demonstrated that oxygen does not transcriptionally regulate hemB transcription. Porphobilinogen synthase activity is not regulated by oxygen nor is the enzyme feedback inhibited by hemin or protoporphyrin IX. It was demonstrated that less than 20% of [(14)C]aminolevulinate was incorporated into bacteriochlorophyll, suggesting that the majority of the aminolevulinate is diverted from the common tetrapyrrole pathway. Porphobilinogen oxygenase activity was not observed in this organism; however, an NADPH-linked aminolevulinate dehydrogenase activity was demonstrated. The specific activity of this enzyme increased with increasing oxygen tension. The results presented here suggest that carbon flow over the common tetrapyrrole pathway is regulated by a combination of feedback inhibition of aminolevulinate synthase and diversion of aminolevulinate from the pathway by aminolevulinate dehydrogenase.

Graves' disease in patients with 22q11.2 deletion

We report 4 female patients and 1 male patient with a 22q11.2 deletion and Graves' disease diagnosed at age 27 months, 7, 10, 17, and 16 years, respectively. The clinical presentations were typical for hyperthyroidism, but 1 female infant had seizures in addition to symptoms of hyperthyroidism. All patients had elevated serum levels of thyroid hormones in association with suppressed thyroid-stimulating hormone levels. From these observations, we suggest that Graves' disease may be a part of the clinical spectrum associated with the 22q11.2 deletion syndrome.

Beta-adrenergic antagonist exposures in children

Since limited toxicological data exists for beta-adrenergic antagonist (BA) exposures in children, a survey to describe triage practices by regional poison centers nationwide and to characterize clinical manifestations of unintentional pediatric BA exposures was sent to 49 poison centers. A 7-y retrospective review of acute BA exposures in children aged < 7years from 1 regional poison center was also undertaken. Thirty-three centers (67%) responded: 19/33 (58%) had no established BA triage guideline for young children. The 14/33 remaining centers (42%) most often referred these children to a hospital if any BA was ingested. In the 1-center review, metoprolol (28%) and atenolol (27%) exposures were most common, but = 1 tablet of BA was involved in 83% of the exposures. Symptoms occurred in 8 children; 2/378 had lethargy and 6/378 had bradycardia and/or hypotension. Immediate-release preparations were ingested by 7/8 symptomatic patients (median time to onset of symptoms = 3.0 h, range 45 min to 3.5 h). Of 280 children with definitive follow-up, 272 had no clinical effects, 4 had minor effects, and 4 had moderate effects. Regional poison centers commonly refer children exposed to any amount of BA to the hospital. The majority of BA exposures involved a small amount and significant clinical effects were rare. The range of toxicity for BA in children needs to be established.

Mapping from sound to meaning: reduced lexical activation in Broca's aphasics

Recent studies of lexical access in Broca's aphasics suggest that lexical activation levels are reduced in these patients. The present study compared the performance of Broca's aphasics with that of normal subjects in an auditory semantic priming paradigm. Lexical decision times were measured in response to word targets preceded by an intact semantically related prime word ("cat"-"dog"), by a related prime in which one segment was acoustically altered to produce a poorer phonetic exemplar ("c*at"-"dog"), and by a semantically unrelated prime ("ring"-"dog"). The effects of the locus of the acoustic distortion within the prime word (initial or final position) and the presence of potential lexical competitors ("cat" --> /gaet/versus "coat" --> "goat") were examined. In normal subjects, the acoustic manipulations produce a small, short-lived reduction in semantic facilitation irrespective of the position of the distortion in the prime word or the presence of a voiced lexical competitor. In contrast, Broca's aphasics showed a large and lasting reduction in priming in response to word-initial acoustic distortions, but only a weak effect of word-final distortions on priming. In both phonetic positions, the effect of distortion was greater for prime words with a lexical competitor. These findings are compatible with the claim that Broca's aphasics have reduced lexical activation levels, which may result in a disruption of the bottom-up access of words on the basis of acoustic input as well as increased vulnerability to competition between acoustically similar lexical items.

Remote delivery of rAAV-GFP to the rat brainstem through the recurrent laryngeal nerve

OBJECTIVE

To demonstrate that a recombinant adeno-associated viral vector (rAAV) carrying the gene for green fluorescent protein (GFP) could be delivered to the rat brainstem by remote injection into the recurrent laryngeal nerve.

