Therapeutic benefit of intravenous administration of bone marrow stromal cells after cerebral ischemia in rats

BACKGROUND AND PURPOSE

We tested the hypothesis that intravenous infusion of bone marrow derived-marrow stromal cells (MSCs) enter the brain and reduce neurological functional deficits after stroke in rats.

METHODS

Rats (n=32) were subjected to 2 hours of middle cerebral artery occlusion (MCAO). Test groups consisted of MCAO alone (group 1, n=6); intravenous infusion of 1x10(6) MSCs at 24 hours after MCAO (group 2, n=6); or infusion of 3x10(6) MSCs (group 3, n=7). Rats in groups 1 to 3 were euthanized at 14 days after MCAO. Group 4 consisted of MCAO alone (n=6) and group 5, intravenous infusion of 3x10(6) MSCs at 7 days after MCAO (n=7). Rats in groups 4 and 5 were euthanized at 35 days after MCAO. For cellular identification, MSCs were prelabeled with bromodeoxyuridine. Behavioral tests (rotarod, adhesive-removal, and modified Neurological Severity Score [NSS]) were performed before and at 1, 7, 14, 21, 28, and 35 days after MCAO. Immunohistochemistry was used to identify MSCs or cells derived from MSCs in brain and other organs. RESULTS Significant recovery of somatosensory behavior and Neurological Severity Score (P<0.05) were found in animals infused with 3x10(6) MSCs at 1 day or 7 days compared with control animals. MSCs survive and are localized to the ipsilateral ischemic hemisphere, and a few cells express protein marker phenotypic neural cells.

CONCLUSIONS

MSCs delivered to ischemic brain tissue through an intravenous route provide therapeutic benefit after stroke. MSCs may provide a powerful autoplastic therapy for stroke.

Intravenous administration of human umbilical cord blood reduces behavioral deficits after stroke in rats

BACKGROUND AND PURPOSE

Human umbilical cord blood cells (HUCBC) are rich in stem and progenitor cells. In this study we tested whether intravenously infused HUCBC enter brain, survive, differentiate, and improve neurological functional recovery after stroke in rats. In addition, we tested whether ischemic brain tissue extract selectively induces chemotaxis of HUCBC in vitro.

METHODS

Adult male Wistar rats were subjected to transient (2-hour) middle cerebral artery occlusion (MCAO). Experimental groups were as follows: group 1, MCAO alone (n=5); group 2, 3x10(6) HUCBC injected into tail vein at 24 hours after MCAO (n=6) (animals of groups 1 and 2 were killed at 14 days after MCAO); group 3, MCAO alone (n=5); group 4, MCAO injected with PBS at 1 day after stroke (n=8); and group 5, 3x10(6) HUCBC injected into tail vein at 7 days after MCAO (n=5). Rats of groups 3, 4, and 5 were killed at 35 days after MCAO. Behavioral tests (rotarod and Modified Neurological Severity Score [mNSS]) were performed. Immunohistochemical staining was used to identify cells derived from HUCBC. Chemotactic activity of ischemia brain tissue extracts toward HUCBC at different time points was evaluated in vitro.

RESULTS

Treatment at 24 hours after MCAO with HUCBC significantly improved functional recovery, as evidenced by the rotarod test and mNSS (P<0.05). Treatment at 7 days after MCAO with HUCBC significantly improved function only on the mNSS (P<0.05). Some HUCBC were reactive for the astrocyte marker glial fibrillary acidic protein and the neuronal markers NeuN and microtubule-associated protein 2. In vitro, significant HUCBC migration activity was present at 24 hours after MCAO (P<0.01) compared with normal brain tissue.

CONCLUSIONS

Intravenously administered HUCBC enter brain, survive, migrate, and improve functional recovery after stroke. HUCBC transplantation may provide a cell source to treat stroke.

The genome of the social amoeba Dictyostelium discoideum

The social amoebae are exceptional in their ability to alternate between unicellular and multicellular forms. Here we describe the genome of the best-studied member of this group, Dictyostelium discoideum. The gene-dense chromosomes of this organism encode approximately 12,500 predicted proteins, a high proportion of which have long, repetitive amino acid tracts. There are many genes for polyketide synthases and ABC transporters, suggesting an extensive secondary metabolism for producing and exporting small molecules. The genome is rich in complex repeats, one class of which is clustered and may serve as centromeres. Partial copies of the extrachromosomal ribosomal DNA (rDNA) element are found at the ends of each chromosome, suggesting a novel telomere structure and the use of a common mechanism to maintain both the rDNA and chromosomal termini. A proteome-based phylogeny shows that the amoebozoa diverged from the animal-fungal lineage after the plant-animal split, but Dictyostelium seems to have retained more of the diversity of the ancestral genome than have plants, animals or fungi.

