Val193 and Phe195 of the gamma 1 34.5 protein of herpes simplex virus 1 are required for viral resistance to interferon-alpha/beta

Herpes simplex viruses (HSV) are resistant to the antiviral action of interferon. However, the underlying mechanisms are not well understood. In this report, we show that unlike that of wild-type HSV-1, replication of the gamma 1 34.5 null mutants was significantly inhibited by exogenous interferon-alpha in cells devoid of interferon-alpha/beta genes. Using a series of gamma 1 34.5 deletion mutants, the domain required for interferon resistance was mapped to the region containing amino acids 146 to 263 in the gamma 1 34.5 protein. Interestingly, Val193 Glu and Phe195 Leu substitutions in the protein phosphatase 1 interacting motif of the gamma 1 34.5 protein rendered HSV-1 sensitive to interferon-alpha. Furthermore, gamma 1 34.5 null mutants were sensitive to interferon-alpha/beta in PKR+/+ but not in PKR-/- mouse embryo fibroblasts. These findings provide evidence that the gamma 1 34.5 protein contributes to HSV-1 resistance to interferon-alpha/beta by inhibiting PKR function.

Androgen-induced NH2- and COOH-terminal Interaction Inhibits p160 coactivator recruitment by activation function 2

The androgen receptor undergoes an androgen-specific NH(2)- and COOH-terminal interaction between NH(2)-terminal motif FXXLF and activation function 2 in the ligand binding domain. We demonstrated previously that activation function 2 forms overlapping binding sites for the androgen receptor FXXLF motif and the LXXLL motifs of p160 coactivators. Here we investigate the influence of the NH(2)- and COOH-terminal interaction on androgen receptor function. Specificity and relative potency of the motif interactions were evaluated by ligand dissociation rate and the stability of chimeras of transcriptional intermediary factor 2 with full-length and truncated androgen or glucocorticoid receptor. The results indicate that the androgen receptor activation function 2 interacts specifically and with greater avidity with the single FXXLF motif than with the LXXLL motif region of p160 coactivators, whereas this region of the glucocorticoid receptor interacts preferentially with the LXXLL motifs. Expression of the LXXLL motifs as a fusion protein with the glucocorticoid receptor resulted in loss of agonist-induced receptor destabilization and increased half-time of ligand dissociation. The NH(2)- and COOH-terminal interaction inhibited binding and activation by transcriptional intermediary factor 2. We conclude that the androgen receptor NH(2)- and COOH-terminal interaction reduces the dissociation rate of bound androgen, stabilizes the receptor, and inhibits p160 coactivator recruitment by activation function 2.

Human acyl-CoA:diacylglycerol acyltransferase is a tetrameric protein

Acyl-CoA:diacylglycerol acyltransferase (DGAT) is an integral membrane enzyme that catalyses the last step of triacylglycerol synthesis from diacylglycerol and acyl-CoA. Here we provide experimental evidence that DGAT is a homotetramer. Although the predicted molecular mass of human DGAT protein is 55 kDa, CHAPS-solubilized recombinant human DGAT was eluted in fractions over 150 kDa on gel-filtration chromatography. Cross-linking of recombinant DGAT in membranes with disuccinimidyl suberate yielded bands corresponding to the dimer (108 kDa) and the tetramer (214 kDa) in SDS/PAGE. Finally, when two differently epitope-tagged forms of DGAT were co-transfected into mammalian cells, they could be co-immunoprecipitated. From a human adipose tissue cDNA library we cloned a cDNA encoding a novel splice variant of DGAT (designated DGATsv) that contained a 77 nt insert of unspliced intron with an in-frame stop codon. This resulted in a truncated form of DGAT that terminated at Arg-387, deleting 101 residues from the C-terminus containing the putative active site. DGATsv was enzymically inactive when transfected in HEK-293E cells but was still able to form dimer and tetramer on cross-linking, indicating that the ability to form tetramers resides in the N-terminal region. When co-expressed in HEK-293E cells, DGATsv did not inhibit the activity of full-length DGAT, suggesting that the subunits of DGAT catalyse triacylglycerol synthesis independently.

