Asian-Pacific clinical practice guidelines on the management of hepatitis B: a 2015 update

Worldwide, some 240 million people have chronic hepatitis B virus (HBV), with the highest rates of infection in Africa and Asia. Our understanding of the natural history of HBV infection and the potential for therapy of the resultant disease is continuously improving. New data have become available since the previous APASL guidelines for management of HBV infection were published in 2012. The objective of this manuscript is to update the recommendations for the optimal management of chronic HBV infection. The 2015 guidelines were developed by a panel of Asian experts chosen by the APASL. The clinical practice guidelines are based on evidence from existing publications or, if evidence was unavailable, on the experts' personal experience and opinion after deliberations. Manuscripts and abstracts of important meetings published through January 2015 have been evaluated. This guideline covers the full spectrum of care of patients infected with hepatitis B, including new terminology, natural history, screening, vaccination, counseling, diagnosis, assessment of the stage of liver disease, the indications, timing, choice and duration of single or combination of antiviral drugs, screening for HCC, management in special situations like childhood, pregnancy, coinfections, renal impairment and pre- and post-liver transplant, and policy guidelines. However, areas of uncertainty still exist, and clinicians, patients, and public health authorities must therefore continue to make choices on the basis of the evolving evidence. The final clinical practice guidelines and recommendations are presented here, along with the relevant background information.

Hippocampal interneuron loss and plasticity in human temporal lobe epilepsy

It has been hypothesized on the basis of animal models of epilepsy that abnormal neural activity in epilepsy may be related to reorganized neural circuits that facilitate epileptogenesis. Little evidence of this was available for human epilepsy. This paper provides the first evidence of such reorganization of a hippocampal seizure focus in human temporal lobe epilepsy (TLE). This reorganization involves the selective loss of somatostatin and neuropeptide Y immunoreactive interneurons, and axonal sprouting of other neuropeptide Y neurons and dynorphin-A immunoreactive granule cells. This set of changes is not exactly like those that are reported in animal models.

Epidural spinal cord compression from metastatic tumor: diagnosis and treatment

The clinical findings in 130 conseucutive cases of spinal cord compression by metastatic extradural tumors were analyzed. These 130 patients were combined with a previous survey of 105 patients to compare the effectiveness of radiation therapy (RT) alone with that of surgical decompression followed by RT. Ambulation after treatment was considered a successful outcome. The most common primary tumors producing spinal cord compression were (in order) breast, lung, prostate, and kidney. In 68% of these tumors the thoracic region was involved. Pain was the primary symptom of 96% of the patients, while motor or sensory deficits (or both) were found in 82% of them. Therapy consisted of surgery and RT in 65 patients and RT alone in 170 patients. There were no differences in outcome between those treated by surgery combined with RT and those managed by RT alone. Patients with radiosensitive tumors and those ambulatory at the onset of treatment benefited whether treated by surgery or by RT. Seventy-five percent of living patients who improved from treatment remained ambulatory at 6 months, and approximately 50% of living patients were ambulatory at 1 year. We conclude that RT without decompressive laminectomy is as effective as decompressive laminectomy in treating epidural spinal cord compression from systemic cancer.

SynGAP: a synaptic RasGAP that associates with the PSD-95/SAP90 protein family

The PSD-95/SAP90 family of proteins has recently been implicated in the organization of synaptic structure. Here, we describe the isolation of a novel Ras-GTPase activating protein, SynGAP, that interacts with the PDZ domains of PSD-95 and SAP102 in vitro and in vivo. SynGAP is selectively expressed in brain and is highly enriched at excitatory synapses, where it is present in a large macromolecular complex with PSD-95 and the NMDA receptor. SynGAP stimulates the GTPase activity of Ras, suggesting that it negatively regulates Ras activity at excitatory synapses. Ras signaling at the postsynaptic membrane may be involved in the modulation of excitatory synaptic transmission by NMDA receptors and neurotrophins. These results indicate that SynGAP may play an important role in the modulation of synaptic plasticity.