Human marrow stromal cell therapy for stroke in rat: neurotrophins and functional recovery

OBJECTIVE

To test the effect of i.v.-injected human bone marrow stromal cells (hMSC) on neurologic functional deficits after stroke in rats.

METHODS

Rats were subjected to transient middle cerebral artery occlusion and IV injected with 3 x 10(6) hMSC 1 day after stroke. Functional outcome was measured before and 1, 7, and 14 days after stroke. Mixed lymphocyte reaction and the development of cytotoxic T lymphocytes measured the immune rejection of hMSC. A monoclonal antibody specific to human cellular nuclei (mAb1281) was used to identify hMSC and to measure neural phenotype. ELISA analyzed neurotrophin levels in cerebral tissue from hMSC-treated or nontreated rats. Bromodeoxyuridine injections were used to identify newly formed cells.

RESULTS

Significant recovery of function was found in rats treated with hMSC at 14 days compared with control rats with ischemia. Few (1 to 5%) hMSC expressed proteins phenotypic of brain parenchymal cells. Brain-derived neurotrophic factor and nerve growth factor significantly increased, and apoptotic cells significantly decreased in the ischemic boundary zone; significantly more bromodeoxyuridine-reactive cells were detected in the subventricular zone of the ischemic hemisphere of rats treated with hMSC. hMSC induced proliferation of lymphocytes without the induction of cytotoxic T lymphocytes.

CONCLUSION

Neurologic benefit resulting from hMSC treatment of stroke in rats may derive from the increase of growth factors in the ischemic tissue, the reduction of apoptosis in the penumbral zone of the lesion, and the proliferation of endogenous cells in the subventricular zone.

Local Control of Microdomain Orientation in Diblock Copolymer Thin Films with Electric Fields

Local control of the domain orientation in diblock copolymer thin films can be obtained by the application of electric fields on micrometer-length scales. Thin films of an asymmetric polystyrene-polymethylmethacrylate diblock copolymer, with cylindrical polymethylmethacrylate microdomains, were spin-coated onto substrates previously patterned with planar electrodes. The substrates, 100-nanometer-thick silicon nitride membranes, allow direct observation of the electrodes and the copolymer domain structure by transmission electron microscopy. The cylinders aligned parallel to the electric field lines for fields exceeding 30 kilovolts per centimeter, after annealing at 250&deg;C in an inert atmosphere for 24 hours. This technique could find application in nanostructure fabrication.

A method for efficient isotopic labeling of recombinant proteins

A rapid and efficient approach for preparing isotopically labeled recombinant proteins is presented. The method is demonstrated for 13C labeling of the C-terminal domain of angiopoietin-2, 15N labeling of ubiquitin and for 2H/13C/15N labeling of the Escherichia coli outer-membrane lipoprotein Lpp-56. The production method generates cell mass using unlabeled rich media followed by exchange into a small volume of labeled media at high cell density. Following a short period for growth recovery and unlabeled metabolite clearance, the cells are induced. The expression yields obtained provide a fourfold to eightfold reduction in isotope costs using simple shake flask growths.

A trimeric structural domain of the HIV-1 transmembrane glycoprotein

Infection with HIV-1 is initiated by fusion of cellular and viral membranes. The gp41 subunit of the HIV-1 envelope plays a major role in this process, but the structure of gp41 is unknown. We have identified a stable, proteinase-resistant structure comprising two peptides, N-51 and C-43, derived from a recombinant protein fragment of the gp41 ectodomain. In isolation, N-51 is predominantly aggregated and C-43 is unfolded. When mixed, however, these peptides associate to form a stable, alpha-helical, discrete trimer of heterodimers. Proteolysis experiments indicate that the relative orientation of the N-51 and C-43 helices in the complex is antiparallel. We propose that N-51 forms an interior, parallel, homotrimeric, coiled-coil core, against which three C-43 helices pack in an antiparallel fashion. We suggest that this alpha-helical, trimeric complex is the core of the fusion-competent state of the HIV-1 envelope.

