Amyloid beta protein forms ion channels: implications for Alzheimer's disease pathophysiology

Amyloid beta protein (AbetaP) is the major constituent of senile plaques associated with Alzheimer's disease (AD). However, its mechanistic role in AD pathogenesis is poorly understood. Globular and nonfibrillar AbetaPs are continuously released during normal metabolism. Using techniques of atomic force microscopy, laser confocal microscopy, electrical recording, and biochemical assays, we have examined the molecular conformations of reconstituted globular AbetaPs as well as their real-time and acute effects on neuritic degeneration. Atomic force microscopy (AFM) of AbetaP1-42 shows globular structures that do not form fibers in physiological-buffered solution for up to 8 h of continuous imaging. AFM of AbetaP1-42 reconstituted in a planar lipid bilayer reveals multimeric channel-like structures. Consistent with these AFM resolved channel-like structures, biochemical analysis demonstrates that predominantly monomeric AbetaPs in solution form stable tetramers and hexamers after incorporation into lipid membranes. Electrophysiological recordings demonstrate the presence of multiple single channel currents of different sizes. At the cellular level, AbetaP1-42 allows calcium uptake and induces neuritic abnormality in a dose- and time-dependent fashion. At physiological nanomolar concentrations, rapid neuritic degeneration was observed within minutes; at micromolar concentrations, neuronal death was observed within 3-4 h. These effects are prevented by zinc (an AbetaP channel blocker) and by the removal of extracellular calcium, but are not prevented by antagonists of putative AbetaP cell surface receptors. Thus, AbetaP channels may provide a direct pathway for calcium-dependent AbetaP toxicity in AD.

Regional leptomeningeal score on CT angiography predicts clinical and imaging outcomes in patients with acute anterior circulation occlusions

BACKGROUND AND PURPOSE

The regional leptomeningeal score is a strong and reliable imaging predictor of good clinical outcomes in acute anterior circulation ischemic strokes and can therefore be used for imaging based patient selection. Efforts to determine biological determinants of collateral status are needed if techniques to alter collateral behavior and extend time windows are to succeed.

MATERIALS AND METHODS

This was a retrospective Institutional Review Board-approved study of patients with acute ischemic stroke and M1 middle cerebral artery+/- intracranial internal carotid artery occlusion at our center from 2003 to 2009. The rLMC score is based on scoring pial and lenticulostriate arteries (0, no; 1, less; 2, equal or more prominent compared with matching region in opposite hemisphere) in 6 ASPECTS regions (M1-6) plus anterior cerebral artery region and basal ganglia. Pial arteries in the Sylvian sulcus are scored 0, 2, or 4. Good clinical outcome was defined as mRS ≤ 2 at 90 days.

RESULTS

The analysis included 138 patients: 37.6% had a good (17-20), 40.5% a medium (11-16), and 21.7% a poor (0-10) rLMC score. Interrater reliability was high, with an intraclass correlation coefficient of 0.87 (95% CI, 0.77%-0.95%). On univariate analysis, no single vascular risk factor was associated with the presence of poor rLMCs (P ≥ .20 for all comparisons). In multivariable analysis, the rLMC score (good versus poor: OR, 16.7; 95% CI, 2.9%-97.4%; medium versus poor: OR, 9.2, 95% CI, 1.7%-50.6%), age (< 80 years), baseline ASPECTS (≥ 8), and clot burden score (≥ 8) were independent predictors of good clinical outcome.

CONCLUSIONS

The rLMC score is a strong imaging parameter on CT angiography for predicting clinical outcomes in patients with acute ischemic strokes.

Solid cancers after bone marrow transplantation

PURPOSE

To evaluate the incidence and associated risk factors of solid cancers after bone marrow transplantation (BMT).

PATIENTS AND METHODS

We analyzed 2,129 patients who had undergone BMT for hematologic malignancies at the City of Hope National Medical Center between 1976 and 1998. A retrospective cohort and nested case-control study design were used to evaluate the role of pretransplantation therapeutic exposures and transplant conditioning regimens.