Angiopoietin-1 regulates endothelial cell survival through the phosphatidylinositol 3'-Kinase/Akt signal transduction pathway

Angiopoietin-1 (Ang1) is a strong apoptosis survival factor for endothelial cells. In this study, the receptor/second messenger signal transduction pathway for the antiapoptotic effect of Ang1 on human umbilical vein endothelial cells was examined. Pretreatment with soluble Tie2 receptor, but not Tie1 receptor, blocked the Ang1-induced antiapoptotic effect. Ang1 induced phosphorylation of Tie2 and the p85 subunit of phosphatidylinositol 3'-kinase (PI 3'-kinase) and increased PI 3'-kinase activity in a dose-dependent manner. The PI 3'-kinase-specific inhibitors wortmannin and LY294002 blocked the Ang1-induced antiapoptotic effect. Ang1 induced phosphorylation of the serine-threonine kinase Akt at Ser473 in a PI 3'-kinase-dependent manner. Expression of a dominant-negative form of Akt reversed the Ang1-induced antiapoptotic effect. Ang1 mRNA and protein were present in vascular smooth muscle cells but not in endothelial cells. Cultured vascular smooth muscle cells, but not human umbilical vein endothelial cells, secreted Ang1. These findings indicate that the Tie2 receptor, PI 3'-kinase, and Akt are crucial elements in the signal transduction pathway leading to endothelial cell survival induced by the paracrine activity of Ang1.

Thoracic pedicle screw fixation in spinal deformities: are they really safe?

STUDY DESIGN

A retrospective study.

OBJECTIVE

To determine the safety of pedicle screw fixation in thoracic deformity correction.

SUMMARY OF BACKGROUND DATA

Pedicle screw fixation enables enhanced correction of spinal deformities. However, the technique is still not widely applied for thoracic deformities for fear of neurologic complications.

MATERIALS AND METHODS

A total of 462 patients subjected to thoracic pedicle screw fixation for spinal deformities were analyzed after a minimum follow-up of 2 years. Etiologic diagnoses were idiopathic scoliosis in 330, congenital kyphoscoliosis in 68, kyphosis in 50, and others in 14. They were reviewed using the medical records and preoperative, intraoperative, and postoperative roentgenograms. Computed tomography was performed when screw position was questionable.

RESULTS

A total of 4604 thoracic pedicle screws were inserted (10.1 screws/patient). There were 67 screw malpositions (1.5%) in 48 patients (10.4%). The malpositions were inferior in 33, lateral in 18, superior in 12, and medial in 4. Screw-related neurologic complications occurred in four patients (0.8%); these comprised a transient paraparesis and three dural tears. Other complications comprised 11 intraoperative pedicle fractures, 35 screw loosenings, 9 postoperative infections, and 1 pneumothorax. There were no significant screw-related neurologic or visceral complications that adversely affected the long-term result. The deformity correction was 69.9% for idiopathic scoliosis and 60.7% for congenital scoliosis. The sagittal plane deformity correction was 47 degrees for kyphosis.

CONCLUSIONS

Thoracic pedicle screw fixation is a reliable method of treating spinal deformities, with an excellent deformity correction and a high margin of safety.

Radiation therapy for brain metastases

We treated 183 patients who had brain metastases with whole-brain radiation therapy (RT) and adrenocorticosteroids utilizing a new high-dose radiation protocol. Treatment produced neurological improvement in 135 patients (74%); there was no change in 37 (20%), and deterioration occurred in 11 (6%). Of those patients who improved, two-thirds maintained neurological improvement for the remainder of their lives or for at least nine months, and one-third relapsed. One-third of those who relapsed improved again with steroids or further RT. Clinical improvement paralleled tumor regression on CT scan. Despite the clinical response, median survival was only twelve weeks; 24% lived six months and 8% lived one year. Death resulted from progressive brain disease in 16% of the patients. Two-thirds of the patients died of advancing systemic disease in the setting of stable, improved neurological function. These data suggest that the majority of patients with brain metastases benefit from RT and that systemic cancer, not central nervous system disease, limits the length of life.