Early stroke treatment associated with better outcome: the NINDS rt-PA stroke study

BACKGROUND

The National Institute of Neurological Disorders and Stroke (NINDS) rt-PA Stroke Study showed a similar percentage of intracranial hemorrhage and good outcome in patients 3 months after stroke treatment given 0 to 90 minutes and 91 to 180 minutes after stroke onset. At 24 hours after stroke onset more patients treated 0 to 90 compared to 91 to 180 minutes after stroke onset had improved by four or more points on the NIH Stroke Scale (NIHSS). The authors performed further analyses to characterize the relationship of onset-to-treatment time (OTT) to outcome at 3 months, early improvement at 24 hours, and intracranial hemorrhage within 36 hours.

METHODS

Univariate analyses identified potentially confounding variables associated with OTT that could mask an OTT-treatment interaction. Tests for OTT-treatment interactions adjusting for potential masking confounders were performed. An OTT-treatment interaction was considered significant if p < or = 0.10, implying that treatment effectiveness was related to OTT.

RESULTS

For 24-hour improvement, there were no masking confounders identified and there was an OTT-treatment interaction (p = 0.08). For 3-month favorable outcome, the NIHSS met criteria for a masking confounder. After adjusting for NIHSS as a covariate, an OTT-treatment interaction was detected (p = 0.09): the adjusted OR (95% CI) for a favorable 3-month outcome associated with recombinant tissue-type plasminogen activator (rt-PA) was 2.11 (1.33 to 3.35) in the 0 to 90 minute stratum and 1.69 (1.09 to 2.62) in the 91 to 180 minute stratum. In the group treated with rt-PA, after adjusting for baseline NIHSS, an effect of OTT on the occurrence of intracranial hemorrhage was not detected.

CONCLUSIONS

If the NINDS rt-PA Stroke Trial treatment protocol is followed, this analysis suggests that patients treated 0 to 90 minutes from stroke onset with rt-PA have an increased odds of improvement at 24 hours and favorable 3-month outcome compared to patients treated later than 90 minutes. No effect of OTT on intracranial hemorrhage was detected within the group treated with rt-PA, possibly due to low power.

Self-assembly of mesoscopically ordered chromatic polydiacetylene/silica nanocomposites

Nature abounds with intricate composite architectures composed of hard and soft materials synergistically intertwined to provide both useful functionality and mechanical integrity. Recent synthetic efforts to mimic such natural designs have focused on nanocomposites, prepared mainly by slow procedures like monomer or polymer infiltration of inorganic nanostructures or sequential deposition. Here we report the self-assembly of conjugated polymer/silica nanocomposite films with hexagonal, cubic or lamellar mesoscopic order using polymerizable amphiphilic diacetylene molecules as both structure-directing agents and monomers. The self-assembly procedure is rapid and incorporates the organic monomers uniformly within a highly ordered, inorganic environment. Polymerization results in polydiacetylene/silica nanocomposites that are optically transparent and mechanically robust. Compared to ordered diacetylene-containing films prepared as Langmuir monolayers or by Langmuir-Blodgett deposition, the nanostructured inorganic host alters the diacetylene polymerization behaviour, and the resulting nanocomposite exhibits unusual chromatic changes in response to thermal, mechanical and chemical stimuli. The inorganic framework serves to protect, stabilize, and orient the polymer, and to mediate its function. The nanocomposite architecture also provides sufficient mechanical integrity to enable integration into devices and microsystems.

Atomic structure of a thermostable subdomain of HIV-1 gp41

Infection by HIV-1 involves the fusion of viral and cellular membranes with subsequent transfer of viral genetic material into the cell. The HIV-1 envelope glycoprotein that mediates fusion consists of the surface subunit gp120 and the transmembrane subunit gp41. gp120 directs virion attachment to the cell-surface receptors, and gp41 then promotes viral-cell membrane fusion. A soluble, alpha-helical, trimeric complex within gp41 composed of N-terminal and C-terminal extraviral segments has been proposed to represent the core of the fusion-active conformation of the HIV-1 envelope. A thermostable subdomain denoted N34(L6)C28 can be formed by the N-34 and C-28 peptides connected by a flexible linker in place of the disulfide-bonded loop region. Three-dimensional structure of N34(L6)C28 reveals that three molecules fold into a six-stranded helical bundle. Three N-terminal helices within the bundle form a central, parallel, trimeric coiled coil, whereas three C-terminal helices pack in the reverse direction into three hydrophobic grooves on the surface of the N-terminal trimer. This thermostable subdomain displays the salient features of the core structure of the isolated gp41 subunit and thus provides a possible target for therapeutics designed selectively to block HIV-1 entry.