RESULTS

Twenty-nine patients developed solid cancers after BMT, which represents a two-fold increase in risk compared with a comparable normal population. The estimated cumulative probability (+/- SE) for development of a solid cancer was 6.1% +/- 1.6% at 10 years. The risk was significantly elevated for liver cancer (standardized incidence ratio [SIR], 27.7; 95% confidence interval [CI], 1.9 to 57.3), cancer of the oral cavity (SIR, 17.4; 95% CI, 6.3 to 34.1), and cervical cancer (SIR, 13.3; 95% CI, 3.5 to 29.6). Each of the two patients with liver cancer had a history of chronic hepatitis C infection. All six patients with squamous cell carcinoma of the skin had chronic graft-versus-host disease. The risk was significantly higher for survivors who were younger than 34 years of age at time of BMT (SIR, 5.3; 95% CI, 2.7 to 8.6). Cancers of the thyroid gland, liver, and oral cavity occurred primarily among patients who received total-body irradiation.

CONCLUSION

The risk of radiation-associated solid tumor development after BMT is likely to increase with longer follow-up. This underscores the importance of close monitoring of patients who undergo BMT.

Fresh and globular amyloid beta protein (1-42) induces rapid cellular degeneration: evidence for AbetaP channel-mediated cellular toxicity

Amyloid beta peptides (AbetaP) deposit as plaques in vascular and parenchymal areas of Alzheimer's disease (AD) tissues and Down's syndrome patients. Although neuronal toxicity is a feature of late stages of AD, vascular pathology appears to be a feature of all stages of AD. Globular and nonfibrillar AbetaPs are continuously released during normal cellular metabolism, form calcium-permeable channels, and alter cellular calcium level. We used atomic force microscopy, laser confocal microscopy, and calcium imaging to examine the real-time and acute effects of fresh and globular AbetaP(1-42), AbetaP(1-40), and AbetaP(25-35) on cultured endothelial cells. AbetaPs induced morphological changes that were observed within minutes after AbetaP treatment and led to eventual cellular degeneration. Cellular morphological changes were most sensitive to AbetaP(1-42). AbetaP(1-42)-induced morphological changes were observed at nanomolar concentrations and were accompanied by an elevated cellular calcium level. Morphological changes were prevented by anti-AbetaP antibody, AbetaP-channel antagonist zinc, and the removal of extracellular calcium, but not by tachykinin neuropeptide, voltage-sensitive calcium channel blocker cadmium, or antioxidants DTT and Trolox. Thus, nanomolar fresh and globular AbetaP(1-42) induces rapid cellular degeneration by elevating intracellular calcium, most likely via calcium-permeable AbetaP channels and not by its interaction with membrane receptors or by activating oxidative pathways. Such rapid degeneration also suggests that the plaques, and especially fibrillar AbetaPs, may not have a direct causative role in AD pathogenic cascades.

Interferon-alpha restores normal adhesion of chronic myelogenous leukemia hematopoietic progenitors to bone marrow stroma by correcting impaired beta 1 integrin receptor function

Treatment of chronic myelogenous leukemia (CML) with interferon-alpha frequently results in normalization of peripheral blood counts and, in up to 20% of patients, reestablishment of normal hematopoiesis. We hypothesize that interferon-alpha may restore normal adhesive interactions between CML progenitors and the bone marrow microenvironment and restore normal growth regulatory effects resulting from these progenitor-stroma interactions. We demonstrate that treatment with interferon-alpha induces a significant, dose-dependent increase in the adhesion of primitive long-term culture initiating cells and committed colony-forming cells (CFC) from CML bone marrow to normal stroma. Adhesion of CFC seen after interferon-alpha treatment could be inhibited by blocking antibodies directed at the alpha 4, alpha 5, and beta 1 integrins and vascular cell adhesion molecule, but not CD44 or intracellular adhesion molecule, suggesting that interferon-alpha induces normalization of progenitor-stroma interactions in CML. Because FACS analysis showed that the level of alpha 4, alpha 5, and beta 1 integrin expression after interferon-alpha treatment is unchanged, this suggests that interferon-alpha may restore normal beta 1 integrin function. Normalization of interactions between CML progenitors and the bone marrow microenvironment may then result in the restoration of normal regulation of CML progenitor proliferation, and explain, at least in part, the therapeutic efficacy of interferon-alpha in CML.