Epidural spinal cord compression from metastatic tumor: results with a new treatment protocol

Eighty-three patients with epidural spinal cord compression, from metastatic cancer were treated with high-dose adrenocorticosteroids and a new radiation fractionation protocol. Only those patients were included who had complete or almost complete block on myelography and who had not received prior radiation therapy to the area of compression. Patients were given 100 mg of dexamethasone intravenously at the time of diagnosis and 500 rads of radiation on each of the first three days. After a four-day rest, radiation therapy was continued at 300 rads to a total dose of 3,000 rads. The effects of this new protocol on the patient's motor abilities did not differ from those of previous protocols, namely, 47 of 83 patients (57%) were ambulatory after treatment, with no responses in patients totally paraplegic before treatment. However, early administration of high doses of dexamethasone substantially ameliorated pain in the majority of patients, with relief often coming within hours after the drug was given. On the basis of these data, we recommend high doses of adrenocorticosteroids combined with radiation therapy for acute treatment of spinal cord compression. The optimum fractionation schedule for radiation therapy is not established.

Calcium mobilization via sphingosine kinase in signalling by the Fc epsilon RI antigen receptor

Calcium mobilization through antigen receptors, including high-affinity IgE receptors (Fc epsilon RI), is thought to be mediated by inositol-1,4,5-trisphosphate production (InsP3). Here we show that antigen clustering of Fc epsilon RI on the rat mast-cell line (RBL-2H3) activates a sphingosine kinase (SK) and produces sphingosine-1-phosphate (S1P), and alternative second messenger for intracellular calcium mobilization. The sphingosine analogue, D-L-threo-dihydrosphingosine (DHS), inhibits the SK enzyme competitively with a dissociation constant, K1, of 5 to 18 microM. This inhibition substantially suppresses the Fc epsilon RI-mediated calcium signal, but leaves intact the syk tyrosine kinase activation and the small InsP3 production. The entire InsP3-dependent pathway activated by a transfected G-protein coupled receptor, used here as a positive control, also remained intact. Thus Fc epsilon RI principally utilizes a SK pathway to mobilize calcium.

Monitoring community responses to the SARS epidemic in Hong Kong: from day 10 to day 62

STUDY OBJECTIVE

To report the evolution in perceptions and behaviours of the general public in response to the severe acute respiratory syndrome (SARS) epidemic in Hong Kong.

DESIGN

Ten similar and sequential telephone surveys were conducted during outbreak of SARS, which are classified as belonging to the first and second phases of the epidemic.

SETTING

Hong Kong, China.

PARTICIPANTS

1397 Hong Kong residents between 18 and 60 years of age.

MAIN OUTCOME MEASURES

Perceptions and behaviours to SARS and its prevention.

RESULTS

Most of the respondents believed that SARS could be transmitted via direct body contact and droplets. About half of respondents believed that SARS was curable, which increased in the initial phase and decreased in the second phase. Perceived chance of infection was low (9%) but fear of infection in public places was high (48%). Perceived efficacy of hygiene measures (wearing a mask: 82%, hand washing: 93%, and home disinfection: 75%) remained high in both phases and the perceived efficacy of avoiding crowded place, and using public transportation, etc, increased initially and decreased in the second phase. In parallel, use of the three hygiene measures increased significantly in the first phase and remained high for wearing a mask and washing hands in the second phase. Percentages of people avoiding crowded place and public transportation significantly increased initially and decreased in the second phase.

CONCLUSION

SARS related perceptions and behaviours evolved rapidly during the epidemic and Hong Kong residents quickly adopted appropriate SARS prevention measures. Timely dissemination of information seems effective in public health crises management.