Therapeutic benefit of intracerebral transplantation of bone marrow stromal cells after cerebral ischemia in rats

We tested the hypothesis that bone marrow stromal cells (MSCs) transplanted into the ischemic boundary zone, survive, differentiate and improve functional recovery after middle cerebral artery occlusion (MCAo). MSCs were harvested from adult rats and cultured with or without nerve growth factor (NGF). For cellular identification, MSCs were prelabeled with bromodeoxyuridine (BrdU). Rats (n=24) were subjected to 2 h of MCAo, received grafts at 24 h and were euthanized at 14 days after MCAo. Test groups consisted of: (1) control-MCAo alone (n=8); (2) intracerebral transplantation of MSCs (n=8); (3) intracerebral transplantation of MSCs cultured with NGF (n=8). Immunohistochemistry was used to identify cells from MSCs. Behavioral tests (rotarod, adhesive-removal and modified neurological severity score [NSS]) were performed before and after MCAo. The data demonstrate that MSCs survive, migrate and differentiate into phenotypic neural cells. Significant recovery of somatosensory behavior (p<0.05) and NSS (p<0.05) were found in animals transplanted with MSCs compared with control animals. Animals that received MSCs cultured with NGF displayed significant recovery in motor (p<0.05), somatosensory (p<0.05) and NSS (p<0.05) behavioral tests compared with control animals. Our data suggest that intracerebral transplantation of MSCs may provide a powerful autoplastic therapy for stroke.

Spinal cord injury in rat: treatment with bone marrow stromal cell transplantation

We tested the hypothesis that transplantation of bone marrow stromal cells (MSCs) into the spinal cord after a contusion injury promotes functional outcome. Rats (n = 31) were subjected to a weight driven implant injury. MSCs or phosphate buffered saline was injected into the spinal cord 1 week after injury. Sections of tissue were analyzed by double-labeled immunohistochemistry for MSC identification. Functional outcome measurements using the Basso-Beattie-Bresnehan score were performed weekly to 5 weeks post-injury. The data indicate significant improvement in functional outcome in animals treated with MSC transplantation compared to control animals. Scattered cells derived from MSCs expressed neural protein markers. These data suggest that transplantation of MSCs may have a therapeutic role after spinal cord injury.

SeqA: a negative modulator of replication initiation in E. coli

In E. coli, replication initiates at a genetically unique origin, oriC. Rapidly growing cells contain multiple oriC copies. Initiation occurs synchronously, once and only once per cell cycle at all origins present. Secondary initiations are prevented by a sequestration process that acts uniquely on newly replicated origins, which are marked because they are hemimethylated at GATC sites. We report the identification of a gene required for sequestration and demonstrate that this gene, seqA, also serves as a negative modulator of the primary initiation process. All previously identified in vivo initiation factors play positive roles. Thus, precise control of replication initiation may involve a balance between positive and negative elements. We suggest that SeqA might be a cooperativity factor, acting to make the replication initiation process dependent upon cooperative interactions among components.

Effects of tissue plasminogen activator for acute ischemic stroke at one year. National Institute of Neurological Disorders and Stroke Recombinant Tissue Plasminogen Activator Stroke Study Group

BACKGROUND

In 1995, the two-part National Institute of Neurological Disorders and Stroke (NINDS) Recombinant Tissue Plasminogen Activator Stroke Trial found that patients who were treated with tissue plasminogen activator (t-PA) within three hours after the onset of symptoms of acute ischemic stroke were at least 30 percent more likely than patients given placebo to have minimal or no disability three months after the stroke. It was unknown, however, whether the benefit would be sustained for longer periods.

METHODS

In the NINDS Trial, a total of 624 patients with stroke were randomly assigned to receive either t-PA or placebo. We collected outcome data over a period of 12 months after the occurrence of stroke. The primary outcome measure was a "favorable outcome," defined as minimal or no disability as measured by the Barthel index, the modified Rankin Scale, and the Glasgow Outcome Scale. We assessed the treatment effect using a global statistic.

RESULTS

Using an intention-to-treat analysis for the combined results of the two parts of the trial at 6 months and 12 months, we found that the global statistic favored the t-PA group (odds ratio for a favorable outcome at 6 months, 1.7; 95 percent confidence interval, 1.3 to 2.3; odds ratio at 12 months, 95 percent confidence interval, 1.7; 1.2 to 2.3). The patients treated with t-PA were at least 30 percent more likely to have minimal or no disability at 12 months than were the placebo-treated patients (absolute increase in the proportion with a favorable outcome, 11 to 13 percentage points). There was no significant difference in mortality at 12 months between the t-PA group and the placebo group (24 percent vs. 28 percent, P=0.29). There was no interaction between the type of stroke identified at base line and treatment with respect to the long-term response. The rate of recurrent stroke at 12 months was similar in the two groups.