Nonproliferating CML CD34+ progenitors are resistant to apoptosis induced by a wide range of proapoptotic stimuli

Imatinib mesylate, a Bcr-Abl kinase inhibitor, has been very successful in the treatment of chronic myelogenous leukemia (CML). However, the majority of patients achieving cytogenetic remissions with imatinib treatment have molecular evidence of persistent disease, and residual BCR/ABL(+) progenitors can be detected. There is a need to develop new approaches that enhance elimination of malignant progenitors in imatinib-treated patients. Here we show that CML CD34(+) progenitors are sensitive to several apoptosis-inducing stimuli including the chemotherapeutic agents Ara-C and VP-16, radiation, arsenic trioxide, ceramide, growth factor withdrawal, and the death receptor activators TNFalpha and TRAIL. Bcr-Abl kinase inhibition by imatinib did not enhance sensitivity of CML progenitors to Ara-C, VP-16, ceramide, radiation or TRAIL-induced apoptosis but did enhance arsenic and TNFalpha-induced apoptosis. We further demonstrate that apoptosis was restricted to dividing cells, whereas nonproliferating BCR/ABL(+) CD34(+) cells were resistant to apoptosis induced by imatinib, Ara-C or arsenic, either alone or in combination. Resistance of quiescent CML progenitors to imatinib-induced apoptosis could contribute to persistence of residual malignant progenitors in imatinib-treated patients. Combination treatment with Ara-C or arsenic may not enhance targeting of nonproliferating CML progenitors. The assay described here may be useful for identifying agents targeting quiescent CML progenitors.

Elasticity and adhesion force mapping reveals real-time clustering of growth factor receptors and associated changes in local cellular rheological properties

Cell surface macromolecules such as receptors and ion channels serve as the interface link between the cytoplasm and the extracellular region. Their density, distribution, and clustering are key spatial features influencing effective and proper physical and biochemical cellular responses to many regulatory signals. In this study, the effect of plasma-membrane receptor clustering on local cell mechanics was obtained from maps of interaction forces between antibody-conjugated atomic force microscope tips and a specific receptor, a vascular endothelial growth factor (VEGF) receptor. The technique allows simultaneous measurement of the real-time motion of specific macromolecules and their effect on local rheological properties like elasticity. The clustering was stimulated by online additions of VEGF, or antibody against VEGF receptors. VEGF receptors are found to concentrate toward the cell boundaries and cluster rapidly after the online additions commence. Elasticity of regions under the clusters is found to change remarkably, with order-of-magnitude stiffness reductions and fluidity increases. The local stiffness reductions are nearly proportional to receptor density and, being concentrated near the cell edges, provide a mechanism for cell growth and angiogenesis.

A long-term follow-up report on allogeneic stem cell transplantation for patients with primary refractory acute myelogenous leukemia: impact of cytogenetic characteristics on transplantation outcome

The prognosis of patients with primary refractory acute myelogenous leukemia (AML) is poor. Our initial report suggested that some patients could achieve durable remission after allogeneic stem cell transplantation (SCT). Herein, we update our initial experience and report further analysis of this group of patients to determine whether there are pre-SCT prognostic factors predictive of posttransplantation relapse and survival. We reviewed the records of 68 patients who consecutively underwent transplantation at the City of Hope Cancer Center with allogeneic SCT for primary refractory AML between July 1978 and August 2000. Potential factors associated with overall survival and disease-free survival were examined. With a median follow-up of 3 years, the 3-year cumulative probabilities of disease-free survival (DFS), overall survival (OS), and relapse rate for all 68 patients were 31% (95% confidence interval [CI], 20%-42%), 30% (95% CI, 18%-41%), and 51% (95% CI, 38%-65%), respectively. In multivariate analysis, the only variables associated with shortened OS and DFS included the use of an unrelated donor as the stem cell source (relative risk, 2.23 [OS] and 2.05 [DFS]; P =.0005 and.0014, respectively) and unfavorable cytogenetics before SCT (relative risk: 1.68 [OS] and 1.58 [DFS]; P =.0107 and.0038, respectively). Allogeneic SCT can cure approximately one third of patients with primary refractory AML. Cytogenetic characteristics before SCT correlate with transplantation outcome and posttransplantation relapse.

