Onset seizures independently predict poor outcome after subarachnoid hemorrhage

OBJECTIVE

To determine whether onset seizures after subarachnoid hemorrhage (SAH) carry independent prognostic information and to investigate the risk factors for late seizures after SAH.

BACKGROUND

Modern management of SAH, including early operation, has substantially reduced mortality. No study has adequately assessed the importance of onset seizures in a contemporary SAH cohort.

METHODS

The authors analyzed the records and initial CT scans of 412 consecutive patients with aneurysmal or nonaneurysmal SAH admitted to the Royal Melbourne Hospital from 1990 to 1996. Each patient with an onset seizure (n = 32, 7.8% of cohort) was age and sex matched to two nonseizure patients of the same cohort. Each patient with a late seizure (n = 17, 5.1% of cohort) was matched to five control subjects of the same cohort.

RESULTS

With use of logistic regression analysis, onset seizures correlated with the sum score of blood on initial CT scan (OR = 1.1, p = 0.05), but there was no significant correlation with duration of loss of consciousness at onset, Glasgow Coma Score (GCS), presence of aneurysm, or past history of hypertension or epilepsy. Disability 6 weeks after SAH according to the Glasgow Outcome Scale was independently predicted by initial GCS of <6 (OR = 13.7, p < 0.01) and onset seizure (OR = 7.8, p = 0.04). Late seizures within the first 6 weeks were independently related to rebleeding (OR = 94, p < 0.01) and onset seizures (OR = 27, p < 0.01) but not to other onset variables, development of hydrocephalus, or vasospasm.

CONCLUSION

In this single-institution cohort of patients with SAH, onset seizures were an independent risk factor for late seizures and a predictor of poor outcome.

Gender differences in chronic major and double depression

BACKGROUND

While the sex difference in prevalence rates of unipolar depression is well established, few studies have examined gender differences in clinical features of depression. Even less is known about gender differences in chronic forms of depression.

METHODS

235 male and 400 female outpatients with DSM-III-R chronic major depression or double depression (i.e., major depression superimposed on dysthymia) were administered an extensive battery of clinician-rated and self-report measures.

RESULTS

Women were less likely to be married and had a younger age at onset and greater family history of affective disorder compared to men. Symptom profile was similar in men and women, with the exception of more sleep changes, psychomotor retardation and anxiety/somatization in women. Women reported greater severity of illness and were more likely to have received previous treatment for depression with medications and/or psychotherapy. Greater functional impairment was noted by women in the area of marital adjustment, while men showed more work impairment.

LIMITATIONS

Since our population consisted of patients enrolling in a clinical trial, study exclusion criteria may have affected gender-related differences found.

CONCLUSIONS

Chronicity of depression appears to affect women more seriously than men, as manifested by an earlier age of onset, greater family history of affective disorders, greater symptom reporting, poorer social adjustment and poorer quality of life. These findings represent the largest study to date of gender differences in a population with chronic depressive conditions.

Gender differences in treatment response to sertraline versus imipramine in chronic depression

OBJECTIVE

The authors examined gender differences in treatment response to sertraline, a selective serotonin reuptake inhibitor (SSRI), and to imipramine, a tricyclic antidepressant, in chronic depression.

METHOD

A total of 235 male and 400 female outpatients with DSM-III-R chronic major depression or double depression (i.e., major depression superimposed on dysthymia) were randomly assigned to 12 weeks of double-blind treatment with sertraline or with imipramine after placebo washout.

RESULTS

Women were significantly more likely to show a favorable response to sertraline than to imipramine, and men were significantly more likely to show a favorable response to imipramine than to sertraline. Gender and type of medication were also significantly related to dropout rates; women who were taking imipramine and men who were taking sertraline were more likely to withdraw from the study. Gender differences in time to response were seen with imipramine, with women responding significantly more slowly than men. Comparison of treatment response rates by menopausal status showed that premenopausal women responded significantly better to sertraline than to imipramine and that postmenopausal women had similar rates of response to the two medications.