CONCLUSIONS

During 12 months of follow-up, the patients with acute ischemic stroke who were treated with t-PA within three hours after the onset of symptoms were more likely to have minimal or no disability, than the patients given placebo. These results indicate a sustained benefit of t-PA for such patients.

Treatment of stroke in rat with intracarotid administration of marrow stromal cells

OBJECTIVE

To measure the therapeutic efficacy for the treatment of stroke with intra-arterial administration of bone marrow stromal cells (MSC).

BACKGROUND

MSC have characteristics of stem and progenitor cells. The hypothesis that MSC injected into the internal carotid artery after stroke enter into ischemic brain and improve neurologic recovery was tested.

METHODS

Twenty-five adult Wistar rats were subjected to transient (2-hour) middle cerebral artery occlusion alone (n = 9), or treated with intracarotid arterial injection of 200 microL phosphate-buffered saline (n = 8) or 2 x 10(6) MSC in 200 microL phosphate-buffered saline (n = 8) 1 day after ischemia. MSC were harvested and isolated from additional adult rats and then cultured and labeled with bromodeoxyuridine. Rats were subjected to neurologic functional tests (adhesive-removal, modified neurologic severity scores) before and at 1, 7, and 14 days after middle cerebral artery occlusion. Immunohistochemistry was used to identify cell-specific proteins of bromodeoxyuridine-reactive MSC.

RESULTS

Bromodeoxyuridine-reactive cells ( approximately 21% of 2 x 10(6) injected MSC) distributed throughout the territory of the middle cerebral artery by 14 days after ischemia. Some bromodeoxyuridine-reactive cells expressed proteins characteristic of astrocytes and neurons. Rats with intra-arterial transplantation of MSC exhibited improvement on the adhesive-removal test (p < 0.05) and the modified neurologic severity scores (p < 0.05) at 14 days compared with controls.

CONCLUSIONS

MSC injected intra-arterially are localized and directed to the territory of the middle cerebral artery, and these cells foster functional improvement after cerebral ischemia.

Atomic-beam alignment of inorganic materials for liquid-crystal displays

The technique used to align liquid crystals-rubbing the surface of a substrate on which a liquid crystal is subsequently deposited-has been perfected by the multibillion-dollar liquid-crystal display industry. However, it is widely recognized that a non-contact alignment technique would be highly desirable for future generations of large, high-resolution liquid-crystal displays. A number of alternative alignment techniques have been reported, but none of these have so far been implemented in large-scale manufacturing. Here, we report a non-contact alignment process, which uses low-energy ion beams impinging at a glancing angle on amorphous inorganic films, such as diamond-like carbon. Using this approach, we have produced both laptop and desktop displays in pilot-line manufacturing, and found that displays of higher quality and reliability could be made at a lower cost than the rubbing technique. The mechanism of alignment is explained by adopting a random network model of atomic arrangement in the inorganic films. Order is induced by exposure to an ion beam because unfavourably oriented rings of atoms are selectively destroyed. The planes of the remaining rings are predominantly parallel to the direction of the ion beam.

Expression cloning and characterization of the canine parietal cell gastrin receptor

Gastrin is an important stimulant of acid secretion by gastric parietal cells and is structurally related to the peptide hormone cholecystokinin (CCK). The pharmacologic properties of the parietal cell gastrin receptor are very similar to the predominant CCK receptor in the brain, CCK-B. Neither the gastrin nor the CCK-B receptor have been cloned thus far, making it difficult to resolve whether these two receptors are distinct. We have isolated a clone encoding the canine gastrin receptor by screening a parietal cell cDNA expression library using a radioligand-binding strategy. Nucleotide sequence analysis revealed an open reading frame encoding a 453-amino acid protein with seven putative hydrophobic transmembrane domains and significant homology with members of the beta-adrenergic family of G protein-coupled receptors. The expressed recombinant receptor shows the same binding specificity for gastrin/CCK agonists and antagonists as the canine parietal cell receptor. Gastrin-stimulated phosphatidylinositol hydrolysis and intracellular Ca2+ mobilization in COS-7 cells expressing the cloned receptor suggest second-messenger signaling through phospholipase C. Affinity labeling of the expressed receptor in COS-7 cells revealed a protein identical in size to the native parietal cell receptor. Gastrin receptor transcripts were identified by high-stringency RNA blot analysis in both parietal cells and cerebral cortex, suggesting that the gastrin and CCK-B receptors are either highly homologous or identical.

