Are we assuming too much with our statistical assumptions? Lessons learned from the ALTTO trial

BACKGROUND

Design, conduct, and analysis of randomized clinical trials (RCTs) with time to event end points rely on a variety of assumptions regarding event rates (hazard rates), proportionality of treatment effects (proportional hazards), and differences in intensity and type of events over time and between subgroups.

DESIGN AND METHODS

In this article, we use the experience of the recently reported Adjuvant Lapatinib and/or Trastuzumab Treatment Optimization (ALTTO) RCT, which enrolled 8381 patients with human epidermal growth factor 2-positive early breast cancer between June 2007 and July 2011, to highlight how routinely applied statistical assumptions can impact RCT result reporting.

RESULTS AND CONCLUSIONS

We conclude that (i) futility stopping rules are important to protect patient safety, but stopping early for efficacy can be misleading as short-term results may not imply long-term efficacy, (ii) biologically important differences between subgroups may drive clinically different treatment effects and should be taken into account, e.g. by pre-specifying primary subgroup analyses and restricting end points to events which are known to be affected by the targeted therapies, (iii) the usual focus on the Cox model may be misleading if we do not carefully consider non-proportionality of the hazards. The results of the accelerated failure time model illustrate that giving more weight to later events (as in the log rank test) can affect conclusions, (iv) the assumption that accruing additional events will always ensure gain in power needs to be challenged. Changes in hazard rates and hazard ratios over time should be considered, and (v) required family-wise control of type 1 error ≤ 5% in clinical trials with multiple experimental arms discourages investigations designed to answer more than one question.

TRIAL REGISTRATION

clinicaltrials.gov Identifier NCT00490139.

Bleeding risk, physical functioning and non-use of anticoagulation among patients with stroke and atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) is common among people with stroke. Anticoagulation medications can be used to manage the deleterious impact of AF after stroke, however, may not be prescribed due to concerns about post-stroke falls and decreased functioning. Thus, the purpose of this study was to identify, among people with stroke and AF, predictors of anticoagulation prescription at hospital discharge.

METHODS

This is a secondary analysis of a retrospective cohort study of data retrieved via medical records, including National Institutes of Health Stroke Scale score, Functional Independence Measure (FIM) motor score (motor or physical function), ambulation on second day of hospitalization, Morse Falls Scale (fall risk) and HAS-BLED score (Hypertension; Abnormal renal and liver function; Stroke; Bleeding; Labile INRs; Elderly >65; and Drugs or alcohol). Data analyses included bivariate comparisons between people with and without anticoagulation at discharge. Logistic-regression modeling was used to assess predictors of discharge anticoagulation.

RESULTS

There were 334 subjects included in the analyses, whose average age was 75 years old. Anticoagulation was prescribed at discharge for 235 (70%) of patients. In the adjusted regression analyses, only the FIM motor score (adjusted OR = 1.015, 95% CI 1.001-1.028) and the HAS-BLED score (adjusted OR = 0.36, 95% CI 0.22-0.58) were significantly associated with anticoagulation prescription at discharge.

CONCLUSION

It appears that in this sample, post-stroke anticoagulation decisions appear to be made based on clinical factors associated with bleed risk and motor deficits or physical functioning. However, opportunities may exist for improving clinician documentation of specific reasoning for non-anticoagulation prescription.

OT1-02-09: A Phase II Randomized Trial of Lapatinib with Either Vinorelbine or Capecitabine as First- and Second-Line Therapy for HER2−Overexpressing Metastatic Breast Cancer

Background: Lapatinib, a dual kinase inhibitor of epidermal growth factor receptor (EGFR) and the human epidermal growth factor receptor-2 (HER2/ErbB2), is approved for the treatment of HER2−overexpressing (HER2+) metastatic breast cancer (MBC) in combination with capecitabine following progression after trastuzumab, anthracyclines, and taxanes. Vinorelbine is an important chemotherapy option in MBC, and multiple phase II trials in combination with trastuzumab have been conducted.

Methods: This randomized, open-label, multicenter, phase II study (VITAL, LAP112620, NCT01013740) is evaluating the efficacy and safety of lapatinib with either vinorelbine or capecitabine in women with HER2+ MBC. A total of 105 stage IV breast cancer patients with disease progression who have received ≤1 chemotherapy regimen in the metastatic setting with an ECOG performance status of ≤1 are randomized 2:1 to either: lapatinib 1250 mg orally once daily (QD) continuously plus vinorelbine 20 mg/m2 intravenously on days 1 and 8 every third week; or lapatinib 1250 mg orally QD continuously plus capecitabine 2000 mg/m2/d orally in 2 doses 12 hours apart on days 1 to 14 every third week. Following progression in the randomized phase, patients will be given the option to cross over to the other arm. The primary endpoint is progression-free survival and will be analyzed with a descriptive intent since the study is not powered to detect differences between treatment arms. Secondary endpoints include overall response rate, overall survival, duration of response, time to response, and clinical benefit rate.

The study is currently recruiting in 8 countries in Europe (Bulgaria, France, Germany, Greece, Italy, Poland, Serbia, Spain) and 2 in Latin America (Chile, Mexico).

Funding Source: GlaxoSmithKline

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT1-02-09.

Poststroke depression and treatment effects on functional outcomes

BACKGROUND

Poststroke depression (PSD) is common after stroke; however, the relationship to poststroke function is inconclusive. Our objectives were to 1) determine the relationship between PSD at baseline (1 month poststroke) and function (12 weeks later) and 2) assess the impact of depression improvement on 12-week function among those with depression at baseline.

METHODS

We completed a secondary analysis of data from a cohort study of participants with and without PSD. We used logistic regression to identify factors associated with 12-week functional dependence for 1) all 367 participants and 2) the 174 participants with PSD.

RESULTS

In the PSD cohort, 3 characteristics were found to be independently associated with 12-week dependence: increased medical comorbidity (odds ratio [OR] 1.10, 95%confidence interval [CI] 1.02-1.22), increased stroke severity (OR 1.42, 95% CI 1.19-1.69), and increased baseline depression severity (OR 1.13, 95% CI 1.03-1.23). Depression severity was significantly different between those considered dependent and independent at 12 weeks (entire cohort, PHQ-9 7.31 vs 5.18, p = 0.008; depressed cohort, PHQ-9 9.94 vs 7.27, p = 0.019).

CONCLUSION

Among study participants with PSD, the severity of depression symptoms at baseline was associated with dependence; however, our results are inconclusive as to whether improvement of depression is independently associated with functional recovery at 12 weeks. Even if the treatment and improvement of PSD does not directly influence functional recovery poststroke, it is essential for PSD to be identified and treated due to its high symptom burden and association with other negative health and social outcomes.

Racial/ethnic disparities in access to physician care and medications among US stroke survivors

BACKGROUND

Mexican Americans and non-Hispanic blacks have higher stroke recurrence rates and lower rates of secondary stroke prevention than non-Hispanic whites. As a potential explanation for this disparity, we assessed racial/ethnic differences in access to physician care and medications in a national sample of US stroke survivors.