Loss of glutamine synthetase in the human epileptogenic hippocampus: possible mechanism for raised extracellular glutamate in mesial temporal lobe epilepsy

BACKGROUND

High extracellular glutamate concentrations have been identified as a likely trigger of epileptic seizures in mesial temporal lobe epilepsy (MTLE), but the underlying mechanism remains unclear. We investigated whether a deficiency in glutamine synthetase, a key enzyme in catabolism of extracellular glutamate in the brain, could explain the perturbed glutamate homoeostasis in MTLE.

METHODS

The anteromedial temporal lobe is the focus of the seizures in MTLE, and surgical resection of this structure, including the hippocampus, leads to resolution of seizures in many cases. By means of immunohistochemistry, western blotting, and functional enzyme assays, we assessed the distribution, quantity, and activity of glutamine synthetase in the MTLE hippocampus.

FINDINGS

In western blots, the expression of glutamine synthetase in the hippocampus was 40% lower in MTLE than in non-MTLE samples (median 44 [IQR 30-58] vs 69 [56-87]% of maximum concentration in standard curve; p=0.043; n=8 and n=6, respectively). The enzyme activity was lower by 38% in MTLE vs non-MTLE (mean 0.0060 [SD 0.0031] vs 0.0097 [0.0042] U/mg protein; p=0.045; n=6 and n=9, respectively). Loss of glutamine synthetase was particularly pronounced in areas of the MTLE hippocampus with astroglial proliferation, even though astrocytes normally have high content of the enzyme. Quantitative immunoblotting showed no significant change in the amount of EAAT2, the predominant glial glutamate transporter in the hippocampus.

INTERPRETATION

A deficiency in glutamine synthetase in astrocytes is a possible molecular basis for extracellular glutamate accumulation and seizure generation in MTLE. Further studies are needed to define the cause, but the loss of glutamine synthetase may provide a new focus for therapeutic interventions in MTLE.

High-speed spiral-scan echo planar NMR imaging-I

An improved echo planar high-speed imaging technique using spiral scan is presented and experimental advantages are discussed. This proposed spiral-scan echo planar imaging (SEPI) technique employs two linearly increasing sinusoidal gradient fields, which results in a spiral trajectory in the spatial frequency domain (k-domain) that covers the entire frequency domain uniformly. The advantages of the method are: 1) circularly symmetric T2 weighting, resulting in a circularly symmetric point spread function in the image domain; 2) elimination of discontinuities in gradient waveforms which in turn will reduce initial transient as well as steady-state distortions; and 3) effective rapid spiral-scan from dc to high frequency in a continuous fashion, which ensures multiple pulsing with interlacing for further resolution improvement without T2 decay image degradation. Some preliminary experimental results will be presented and further possible improvements suggested.

Sphingosine 1-phosphate induces angiogenesis: its angiogenic action and signaling mechanism in human umbilical vein endothelial cells

Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid metabolite abundantly stored in platelets and released upon platelet activation. Recently, S1P has been postulated for its potential roles in angiogenesis. In this study, we provided several lines of evidence showing that S1P has angiogenic activity. In vitro, S1P stimulated DNA synthesis and chemotactic motility of human umbilical vein endothelial cells (HUVECs) in a dose-dependent manner, reaching a near maximum at 1 microM. S1P also significantly induced tube formation of HUVECs on Matrigel. Matrigel plug assay in mice revealed that S1P promotes angiogenesis in vivo. In addition, exposure of HUVECs to S1P led to rapid activation of extracellular signal-regulated kinases (ERKs) and p38 mitogen-activated protein kinase (p38 MAPK) in a pertussis toxin (PTX)-sensitive manner. Notably, HUVEC migration and tube formation in response to S1P were completely blocked by pretreatment with PTX. Further, the MEK inhibitor U0126 markedly inhibited S1P-induced tube formation but S1P-induced migration was not affected by inhibition of ERK and p38 MAPK. Taken together, these results indicate that S1P induces angiogenesis predominantly via G(i) protein-coupled receptors in endothelial cells and suggest that S1P may act as an important modulator of platelet-induced angiogenesis.