Trastuzumab emtansine (T-DM1) versus lapatinib plus capecitabine in patients with HER2-positive metastatic breast cancer and central nervous system metastases: a retrospective, exploratory analysis in EMILIA

BACKGROUND

We characterized the incidence of central nervous system (CNS) metastases after treatment with trastuzumab emtansine (T-DM1) versus capecitabine-lapatinib (XL), and treatment efficacy among patients with pre-existing CNS metastases in the phase III EMILIA study.

PATIENTS AND METHODS

In EMILIA, patients with human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer previously treated with trastuzumab and a taxane were randomized to T-DM1 or XL until disease progression. Patients with treated, asymptomatic CNS metastases at baseline and patients developing postbaseline CNS metastases were identified retrospectively by independent review; exploratory analyses were carried out.

RESULTS

Among 991 randomized patients (T-DM1 = 495; XL = 496), 95 (T-DM1 = 45; XL = 50) had CNS metastases at baseline. CNS progression occurred in 9 of 450 (2.0%) and 3 of 446 (0.7%) patients without CNS metastases at baseline in the T-DM1 and XL arms, respectively, and in 10 of 45 (22.2%) and 8 of 50 (16.0%) patients with CNS metastases at baseline. Among patients with CNS metastases at baseline, a significant improvement in overall survival (OS) was observed in the T-DM1 arm compared with the XL arm [hazard ratio (HR) = 0.38; P = 0.008; median, 26.8 versus 12.9 months]. Progression-free survival by independent review was similar in the two treatment arms (HR = 1.00; P = 1.000; median, 5.9 versus 5.7 months). Multivariate analyses demonstrated similar results. Grade ≥3 adverse events were reported in 48.8% and 63.3% of patients with CNS metastases at baseline administered T-DM1 and XL, respectively; no new safety signals were observed.

CONCLUSION

In this retrospective, exploratory analysis, the rate of CNS progression in patients with HER2-positive advanced breast cancer was similar for T-DM1 and for XL, and higher overall in patients with CNS metastases at baseline compared with those without CNS metastases at baseline. In patients with treated, asymptomatic CNS metastases at baseline, T-DM1 was associated with significantly improved OS compared with XL.

Lack of clinical significance of early ischemic changes on computed tomography in acute stroke

CONTEXT

The prevalence and clinical significance of early ischemic changes (EICs) on baseline computed tomography (CT) scan of the head obtained within 3 hours of ischemic stroke are not established.

OBJECTIVE

To determine the frequency and significance of EIC on baseline head CT scans in the National Institute of Neurological Disorders and Stroke (NINDS) rt-PA (recombinant tissue plasminogen activator) Stroke Trial.

DESIGN AND SETTING

The original study, a randomized controlled trial, took place from January 1991 through October 1994 at 43 sites, during which CT images were obtained within 3 hours of symptom onset and prior to the initiation of rt-PA or placebo. For the current analysis, detailed reevaluation was undertaken after October 1994 of all baseline head CT scans with clinical data available pretreatment (blinded to treatment arm).

PATIENTS

Of 624 patients enrolled in the trial, baseline CT scans were retrieved and reviewed for 616 (99%).

MAIN OUTCOME MEASURES

Frequency of EICs on baseline CT scans; association of EIC with other baseline variables; effect of EICs on deterioration at 24 hours (>/=4 points increase from the baseline National Institutes of Health Stroke Scale [NIHSS] score); clinical outcome (measured by 4 clinical scales) at 3 months, CT lesion volume at 3 months, death at 90 days; and symptomatic intracranial hemorrhage (ICH) within 36 hours of treatment.

RESULTS

The prevalence of EIC on baseline CT in the combined rt-PA and placebo groups was 31% (n = 194). The EIC was significantly associated with baseline NIHSS score (rho = 0.23; P<.001) and time from stroke onset to baseline CT scan (rho = 0.11; P =.007). After adjusting for baseline variables, there was no EIC x treatment interaction detected for any clinical outcome, including deterioration at 24 hours, 4 clinical scales, lesion volume, and death at 90 days (P>/=.25), implying that EIC is unlikely to affect response to rt-PA treatment. After adjusting for NIHSS score (an independent predictor of ICH), no EIC association with symptomatic ICH at 36 hours was detected in the group treated with rt-PA (P>/=.22).