Role of heterotrophic aerobic denitrifying bacteria in nitrate removal from wastewater

With the increase in industrial and agricultural activities, a large amount of nitrogenous compounds are released into the environment, leading to nitrate pollution. The perilous effects of nitrate present in the environment pose a major threat to human and animal health. Bioremediation provides a cost-effective and environmental friendly method to deal with this problem. The process of aerobic denitrification can reduce nitrate compounds to harmless dinitrogen gas. This review provides a brief view of the exhaustive role played by aerobic denitrifiers for tackling nitrate pollution under different ecological niches and their dependency on various environmental parameters. It also provides an understanding of the enzymes involved in aerobic denitrification. The role of aerobic denitrification to solve the issues faced by the conventional method (aerobic nitrification-anaerobic denitrification) in treating nitrogen-polluted wastewaters is elaborated.

Efficacy of minocycline in acute ischemic stroke: a single-blinded, placebo-controlled trial

BACKGROUND

Minocycline is a semisynthetic derivative of the tetracycline group of antibiotics, which have neuroprotective effects. In animal stroke models, minocycline had shown promising evidence to improve clinical and functional outcomes.

OBJECTIVE

To analyze the effect of oral minocycline in acute ischemic stroke patients.

MATERIALS AND METHODS

This was a randomized single-blinded open-label study. The study group received oral minocycline 200 mg/day for 5 days and the control group received oral vitamin B capsules. Baseline assessment included the following: National Institute of Health Stroke Scale (NIHSS) score, modified Barthel Index (mBI), modified Rankin Scale (mRS) score, Magnetic Resonance Imaging (MRI) of brain including Diffusion Weighted Imaging (DWI), chest X-ray, and routine laboratory investigations. The clinical scales were repeated at days 1, 7, and 30. The end point was outcomes at 3 months (90 days). Statistical analysis was done with SPSS 11.5 (P<0.05). Paired t-test and multiple-measures Analysis Of Variance (ANOVA) were used.

RESULTS

Fifty patients with acute ischemic stroke were included in the study. Of these, 23 patients received minocycline and 27 patients received placebo i.e., vitamin B capsules. NIHSS score in patients receiving minocycline had shown statistically significant improvement at day 30 and 90 as compared with the controls. Similarly, mRS scores and BI showed significant improvement in patients receiving minocycline at three months as compared to the control group. No mortality, myocardial infarctions, recurrent strokes, and hemorrhagic transformations were noted in both groups.

CONCLUSIONS

Patients with acute ischemic stroke had significantly better outcome with minocycline treatment as compared with those administered placebo. The above findings suggest that minocycline can be helpful in reducing the clinical deficits after acute ischemic stroke.

Drug solubilization in lung surfactant

The relative affinity of glucocorticosteroids for lung surfactant was determined for the purpose of identifying chemopreventive agents with a high therapeutic index for lung cancer. The aqueous solubility and the extent of solubilization in Survanta, a native extract of bovine lung, of budesonide, triamcinolone acetonide, dexamethasone, and flunisolide were determined as a function of temperature by a dialysis technique. The aqueous solubilites at 37 degrees C were 19.6, 35.8, 104 and 120 microg/ml for the above listed compounds, respectively. The temperature dependence of the solubilities was modest consistent with the hydrophobic properties of the steroids. The amount of drug in solution was significantly enhanced in the presence of Survanta with solubilization ratios of 0. 019, 0.023, 0.014, and 0.02 microg drug dissolved per microg of Survanta phospholipid, respectively. In addition, the extent of solubilization also generally increased with temperature, although the phase transition of the surfactant lipid appeared to complicate the functional relation between temperature and solubilization. These results show that there is enhanced solubilization of glucocortosteroids by lung surfactant which is secreted by the cancer susceptible type II cells of the lung.

Normobaric oxygen therapy in acute ischemic stroke: A pilot study in Indian patients

Purpose:

Clinical and radiological assessment of effects of normobaric high-flow oxygen therapy in patients with acute ischemic stroke (AIS).

Materials and Methods:

Patients with anterior circulation ischemic strokes presenting within 12 h of onset, ineligible for intravenous thrombolysis, an National Institute of Health Stroke Scale (NIHSS) score of >4, a mean transit time (MTT) lesion larger than diffusion-weighted image (DWI) (perfusiondiffusion mismatch), and an evidence of cortical hypoperfusion on magnetic resonance imaging (MRI) were included into the trial. Active chronic obstructive pulmonary disease (COPD), requirement of >3/L min oxygen delivery to maintain SaO2 > 95%, rapidly improving neurological deficits, pregnancy, contraindications to MRI, or unstable medical conditions were excluded. The experimental group received humidified oxygen at flow rates of 10 L/min for 12 h. The NIHSS, modified Rankin Score (mRS), Barthel Index (BI) were measured at 0, 1, 7 day of admission and at 3 months follow-up. MRI with DWI/PWI was performed at admission, 24 h later and at 3 months follow-up.