CONCLUSIONS

Men and women with chronic depression show differential responsivity to and tolerability of SSRIs and tricyclic antidepressants. The differing response rates between the drug classes in women was observed primarily in premenopausal women. Thus, female sex hormones may enhance response to SSRIs or inhibit response to tricyclics. Both gender and menopausal status should be considered when choosing an appropriate antidepressant for a depressed patient.

Combined (1)H MR spectroscopy and diffusion-weighted MRI improves the prediction of stroke outcome

BACKGROUND

The prognostic value of the biochemical changes seen with proton MR spectroscopy (1H MRS) in ischemic stroke was examined. Acute diffusion-weighted imaging (DWI) was used to identify regions of ischemia for 1H MRS voxel localization.

METHODS

Nineteen patients had 36 1H MRS studies, 13 patients acutely (mean, 11.1 hours), 10 subacutely (mean, 3.9 days), and 13 at outcome (mean, 82 days). Single-voxel, long-echo, timepoint-resolved spectroscopy was used to obtain lactate, n-acetylaspartate (NAA), choline, and creatine levels from the infarct core. Outcome measures were final infarct volume and clinical assessment scales (Canadian Neurological Scale, Barthel Index, and Rankin Scale).

RESULTS

Acute lactate/choline ratio correlated more strongly with clinical outcome scores (r = 0.76 to 0.83; p < 0.01) and final infarct size (r = 0. 96; p < 0.01) than acute DWI lesion volume or acute NAA/choline ratio. Combination of acute lactate/choline ratio with acute DWI lesion volume improved prediction of all outcome scores (R2 = 0.80 to 0.90). The predictive effect of acute lactate/choline ratio was independent of acute DWI lesion volume (p < 0.001). In subacute and chronic infarction, both lactate/choline and NAA/choline ratios continued to correlate with outcome (p < 0.05). At the chronic stage, persistent lactate/choline ratio elevation strongly correlated with outcome measures (r = 0.71 to 0.87).

CONCLUSION

Lactate/choline ratio measured in the acute infarct core by 1H MRS improves the prediction of stroke outcome and provides prognostic information complementary to DWI. Lactate/choline ratio could be used as an additional marker to select patients for acute and chronic therapies.

Comparison of DSM-III-R chronic major depression and major depression superimposed on dysthymia (double depression): validity of the distinction

The nosology of chronic depression has become increasingly complex since the publication of the revised third edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R; American Psychiatric Association, 1987), but there are few data available to evaluate the validity of the distinctions between the subtypes of chronic depression. The validity of the distinction between DSM-III-R chronic major depression (CMD) and major depression superimposed on dysthymia (double depression, DD) was examined. Participants were 635 patients with chronic depression in a 12-week trial of antidepressant medications. Patients with CMD, DD, and a 3rd group with a chronic major depressive episode superimposed on dysthymia (DD/CMD) were compared on demographic and clinical characteristics, family history, and response to treatment. Few differences were evident, although the depression of patients with DD/CMD tended to be more severe.

Glycine antagonist (gavestinel) in neuroprotection (GAIN International) in patients with acute stroke: a randomised controlled trial. GAIN International Investigators

BACKGROUND

Early treatment may improve acute ischaemic stroke outcome. Gavestinel is a selective antagonist at the glycine site of the N-methyl-D-aspartate (NMDA) receptor, and is neuroprotective in animal models of ischaemic stroke.

METHODS

We did a randomised, double-blind, placebo-controlled trial to test whether gavestinel could improve functional outcome after acute stroke in human beings. Conscious patients with stroke involving limb weakness received either gavestinel at an intravenous loading dose of 800 mg followed by 200 mg every 12 h for five doses, or matching placebo, within 6 h of stroke onset. Stratification variables were age and stroke severity. A computed tomography brain scan within 18 h of stroke onset identified the primary efficacy population with ischaemic stroke. Outcome was assessed by an independent observer with the Barthel index at 3 months. Three outcome categories were applied: good (Barthel index 95-100), moderate (60-90), and poor (0-55 or dead). Analysis was by intention to treat.