METHODS

Among all 4,864 stroke survivors aged≥45 years who responded to the National Health Interview Survey years 2000-2006, we compared access to care within the last 12 months by race/ethnicity before and after stratification by age (45-64 years vs ≥65 years). With logistic regression, we adjusted associations between access measures and race/ethnicity for sex, comorbidity, neurologic disability, health status, year, income, and health insurance.

RESULTS

Among stroke survivors aged 45-64 years, Mexican Americans, non-Hispanic blacks, and non-Hispanic whites reported similar rates of no generalist physician visit (approximately 15%) and inability to afford medications (approximately 20%). However, among stroke survivors aged≥65 years, Mexican Americans and blacks, compared with whites, reported greater frequency of no generalist visit (15%, 12%, 8%; p=0.02) and inability to afford medications (20%, 11%, 6%; p<0.001). Mexican Americans and blacks more frequently reported no medical specialist visit (54%, 49%, 40%; p<0.001) than did whites and rates did not differ by age. Full covariate adjustment did not fully explain these racial/ethnic differences.

CONCLUSIONS

Among US stroke survivors at least 65 years old, Mexican Americans and blacks reported worse access to physician care and medications than whites. This reduced access may lead to inadequate risk factor modification and recurrent stroke in these high-risk minority groups.

Views on the use of tissue plasminogen activator in acute ischemic stroke: a state-wide survey among neurologists and emergency medicine physicians in Indiana

Indiana emergency medicine physicians and neurologists were presented with 6 brief cases of patients presenting with acute ischemic stroke and asked whether they would administer tissue plasminogen activator (t-PA) in each case; 25% responded in concordance with published American Heart Association guidelines in all cases. Only 19% gave the appropriate exclusion in the 4 cases with definite exclusion criteria. Administering t-PA to a patient with elevated blood pressure was the most common deviation from the guidelines. More neurologists reported that they would have given t-PA in the exclusion-free scenario (85% v 49%; P<.001). Physicians likely to treat acute stroke patients do not consistently follow published guidelines on the use of intravenous t-PA in acute ischemic stroke. Neurologists were more likely to report that they would use t-PA in an exclusion-free scenario. Continued physician education about thrombolytic use in acute ischemic stroke is needed.

Presentation, etiology, and outcome of stroke in pregnancy and puerperium

PURPOSE

The purpose of this study was to evaluate the presentation, timing, etiology, and outcome of ischemic stroke (IS), hemorrhagic stroke (HS), and cerebral venous thrombosis (CVT) occurring during pregnancy and puerperium at 3 Indianapolis hospitals.

METHODS

Medical records of patients with a stroke during pregnancy and the puerperium were identified by using International Classification of Diseases (ICD 9) codes and a computerized records database. The records were available from 1992 to 1999 at 2 of the hospitals and from 1994 to 1999 at the third hospital. The records were retrospectively reviewed for presentation, treatment, etiology, and outcome. The sample included all cases of IS, HS, and CVT occurring in our pregnant population and included events up to 12 weeks postpartum.

RESULTS

Thirty-six patients were identified, including 21 with IS, 11 with HS, and 4 patients with CVT. The majority of events (89%) occurred in the third trimester and postpartum period, and 16 of 36 (44%) events occurred in postpartum week 1. Of the 8 African American patients in our study, 5 had HS (63%), whereas 18 of the 25 white patients (72%) had IS. A definable cause was identified in 72% of IS and 82% of HS. Some causes of IS include pre-eclampsia or eclampsia (13%), cardioembolism (23%), and a diverse array of other causes, include hypercoagulable states, thrombotic thrombocytopenic purpura (TTP), cerebral vasculitis, cerebrovascular mucormycosis, and migrainous infarction. Pre-eclampsia/eclampsia (37%) and ruptured atriovenous malformation (AVM) (36%) were the primary causes of HS. None of the cases of CVT had a clear etiology other than the pregnant or puerperal state, although risk factors included systemic lupus erythematosus (negative antiphospholipid antibodies and lupus anticoagulant) in 1 patient and dehydration in a second. Hypertensive disorders of pregnancy were the most common comorbid conditions in both IS and HS, affecting 45% of those with IS and 64% of patients with HS. IS presented with focal deficits (76%), whereas HS tended to present with an altered level of consciousness (73%) and headache (64%). All patients with CVT (4/4) presented with a headache, and 2 of 4 patients presented with an altered level of consciousness. The majority of patients with HS were discharged to nursing homes or rehabilitation centers (63%), whereas 73% of patients with IS and 3 of 4 patients with CVT were discharged home. Only 1 death occurred in our study, because of a brain herniation after a massive hemispheric IS.

CONCLUSION

The etiology of stroke in pregnancy and the puerperium is diverse. Strokes are most likely to occur in the third trimester and postpartum period and cluster in the first postpartum week.

Lapatinib (L) with paclitaxel compared to paclitaxel as first-line treatment for patients with metastatic breast cancer: A phase III randomized, double-blind study of 580 patients

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Background: L is an oral tyrosine kinase inhibitor of EGFR/HER2, active as monotherapy and in combination for HER2-overexpressing advanced/metastatic breast cancer (BC). A Phase I study of L with paclitaxel (P) indicated no unexpected adverse events (AEs). PK profile indicated no relationship between peak plasma concentration of P+L and neuropathy, neutropenia, diarrhea, rash or myalgia. We report here blinded efficacy and safety data for patients (pts) with incurable Stage IIIb/IIIc/IV BC at first diagnosis or relapse, untested or negative (0/1+ IHC or FISH neg) for HER2. Unblinded data will be presented at ASCO 2007. Methods: Between Jan 2004 and Jul 2005, 580 pts from 24 countries were stratified by metastatic site and randomized 1:1 to L 1500 mg QD + 175 mg/m2 P q3w or placebo QD + 175 mg/m2 P q3w. Primary endpoint was TTP; secondary endpoints were AEs, ORR, PFS, CBR, RFS, and OS. Tumor tissue was obtained from the most recent biopsy of 451 (78%) pts and was centrally analyzed in blinded fashion for biomarker patterns. Serum samples were collected for central EGFR and HER2 ECD analysis. Results and Conclusions: 579 pts were analyzed; 87% presented with Stage IV BC. 55% received prior adjuvant chemotherapy or anti-hormonal therapy. No pts received previous trastuzumab. At the time of analysis, 561 (97%) pts progressed or otherwise withdrew. Most common AEs were alopecia (58%), neurological (55%, gr=3:8%), diarrhea (42%, gr=3:9%), nausea (32%), and rash (32%, gr=3:2%). Neutropenia and thrombocytopenia AEs related to study treatment were 18% and <1%, respectively. LVEF decrease of 20% relative to baseline and below LLN was reported 15 times. 12% of AEs led to treatment withdrawal. Blinded data analysis revealed a median TTP of 25 wks and ORR of 30%. CNS relapse was reported in 11 pts (2%). Enrollment predominantly came from countries with limited HER2 testing capacity thus a subgroup of pts is expected to be HER2+ve. Blinded analyses of HER2, ER and PR are ongoing at this time and final biomarker evaluations will be presented with unblinded efficacy data.