STUDY DESIGN/METHODS

rAAV-GFP is a serotype 2 adeno-associated vector containing the cDNA of GFP and woodchuck hepatitis virus posttranscriptional regulatory element (WPRE) under the control of the CAG promoter (obtained from Matthew During, PhD, Thomas Jefferson Medical College). Five microliters or 10 microL of 1.4 x 109 particles/microL of rAAV-GFP were injected into the right recurrent laryngeal nerve of adult Sprague-Dawley rats. Rats were killed and perfused at 3 (n = 3) and 11 weeks (n = 3). Brainstems were removed and cryosectioned. Fluorescent in-situ hybridization (FISH) was performed on cryosections from animals killed at 3 weeks using a cDNA probe for woodchuck polyribosomal enzyme within the rAAV vector. In a third group (n = 2), Fluoro-Gold (Fluorochrome, Inc., Denver, CO) was injected into the right thyroarytenoid muscle for comparison of neuronal uptake distribution. These rats were killed and perfused at 3 weeks.

RESULTS

The presence of GFP was noted in neurons throughout the medulla of all rat brainstems after unilateral rAAV-GFP injection at both 3 and 11 weeks. In contrast to the Fluoro-Gold, GFP was noted bilaterally and outside of the nucleus ambiguus. FISH confirmed the presence of virus within neurons expressing GFP at 3 weeks.

CONCLUSIONS

Remote delivery of rAAV-GFP to the rat brainstem is possible through injection into the recurrent laryngeal nerve. This has important therapeutic implications for the future treatment of recurrent laryngeal nerve injury and neurodegenerative diseases.

Should a diagnosis of Alzheimer's disease be disclosed?

There is evidence that some health practitioners may be reluctant to disclose a diagnosis of Alzheimer's disease (AD) to patients. However, this reluctance towards disclosure may not be in accordance with patient expectation. This study examined the attitudes of 100 undergraduate psychology students towards disclosure practices in relation to AD, before and after exposure to AD education. After AD education, 93% of participants indicated a desire to be informed of a diagnosis of AD, and 95% of participants were in favour of telling a close relative a diagnosis of AD. Results are discussed in terms of the relationship between age and attitudes towards AD diagnosis. It is concluded that the high rate of support for disclosure of AD diagnoses to patients among younger adults may reflect a change in the information preferences of patients brought about by a shift away from a patriarchal medical model, toward a more autonomous model of health.

Isolation of a unique membrane protein from Naegleria fowleri

Naegleria fowleri, an amoeboflagellate, is the causative agent of Primary Amoebic Meningoencephalitis, a fulminating disease of the central nervous system. In order to elucidate the mechanisms of pathogenicity of this amoeba, a cDNA expression library was prepared from N. fowleri RNA. A specific protein was found to be expressed from a cDNA clone designated Mp2CL5. Northern blot analysis showed that the Mp2CL5 mRNA was expressed in pathogenic N. fowleri but was not expressed in non-pathogenic Naegleria species nor in Acanthamoeba. Western blot analysis using anti-N. fowleri antiserum demonstrated that IPTG-induced Escherichia coli Mp2CL5 expressed a 23-kDa recombinant protein. The Mp2CL5 recombinant protein was histidine-tagged and purified to homogeneity from E. coli. A polyclonal rabbit antiserum was prepared against the purified Mp2CL5 recombinant protein. This antibody was used to further characterize the Mp2CL5 native protein expressed by N. fowleri. Western blot analysis in conjunction with immunofluorescence microscopy demonstrated the presence of a native protein of 17 kDa on the plasma membrane of N. fowleri trophozoites. The native N. fowleri protein was expressed in the logarithmic phase of trophozoite growth and the production of this protein increased through the stationary phase of growth. Studies are in progress to examine further its role as a virulence factor.

Malingering on the RAVLT. Part I. Deterrence strategies

The effect of warning regarding detection of malingering on the Rey Auditory Verbal Learning Test (RAVLT) was examined in this study. Sixty undergraduate students were randomly assigned to one of four conditions: malingerers, malingerers-with-warnings, warning-only, and control. An incentive that appeared differential, but was an actual constant reward, was offered to participants who could fake in a believable manner (for those in malingering conditions), or to those who performed to the best of their ability (non-malingering conditions). It was predicted that warning participants about the possibility that faking could be detected would modify the behaviour of malingerers, but not those instructed to perform to the best of their ability. Warning had no effect on behaviour in either condition, which was consistent with expectations for the warning-only group, but not for the malingering group. Results are discussed in terms of the ethical and legal issues associated with malingering in neuropsychological practice.