FINDINGS

Of 1804 patients randomised, 16 received no treatment, and 333 had primary intracranial haemorrhage. 891 patients received gavestinel and 897 received placebo. Outcome in 721 patients who received gavestinel and were analysed for the primary endpoint at 3 months was good in 246 (34.1%), moderate in 136 (18.8%), and poor in 339 (47.0%), compared with 256 (34.9%), 133 (18.1%), and 345 (47.0%), respectively, of 734 patients who received placebo (p=0.8). Mortality at 3 months was 147 (20.4%) in the gavestinel group and 138 (18.8%) in the placebo group. Outcomes within preplanned subgroup and secondary analyses were also neutral. There were no significant differences in serious side-effects between the groups.

INTERPRETATION

Treatment with gavestinel within 6 h of acute ischaemic stroke did not improve outcome.

Activation of downstream signals by the long form of the leptin receptor

The adipocyte-derived hormone leptin signals the status of body energy stores by activating the long form of the leptin receptor (LRb). Activation of LRb results in the activation of the associated Jak2 tyrosine kinase and the transmission of downstream phosphotyrosine-dependent signals. We have investigated the signaling function of mutant LRb intracellular domains under the control of the extracellular erythropoietin (Epo) receptor. By using this system, we confirm that two tyrosine residues in the intracellular domain of murine LRb become phosphorylated to mediate LRb signaling; Tyr(985) controls the tyrosine phosphorylation of SHP-2, and Tyr(1138) controls STAT3 activation. We furthermore investigated the mechanisms by which LRb controls downstream ERK activation and c-fos and SOCS3 message accumulation. Tyr(985)-mediated recruitment of SHP-2 does not alter tyrosine phosphorylation of Jak2 or STAT3 but results in GRB-2 binding to tyrosine-phosphorylated SHP-2 and is required for the majority of ERK activation during LRb signaling. Tyr(985) and ERK activation similarly mediate c-fos mRNA accumulation. In contrast, SOCS3 mRNA accumulation requires Tyr(1138)-mediated STAT3 activation. Thus, the two LRb tyrosine residues that are phosphorylated during receptor activation mediate distinct signaling pathways as follows: SHP-2 binding to Tyr(985) positively regulates the ERK --> c-fos pathway, and STAT3 binding to Tyr(1138) mediates the inhibitory SOCS3 pathway.

Reduced neuropsychological dysfunction using epiaortic echocardiography and the exclusive Y graft

BACKGROUND

To examine the effect of screening the aorta for atheroma before aortic manipulation and use of exclusive Y graft revascularization on the incidence of neuropsychological dysfunction after coronary artery bypass.

METHODS

Aortic atheroma was detected using epiaortic and transesophageal echocardiography. Atheroma avoidance was facilitated by use of the exclusive Y graft technique, which has no aortic coronary anastomoses. In the control group aortic atheroma was assessed by manual palpation, and we attempted to avoid any atheroma detected. In this group we also used aorta-coronary grafts. Transcranial Doppler imaging of the right middle cerebral artery was used to detect cerebral microemboli. Neuropsychological dysfunction was defined as a 20% or more decline in score for at least 20% of a neuropsychometric battery of ten tests for each patient.

RESULTS

Late dysfunction at 57 +/- 2 days postoperatively in the control group was 38.1% and in the echo/Y group was 3.8% (p' = 0.012). Microemboli detected by transcranial Doppler imaging during periods of aortic manipulation was greater for those with late dysfunction (5.2 +/- 3.0 compared with 0.5 +/- 0.2) (p' = 0.018). No clinical strokes occurred in either group.

CONCLUSIONS

The combined techniques of epiaortic screening and exclusive Y graft for coronary artery bypass operations resulted in a low incidence of late neuropsychological dysfunction.

Selfotel in acute ischemic stroke : possible neurotoxic effects of an NMDA antagonist

BACKGROUND AND PURPOSE

Based on neuroprotective efficacy in animal models, we evaluated the N-methyl D-aspartate antagonist Selfotel in patients with ischemic stroke, after doses up to 1.5 mg/kg were shown to be safe in phase 1 and phase 2a studies.