[Table: see text]

Outcomes of newly referred neurology outpatients with depression and pain

BACKGROUND

Although depression and pain are common in neurology outpatients, patient factors influencing chronicity are poorly understood. The authors sought to determine the predictors of persistent depression and pain symptoms at 3 and 12 months after an initial outpatient neurology clinic visit.

METHODS

Consecutive new patients (n = 483) at three clinics completed the Patient Health Questionnaire nine-item depression scale and the Brief Pain Inventory at baseline and at 3- and 12-month follow-up. Multivariate analysis was used to model 3- and 12-month depression and pain severity.

RESULTS

The prevalence of depression and pain at baseline/3/12 months was depression 33%/28%/27% and pain 66%/61%/62%. Independent predictors of depression severity at follow-up were more severe depression and pain at baseline and less improvement in pain (model r(2) = 0.53 to 0.56). Independent predictors of pain intensity at follow-up were more severe pain and depression at baseline and less improvement in depression (model r(2) = 0.44 to 0.46). Health care utilization and impairments in health status were greatest in patients with coexisting depression and pain and least in those with neither depression nor pain.

CONCLUSIONS

Depression and pain symptoms in neurology outpatients often persist for at least 12 months and have long-term negative effects on patients' health status. Pain is more likely to persist in patients with depression, and depression is more likely to persist in those with coexistent pain.

Prevalence and impact of depression and pain in neurology outpatients

BACKGROUND

We examined the prevalence and health related quality of life (HRQoL) of depression and/or pain in neurology outpatients.

METHODS

Patients at outpatient clinics completed depression, pain, and HRQoL scales. Group comparisons between those with pain alone, depression alone, both conditions, and neither condition were done.

RESULTS

Overall, pain was present in 2/3 and depression in 1/3 of patients. Pain with depression was present in 25%; 75% of depressed patients had pain. These conditions had significant negative impact on mental and physical health status scores. The odds ratio (OR) for having pain was significantly increased in women (OR 2.0), those with depression (OR 2.4), and those with neuropathy/neuromuscular (OR 3.8) or pain syndromes (OR 4.8). The odds of having depression were increased in those with pain (OR 2.4) and with cognitive (OR 4.8) or cerebrovascular (OR 3.3) diagnoses. Neurologists were more likely to recognise and treat pain than depression.

CONCLUSIONS

Depression and pain are common in newly referred neurology outpatients and have substantial negative effects on patients' physical and mental health. Pain is more likely than depression to be recognised and treated by neurologists.

A brief overview of the initial location decisions of immigrants

"The current longitudinal survey of recent migrants has provided information on the factors shaping their locational choices within Australia. The main finding is that family and friends are the dominant influence. Job opportunities are much less influential, even amongst Independent migrants."

Effects of admission hyperglycemia on mortality and costs in acute ischemic stroke

BACKGROUND

Hyperglycemia at the time of acute ischemic stroke has been linked to worse outcome in both human and animal studies.

OBJECTIVE

To describe the prevalence and severity of hyperglycemia on hospital admission among acute ischemic stroke patients, to examine the independent relationship of admission hyperglycemia to all-cause mortality, and to document the inpatient management of hyperglycemia.

METHODS

Patients hospitalized with acute ischemic stroke at one hospital from July 1993 to June 1998 (n = 656) were identified. Demographic data, diagnoses, and blood glucose (BG) values were retrieved from the electronic medical record system. Admission stroke severity, fingerstick BG results, and new diabetes diagnoses were obtained by chart review. Hyperglycemia was defined as admitting random serum BG > or = 130 mg/dL. Hazard ratios (HR) for 30-day, 1-year, and 6-year mortality were calculated using multivariable Cox regression models.

RESULTS

Hyperglycemia at admission to hospital was present in 40% of patients with acute stroke. Patients with hyperglycemia were more often women and more likely to have prior diagnoses of diabetes and heart failure. Almost all of these patients remained hyperglycemic during their hospital stay (mean BG = 206 mg/dL), and 43% received no inpatient hypoglycemic drugs. Hyperglycemic patients had longer hospital stay (7 vs 6 days, p = 0.015) and higher inpatient hospital charges ($6,611 vs $5,262, p < 0.001). Hyperglycemia independently increased the risk for death at 30 days (HR 1.87, p < or = 0.01), 1 year (HR 1.75, p < or = 0.01), and 6 years after stroke (HR 1.41, p </= 0.01).

CONCLUSIONS

Admitting hyperglycemia was common among patients with acute ischemic stroke and was associated with increased short- and long-term mortality and with increased inpatient charges. Inpatient blood glucose management was suboptimal in this hospital. A trial of intensive treatment of hyperglycemia should be considered.

Validating the Questionnaire for Verifying Stroke-Free Status (QVSFS) by neurological history and examination

BACKGROUND AND PURPOSE

The Questionnaire for Verifying Stroke-Free Status (QVSFS) is an 8-item structured interview designed to identify stroke-free individuals. Previously, the QVSFS was validated with medical record review in a cohort with a low prevalence (7.1%) of stroke or transient ischemic attack (TIA). The objective of this study was to evaluate the validity of the QVSFS by comparing it with stroke status as determined by neurological history and examination in a population with a higher prevalence of stroke.

METHODS

A research assistant administered the QVSFS to outpatients from Veterans Administration stroke and general medicine clinics. Subjects were defined as QVSFS negative if responses to all 8 questions were negative. Questions requiring rephrasing or clarification were noted. Neurologists, blinded to QVSFS scores, interviewed and examined all subjects to determine stroke-free status, defined as no history or examination findings of previous stroke and/or TIA.

RESULTS

One hundred fifty-five subjects were examined; mean age was 70 years; 98.1% were male. Seventy-eight subjects were determined to be stroke free by the neurologist. The negative predictive value of the QVSFS was 0.96, with positive predictive value of 0.71. No question required rephrasing or clarification >5 times. Twenty-two subjects (14.2%) required rephrasing or clarification of at least 1 question.

CONCLUSIONS

The QVSFS can effectively identify stroke-free individuals with a high degree of accuracy, even in a population with a large proportion of patients with prior stroke or TIA. Accuracy for identifying subjects with stroke and/or TIA is lower, but the QVSFS may still be useful as a screening tool in that regard.

Spectrum of antiphospholipid antibodies (aPL) in patients with cerebrovascular disease

BACKGROUND

The association of stroke and antiphospholipid antibodies (aPL) other than anticardiolipin antibodies (aCL) is not well documented.

OBJECTIVE

To report the distribution of aCL, antiphosphatidylethanolamine (aPE), and antiphosphatidylserine (aPS) aPL among patients with symptomatic cerebrovascular disease evaluated by our Stroke Service at Indiana University Hospital from January 1997 to November 1999.