Phase I/II trial of autologous stem cell transplantation in systemic sclerosis: procedure related mortality and impact on skin disease

BACKGROUND

Systemic sclerosis (SSc, scleroderma) in either its diffuse or limited skin forms has a high mortality when vital organs are affected. No treatment has been shown to influence the outcome or significantly affect the skin score, though many forms of immunosuppression have been tried. Recent developments in haemopoietic stem cell transplantation (HSCT) have allowed the application of profound immunosuppression followed by HSCT, or rescue, to autoimmune diseases such as SSc.

METHODS

Results for 41 patients included in continuing multicentre open phase I/II studies using HSCT in the treatment of poor prognosis SSc are reported. Thirty seven patients had a predominantly diffuse skin form of the disease and four the limited form, with some clinical overlap. Median age was 41 years with a 5:1 female to male ratio. The skin score was >50% of maximum in 20/33 (61%) patients, with some lung disease attributable to SSc in 28/37 (76%), the forced vital capacity being <70% of the predicted value in 18/36 (50%). Pulmonary hypertension was described in 7/37 (19%) patients and renal disease in 5/37 (14%). The Scl-70 antibody was positive in 18/32 (56%) and the anticentromere antibody in 10% of evaluable patients. Peripheral blood stem cell mobilisation was performed with cyclophosphamide or granulocyte colony stimulating factor, alone or in combination. Thirty eight patients had ex vivo CD34 stem cell selection, with additional T cell depletion in seven. Seven conditioning regimens were used, but six of these used haemoimmunoablative doses of cyclophosphamide +/- anti-thymocyte globulin +/- total body irradiation. The median duration of follow up was 12 months (3-55).

RESULTS

An improvement in skin score of >25% after transplantation occurred in 20/29 (69%) evaluable patients, and deterioration in 2/29 (7%). Lung function did not change significantly after transplantation. One of five renal cases deteriorated but with no new occurrences of renal disease after HSCT, and the pulmonary hypertension did not progress in the evaluable cases. Disease progression was seen in 7/37 (19%) patients after HSCT with a median period of 67 (range 49-255) days. Eleven (27%) patients had died at census and seven (17%) deaths were considered to be related to the procedure (direct organ toxicity in four, haemorrhage in two, and infection/neutropenic fever in one). The cumulative probability of survival at one year was 73% (95% CI 58 to 88) by Kaplan-Meier analysis.

CONCLUSION

Despite a higher procedure related mortality rate from HSCT in SSc compared with patients with breast cancer and non-Hodgkin's lymphoma, the marked impact on skin score, a surrogate marker of mortality, the trend towards stabilisation of lung involvement, and lack of other treatment alternatives justify further carefully designed studies. If future trials incorporate inclusion and exclusion criteria based on this preliminary experience, the predicted procedure related mortality should be around 10%.

Changing from cyclosporine to tacrolimus as salvage therapy for chronic graft-versus-host disease

Chronic graft-versus-host disease (GVHD) is the principal cause of transplantation-related morbidity and nonrelapse mortality late after allogeneic hematopoietic stem cell transplantation. The safety and potential efficacy of tacrolimus for the salvage treatment of chronic GVHD was evaluated in a single-arm, open-label phase 2 study. A total of 39 evaluable patients with chronic GVHD who failed previous immunosuppressive therapy with cyclosporine and prednisone were treated with tacrolimus starting at a median of 20 months (range, 3-68 months) after transplantation. At 3 years after the start of treatment, 5 patients (13%) had discontinued tacrolimus and were in complete remission, and 3 were considered clinically stable but not able to discontinue tacrolimus. A total of 31 patients (79%) experienced treatment failure; 22 (56%) who failed therapy had a change in immunosuppressive regimen because of progression (n = 18) or toxicity (n = 4). Nine patients (23%) died during continued treatment with tacrolimus. Two patients were lost to follow-up, at 11 and 19 months. The median duration of treatment with tacrolimus was 9 months (range, 1-29 months). Infections (144 episodes) were the most frequent adverse event. Nephrotoxicity occurred in 16 patients (41%); tacrolimus was discontinued in only 2 patients because of progressive deterioration in renal function. The Kaplan-Meier estimate of survival was 64% (95% confidence interval, 49%-79%) at 3 years posttransplantation. Seven patients had discontinued all immunosuppression at last contact, leading to an estimated 29% probability of stopping all immunosuppression by 3 years posttransplantation. Four patients died after relapse of malignancy. The response rate is consistent with previous reports of salvage treatment for chronic GVHD, indicating that a small group of patients failing cyclosporine may respond or stabilize with tacrolimus.