Results:

Of 40 patients (mean age = 55.8 years ± 13.2) (range, 26–82), 20 patients were randomized to normobaric oxygen (NBO). The mean NIHSS in NBO and control groups were 14.25 and 12.7 at admission which decreased to 11.6 and 9.5 on the seventh day, and 9.4 and 9.05 at 3 months, respectively. The mean mRS (3.7/3.7) and BI (58.2/53.9) in NBO and control groups improved to 2/2.2 and 73.05/73.8 at the end of 3 months, respectively.

Conclusions:

NBO did not improve the clinical scores of stroke outcome in Indian patients with AIS.

Integrin-mediated regulation of hematopoiesis: do BCR/ABL-induced defects in integrin function underlie the abnormal circulation and proliferation of CML progenitors?

Hematopoiesis takes place in close contact with the marrow microenvironment. Normal progenitors adhere through a variety of receptors to stroma and extracellular matrix components, including fibronectin. Adhesion through integrins to fibronectin may not only serve to anchor progenitors to the microenvironment but also to directly alter the proliferative behavior of normal hematopoietic progenitors. Chronic myelogenous leukemia (CML) is a malignant disease of the hematopoietic stem cell. At the molecular level, CML is characterized by the BCR/ABL gene rearrangement which encodes for the oncoprotein, p210bcr-abl. Presence of the p210bcr-abl tyrosine kinase is necessary and sufficient for the malignant transformation of hematopoietic cells. Clinically, CML is characterized by an abnormal, premature release of primitive progenitors and precursors in the blood and by the continuous proliferation of the malignant progenitor population. In vitro, CML progenitors fail to adhere to or be regulated by marrow stroma. Since CML progenitors express similar numbers of integrin adhesion receptors as normal progenitors, functional rather than quantitative differences of these receptors on CML progenitors may be responsible for the abnormal circulation and proliferation of the malignant clone. In this manuscript we will review the role of integrin adhesion receptors present on normal hematopoietic progenitors in the regulation of their proliferation and discuss signal transduction mechanisms that may be responsible for these effects. We will also discuss the integrin defect in CML which may be caused by the presence of the oncoprotein, P210bcr-abl, and may explain the abnormal trafficking and proliferation observed in CML.

Antenatal phenobarbital for the prevention of neonatal intracerebral hemorrhage

Forty-six pregnant women less than 35 weeks of gestation were enrolled in a prospective randomized controlled study evaluating the effects of antenatal phenobarbital on neonatal intracerebral hemorrhage. The women were randomly assigned to control (n = 22) or treatment (n = 24) groups; the treatment group received 500 mg of phenobarbital intravenously. The time interval between the dose of phenobarbital and delivery was 5.5 +/- 4.8 hours (mean +/- SD). The infants in the control group (n = 23) and those in the phenobarbital-treated group (n = 25) were comparable regarding birth weight, gestational age, and other obstetric and neonatal risk factors associated with intracerebral hemorrhage. The incidence of intracerebral hemorrhage was 56.5% (13 of 23 infants) in the control group and 32% (eight of 25 infants) in the phenobarbital-treated group (p = 0.08). Moderate or severe hemorrhage was diagnosed in six of 13 control infants and in none of the phenobarbital-treated infants (p less than 0.01). The mortality rate was significantly lower in the phenobarbital-treated group (two of 25 infants) than in the control group (eight of 23 infants; p less than 0.05). Our study suggests that antenatal phenobarbital administration results in a decrease in mortality and in the severity of intracerebral hemorrhage in the preterm neonate.