METHODS

We retrospectively reviewed medical records from 1997 to 1999 at Indiana University Hospital for all patients with symptomatic cerebrovascular disease using the International Statistical Classification of Diseases, 9th Revision, (ICD-9) codes. We identified patients with elevated titers of aPL. Sera from these patients were obtained within the first 30 days of the index event. We included only those patients for whom the serum samples were tested in a single laboratory by an in-house enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G (IgG) immunoglobulin A (IgA) and immunoglobulin M (IgM) aCL, aPE, and aPS. We examined the clinical presentation, stroke risk factors, associated rheumatologic disorders, and distribution of aPL specificity and isotype.

RESULTS

Thirty-four of 185 patients, 26 women (76%), with a mean age of 46 years, and 8 men (24%) with a mean age of 46 years, had aPL. Nine patients had transient ischemic attacks (TIA), 25 suffered strokes, 23 had ischemic infarcts, and 2 had hemorrhagic infarcts (1 had a superior sagittal sinus thrombosis with bilateral hemispheric hemorrhagic infarcts, and one had bilateral hemorrhagic infarcts associated with systemic lupus erythematosus [SLE]). Six patients had SLE. The most common stroke risk factors were cigarette smoking (38%) and arterial hypertension (26%). Approximately two thirds (60%) of patients had a single positive aPL finding: aPE in 35%, aCL in 18%, and aPS in 6%. Multiple specificities were seen in 40%. IgA was the only aPL antibody isotype detected in 26% of the patients, IgG was the lone isotype in 24%, and IgM alone in 12%. Multiple aPL isotypes were detected in 38% of patients. Five patients (15%) presented with aPE IgA as the exclusive aPL.

CONCLUSION

In our series, aPE was the most frequent finding in stroke patients who were suspected to have an associated aPL syndrome. These specific types of aPL may be present relatively often in stroke patients and are often not assessed. Further studies are needed to determine how specific these aPL are in stroke versus other acute illnesses and versus healthy controls, and how these aPL are associated with stroke risk.

Recurrence in pituitary adenomas in childhood and adolescence

Pediatric pituitary adenomas are thought to behave more aggressively than their adult counterparts, and the ability to predict the degree of such behavior remains elusive. Proliferation marker Ki-67 and tumor suppressor gene p53 mutations have been used in adults to assist in the evaluation of invasiveness and recurrence; however, their use in childhood and adolescence remains anecdotal. Our study evaluates the proliferative potential in pituitary adenomas of five patients and its relationship with recurrence or persistence of endocrinologic or clinical abnormalities. For such assessment, tissues were stained with monoclonal antibodies BP53-12 forp53 tumor suppressor gene mutation and MIB-1, which binds to cell cycle-specific nuclear antigen Ki-67. In our series, one patient with recurrent adenoma demonstrated the highest (50%) p53 immunoreactivity. Ki-67-stained nuclei ranged from 0 to 2%, failing to identify the recurrent tumor. Therefore, p53 immunoreactivity, rather than Ki-67 nuclear stain, may be useful for identification of recurrent pituitary adenomas in childhood and adolescence.

Cerebellar dysfunction is associated with overexpression of proinflammatory cytokine genes in lupus

Systemic lupus erythematosus (SLE) is an autoimmune disease of unknown etiology accompanied by central nervous system involvement in up to 60% of patients. The current study chronicles the expression of cerebellar dysfunction in SLE using MRL-lpr/lpr mice as the experimental model. These mice spontaneously develop an illness that has immunological and clinical features of human lupus. We found that MRL-lpr/lpr mice manifest severe and progressive behavioral disturbances indicative of cerebellar dysfunction beginning at 11 weeks of age. Although the lpr gene is known to induce autoimmune features, immunologically normal mice rendered congenic for lpr failed to exhibit disturbances in cerebellar function. Because lupus is a cytokine-driven disease and overexpression of certain proinflammatory cytokines has been associated with neurodegeneration, the relationship between cerebellar dysfunction and cytokine gene expression was examined. Relative to immunologically normal CBA/J mice, the cerebellum of young (11-15 weeks of age) MRL-lpr/lpr mice contained high levels of interleukin (IL)-6 and interferon-gamma (IFNgamma) mRNA, which became even more pronounced in old (22-30 weeks of age) autoimmune mice. mRNA levels for the cytokines IL-1beta and IL-10 were elevated in the cerebellum of old, but not young, MRL-lpr/lpr mice relative to CBA/J. In contrast, the levels of cerebellar transcripts for IL-3 and tumor necrosis factor-alpha were comparable in autoimmune and normal mice, indicating that enhanced gene expression of IL-6, IFNgamma, IL-1beta, and IL-10 was selective. These results suggest a potential role for certain proinflammatory cytokines in the pathogenesis of cerebellar disturbances in SLE.

GABA(A) receptors containing (alpha)5 subunits in the CA1 and CA3 hippocampal fields regulate ethanol-motivated behaviors: an extended ethanol reward circuitry

GABA receptors within the mesolimbic circuitry have been proposed to play a role in regulating alcohol-seeking behaviors in the alcohol-preferring (P) rat. However, the precise GABA(A) receptor subunit(s) mediating the reinforcing properties of EtOH remains unknown. We examined the capacity of intrahippocampal infusions of an alpha5 subunit-selective ( approximately 75-fold) benzodiazepine (BDZ) inverse agonist [i.e., RY 023 (RY) (tert-butyl 8-(trimethylsilyl) acetylene-5,6-dihydro-5-methyl-6-oxo-4H-imidazo [1,5a] [1,4] benzodiazepine-3-carboxylate)] to alter lever pressing maintained by concurrent presentation of EtOH (10% v/v) and a saccharin solution (0.05% w/v). Bilateral (1.5-20 microgram) and unilateral (0.01-40 microgram) RY dose-dependently reduced EtOH-maintained responding, with saccharin-maintained responding being reduced only with the highest doses (e.g., 20 and 40 microgram). The competitive BDZ antagonist ZK 93426 (ZK) (7 microgram) reversed the RY-induced suppression on EtOH-maintained responding, confirming that the effect was mediated via the BDZ site on the GABA(A) receptor complex. Intrahippocampal modulation of the EtOH-maintained responding was site-specific; no antagonism by RY after intra-accumbens [nucleus accumbens (NACC)] and intraventral tegmental [ventral tegmental area (VTA)] infusions was observed. Because the VTA and NACC contain very high densities of alpha1 and alpha2 subunits, respectively, we determined whether RY exhibited a "negative" or "neutral" pharmacological profile at recombinant alpha1beta3gamma2, alpha2beta3gamma2, and alpha5beta3gamma2 receptors expressed in Xenopus oocytes. RY produced "classic" inverse agonism at all alpha receptor subtypes; thus, a neutral efficacy was not sufficient to explain the failure of RY to alter EtOH responding in the NACC or VTA. The results provide the first demonstration that the alpha5-containing GABA(A) receptors in the hippocampus play an important role in regulating EtOH-seeking behaviors.