METHODS

Two pivotal phase 3 ischemic stroke trials tested the hypothesis, by double-blind, randomized, placebo-controlled parallel design, that a single intravenous 1.5 mg/kg dose of Selfotel, administered within 6 hours of stroke onset, would improve functional outcome at 90 days, defined as the proportion of patients achieving a Barthel Index score of >/=60. The trials were performed in patients aged 40 to 85 years with acute ischemic hemispheric stroke and a motor deficit.

RESULTS

The 2 trials were suspended on advice of the independent Data Safety Monitoring Board because of an imbalance in mortality after a total enrollment of 567 patients. The groups were well matched for initial stroke severity and time from stroke onset to therapy. There was no difference in the 90-day mortality rate, with 62 deaths (22%) in the Selfotel group and 49 (17%) in the placebo-treated group (RR=1.3; 95% CI 0.92 to 1.83; P=0.15). However, early mortality was higher in the Selfotel-treated patients (day 30: 54 of 280 versus 37 of 286; P=0.05). In patients with severe stroke, mortality imbalance was significant throughout the trial (P=0.05).

CONCLUSIONS

Selfotel was not an effective treatment for acute ischemic stroke. Furthermore, a trend toward increased mortality, particularly within the first 30 days and in patients with severe stroke, suggests that the drug might have a neurotoxic effect in brain ischemia.

Assessing food selection in a health promotion program: validation of a brief instrument for American Indian children in the southwest United States

OBJECTIVE

Brief dietary assessment instruments are needed to evaluate behavior changes of participants in dietary intervention programs. The purpose of this project was to design and validate an instrument for children participating in Pathways to Health, a culturally appropriate, cancer prevention curriculum.

DESIGN

Validation of a brief food selection instrument, Yesterday's Food Choices (YFC), which contained 33 questions about foods eaten the previous day with response choices of yes, no, or not sure. Reference data for validation were 24-hour dietary recalls administered individually to 120 students selected randomly.

SUBJECTS

The YFC and 24-hour dietary recalls were administered to American Indian children in fifth- and seventh-grade classes in the Southwest United States.

STATISTICAL ANALYSES PERFORMED

Dietary recalls were coded for food items in the YFC and results were compared for each item using percentage agreement and the kappa statistic.

RESULTS

Percentage agreement for all items was greater than 60%; for most items it was greater than 70%, and for several items it was greater than 80%. The amount of agreement beyond that explained by chance (kappa statistic) was generally small. Three items showed substantial agreement beyond chance (kappa > or = 0.6); 2 items showed moderate agreement (kappa = 0.40 to 0.59) most items showed fair agreement (kappa = 0.20 to 0.39). The food items showing substantial agreement were hot or cold cereal, low-fat milk, and mutton or chile stew. Fried or scrambled eggs and deep-fried foods showed moderate agreement beyond chances.

CONCLUSIONS

Previous development and validation of brief food selection instruments for children participating in health promotion programs has had limited success. In this study, instrument-related factors that apparently contributed to poor agreement between data from the YFC and 24-hour dietary recall were inclusion of categories of foods vs specific foods; food knowledge, preparation, and vocabulary, item length, and overreporting of attractive foods. Collecting and scoring the 24-hour recall data may also have contributed to poor agreement. Further development of brief instruments for evaluating changes in children's behavior in dietary programs is necessary. Factors related to the YFC that need further development may be issues that are also important in the development of effective, brief dietary assessments for children as individual clients or patients.

Recent advances in the assessment of intelligence and cognition

In this paper, we review current issues in cognitive assessment. After addressing important definitional and theoretical issues, we discuss some recently developed cognitive assessment instruments as well as some recently revised instruments. Tests that are scheduled for revision will also be mentioned. As most readers are generally familiar with the widely used and nationally standardized IQ tests, we will summarize these tests according to their general usage. The testing of intelligence has been a major focus and contribution since the early days of Psychology, when the birthplace of the intelligence testing movement began in France with the work of Alfred Binet toward the end of the 19th century. Many of the most widely known and used IQ tests have been developed in the U.S.A. and are used internationally. In addition, other IQ tests have been developed in many other countries outside the U.S.A. The use of IQ tests and selected assessment considerations will be reviewed. Finally, we make some predictions about the future role of cognitive assessment in the coming century.