Treatment of marrow stroma with interferon-alpha restores normal beta 1 integrin-dependent adhesion of chronic myelogenous leukemia hematopoietic progenitors. Role of MIP-1 alpha

The mechanisms by which interferon-alpha (IFN-alpha) restores normal hematopoiesis in chronic myelogenous leukemia (CML) are not well understood. We have recently demonstrated that IFN-alpha acts directly on CML hematopoietic progenitors to restore their adhesion to marrow stroma by modulating beta 1 integrin receptor function. In the present study we examined the effect of IFN-alpha treatment of marrow stroma on subsequent adhesion of CML progenitors. Stromal layers were preincubated with IFN-alpha (10,000 microns/ml) for 48 h. Subsequent coincubation with CML progenitors for 2 h resulted in significantly increased adhesion of CML progenitors. We demonstrated that alpha 4 beta 1 and alpha 5 beta 1 integrin receptors were involved in the enhanced adhesion of CML progenitors, suggesting that IFN-alpha-treated stroma can upregulate CML integrin function. This effect is due, at least in part, to IFN-alpha-induced increased stromal production of the chemokine macrophage inflammatory protein-1 alpha (MIP-1 alpha), which upregulates beta 1 integrin-dependent adhesion of CML progenitors to stroma. Thus, IFN-alpha treatment of marrow stroma restores beta 1 integrin-dependent adhesion of CML progenitors, at least in part through induction of MIP-1 alpha production. These observations provide further insights into mechanisms by which IFN-alpha may restore normal hematopoiesis in CML.

Autologous stem-cell transplantation for poor-risk and relapsed intermediate- and high-grade non-Hodgkin's lymphoma

The primary objective of this study was to evaluate the outcome of patients treated with high-dose chemo-/radiotherapy or high-dose chemotherapy and autologous stem-cell transplant (ASCT) for relapsed, refractory, or poor-risk intermediate-grade (IG) and high-grade (HG) non-Hodgkin's lymphoma (NHL). The secondary objectives were to determine prognostic factors for relapse and survival. Between February 1987 and August 1998, 264 patients, 169 (64%) IG and 95 (36%) HG, underwent high-dose therapy and ASCT at City of Hope National Medical Center (COHNMC). There were 157 (59%) males and 107 (41%) females with a median age of 44 years (range, 5-69 years). The median number of prior chemotherapy regimens was 2 (range, 1-4), and 71 (27%) had received prior radiation as part of induction or as salvage therapy. The median time from diagnosis to ASCT was 10.8 months (range, 3-158 months). Ninety-four patients (36%) underwent transplantation in first complete/partial remission (CR/PR), 40 (15%) in induction failure, and 130 (49%) in relapse or subsequent remission. Two preparative regimens were used: total body irradiation/high-dose etoposide/cyclophosphamide (TBI/VP/CY) in 208 patients (79%) and carmustine/etoposide/cyclophosphamide (BCNU/VP/CY) in 56 patients (21%). One hundred sixty-three patients (62%) received peripheral blood stem cells (PBSC) and 101 (38%) received bone marrow (BM) alone or BM plus PBSC. At a median follow-up of 4.43 years for surviving patients (range, 1-12.8 years), the 5-year Kaplan-Meier estimates of probability of overall survival (OS), progression-free survival (PFS), and relapse for all patients are 55% (95% confidence interval [CI]: 49%-61%), 47% (95% CI: 40%-53%), and 47% (95% CI: 40%-54%), respectively. There were 27 deaths (10%) from nonrelapse mortality, including seven (3%) patients who developed second malignancies (five with myelodysplasia/acute myelogenous leukemia and two with solid tumors). By stepwise Cox regression analysis, disease status at ASCT was the only prognostic factor that predicted for both relapse and survival. The 5-year probability of PFS for patients transplanted in first CR/PR was 73% (95% CI: 62%-81%) as compared to 30% (95% CI: 16%-45%) for induction failure and 34% (95% CI: 26%-42%) for relapsed patients. Our results further support the role of high-dose therapy and ASCT during first CR/PR for patients with poor-risk intermediate- and high-grade NHL. Early transplant is recommended for patients failing initial induction therapy or relapsing after chemotherapy-induced remission. Relapse continues to be the most common cause of treatment failure. An alternative approach to prevent relapse, the incorporation of radioimmunotherapy into the high-dose regimen, is being investigated. The development of a second malignancy is a serious complication of high-dose therapy, which requires close surveillance.

Autologous intravenous mononuclear stem cell therapy in chronic ischemic stroke

BACKGROUND

The regenerative potential of brain has led to emerging therapies that can cure clinico-motor deficits after neurological diseases. Bone marrow mononuclear cell therapy is a great hope to mankind as these cells are feasible, multipotent and aid in neurofunctional gains in Stroke patients.