Perineural spread of cutaneous squamous and basal cell carcinoma: CT and MR detection and its impact on patient management and prognosis

PURPOSE

To analyze the pretreatment imaging findings and outcome of patients with perineural spread of squamous or basal cell carcinoma of the face and scalp treated with radiotherapy, to determine whether CT (computed tomography) or MR (magnetic resonance) imaging can be effectively used to identify patients who would benefit from aggressive treatment, and to characterize the imaging features associated with cure.

METHODS

Thirty-five patients had perineural spread of squamous and basal cell carcinoma along the divisions of the trigeminal and/or facial nerves based on clinical findings and/or histopathological proof. Perineural extension seen on imaging was divided into three zones of involvement. The volume of perineural disease was graded semiquanitatively. All patients received radiotherapy with curative intent.

RESULTS

Eighteen of the 35 patients had imaging evidence of perineural spread of tumor, and the remaining 17 were imaging negative for perineural spread. The absolute 5-year survival of the imaging positive group was 50% compared with 86% in the imaging-negative group (p = 0.048).

CONCLUSIONS

Imaging can be used to identify patients with advanced perineural spread who warrant aggressive radiotherapy. Imaging evidence of perineural invasion worsens prognosis; however, low-volume and peripheral perineural disease is radiocurable. Greater perineural tumor volume with more central disease was associated with an unfavorable outcome.

Middle ear prosthesis displacement in high-strength magnetic fields

HYPOTHESIS

Middle ear prostheses made from nonmagnetic, magnetic resonance (MR)-compatible metals reportedly displace ex vivo in the presence of high magnetic fields used in MR imaging (MRI). The authors postulate that the prosthesis displacement seen with "nonmagnetic" MR-compatible prostheses ex vivo may not be clinically significant in vivo.

METHODS

Middle ear prostheses made from ferromagnetic (420F stainless steel) and nonmagnetic MR-compatible metals (316L stainless steel and platinum) were examined for magnetic field interactions at 4.7 Tesla (T). Ex vivo testing consisted of measurements of the translational and rotational motion of the prosthesis induced by the static magnetic field. In vivo testing was assessed by implanting prostheses in cadaveric temporal bones and performing clinical MRI sequences. Prosthesis displacement was measured semiquantitatively.

RESULTS

Angular deflection was observed in all samples made from nonmagnetic stainless steel. The negative control (platinum) demonstrated no deflection, and the positive controls (ferromagnetic stainless steel) deflected >90 degrees. Torque analysis showed movement in five of five nonmagnetic stainless steel prostheses. Prostheses made from nonmagnetic stainless steel remained in place without appreciable loosening in vivo after MRI. Prostheses made with known ferromagnetic properties were displaced at 4.7 T but not at 1.5 T.

CONCLUSION

Middle ear prostheses made from low-magnetic stainless steel do move in the presence of high magnetic fields ex vivo; however, this does not appear to be clinically or statistically significant in vivo at 4.7 T. Magnetic resonance imaging should be undertaken with caution in individuals with prostheses made from stainless steel with strong ferromagnetic properties.

Protocol violations in community-based rTPA stroke treatment are associated with symptomatic intracerebral hemorrhage

BACKGROUND

Recombinant tissue plasminogen activator (rTPA) is an established treatment for acute ischemic stroke. The rate and type of protocol violations in rTPA use and their effect on patient outcomes in this setting are not well understood.

OBJECTIVE

The objective of this study was to examine associations between protocol violations and outcomes in community-based rTPA use.

METHODS

We reviewed medical records of stroke patients treated with rTPA in 10 acute-care hospitals in Indianapolis from July 1996 to February 1998 and assessed complications and outcome. Retrospective National Institute of Health Stroke Scale (on admission and discharge), Canadian Neurological Scale, and length of hospital stay were calculated. Appropriate use of rTPA was determined by the National Institute of Neurological Disorders and Stroke (NINDS) protocol.

RESULTS

Fifty patients (mean age, 66 years; 76% white; 56% men) were treated by general neurologists (70%), stroke neurologists (24%), or emergency physicians (6%). Mean times to hospital arrival, brain CT, and start of rTPA infusion were 44, 86, and 141 minutes, respectively. In-hospital mortality rate was 10% (4 intracerebral hemorrhage [ICH], 1 cardiogenic shock). Complications were more frequent among patients with protocol violations (n=8) compared with those without all hemorrhages (75% versus 10%, P:<0.001), symptomatic ICH (38% versus 5%, P:<0.02), and ICH attributable to rTPA, occurring within 36 hours (38% versus 2.4%, P:<0.01), respectively.

CONCLUSIONS

NINDS protocol violations are relatively common and are associated with symptomatic cerebral and systemic hemorrhages. When the NINDS protocol is strictly followed, hemorrhage rates in community-based rTPA use are similar to those in the NINDS trial.

Retrospective assessment of initial stroke severity with the NIH Stroke Scale

BACKGROUND AND PURPOSE

It is important to adjust stroke outcomes for differences in initial stroke severity. The NIH Stroke Scale (NIHSS) is a commonly used stroke severity measure but has been validated for retrospective scoring only in a subset of stroke clinical trial participants. The purpose of this research was to assess the validity and reliability of an algorithm for retrospective NIHSS scoring in a setting with usual chart documentation.

METHODS

An algorithm for retrospective NIHSS scoring was developed with written history and physical admission notes. Missing physical examination data were scored as normal. One investigator prospectively scored the admission NIHSS in 32 consecutive stroke patients. Two raters retrospectively scored the NIHSS by applying the algorithm to photocopied admission notes. Linear regression was used to assess interrater reliability and agreement between prospective and retrospective NIHSS scores. The Wilcoxon signed rank test was used to assess systematic scoring bias. Weighted kappa statistics were calculated to assess the level of agreement of individual NIHSS items.

RESULTS

Only 1 admission note was complete for all NIHSS elements. Interrater reliability was near perfect (r(2)=0.98, P<0. 001). Agreement between prospective and retrospective NIHSS score was also excellent (r(2)=0.94, P<0.001) and there was no systematic bias in retrospective scores. Agreement for individual items was moderate to high for all items except level of consciousness.

CONCLUSIONS

Retrospective NIHSS scoring with the algorithm is reliable and unbiased even when physical examination elements are missing from the written record. Stroke research using retrospective review of charts or of administrative databases should adjust for differences in stroke severity using such an algorithm.

Effects of fosinopril or sustained-release verapamil on blood pressure and serum catecholamine concentrations in elderly hypertensive men

A randomized, double-blind, placebo-controlled clinical trial showed 14 of 18 (78%) of the elderly hypertensive men in this study had an uncomplicated and beneficial response to either fosinopril or verapamil. There was a well-tolerated reduction in systolic blood pressure (SBP) and diastolic blood pressure (DRP). There were no significant adverse drug events. Only the sitting SBP and the sitting DBP were significantly lowered by fosinopril and verapamil SR. Because reduction in both SBP and DBP in elderly hypertensives has been shown to be beneficial, these findings take on further importance when considering the choice of medication for antihypertensive therapy in the elderly. The increase in norepinephrine in the fosinopril-treated patients may explain why patients treated with long-term angiotensin-converting enzyme inhibitors alone or in combination with diuretics rarely complain of orthostatic symptoms.