A self-coherence enhancement algorithm and its application to enhancing three-dimensional source estimation from EEGs

In this paper a new algorithm is proposed to enhance the spatial resolution of solutions of the underdetermined EEG inverse problem. Termed the self-coherence enhancement algorithm (SCEA), the present algorithm provides a self-coherence solution, which is a function of the high order self-coherence estimate of an unbiased smooth estimate of the underdetermined EEG inverse solution. The order of the high order self-coherence function is determined by the blurring level of the actual source distribution as represented by a normalized blurring index. The proposed SCEA algorithm may be used to enhance the spatial resolution of an inverse solution obtained by any inverse reconstruction algorithm. Computer simulation studies have been conducted to evaluate the performance of the SCEA and to compare its performance to that of the LORETA and the FOCUSS algorithms.

Comparative observation with MRI and pathology of brain edema at the early stage of severe burn

OBJECTIVE

To investigate the correlation between MRI features and pathology in brain edema at the early stage of severe burn (5 0% TBSA III degree) in dogs.

METHODS

Fifty-two dogs were randomized into control, simple b urn (SB), burn plus sodium lactate (BSL), and burn plus glucose solution groups (BGS). The manifestation of the brain of control group was compared with that of burn groups at 6, 12, 18 and 24 hours postburn with MRI and pathological examination (gross appearance, electron microscopy and light microscopy).

RESULTS

The earliest findings of brain edema were seen at 12 h ours after burn in BGS group, in which brain swelling was the main feature of MR I. The decrease of SIR on T(1)WI was not observed until it was exceeded 10%. Sig nal of T(2)WI increased by 8.29% at 24 hours after burn. It was difficult to distinguish the gray matter from the white matter at the boundary line, which became blurred later. Histological changes of brain edema were observed as early as 6 hours after burn, being accompanied by swelling of endothelial cells and peri-vescular astrocytes, and vacuolation took place in neurons at 12 hours after burn, with different degrees of necrosis of capillary endothelium, neurons, and axons. These changes became more marked with elapse of time. The BGS group showed the most obvious changes mentioned above at 24 hours after burn.

CONCLUSIONS

The model of the brain edema after severe burn has the feature of both vasogenic edema and cytotoxic edema on the MRI and pathology. Positive MRI findings lagged behind that of the pathomorphological changes.

Nationality differences in distributions of serum lipids, lipoproteins and apolipoproteins levels in Xinjiang China

OBJECTIVE

To reveal the distribution characteristics of serum lipids, lipoproteins, and apolipoproteins levels in different nationalities.

METHODS

Quantitative levels of those traits mentioned above were determined and body height (H), weight (W) and body mass index (BMI = W/H2) were assessed in 773 Kazaks (men 360 and women 413) and 911 Han nationality (men 466 and women 445) from the Xinjiang Autonomous Region of China.

RESULTS

Kazaks men and women, respectively, had significantly higher serum levels of HDL-c and ApoA1 (all P < 0.001) and significantly lower serum levels of TG (men P < 0.01, women P < 0.001), Lp(a) (all P < 0.005), ApoB (men P < 0.005, women P < 0.001) and ApoB/A1 (men P < 0.01, women P < 0.001) than their Han nationality controls. The threshold points of ApoA1 (< 1.2 g/L) and ApoB (> 1.2 g/L) are higher in Hans than in Kazaks for ApoA1 (20.7 vs 9.8%) and ApoB (18.6 vs 14.3%); the serum levels of TG, HDL-c, Lp(a), ApoA1 and ApoB/A1 are all closely correlated with nationality (P < 0.001, P = 0.001, and P < 0.05, respectively).

CONCLUSION

The results suggest that the nationality differences exist in serum levels of lipids, lipoproteins, and apolipoproteins, and Kazaks have a superior serum lipid pedigree to Hans. This differences may come from genetic differences, which affect the serum levels of lipids, lipoproteins, and apolipoproteins by controlling lipid metabolism patterns. Future study will be needed to dissect to the role of genetic factors on serum lipids.

[The effects of resuscitation with hypertonic saline solution on the postburn pulmonary injury in scalded dogs]

OBJECTIVE

To explore the preventive and curative effects of resuscitation with hypertonic saline solution on postburn pulmonary injury in scalded dogs.