Antigenic modulation. Loss of TL antigen from cells exposed to TL antibody. Study of the phenomenon in vitro

Antigenic modulation (the loss of TL antigens from TL+ cells exposed to TL antibody in the absence of lytic complement) has been demonstrated in vitro. An ascites leukemia, phenotype TL.1,2,3, which modulates rapidly and completely when incubated with TL antiserum in vitro, was selected for further study of the phenomenon. Over a wide range of TL antibody concentrations modulation at 37 degrees C was detectable within 10 min and was complete within approximately 1 hr. The cells were initially sensitized to C' by their contact with antibody, thereafter losing this sensitivity to C' lysis together with their sensitivity to TL antibody and C' in the cytotoxic test. The capacity of the cells to undergo modulation was abolished by actinomycin D and by iodoacetamide, and by reducing the temperature of incubation to 0 degrees C. Thus modulation apparently is an active cellular process. Antigens TL. 1,2, and 3 are all modulated by anti-TL.1,3 serum and by anti-TL.3 serum. This modulation affects all three TL components together, even when antibody to one or two of them is lacking. aAnti-TL.2 serum does not induce modulation and in fact impairs modulation by the other TL antibodies. The influence of the TL phenotype of cells upon the demonstrable content of H-2 (D region) isoantigen, first shown in cells modulated in vivo, has been observed with cells modulated in vitro. Cells undergoing modulation show a progressive increase in H-2 (D region) antigen over a period of 4 hr, with no change in H-2 antigens of the K region. Restoration of the TL+ phenotype of modulated cells after removal of antibody is less rapid than TL+ --> TL- modulation and may require several cell divisions.

Characteristics of medial temporal lobe epilepsy: II. Interictal and ictal scalp electroencephalography, neuropsychological testing, neuroimaging, surgical results, and pathology

Sixty-seven patients with temporal lobe epilepsy without circumscribed, potentially epileptogenic lesions, who were studied with intracranial electrodes and who became seizure free following temporal lobectomy were retrospectively evaluated with regard to preoperative scalp electroencephalographic (EEG) findings, neuropsychological test results, neuroimaging findings, results of surgery, and pathology of resected tissue. Interictal scalp EEG showed paroxysmal abnormalities during prolonged monitoring in 64 patients (96%). These were localized in the anterior temporal region in 60 (94%) of these 64 patients. Bilateral independent paroxysmal activity occurred in 42% of the patients and was preponderant over the side of seizure origin in half. Ictal EEG changes were rarely detected at the time of clinical seizure onset, but lateralized buildup of rhythmic seizure activity during the seizure occurred in 80% of patients. In 13%, the scalp EEG seizure buildup was, however, contralateral to the side of seizure origin as subsequently determined by depth EEG and curative surgery. Lateralized postictal slowing, when present, was a very reliable lateralizing finding. Neuropsychological testing provided lateralizing findings concordant with the side of seizure origin in 73% of patients. When neuropsychological testing produced discordant results or nonlateralizing findings, those patients were usually found to have right temporal seizure origin. Intracarotid amobarbital (Amytal) testing demonstrated absent or marginal memory functions on the side of seizure onset in 63% of patients, but 26 patients (37%) had bilaterally intact memory. In those patients who had magnetic resonance imaging, it was very sensitive in detecting subtle medial temporal abnormalities. These abnormalities were present in 23 of 28 magnetic resonance images, and corresponded with mesial temporal sclerosis on pathological examination in all but 2 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Activation of NF-kappaB via a Src-dependent Ras-MAPK-pp90rsk pathway is required for Pseudomonas aeruginosa-induced mucin overproduction in epithelial cells