Cervicocerebral artery dissections

OBJECTIVE

To determine the aetiology, frequency, presentation, and outcome of blunt cervicocerebral arterial dissection presentations.

PATIENTS AND METHODS

Cases were retrospectively identified through the stroke registers at Royal Melbourne Hospital (a tertiary teaching hospital) and Geelong Hospital (a regional referral centre). Medical notes were then reviewed.

RESULTS

A total of 18 cases were identified, with ages ranging from 28 to 53 years. Fifty five per cent of the injuries sustained were to the internal carotid artery and 45% to the vertebral artery. The majority of the injuries were either spontaneous or associated with trivial forces. Other causes included motor vehicle accidents, falls, and cervical manipulations. Fifty five per cent of patients complained of significant neck pain before presentation. Most patients had delayed presentations, with only 39% presenting on the day of the incident. Seventy eight per cent presented with a neurological deficit. Initial computed tomography was normal in 71% of patients. The majority of patients were managed with anticoagulation, and had minimal functional deficit on discharge. Other treatment modalities included surgery (one patient) and thrombolysis (two patients). One patient was managed conservatively.

CONCLUSIONS

The incidence of blunt cervicocerebral arterial dissection is unknown; however it is an uncommon diagnosis. The most common presentation is that of a delayed neurological event. Initial brain computed tomography is usually normal. Minimal adverse outcomes at discharge were noted in patients treated with anticoagulation only.

Serial study of apparent diffusion coefficient and anisotropy in patients with acute stroke

BACKGROUND AND PURPOSE

We sought to characterize the evolution of apparent diffusion coefficient (ADC) and apparent diffusion anisotropy (ADA) in acute stroke and to evaluate their roles in predicting stroke evolution and outcome.

METHODS

We studied 26 stroke patients acutely (<24 hours), subacutely (3 to 5 days), and at outcome (3 months). Ratios of the ADC and ADA within a region of infarction and the normal contralateral region were evaluated and compared with the Canadian Neurological Scale, Barthel Index, and Rankin Scale.

RESULTS

Heterogeneity in ADC and ADA evolution was observed not only between patients but also within individual lesions. Three patterns of ADA evolution were observed: (1) elevated ADA acutely and subacutely; (2) elevated ADA acutely and reduced ADA subacutely; and (3) reduced ADA acutely and subacutely. At outcome, reduced ADA with elevated ADC was observed generally. We identified 3 phases of diffusion abnormalities: (1) reduced ADC and elevated ADA; (2) reduced ADC and reduced ADA; and (3) elevated ADC and reduced ADA. The ADA ratios within 12 hours correlated with the acute Canadian Neurological Scale (r=0.46, P=0.06), subacute Canadian Neurological Scale (r=0.55, P=0.02), outcome Barthel Index (r=0.62, P=0.01), and Rankin Scale (r=-0.77, P<0.0005) scores.

CONCLUSIONS

Combined ADC and ADA provide differential patterns of stroke evolution. Early ADA changes reflect cellular alterations in acute ischemia and may provide a potential marker to predict stroke outcome.

Pathophysiological topography of acute ischemia by combined diffusion-weighted and perfusion MRI

BACKGROUND AND PURPOSE

Combined echoplanar MRI diffusion-weighted imaging (DWI), perfusion imaging (PI), and magnetic resonance angiography (MRA) can be used to visualize acute brain ischemia and predict lesion evolution and functional outcome. The appearance of a larger lesion by PI than by DWI quantitatively defines a mismatch of potential clinical importance. Qualitative lesion variations exist in the topographic concordance of this mismatch. We examined both the topographic heterogeneity and relative frequency of mismatched patterns in acute stroke using these MRI techniques.

METHODS

Acute DWI, PI, and MRA studies of 34 prospectively recruited patients with supratentorial ischemic lesions scanned within 24 hours of stroke onset (range 2.5 to 23.3 hours, 12 patients <6 hours) were analyzed.