Advanced concepts in the imaging of perineural spread of tumor to the trigeminal nerve

Perineural spread of head and neck tumor represents extension of the primary tumor along the perineurium. Diagnosis of perineural spread of carcinoma often is delayed unless the clinician maintains a high index of suspicion. It may be insidious, and patients may be asymptomatic for years. Perineural spread of carcinoma has been associated with a poor prognosis; however, it is becoming increasingly realized that cure is possible in some cases, if the full extent of the disease is known and treated. Magnetic resonance imaging (MRI) can detect perineural spread of head and neck carcinoma and define its extent. MRI is the imaging modality of choice to assess perineural disease due to its superior tissue contrast and multiplanar capability. Perineural spread of head and neck carcinomas most commonly involves the trigeminal nerve. Obliteration of the fat within (a) the superior medial orbital (ophthalmic division territory), (b) the periantral fat plane (maxillary division distribution), and (c) the pterygopalatine fossa all are useful indicators of distal perineural disease. A perineural vascular plexus (PNVP) surrounds the trigeminal ganglion and proximal portions of the trigeminal nerve divisions. The trigeminal ganglion and proximal portions of its divisions usually are seen as discrete nonenhancing structures separate from the PNVP. Occasionally, isolated enhancement of the ganglion and the proximal portions of the maxillary and mandibular divisions as they exit the skull base may be seen. This may be an artifact related to head position or may represent avid enhancement of the PNVP. In these situations, evaluating all branches, and the entire course, of the trigeminal nerve for perineural spread can aid in determining whether the apparent enhancement is an isolated normal variant or represents nerve pathology such as perineural spread.

Measuring quality of life in a way that is meaningful to stroke patients

OBJECTIVE

To identify predictors of poststroke quality of life.

BACKGROUND

Health-related quality of life (HRQOL) measures assess the impact of disease on the physical, emotional, and social aspects of patients' lives. Although HRQOL measures are used increasingly, factors associated with HRQOL poststroke and the ability of stroke-specific versus generic HRQOL measures to predict patient-reported HRQOL are not well known.

METHODS

A total of 71 patients were evaluated 1 month postischemic stroke with a new stroke-specific HRQOL measure-the SS-QOL-and the SF-36, a generic HRQOL measure. Stroke severity, impairments, and functional limitations were also measured. Demographic variables and outcome measure scores were compared between patients rating their overall HRQOL the same as pre-stroke versus those with overall HRQOL worse than prestroke. Independent predictors of overall HRQOL were identified using multivariable modeling.

RESULTS

Variables associated with better overall HRQOL were higher (better) SS-QOL and Barthel Index scores, and lower (better) NIH Stroke Scale and Beck Depression Inventory scores. Independent predictors of good overall HRQOL were the SS-QOL score (odds ratio [OR], 2.97; 95% CI, 1.3, 7.1; p = 0.01) and NIH Stroke Scale score (OR, 0.69; 95% CI, 0.47, 0.99; p = 0.05). Demographic factors and SF-36 scores were not associated with overall HRQOL ratings.

CONCLUSIONS

Stroke-specific quality of life score and patient impairments predict patient-reported overall health-related quality of life (HRQOL) poststroke. SF-36 scores were not associated with overall HRQOL ratings. Disease-specific HRQOL measures are more sensitive to meaningful changes in poststroke HRQOL and may thus aid in identifying specific aspects of poststroke function that clinicians and "trialists" can target to improve patients' HRQOL after stroke.

Chemotherapy for pancreatic cancer: a neuroimaging clinicopathologic correlation

This 52-year-old male without a significant medical history was receiving chemotherapy with diethylnorspermine (DENSPM), a polyamine analogue, for a partially resected pancreatic adenocarcinoma. Ten months after his initial diagnosis, he was admitted to an outside hospital for evaluation of altered mental status. Over the course of the next few days the patient developed progressive neurologic signs and symptoms including lethargy, tonic deviation of his eyes to the left, asymmetic pupils, and right-sided decerebrate posturing elicited by painful stimuli. Neuroimaging studies revealed multiple lesions scattered in the periventricular white matter, thalamus, midbrain pons, and cerebellar peduncles. The clinical and neuroimaging differential diagnoses are discussed, and postmortem neuropathologic correlation is presented.

Development of a stroke-specific quality of life scale

BACKGROUND AND PURPOSE

Clinical stroke trials are increasingly measuring patient-centered outcomes such as functional status and health-related quality of life (HRQOL). No stroke-specific HRQOL measure is currently available. This study presents the initial development of a valid, reliable, and responsive stroke-specific quality of life (SS-QOL) measure, for use in stroke trials.

METHODS

Domains and items for the SS-QOL were developed from patient interviews. The SS-QOL, Short Form 36, Beck Depression Inventory, National Institutes of Health Stroke Scale, and Barthel Index were administered to patients 1 and 3 months after ischemic stroke. Items were eliminated with the use of standard psychometric criteria. Construct validity was assessed by comparing domain scores with similar domains of established measures. Domain responsiveness was assessed with standardized effect sizes.

RESULTS

All 12 domains of the SS-QOL were unidimensional. In the final 49-item scale, all domains demonstrated excellent internal reliability (Cronbach's alpha values for each domain >/=0.73). Most domains were moderately correlated with similar domains of established outcome measures (r2 range, 0.3 to 0.5). Most domains were responsive to change (standardized effect sizes >0.4). One- and 3-month SS-QOL scores were associated with patients' self-report of HRQOL compared with before their stroke (P<0.001).

CONCLUSIONS

The SS-QOL measures HRQOL, its primary underlying construct, in stroke patients. Preliminary results regarding the reliability, validity, and responsiveness of the SS-QOL are encouraging. Further studies in diverse stroke populations are needed.

Acute blood glucose level and outcome from ischemic stroke. Trial of ORG 10172 in Acute Stroke Treatment (TOAST) Investigators

OBJECTIVE

To study the relation between acute blood glucose level and outcome from ischemic stroke.

BACKGROUND

Hyperglycemia may augment acute ischemic brain injury and increase the risk of hemorrhagic transformation of the infarct.

METHODS

The authors analyzed the relation between admission blood glucose level (within 24 hours from ischemic stroke onset) and clinical outcome in 1,259 patients enrolled in the Trial of ORG 10172 in Acute Stroke Treatment (TOAST)-a placebo-controlled, randomized, double-blind trial to test the efficacy of a low-molecular weight heparinoid in acute ischemic stroke. Very favorable outcome was defined as a Glasgow Outcome Scale score of 1 and a modified Barthel index of 19 or 20. Neurologic improvement at 3 months was defined as a decrease by > or =4 points on the NIH Stroke Scale compared with baseline or a final score of 0. Hemorrhagic transformation of infarct was assessed within 10 days after onset of stroke with repeat cerebral CT. Stroke subtype as lacunar or nonlacunar (atherothromboembolic, cardioembolic, and other or undetermined etiology) was classified by one investigator after completion of stroke evaluation according to study protocol.