AIMS

This study evaluates safety, feasibility and efficacy of autologous mononuclear (MNC) stem cell transplantation in patients with chronic ischemic stroke (CIS) using clinical scores and functional imaging (fMRI and DTI).

DESIGN

Non randomised controlled observational study Study: Twenty four (n=24) CIS patients were recruited with the inclusion criteria as: 3 months-2years of stroke onset, hand muscle power (MRC grade) at least 2; Brunnstrom stage of recovery: II-IV; NIHSS of 4-15, comprehendible. Fugl Meyer, modified Barthel Index (mBI) and functional imaging parameters were used for assessment at baseline, 8 weeks and at 24 weeks. Twelve patients were administered with mean 54.6 million cells intravenously followed by 8 weeks of physiotherapy. Twelve patients served as controls. All patients were followed up at 24 weeks.

OUTCOMES

The laboratory and radiological outcome measures were within normal limits in MNC group. Only mBI showed statistically significant improvement at 24 weeks (p<0.05) whereas the mean FM, MRC, Ashworth tone scores in the MNC group were high as compared to control group. There was an increased number of cluster activation of Brodmann areas BA 4, BA 6 post stem cell infusion compared to controls indicating neural plasticity. Cell therapy is safe and feasible which may facilitate restoration of function in CIS.

Cranio-cerebral erosion (growing fracture of the skull in children). Part II. Clinical and radiological observations

This paper is based on a study of sixty cases of cranio-cerebral erosion treated in the Department of Neurosurgery. All India Institute of Medical Sciences, New Delhi during the last 20 years. This constitutes the largest series, so far reported from anywhere. It has provided a unique opportunity to get a comprehensive picture of the clinical and radiological features of this lesion, as also their evolution. These have been correlated with the findings at surgery and histopathological observations. The study highlights the incidence, pattern and severity of the brain damage associated with this lesion. Evidence has been provided for the progressive nature of the brain damage, not adequately emphasized in the existing literature. Pathogenesis of this brain damage has been discussed. The role of surgery in the management of this lesion has been outlined. Emphasis on the osseous changes or the "leptomeningeal cyst" (not really a consistent or important feature) in most publications on this subject has tended to minimize the significance of the brain damage in this condition. The authors suggest that the latter is far more important and therefore, recommend the use of nomenclature which takes this into account.

The T-ALL related gene BCL11B regulates the initial stages of human T-cell differentiation

The initial stages of T-cell differentiation are characterized by a progressive commitment to the T-cell lineage, a process that involves the loss of alternative (myelo-erythroid, NK, B) lineage potentials. Aberrant differentiation during these stages can result in T-cell acute lymphoblastic leukemia (T-ALL). However, the mechanisms regulating the initial stages of human T-cell differentiation are obscure. Through loss of function studies, we showed BCL11B, a transcription factor recurrently mutated T-ALL, is essential for T-lineage commitment, particularly the repression of NK and myeloid potentials, and the induction of T-lineage genes, during the initial stages of human T-cell differentiation. In gain of function studies, BCL11B inhibited growth of and induced a T-lineage transcriptional program in T-ALL cells. We found previously unknown differentiation stage-specific DNA binding of BCL11B at multiple T-lineage genes; target genes showed BCL11B-dependent expression, suggesting a transcriptional activator role for BCL11B at these genes. Transcriptional analyses revealed differences in the regulatory actions of BCL11B between human and murine thymopoiesis. Our studies show BCL11B is a key regulator of the initial stages of human T-cell differentiation and delineate the BCL11B transcriptional program, enabling the dissection of the underpinnings of normal T-cell differentiation and providing a resource for understanding dysregulations in T-ALL.

Undisplaced scaphoid waist fractures: is 4 weeks' immobilisation in a below-elbow cast sufficient if a week 4 CT scan suggests fracture union?

This prospective study investigated a cohort of 59 scaphoid waist fractures which were treated nonoperatively in a below-elbow plaster cast for 4 weeks and then underwent a Week 4 CT scan to assess displacement and progress to union. Forty-three were classed as undisplaced and 37 of these 43 were also classed as 'united'. All the 37 undisplaced and 'united' fractures united with up to 8 weeks' cast immobilisation, including 26 which were taken out of plaster at 4 weeks and mobilised. We conclude that scaphoid waist fractures which appear to be undisplaced and united on a week 4 CT scan will unite, and may not need to be immobilised in a plaster cast for more than 4 weeks. Such a treatment policy may reduce the period of disability and time off work associated with nonoperative treatment.