CONCLUSIONS

Our analysis suggests that EICs are prevalent within 3 hours of stroke onset and correlate with stroke severity. However, EICs are not independently associated with increased risk of adverse outcome after rt-PA treatment. Patients treated with rt-PA did better whether or not they had EICs, suggesting that EICs on CT scan are not critical to the decision to treat otherwise eligible patients with rt-PA within 3 hours of stroke onset.

Advanced glycation end products increase retinal vascular endothelial growth factor expression

Advanced glycation end products (AGEs) are linked with the development of diabetic retinopathy; however, the pathogenic mechanisms are poorly defined. Vascular endothelial growth factor (VEGF) levels are increased in ischemic and nonischemic diabetic retina, and VEGF is required for the development of retinal and iris neovascularization. Moreover, VEGF alone can induce much of the concomitant pathology of diabetic retinopathy. In this study, we found that AGEs increased VEGF mRNA levels in the ganglion, inner nuclear, and retinal pigment epithelial (RPE) cell layers of the rat retina. In vitro, AGEs increased VEGF mRNA and secreted protein in human RPE and bovine vascular smooth muscle cells. The AGE-induced increases in VEGF expression were dose- and time-dependent, inhibited by antioxidants, and additive with hypoxia. Use of an anti-VEGF antibody blocked the capillary endothelial cell proliferation induced by the conditioned media of AGE-treated cells. AGEs may participate in the pathogenesis of diabetic retinopathy through their ability to increase retinal VEGF gene expression.

Adult bone marrow stromal cells administered intravenously to rats after traumatic brain injury migrate into brain and improve neurological outcome

To measure effect of bone marrow stromal cells (MSCs) administered i.v. on rats subjected to traumatic brain injury (TBI), we injected MSCs labeled by BrdU into the tail vein 24 h after TBI and sacrificed rats 15 days later. The neurological severity score (NSS) and the Rotarod test were used to evaluate neurological function. The distribution of the donor cells in brain, heart, lung, kidney, liver and spleen were analyzed in recipient rats using immunohistochemical staining. MSCs injected i.v. significantly reduced motor and neurological deficits compared with control groups by day 15 after TBI. The cells preferentially entered and migrated into the parenchyma of the injured brain and expressed the neuronal marker NeuN and the astrocytic marker GFAP. MSCs were also found in other organs and primarily localized to the vascular structures, without any obvious adverse effects. Our data suggest that i.v. administration of MSCs may be useful in the treatment of TBI.

E. coli SeqA protein binds oriC in two different methyl-modulated reactions appropriate to its roles in DNA replication initiation and origin sequestration

The seqA gene negatively modulates replication initiation at the E. coli origin, oriC. seqA is also essential for sequestration, which acts at oriC and the dnaA promoter to ensure that replication initiation occurs exactly once per chromosome per cell cycle. Initiation is promoted by full methylation of GATC sites clustered in oriC; sequestration is specific to the hemimethylated forms generated by replication. SeqA protein purification and DNA binding are described. SeqA interacts with fully methylated oriC strongly and specifically. This reaction requires multiple molecules of SeqA and determinants throughout oriC, including segments involved in open complex formation. SeqA interacts more strongly with hemimethylated DNA; in this case, oriC and non-oriC sequences are bound similarly. Also, binding of hemimethylated oriC by membrane fractions is due to SeqA. Direct interaction of SeqA protein with the replication origin is likely to be involved in both replication initiation and sequestration.

Induction of cancer cell apoptosis by alpha-tocopheryl succinate: molecular pathways and structural requirements

The vitamin E analog alpha-tocopheryl succinate (alpha-TOS) can induce apoptosis. We show that the proapoptotic activity of alpha-TOS in hematopoietic and cancer cell lines involves inhibition of protein kinase C (PKC), since phorbol myristyl acetate prevented alpha-TOS-triggered apoptosis. More selective effectors indicated that alpha-TOS reduced PKCalpha isotype activity by increasing protein phosphatase 2A (PP2A) activity. The role of PKCalpha inhibition in alpha-TOS-induced apoptosis was confirmed using antisense oligonucleotides or PKCalpha overexpression. Gain- or loss-of-function bcl-2 mutants implied modulation of bcl-2 activity by PKC/PP2A as a mitochondrial target of alpha-TOS-induced proapoptotic signals. Structural analogs revealed that alpha-tocopheryl and succinyl moieties are both required for maximizing these effects. In mice with colon cancer xenografts, alpha-TOS suppressed tumor growth by 80%. This epitomizes cancer cell killing by a pharmacologically relevant compound without known side effects.