Cystic fibrosis (CF) is an autosomal recessive disorder, the most common lethal genetic disease in Caucasians. Respiratory disease is the major cause of morbidity and mortality. Indeed, 95% of CF patients die of respiratory failure. Pseudomonas aeruginosa, an opportunistic pathogen, chronically infects the lungs of over 85% of CF patients. It is ineradicable by antibiotics and responsible for airway mucus overproduction that contributes to airway obstruction and death. The molecular mechanisms underlying this pathology are unknown. Here we show that P. aeruginosa activates a c-Src-Ras-MEK1/2-MAPK-pp90rsk signaling pathway that leads to activation of nuclear factor NF-kappaB (p65/p50). Activated NF-kappaB binds to a kappaB site in the 5'-flanking region of the MUC2 gene and activates MUC2 mucin transcription. These studies bring new insight into bacterial-epithelial interactions and more specifically into the molecular pathogenesis of cystic fibrosis. Understanding these signaling and gene regulatory mechanisms opens up new therapeutic targets for cystic fibrosis.

Expression profile of histone deacetylase 1 in gastric cancer tissues

Although histone deacetylases (HDACs) appear to play a crucial role in carcinogenesis, the expression status of HDACs in primary human cancer tissues has not yet been reported. In this study, we investigated the expression level of HDAC1 in 25 paired primary human gastric cancer (GC) tissues and corresponding normal tissues through semi-quantitative RT-PCR and immunoblot analysis. The HDAC1 expression pattern was also topologically examined through immunohistochemistry. Overexpression of HDAC1 mRNA was detected in 68% of GC tissues (17 of 25), and the relative density of HDAC1 mRNA in GC tissue was increased 1.8-fold versus the normal counterpart (P < 0.01). Elevated expression of HDAC1 protein was also detected in 61% of GC samples (11 of 18), which also showed an increased mRNA level of HDAC. Immunohistochemically, overexpression of HDAC1 was predominantly localized in the nuclei of most neoplastic cells, including embolic tumor cells, whereas normal glandular epithelial cells revealed only weak HDAC1 expression that was focal in distribution. Thus, the present study clearly demonstrates that HDAC1 is overexpressed in GC and probably plays a significant role in gastric carcinogenesis.

Quantitative magnetic resonance imaging in temporal lobe epilepsy: relationship to neuropathology and neuropsychological function

Magnetic resonance images (MRIs) were obtained from 25 patients with medically refractory epilepsy of temporal lobe origin (12 on the left, 13 on the right) and 14 right-handed control subjects. The hippocampi and temporal lobes were traced by computer on successive coronal images and the resulting measurements of area were summed for each region. The left and right hippocampi were symmetrical in the control subjects; however, for patients the hippocampus was smaller on the side of the seizure focus. Moreover, the left-right hippocampal ratio significantly differentiated the control subjects from each patient group. The left temporal lobe was significantly smaller than the right in control subjects. The epileptics' temporal lobes were smaller on the side of the seizure focus, compared to the temporal lobes in the control subjects. MRI hippocampal measurements were compared to hippocampal neuronal densities obtained postoperatively. Significant correlations were obtained between the ratio (side ipsilateral to focus/side contralateral to focus) of MRI hippocampal measurements and neuronal densities in all hippocampal subfields except CA2. Prior to surgery, patients were administered the Wechsler Memory Scale and the verbal Selective Reminding Test. Significant correlations existed between MRI measurements of the left hippocampus and the Wechsler logical memory percent retention scores and between the left temporal lobe measurements and the verbal Selective Reminding Test scores for patients with seizure foci in the left temporal lobe.

Tumour-infiltrating CD8+ lymphocytes as an independent predictive factor for pathological complete response to primary systemic therapy in breast cancer

Background:

Tumour-infiltrating lymphocytes (TILs) are known to be associated with response to primary systemic therapy (PST) in breast cancer. This study was conducted to assess the association of TIL subsets with pathological complete response (pCR) after PST in breast cancer in relation to breast cancer subtype, breast cancer stem cell (BCSC) phenotype and epithelial–mesenchymal transition (EMT).

Methods:

The pre-chemotherapeutic biopsy specimens of 153 breast cancer patients who underwent surgical resection after anthracycline- or anthracycline/taxane-based PST were analysed. TIL subsets (CD4+, CD8+, and FOXP3+ TILs), BCSC phenotype, and the expression of EMT markers were evaluated by immunohistochemistry and were correlated with pCR after PST.