RESULTS

In all strokes combined (p = 0.03) and in nonlacunar strokes (p = 0.02), higher admission blood glucose levels were associated with worse outcome at 3 months according to multivariate logistic regression analysis adjusted for stroke severity, diabetes mellitus, and other vascular risks. In lacunar strokes, the relationship between acute blood glucose level and outcome was related to treatment. In the placebo group, higher admission blood glucose levels were associated with better outcome at 3 months. However, in the active drug group, as the glucose level increased from 50 to 150 mg/dL, the probability of a very favorable outcome decreased sharply and remained relatively unchanged as the glucose level increased further (p = 0.002, for overall effect of glucose on outcome). Acute blood glucose level was not associated with symptomatic hemorrhagic transformation of infarcts or with neurologic improvement at 3 months.

CONCLUSIONS

During acute ischemic stroke hyperglycemia may worsen the clinical outcome in nonlacunar stroke, but not in lacunar stroke, and is not associated with an increased risk of hemorrhagic transformation of the infarct.

The opioid receptor antagonist nalmefene reduces responding maintained by ethanol presentation: preclinical studies in ethanol-preferring and outbred Wistar rats

Nalmefene, the 6-methylene derivative of naltrexone, was examined after subcutaneous (s.c.) (0.0001 to 8.0 mg/kg) and oral (10 to 80.0 mg/kg) administration in ethanol (EtOH)-preferring rats whose responding (i.e., lever pressing) was maintained by the presentation of EtOH. Naltrexone (0.01 to 40 mg/kg) was used as a reference opioid antagonist. EtOH (10% v/v) and saccharin (0.025 to 0.1% w/v) solutions were concurrently available for 1 hr each day under a two-lever, fixed-ratio schedule in which four responses on one lever produced the EtOH solution and four responses on the other lever produced the saccharin solution. When basal response rates for saccharin were 10% that of EtOH, all routes of nalmefene administration reduced control levels of responding maintained by EtOH by 38 to 84%. When basal response rates for saccharin-maintained responding were 60% or 82% that of EtOH, only lower s.c. naltrexone (e.g., 0.01 to 0.025 mg/kg) and nalmefene (e.g., 0.01 to 0.10 mg/kg) doses produced a selective dose-dependent suppression of EtOH-maintained responding. Higher nalmefene (0.25 to 8.0 mg/kg) and naltrexone (1.0 to 20.0 mg/kg) doses failed to produce a dose-dependent suppression on EtOH or saccharin maintained responding. Both antagonists suppressed responding maintained by EtOH primarily during the initial 10-min period, with little additional suppression occurring across the remainder of the 60-min period. Subcutaneous nalmefene was 3200- to 6400-fold more potent than oral nalmefene, suggesting bioavailability was optimized using the s.c. route. Nalmefene (0.5 mg/kg, s.c.) treatment for 10 consecutive days produced mild tolerance development, whose effects dissipated by day 8. Naltrexone (10 to 40 mg/kg) and nalmefene (1.5 to 3.0 mg/kg), given 8 to 24 hr before the test session, reduced control levels of responding maintained by EtOH by 82%. Thus, immediate opioid receptor occupancy was not required to observe antagonism. These data demonstrate that, under a variety of experimental conditions, nalmefene is an effective antagonist of responding maintained by EtOH and lend support to clinical reports that nalmefene may function as an alternative pharmacotherapy to naltrexone to reduce EtOH-motivated behavior and prevent relapse.

Frustrated by lack of job opportunities in Canada, MD moves to US space-medicine program

A Canadian physician-engineer who had difficulty finding suitable work in Canada is now employed by an American company that is helping develop the medical systems that will serve astronauts. Dr. Douglas Hamilton thinks research in space medicine will have applications on earth.

Physical activity and cardiovascular health in the elderly

People over the age of 65 constitute a growing proportion of the world population both in western and in developing countries. A unique feature of this group is the high prevalence of cardiovascular diseases, which negatively affect its quality of life as well as its life expectancy. Among the interventions able to reduce the health burden of cardiovascular diseases is physical activity. The benefits of physical activity have been demonstrated both in healthy and chronically ill elderly subjects, while the risks have been found to be modest. Physicians should recommend moderate-intensity physical activity to sedentary older subjects, who are still the majority within the elderly population.

Retrorectal cyst-hamartomas and sacral dysplasia: MR appearance

Retrorectal cyst-hamartoma, an uncommon lesion, arises from hindgut embryonic remnants and may be associated with sacral anomalies. Such a lesion is presacral, multicystic, and lined with glandular or transitional epithelium. Malignant transformation of these lesions has been reported. We describe the clinical, pathologic, and imaging findings in an infant.

Subtypes of ischemic stroke in children and young adults

Specific strategies for primary and secondary stroke prevention in children and young adults can only be recommended once the causes of stroke in these age groups are well described. ICD-9 codes were used to identify children aged 1 to 18 years with acute ischemic stroke. Young adults aged > 18 to 45 years were identified from the Indiana University and Northwestern University Young Adults Stroke Registries. Validated criteria were used to subtype ischemic stroke as atherothrombotic (AT), cardioembolic (CE), small-vessel (SV), other determined cause, or unknown cause. Ninety-two children and 116 young adults were identified. Stroke subtypes in children/young adults (percentages) were as follows: AT 0/16 (p < 0.001), CE 15/14 (p = 1.0), SV 0/3 (p = 0.26), other 49/44 (p = 0.40), and unknown 36/23 (p = 0.04). Children had more prothrombotic causes (25% versus 14%, p = 0.03), and young adults had more dissections (3% versus 15%, p = 0.005). Children aged 15 to 18 years had causes of ischemic stroke more similar to those in young adults. The cause of ischemic stroke is less often identified in children than it is in young adults. Children have more prothrombotic causes of stroke, and adults have more atherothrombotic causes and dissections. Lacunar strokes are rare in both children and young adults. The age of 15 years should be used to separate childhood from young-adult ischemic stroke.

[Stroke therapy in children]

OBJECTIVE

To evaluate the treatment modalities used in children (ages 1-18 years) with cerebral infarction.

BACKGROUND

[corrected] Cerebrovascular disease in children is more common than once suspected but its treatment has not been rigorously studied.

MATERIAL AND METHODS

We reviewed all cases of cerebral infarction at the James Whitcomb Riley Hospital for Children at the Indiana University Medical Center from 01.01.80 to 31.12.95.

RESULTS

Ninety-three children who experienced ischemic strokes were followed over the past fifteen years. Fifty-seven males and thirty-six females comprised the sample. Mean age was 6.9 years at the time of stroke. No medication or surgical intervention was the therapeutic recommendation in 44% of patients. For cardioembolic strokes, warfarin was used later in the course for a few patients who went on to have atrial fibrillation or valve replacement. Aspirin was used in all patients with carotid artery dissections. Aspirin was used in most children with Moya-Moya, with calcium channel blockers and surgical intervention used in later cases. Exchange transfusion followed by monthly transfusion and chelation therapy has been the treatment of choice for children with cerebral infarction complicating sickle cell disease.