Underlying structure of the National Institutes of Health Stroke Scale: results of a factor analysis. NINDS tPA Stroke Trial Investigators

BACKGROUND AND PURPOSE

No stroke scale has been validated as an outcome measure using data from a clinical trial demonstrating a positive therapeutic effect. Therefore, we proposed to use data from the National Institute of Neurological Disorders and Stroke (NINDS) tPA Stroke Trial to determine whether the National Institutes of Health Stroke Scale (NIHSS) was valid in patients treated with tissue plasminogen activator (tPA) and to explore the underlying clinimetric structure of the NIHSS.

METHODS

We performed an exploratory factor analysis of NIHSS data from Part 1 (n=291) of the NINDS tPA Stroke Trial to derive a hypothesized underlying factor structure. We then performed a confirmatory factor analysis of this structure using NIHSS data from Part 2 of the same trial (n=333). We then tested whether this final factor structure could be found in tPA- and placebo-treated patients serially over time after stroke treatment. Using 3-month outcome data, we tested for an association between the NIHSS and other measures of stroke outcome.

RESULTS

The exploratory analysis suggested that there were 2 factors underlying the NIHSS, representing left and right brain function, confirming the content validity of the scale. An alternative structure composed of 4 factors could be derived, with a better goodness of fit: the first 2 factors could represent left brain cortical and motor function, respectively, and the second 2 factors could represent right brain cortical and motor function, respectively. The same factor structures were then found in tPA and placebo patient groups studied serially over time, confirming the exploratory analysis. All 3-month clinical outcomes were associated with each other at subsequent time points, confirming predictive validity.

CONCLUSIONS

This is the first study of the validity of a stroke scale in patients treated with effective stroke therapy. The NIHSS appeared to be valid in patients with acute stroke and for finding treatment-related differences. The scale was valid when used serially over time after stroke, up to 3 months, and showed good agreement with other measures of outcome.

A modified National Institutes of Health Stroke Scale for use in stroke clinical trials: preliminary reliability and validity

BACKGROUND AND PURPOSE

The National Institutes of Health Stroke Scale (NIHSS) is accepted widely for measuring acute stroke deficits in clinical trials, but it contains items that exhibit poor reliability or do not contribute meaningful information. To improve the scale for use in clinical research, we used formal clinimetric analyses to derive a modified version, the mNIHSS. We then sought to demonstrate the validity and reliability of the new mNIHSS.

METHODS

The mNIHSS was derived from our prior clinimetric studies of the NIHSS by deleting poorly reproducible or redundant items (level of consciousness, face weakness, ataxia, dysarthria) and collapsing the sensory item into 2 responses. Reliability of the mNIHSS was assessed with the certification data originally collected to assess the reliability of investigators in the National Institute of Neurological Disorders and Stroke (NINDS) rtPA (recombinant tissue plasminogen activator) Stroke

TRIAL

Validity of the mNIHSS was assessed with the outcome results of the NINDS rtPA Stroke Trial:

RESULTS

Reliability was improved with the mNIHSS: the number of scale items with poor kappa coefficients on either of the certification tapes decreased from 8 (20%) to 3 (14%) with the mNIHSS. With the use of factor analysis, the structure underlying the mNIHSS was found identical to the original scale. On serial use of the scale, goodness of fit coefficients were higher with the mNIHSS. With data from part I of the trial data, the proportion of patients who improved >/=4 points within 24 hours after treatment was statistically significantly increased by tPA (odds ratio, 1.3; 95% confidence limits, 1.0, 1.8; P=0.05). Likewise, the odds ratio for complete/nearly complete resolution of stroke symptoms 3 months after treatment was 1.7 (95% confidence limits, 1.2, 2.6) with the mNIHSS. Other outcomes showed the same agreement when the mNIHSS was compared with the original scale. The mNIHSS showed good responsiveness, ie, was useful in differentiating patients likely to hemorrhage or have a good outcome after stroke.

CONCLUSIONS

The mNIHSS appears to be identical clinimetrically to the original NIHSS when the same data are used for validation and reliability. Power appears to be greater with the mNIHSS with the use of 24-hour end points, suggesting the need for fewer patients in trials designed to detect treatment effects comparable to rtPA. The mNIHSS contains fewer items and might be simpler to use in clinical research trials. Prospective analysis of reliability and validity, with the use of an independently collected cohort, must be obtained before the mNIHSS is used in a research setting.