On the "efficiency" of managed care plans

The claim that managed care plans are more efficient than fee-for-service plans has been made so often that it has reached the status of folklore, but the evidence is inconclusive. The claim is usually based on one or both of the following errors: (1) lower medical care costs mean lower total costs (medical plus administrative costs) and (2) lower HMO premiums mean HMOs are more efficient than fee-for-service plans. The first assertion ignores evidence indicating that managed care has driven up administrative costs for both insurers and providers. The second ignores evidence that managed care plans have numerous methods of shifting costs that are unavailable or less available to fee-for-service plans. The lull in health care inflation during the mid-1990s is often cited as evidence that managed care is efficient. But the lull may have been caused not by the spread of managed care but by the near-simultaneous occurrence of four events: a downturn in the insurance underwriting cycle, the 1990-1991 recession, endorsement of managed competition by numerous politicians, and the merger fever triggered by those endorsements.

Intravenous ketorolac in the emergency department management of sickle cell pain and predictors of its effectiveness

OBJECTIVES

To evaluate the effectiveness of intravenous (IV) ketorolac tromethamine in the treatment of children with sickle cell disease with moderate to severe acute vaso-occlusive pain (VOP) and to develop a predictive model that would determine who would need additional IV analgesics.

DESIGN

A prospective case series.

SETTING

The emergency department of an urban children's hospital in the southeastern United States.

PATIENTS

A convenience sample of 51 children aged 6 to 18 years, representing 70 distinct episodes of VOP requiring IV analgesics.

INTERVENTION

All patients were given 0.5 to 1 mg/kg IV ketorolac and IV fluids.

MAIN OUTCOME MEASURES

Patients, parents, nurses, and physicians assessed pain before and after ketorolac using a standard 100-mm visual analog scale (VAS).

RESULTS

Of the 70 episodes of VOP, 37 (53%) adequately resolved with IV ketorolac and IV fluids and required no IV opioids (group A). Thirty-one episodes (47%) required the addition of an IV opioid (group B). Group B had a significantly greater proportion of episodes reporting 4 or more painful sites than group A, 43% (12/28) vs 9% (3/33), respectively (P<.01). Group B also had significantly higher mean initial VAS scores than group A as assessed by the patient (81 vs 60; P<.01), parent (71 vs 54; P<.01), nurse (78 vs 51, P<.01), and physician (69 vs 53; P =.01). Of the patient assessments with an initial VAS score greater than 70, 69% (18/26) required the addition of an opioid.

CONCLUSIONS

First-line therapy with IV ketorolac and IV fluids resulted in adequate resolution of pain in 53% of episodes with acute VOP. A reported 4 or more painful sites and an initial VAS score greater than 70 were predictors of the likelihood to need additional IV analgesics.

The 22q11.2 deletion: screening, diagnostic workup, and outcome of results; report on 181 patients

A submicroscopic deletion of chromosome 22q11.2 has been identified in the majority of patients with the DiGeorge syndrome, velocardiofacial syndrome, conotruncal anomaly face syndrome, and in some patients with isolated conotruncal cardiac anomalies, Opitz G/BBB syndrome, and Cayler cardiofacial syndrome. We have evaluated 181 patients with this deletion. We describe our cohort of patients, how they presented, and what has been learned by having the same subspecialists evaluate all of the children. The results help define the extremely variable phenotype associated with this submicroscopic deletion and will assist clinicians in formulating a management plan based on these findings.

Impact of contrast sensitivity performance on visually presented neurobehavioral tests in mercury-exposed children

Presentation of neuropsychological tests on a computer screen may involve a visual challenge to the examinee. The possible need for adjustment for visual contrast sensitivity on test performance was therefore determined from data on 917 mercury-exposed children who were examined at age 7 years. Contrast sensitivity was found to be associated with performance on the computer-assisted Continuous Performance Test. However, it showed similar associations with performance on traditional pencil-and-paper tests, especially Bender Visual Motor Gestalt Test and Wechsler Intelligence Scale for Children-Revised (WISC-R) Block Designs. Contrast sensitivity was not associated with prenatal mercury exposure, and adjustment for visual function had only a negligible effect on the regression coefficients for mercury as predictor of neuropsychological deficits. The mercury-associated neurobehavioral deficits are therefore unlikely to be due to mercury-induced visual system dysfunction causing secondary deficits in cognitive domain testing. Visuospatial processing appears to be a determinant in contrast sensitivity performance, and careful consideration of whether to control for contrast sensitivity in future studies of neurotoxicant effects is therefore recommended.