Hyperacute thrombolysis with IV rtPA of acute ischemic stroke: Efficacy and safety profile of 54 patients at a tertiary referral center in a developing country

BACKGROUND

Given the constraints of resources, thrombolysis for acute ischemic stroke (AIS) is under evaluation in developing countries. Prothrombin time (PT), platelet count and activated partial thromboplastin time (aPTT) may not be feasible within the time window.

AIM

To evaluate the safety and efficacy of thrombolysis in selected patients without the coagulation profile.

DESIGN

Open, nonrandomized, observational study.

MATERIALS AND METHODS

Fifty-four stroke patients were classified using TOAST criteria (large artery atherosclerotic = 13; cardioembolic = 12; small vessel occlusion = 22; other determined etiology =three; undetermined etiology = four). The mean time to reach emergency was 2.4h (1.15-3.4), the mean door to CT, 24 min (10-47) and the door to recombinant tissue plasminogen activator (r-tPA) injection, 26.8 min (25-67). The NIHSS scores ranged from 11 to 22 (mean = 15.5 +/- 2.7). Patients with history of liver or renal disease or those on anticoagulants were excluded. The PT, aPTT and platelet count were not done. Recombinant tissue plasminogen activator was administered at a dosage of 0.9 mg/Kg.

RESULTS

Thirty-five patients (65%) significantly improved on NIHSS at 48 h (> or =4 points) (mean change = 10; range= 4-17). At one month, 43 (79%) improved on Barthel Index (mean change = 45%). One each developed small frontal lobe hemorrhage and recurrent stroke; one died of aspiration; and eight showed no improvement.

CONCLUSIONS

Hyperacute thrombolysis was found useful and safe in selected patients with AIS even without the coagulation studies.

Elimination of neglected tropical diseases in the South-East Asia Region of the World Health Organization

The neglected tropical diseases (NTDs), which affect the very poor, pose a major public health problem in the South-East Asia Region of the World Health Organization (WHO). Although more than a dozen NTDs affect the region, over the past five years four of them in particular - leprosy, lymphatic filariasis, visceral leishmaniasis (kala-azar) and yaws - have been targeted for elimination. These four were selected for a number of reasons. First, they affect the WHO South-East Asia Region disproportionately. For example, every year around 67% of all new leprosy cases and 60% of all new cases of visceral leishmaniasis worldwide occur in countries of the region, where as many as 850 million inhabitants are at risk of contracting lymphatic filariasis. In addition, several epidemiological, technological and historical factors that are unique to the region make each of these four diseases amenable to elimination. Safe and effective tools and interventions to achieve these targets are available and concerted efforts to scale them up, singly or in an integrated manner, are likely to lead to success. The World Health Assembly and the WHO Regional Committee, through a series of resolutions, have already expressed regional and global commitments for the elimination of these diseases as public health problems. Such action is expected to have a quick and dramatic impact on poverty reduction and to contribute to the achievement of the Millennium Development Goals. This paper reviews the policy rationale for disease control in the WHO South-East Asia Region, the progress made so far, the lessons learnt along the way, and the remaining challenges and opportunities.

Single umbilical artery: accurate diagnosis?

OBJECTIVE

We sought to evaluate the accuracy of ultrasonographic, obstetric, and neonatal diagnosis of a single umbilical artery.

STUDY DESIGN

We studied 17,777 consecutive singleton births from women who had undergone ultrasonographic examination at our hospital. A single umbilical artery was confirmed in 37 cases (0.2%) by two clinical methods or by pathologic assessment. Outcome of neonates with a single umbilical artery was compared with the outcome of neonates with either two or three vessel cords.

RESULTS

Ultrasonographic diagnosis had a 65% sensitivity and positive predictive value. Obstetricians and pediatricians failed to diagnose 24% and 16% of the cases, respectively. On average, neonates with a single umbilical artery weighed 320 gm less, were delivered 1 week earlier, and had lower Apgar scores than neonates with three vessel cords (p < 0.01 in each case.)

CONCLUSION

Although early gestational age may account for some cases not diagnosed by ultrasonography, there is a little justification for missing the diagnosis after delivery. Greater emphasis on clinical examination of the umbilical cord is needed to identify neonates at risk of associated malformations.