Results:

Infiltration of CD4+ and CD8+ T lymphocytes was closely correlated with BCSC phenotype and EMT. High levels of CD4+, CD8+, and FOXP3+ TILs were associated with pCR, and CD8+ TILs were found to be an independent predictive factor for pCR. In addition, CD8+ TILs were associated with pCR irrespective of breast cancer subtype, CD44+/CD24− phenotype, EMT, and chemotherapeutic regimen in subgroup analyses.

Conclusion:

These findings indicate that CD8+ cytotoxic T lymphocytes are a key component of TILs associated with chemo-response and can be used as a reliable predictor of response to anthracycline- or anthracycline/taxane-based PST in breast cancer.

Radiation-induced soft-tissue and bone sarcoma

From the records of Memorial Hospital of the past 50 years, 47 cases with an established diagnosis of radiation-induced sarcoma were identified and divided into two groups: the first included 20 cases of soft-tissue sarcoma arising from irradiated tissues, and the second comprised 27 cases of bone sarcoma arising from normal bones in the irradiated field. Medians for the latent periods from irradiation to diagnosis of bone and soft-tissue sarcoma were 11 and 12, years, respectively. In bone sarcomas, the latent period was longer after larger radiation doses and children appeared to be more susceptible to cancer induction than adults. Criteria for establishing the diagnosis of radiation-induced sarcoma and the magnitude of the risk of bone sarcoma are discussed.

Angiopoietin-2 at high concentration can enhance endothelial cell survival through the phosphatidylinositol 3'-kinase/Akt signal transduction pathway

The angiopoietin-Tie2 system in endothelial cells is an important regulator of vasculogenesis and vascular integrity. High levels of angiopoietin-2 (Ang2) mRNA are observed in vascular activation during tumorigenesis. Although Ang2 is known to be a naturally occurring antagonist of angiopoietin-1 (Ang1) in vivo, the exact function of Ang2 itself is not known. Here, we found that a high concentration of Ang2 (800 ng/ml) acts as an apoptosis survival factor for endothelial cells during serum deprivation apoptosis. The survival effect of high concentration Ang2 was blocked by pre-treatment with soluble Tie2 receptor and the PI 3'-kinase-specific inhibitors, wortmannin and LY294002. Accordingly, 800 ng/ml of Ang2 induced phosphorylation of Tie2, the p85 subunit of phosphatidylinositol 3'-kinase (PI 3'-kinase), and serine-threonine kinase Akt at Ser473 in the human umbilical vein endothelial cells; lower concentrations of Ang2 (50 - 400 ng/ml) did not produce notable effects. These findings indicate that at high concentrations, Ang2, like Ang1, can be an apoptosis survival factor for endothelial cells through the activation of the Tie2 receptor, PI 3'-kinase and Akt, and thus may be a positive regulator of tumor angiogenesis. Oncogene (2000) 19, 4549 - 4552.

Regional grey matter changes in patients with migraine: a voxel-based morphometry study

We used voxel-based morphometry (VBM) to compare grey matter volume (GMV) between 20 migraine patients (five with aura and 15 without aura) with normal conventional magnetic resonance imaging findings and 33 healthy controls matched for age and sex. A separate analysis was also performed to delineate a possible correlation between the GMV changes and the headache duration or lifetime headache frequency. When compared with controls, migraine patients had significant GMV reductions in the bilateral insula, motor/premotor, prefrontal, cingulate cortex, right posterior parietal cortex, and orbitofrontal cortex (P < 0.001, uncorrected for multiple comparisons at a voxel level; corrected P < 0.05 after small volume corrections). All regions of the GMV changes were negatively correlated with headache duration and lifetime headache frequency (P < 0.05, Pearson's correlation test). We found evidence for structural grey matter changes in patients with migraine. Our findings of progressive GMV reductions in relation to increasing headache duration and increasing headache frequency suggest that repeated migraine attacks over time result in selective damage to several brain regions involved in central pain processing.