CONCLUSIONS

In most instances, treatment was widely disparate, probably reflecting the lack of firm therapeutic guidelines for this age group, with a better understanding of the etiology and pathophysiology of strokes in children, multicenter, international, randomized therapeutic trials based strictly on an etiological basis should be organized in the future.

Manitoba suicides force consideration of stresses facing medical residents

The suicides of 3 Winnipeg medical residents within 15 months shocked Manitoba physicians and raised concerns among interns and residents across Canada. The cluster of self-inflicted deaths has observers wondering if the stress of residency programs was a contributing factor in the tragedies.

Stroke patients' knowledge of stroke. Influence on time to presentation

BACKGROUND AND PURPOSE

New treatments for acute stroke will likely have to be given soon after stroke onset. Little is known about stroke patients' general knowledge about stroke, their interpretation of stroke symptoms, and how these factors influence the timing of their decision to seek medical attention.

METHODS

We interviewed consecutive stroke patients within 72 hours of stroke onset to define factors influencing time of arrival to the emergency department. Data recorded included demographic information, method of transportation, type of stroke symptoms, the patient's interpretation of the symptoms, previous stroke, and knowledge of stroke warning signs. Stroke severity was measured with the Barthel Index. Early arrival was defined as within 3 hours of awareness of symptoms.

RESULTS

Sixty-seven patients were interviewed; 96% had an ischemic stroke and 4% a cerebral hemorrhage. Although 38% of patients professed to know the warning signs of stroke, only 25% correctly interpreted their symptoms. Patients with prior stroke were more likely to correctly interpret their symptoms (45% versus 16%; P = .03) but were not more likely to present early (19% versus 39%; P = .35). Eighty-six percent of patients presenting more than 3 hours after stroke onset thought that their symptoms were not serious. The 24% (n = 16) of early arrivals were more likely to arrive by ambulance (81% versus 38%; P = .003) and had more severe stroke (Barthel Index score of 49 versus 72; P = .01) than late arrivals. Arrival by ambulance was independently associated with early arrival (odds ratio, 5.55; 95% confidence interval, 1.37 to 22.6).

CONCLUSIONS

Approximately one quarter of stroke patients correctly interpret their symptoms as representing a stroke. This knowledge is not associated with early presentation to the emergency department. Ambulance transport is independently associated with early arrival at the emergency department. Even when patients know that they are having a stroke, most present late because they perceive their symptoms as "not serious." Widespread public education of stroke-prone individuals may increase the proportion of patients eligible for new acute stroke treatments.

The road to Wisconsin

In this article Lynne Sears Williams of Calgary describes her family's decision to leave for the US, where her husband, Dr. Jim Williams, will pursue his career in family medicine. The decision was not made easily, she writes, but eventually a love for Canada was outweighed by her husband's desire to practise medicine without the financial and other constraints facing physicians in Canada.

Non-isotopic method for quantitation of platelets and erythrocytes in experimental thrombi

Experimental animal models of thrombosis have been established in several species to examine factors responsible for thrombotic disorders in man. One technical facet of all thrombosis models is the need to quantitate cell deposition on thrombogenic surfaces, and this is routinely accomplished with radioisotopic labeling of specific components. Data reported here demonstrate that formalin-fixed thrombi can be hydrolyzed with chymotrypsin allowing recovery and quantitation of platelets and erythrocytes incorporated within the clot. Recovery of platelets from in vitro generated, model thrombi averaged 99 +/- 10% (mean +/- 1 SD; n = 7; range 88-116%) of calculated content; recovery of erythrocytes was 94.1 +/- 1.1% (n = 6) as measured by recovery of cellular hemoglobin after chymotrypsin hydrolysis of clots. Chymotrypsin was also shown to release platelets and erythrocytes from string-bound thrombi generated in vivo with an arterio-venous shunt model in beagle dogs. Platelet recovery from these string clots after chymotrypsin hydrolysis was independently verified with a quantitative Western blot assay of platelet antigens. These data demonstrate that experimental thrombi can be hydrolyzed with chymotrypsin, thereby not only eliminating the need for radioisotopes, but also permitting flow cytometric analysis of cells comprising the thrombus.

Evidence for human thromboxane receptor heterogeneity using a novel series of 9,11-cyclic carbonate derivatives of prostaglandin F2 alpha

1. The pharmacological activity of a novel series of 9,11-cyclic carbonate derivatives of prostaglandin F2 alpha (PGF2 alpha) was investigated in various isolated smooth muscle preparations possessing different prostanoid receptor subtypes as well as in human platelets. Since subdivision of thromboxane (TP-) receptors into vascular/smooth muscle and platelet subtypes is a controversial subject, our studies included a human smooth muscle preparation (myometrium) in addition to the widely used rat aorta and human platelets as TP-receptor preparations. 2. Two members of that series, AGN191976 and AGN192093 were found to be highly potent and selective thromboxane-mimetics. AGN191976 and AGN192093 contracted isolated tissues of the rat thoracic aorta with EC50 values of 0.32 +/- 0.08 and 1.30 +/- 0.53 nM, respectively. Both agonists were at least 10 times more potent than the benchmark TP-agonist, U-46619, in this preparation, whilst being at least 500 times less potent at other prostanoid receptors (DP, EP1, EP3, FP, IP) in vitro. 3. In human myometrial strips from pregnant and non-pregnant donors, both AGN191976 and AGN192093 were potent contractile agonists. The rank order of potency in myometrium of AGN191976 > AGN192093 > U-46619 correlated well with that in the rat aorta. In human platelet-rich plasma (PRP), however, AGN191976 had potent proaggregatory activity (EC50 = 16.3 +/- 1.4 nM), which is a TP-receptor-mediated event, whereas AGN192093 was a much weaker agonist (EC50 = 37.9 +/- 2.0 microM). AGN192093 did not behave as an antagonist in the platelets, since it did not antagonize platelet aggregation induced by ADP, arachidonic acid, U-46619 or AGN191976. In human washed platelets, the activity profile of AGN191976 (EC50 = 4.15 +/- 0.52 nM) and AGN192093 (no aggregation up to 10 microM) was similar to that obtained in PRP. 4. The involvement of TP-receptors was verified with the potent TP-antagonist, SQ29548. SQ29548 (0.1 microM in myometrium; 1 microM in aorta; 1 microM and 10 microM in platelets) antagonized responses to U-46619, AGN191976 and AGN192093 as expected. 5. In conclusion, AGN191976 and AGN192093, both 9,11-cyclic carbonate derivatives of PGF2 alpha, were found to be highly potent and selective thromboxane-mimetics in rat vascular and human myometrial smooth muscle. However, only AGN 191976 was a potent agonist at TP-receptors in human platelets. The differential activity of AGN192093 on TP-receptor-mediated events in platelets and smooth muscle provides further evidence for a subdivision of TP-receptors. AGN192093 appears to be a useful tool for the pharmacological distinction of TP-receptor subtypes.