RESULTS

Ischemic lesions were predominantly in the middle cerebral artery (MCA) territory (94%), with DWI lesions most commonly affecting the insular region. Mismatched patterns with PI lesion larger than DWI lesion occurred in 21 patients (62% overall), in all 4 patients imaged within 3 hours, and in 44% of patients imaged after 18 hours. A patient with a large PI but no DWI lesion and severe clinical deficit at 2.5 hours after stroke onset recovered completely. Regional variations in DWI and PI lesion loci were found, inferring site of proximal MCA occlusion, embolic pathogenesis, and regional arterial reperfusion.

CONCLUSIONS

Analysis of the topographic concordance of PI and DWI lesions in acute stroke reveals regional PI lesions without concomitant DWI lesions, which do not necessarily progress to infarction but may suggest stroke pathogenesis and site of current arterial occlusion. Location of DWI lesions may suggest an earlier site of arterial occlusion and regions of maximal perfusion deficit.

Identification of major ischemic change. Diffusion-weighted imaging versus computed tomography

BACKGROUND AND PURPOSE

Thrombolytic therapy is not recommended in patients with CT changes of recent major infarction, which has been defined as reduced attenuation or cerebral edema involving >33% of the middle cerebral artery territory (European Cooperative Acute Stroke Study [ECASS] criteria). Diffusion-weighted imaging (DWI) is more sensitive than CT in detecting acute ischemia, and the combination of DWI, MR perfusion imaging, and MR angiography provides additional information from a single examination. We sought to determine whether DWI could identify the presence and extent of major ischemia as well as CT in hyperacute stroke patients.

METHODS

Seventeen suspected hemispheric stroke patients were studied with both CT and DWI within 6 hours of symptom onset. None received thrombolytic therapy. The scans were examined separately by 2 neuroradiologists in a blinded fashion for ischemic change and cerebral edema, graded as normal, <33%, or >33% of the MCA territory. Final diagnosis of stroke was determined with the use of standard clinical criteria and T2-weighted imaging at day 90.

RESULTS

Sixteen of 17 patients had a final diagnosis of stroke. Acute ischemic changes were seen in all 16 on DWI (100% sensitivity) and in 12 of 16 on CT (75% sensitivity). DWI identified all 6 patients with major ischemia on CT, with excellent agreement between the 2 imaging techniques (kappa=0.88). One patient eligible for thrombolysis on the ECASS CT criteria had major ischemia on DWI.

CONCLUSIONS

DWI is more sensitive than CT in the identification of acute ischemia and can visualize major ischemia more easily than CT.

Nimodipine and perfusion changes after stroke

BACKGROUND AND PURPOSE

Meta-analysis of previous trials of oral nimodipine in acute stroke has suggested a benefit when commenced within 12 hours of onset. We sought to study the effect of oral nimodipine on reperfusion after acute stroke and the relation between reperfusion and outcome.

METHODS

Fifty patients with acute middle cerebral artery territory cortical infarction were blindly randomized within 12 hours of onset to either oral nimodipine (30 mg every 6 hours) or placebo. Treatment was continued for 2 weeks. Cerebral blood flow was assessed with the use of 99mTc-hexamethylpropyleneamine oxime single-photon emission CT before therapy, 24 hours later, and at 3 months. Hypoperfusion was measured by a validated volumetric technique. Neurological impairment and functional outcome were assessed with the Canadian Neurological Scale and Barthel Index, respectively. Tissue loss was measured with CT at 3 months. Four patients were excluded from analysis for technical reasons.

RESULTS

Twenty-three patients received nimodipine, and 23 received placebo. In the nimodipine group, there was early reperfusion that was not maintained at outcome (P=0.01). In the placebo group, mean infarct hypoperfusion volumes showed no overall change. Nonnutritional reperfusion in nimodipine-treated patients was associated with adverse neurological (P=0.05) and functional outcome (P=0.06). There was, however, no difference in clinical outcome between the 2 groups.

CONCLUSIONS

Oral nimodipine administered within 12 hours enhanced acute reperfusion, but this was largely nonnutritional. Larger studies using a shorter treatment delay are required to evaluate the clinical efficacy of nimodipine in acute ischemic stroke.