Systemic armed oncolytic and immunologic therapy for cancer with JX-594, a targeted poxvirus expressing GM-CSF

Targeted oncolytic viruses and immunostimulatory therapeutics are being developed as novel cancer treatment platforms. These approaches can be combined through the expression of immunostimulatory cytokines from targeted viruses, including adenoviruses and herpesviruses. Although intratumoral injection of such viruses has been associated with tumor growth inhibition, eradication of distant metastases was not reported. The major limitations for this approach to date have been (1) inefficient intravenous virus delivery to tumors and (2) the lack of predictive, immunocompetent preclinical models. To overcome these hurdles, we developed JX-594, a targeted, thymidine kinase(-) vaccinia virus expressing human GM-CSF (hGM-CSF), for intravenous (i.v.) delivery. We evaluated two immunocompetent liver tumor models: a rabbit model with reproducible, time-dependent metastases to the lungs and a carcinogen-induced rat liver cancer model. Intravenous JX-594 was well tolerated and had highly significant efficacy, including complete responses, against intrahepatic primary tumors in both models. In addition, whereas lung metastases developed in all control rabbits, none of the i.v. JX-594-treated rabbits developed detectable metastases. Tumor-specific virus replication and gene expression, systemically detectable levels of hGM-CSF, and tumor-infiltrating CTLs were also demonstrated. JX-594 holds promise as an i.v.-delivered, targeted virotherapeutic. These two tumor models hold promise for the optimization of this approach.

Anti-CD44 treatment abrogates tissue oedema and leukocyte infiltration in murine arthritis

A ubiquitous cell adhesion receptor, CD44, preferentially binds hyaluronan, a polysaccharide macromolecule that is present in most extracellular matrices. Hyaluronan molecules have large hydrodynamic volumes that entrap substantial amounts of water and can therefore control tissue hydration (swelling). CD44 is overexpressed by synovial cells and leukocytes, and hyaluronan is overproduced in the rheumatoid synovium and in other inflammatory sites. Nevertheless, the role of the CD44-hyaluronan interaction during inflammation is unclear. Our evidence shows that the CD44 receptor plays a critical role in governing the migration of inflammatory leukocytes into the extravascular compartment of the synovium in murine arthritis. An anti-CD44 antibody induces a rapid loss of CD44 from both leukocytes and synovial cells and displays an inhibitory effect on cell-extracellular matrix interactions in the synovium. As a result, the administration of such an antibody abrogates tissue swelling and leukocyte infiltration, two major components of inflammation.

CT and MR imaging findings of bowel ischemia from various primary causes

Ischemic bowel disease represents a broad spectrum of diseases with various clinical and radiologic manifestations, which range from localized transient ischemia to catastrophic necrosis of the gastrointestinal tract. The primary causes of insufficient blood flow to the intestine are diverse and include thromboembolism, nonocclusive causes, bowel obstruction, neoplasms, vasculitis, abdominal inflammatory conditions, trauma, chemotherapy, radiation, and corrosive injury. Computed tomography (CT) or magnetic resonance (MR) imaging can demonstrate the ischemic bowel segment and may be helpful in determining the primary cause. The CT and MR imaging findings include bowel wall thickening with or without the target sign, intramural pneumatosis, mesenteric or portal venous gas, and mesenteric arterial or venous thromboembolism. Other CT findings include engorgement of mesenteric veins and mesenteric edema, lack of bowel wall enhancement, increased enhancement of the thickened bowel wall, bowel obstruction, and infarction of other abdominal organs. However, regardless of the primary cause, the imaging findings of bowel ischemia are similar. Furthermore, the bowel changes simulate inflammatory or neoplastic conditions. Understanding the pathogenesis of various conditions leading to mesenteric ischemia helps the radiologist recognize ischemic bowel disease and avoid delayed diagnosis, unnecessary surgery, or less than optimal management.