Antiviral effect of gingyo-san, a traditional Chinese herbal medicine, on influenza A2 virus infection in mice

Gingyo-san is a crude drug containing extracts from 7 medicinal plants and fermented soybeans in a specific ratio. It has been used clinically in China as a therapeutic agent for the common cold. In the present study, we examined the antiviral effect of this agent on influenza virus infection in mice. Gingyo-san and its components were administered orally to mice 1 day before, then 1 and 4 days after the inhalation of a mouse-adopted strain of influenza A2 (H2N2) virus. After infection with a 10 LD50 of the virus, 100% of mice treated with 10 mg/kg of the agent survived as compared with a 0% survival of control mice treated with saline. Also, the mean survival days were increased and consolidation scores were decreased in treated mice as compared with those of control mice. Two components contained in the agent, extracts from Glycyrrhizae radix and Arctii fructus, expressed antiviral activities in mice infected with influenza virus. However, in vitro growth of influenza virus in MDCK cells or viability of the virus was not affected by these extracts or Gingyo-san. From these results Gingyo-san was shown to be an antiviral agent in mice infected with a lethal amount of a mouse-adopted strain of influenza A2 virus.

Association of cytochrome b5 with 16-androstene steroid synthesis in the testis and accumulation in the fat of male pigs

The 16-androstene steroids, one of the principal causes of boar taint, are synthesized in the testis by the andien-beta synthase enzyme system. This system has been shown in vitro to involve both cytochrome P450c17 and cytochrome b5. The objective of this work was to investigate the relationship between the levels of cytochrome b5 in the testis, in vitro steroidogenesis, and the accumulation of 16-androstene steroids in the fat of pubertal boars. We found that the in vitro rate of 16-androstene steroidogenesis in testis microsomes was correlated with 16-androstene steroid concentrations in fat (r = .66, P < .01). Western blots were used to determine the amounts of cytochrome b5 and cytochrome P450c17 protein in testis, and two immunoreactive cytochrome b5 proteins of approximately 12 and 16 kDa were found. Levels of cytochrome P450c17 or the high molecular weight cytochrome b5 in testis were not significantly correlated to levels of 16-androstene steroids in fat. However, levels of total cytochrome b5 immunoreactive protein and levels of the low molecular weight immunoreactive cytochrome b5 were correlated to fat 16-androstene steroid concentrations (r = .59, P < .001; r = .72, P = .0001, respectively). Levels of the low molecular weight immunoreactive cytochrome b5 were also correlated to 16-androstene steroid synthesis rates in vitro (r = .62, P < .05). These results indicate that increased levels of a low molecular weight immunoreactive cytochrome b5 protein, and not of cytochrome P450c17, are related to increased testicular 16-androstene steroid production and accumulation in fat. These results support the hypothesis that selection for reduced levels of this low molecular weight immunoreactive cytochrome b5 protein in the testis may result in decreased levels of 16-androstene steroids in fat and reduced boar taint in uncastrated male pigs.

Absent middle cerebral artery flow predicts the presence and evolution of the ischemic penumbra

OBJECTIVES

In acute ischemic stroke the pattern of a perfusion-imaging (PI) lesion larger than the diffusion-weighted imaging (DWI) lesion may be a marker of the ischemic penumbra. We hypothesized that acute middle cerebral artery (MCA) occlusion would predict the presence of presumed "penumbral" patterns (PI > DWI), ischemic core evolution, and stroke outcome.

METHODS

Echoplanar PI, DWI, and magnetic resonance angiography (MRA) were performed in 26 patients with MCA territory stroke. Imaging and clinical studies (Canadian Neurological Scale, Barthel Index, and Rankin Scale) were performed within 24 hours of onset and repeated at days 4 and 90.

RESULTS

MCA flow was absent in 9 of 26 patients. This was associated with larger acute PI and DWI lesions, greater PI/DWI mismatch, early DWI lesion expansion, larger final infarct size, worse clinical outcome (p < 0.01) and provided independent prognostic information (multiple linear regression analysis, p < 0.05). Acute penumbral patterns were present in 14 of 26 patients. Most of these patients (9 of 14) had no MCA flow, whereas all nonpenumbral patients (PI < or = DWI lesion) had MCA flow (p < 0.001). Penumbral-pattern patients with absent MCA flow had greater DWI lesion expansion (p < 0.05) and worse clinical outcome (Rankin Scale score, p < 0.05).

CONCLUSIONS

Absent MCA flow on MRA predicts the presence of a presumed penumbral pattern on acute PI and DWI and worse stroke outcome. Combined MRA, PI, and DWI can identify individual patients at risk of ischemic core progression and the potential to respond to thrombolytic therapy beyond 3 hours.

Pathways family intervention for third-grade American Indian children

The goal of the feasibility phase of the Pathways family intervention was to work with families of third-grade American Indian children to reinforce health behaviors being promoted by the curriculum, food service, and physical activity components of this school-based obesity prevention intervention. Family behaviors regarding food choices and physical activity were identified and ranked according to priority by using formative assessment and a literature review of school-based programs that included a family component. The family intervention involved 3 primary strategies designed to create an informed home environment supportive of behavioral change: 1) giving the children "family packs" containing worksheets, interactive assignments, healthful snacks, and low-fat tips and recipes to take home to share with their families; 2) implementing family events at the school to provide a fun atmosphere in which health education concepts could be introduced and reinforced; and 3) forming school-based family advisory councils composed of family members and community volunteers who provided feedback on Pathways strategies, helped negotiate barriers, and explored ideas for continued family participation. For strategy 2, a kick-off Family Fun Night provided a series of learning booths that presented the healthful behaviors taught by Pathways. At an end-of-year Family Celebration, a healthy meal was served, students demonstrated newly learned Pathways activities, and certificates were presented in recognition of completion of the Pathways curriculum. Based on evaluation forms and attendance rosters, strategies 1 and 2 were more easily implemented and better received than strategy 3. Implications for developing family involvement strategies for intervention programs are discussed.

Process evaluation in a multisite, primary obesity-prevention trial in American Indian schoolchildren

We describe the development, implementation, and use of the process evaluation component of a multisite, primary obesity prevention trial for American Indian schoolchildren. We describe the development and pilot testing of the instruments, provide some examples of the criteria for instrument selection, and provide examples of how process evaluation results were used to document and refine intervention components. The theoretical and applied framework of the process evaluation was based on diffusion theory, social learning theory, and the desire for triangulation of multiple modes of data collection. The primary objectives of the process evaluation were to systematically document the training process, content, and implementation of 4 components of the intervention. The process evaluation was developed and implemented collaboratively so that it met the needs of both the evaluators and those who would be implementing the intervention components. Process evaluation results revealed that observation and structured interviews provided the most informative data; however, these methods were the most expensive and time consuming and required the highest level of skill to undertake. Although the literature is full of idealism regarding the uses of process evaluation for formative and summative purposes, in reality, many persons are sensitive to having their work evaluated in such an in-depth, context-based manner as is described. For this reason, use of structured, quantitative, highly objective tools may be more effective than qualitative methods, which appear to be more dependent on the skills and biases of the researcher and the context in which they are used.

Practicing participatory research in American Indian communities

The purpose of this article is to explore the historical issues that affect research in American Indian communities and examine the implications of these issues as they relate to culturally sensitive, respectful, and appropriate research with this population. Methods include review and analysis of the literature and examination of our collective experience and that of our colleagues. Recommendations are given for conducting culturally sensitive, participatory research. We conclude that research efforts must build on the establishment of partnerships between investigators and American Indian communities to ensure accurate findings and analyses and to implement culturally relevant benefits.

Ischemic stroke risk and passive exposure to spouses' cigarette smoking. Melbourne Stroke Risk Factor Study (MERFS) Group

OBJECTIVES

This study investigated the association between ischemic stroke risk and passive exposure to cigarette smoking.

METHODS

Risk factors among 452 hospitalized cases of first-episode ischemic stroke were compared with 452 age- and sex-matched "neighbor-hood" controls.

RESULTS

The risk of stroke was twice as high for subjects whose spouses smoked as for those whose spouses did not smoke (95% confidence interval = 1.3, 3.1), after adjustment for the subject's own smoking, heart disease, hypertension, diabetes, and education level. These results were confirmed when analysis was limited to those who never smoked.

CONCLUSIONS

These findings provide evidence that spousal smoking may be a significant risk factor for ischemic stroke.