METHODS

Mongrel dogs inflicted by 40% TBSA III degree scald were employed as the model. Sixteen dogs were randomly divided into two groups with 8 in each group, i.e. hypertonic saline solution group (H group) and isotonic saline solution (N group). The changes in cardiac output (CO), cardiac index (CI), pulmonary arterial pressure (PAP) and pulmonary vascular resistance (PVR) were determined within 48 postburn hours (PBHs). Pulmonary tissue samples were obtained for the measurement of pulmonary water and hydrocarbon (C2 H4 and C2 H6) contents. Bronchoalveolar lavage fluid (BALF) was harvested for white blood cell (WBC) counting and classification and for the detection of the changes in PLA2 activity and LTC4 content.

RESULTS

Compared to those in N group, the CO and CI in H group increased significantly while the pulmonary water content, the hydrocarbon content, the WBC count, and PLA2 activity and LTC4 content in BALF all decreased obviously.

CONCLUSION

Hypertonic saline solution might be beneficial in the management of early postburn pulmonary injury.

Separation of six uremic middle molecular compounds by high performance liquid chromatography and analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

BACKGROUND

Since the postulation of uremic middle molecule (UMM) hypothesis made by Babb et al. [Trans-Am Soc Artif Intern Organs 18 (1972) 98], there has been great interest in the separation and identification of the role of UMM. However, few of the compounds isolated from UMM fractions were demonstrated to play an important role in humans. Thus, the separation and identification of the real UMM is essential for UMM research.

METHODS

Urine and serum samples from uremic patients and healthy subjects were separated by gel permeation chromatography. Two presumed UMM fractions, A and B, were obtained from uremic sera and urine, normal urine, but not normal sera. Fraction A was further isolated by anion exchange chromatography and a series of sub-peaks were obtained. The sub-fraction A-3 obtained in the second step was desalted on a Sephadex G-15 column, and characterized by IR, UV and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Further separation of sub-fraction A-3 was performed by high performance liquid chromatography (HPLC).

RESULTS

By gel permeation chromatography, two UMM peaks (A and B) were detected at 206 nm in normal urine, uremic sera, but they were barely noticed in the profile of normal sera. In contrast, the absorption at 206 nm of fractions A and B from uremic serum and urine were smaller than that of fractions A and B from normal urine. Fractions A from different origins were resolved into eight to nine sub-peaks at 230 nm by anion exchange chromatography. One of these sub-peaks, A-3, was detected in uremic serum and normal urine, but is undetectable in uremic urine. After desalting, sub-fraction A-3 was separated into two parts designated as A-3-I and A-3-II. MALDI-TOF-MS revealed that fraction A-3-I and A-3-II from two origins were identical, respectively-fraction A-3-I contained three components with MW 839.69, 1007.94 and 2015.16 and fraction A-3-II consisted of another three components with MW 873.69, 1106.67 and 1680.28. Six middle molecular compounds in sub-fraction A-3 were thoroughly resolved by HPLC.

CONCLUSION

Our results demonstrated that the UMM sub-fraction A-3 contains the real UMM in the MW range of 800-2015 Da. By multi-step chromatographic isolation, six real middle molecular compounds were purified and characterized with MALDI-TOF-MS. It is likely that three of these UMM compounds are important, as they readily accumulated in sera of uremic patients, but are normally excreted in healthy subjects.

The discovery of novel, potent and selective PDE5 inhibitors

The design and synthesis of a novel scaffold for potent and selective PDE5 inhibitors are described. Compound 3a was more potent (PDE5 IC50=0.31 nM) and selective (>10,000-fold vs PDE1 and 160-fold selective vs PDE6) PDE5 inhibitor than sildenafil.

[The changes of Clara cell in the distal conducting airways of patients with COPD]

OBJECTIVE

To investigate the role of Clara cells in the pathogenesis of COPD.

METHODS

Lung samples of pneumonectomy were collected from 13 patients with COPD and 13 patients without COPD. They had similar age, sex and smoke index. The number and distribution of Clara cells were measured by immunohistochemistry. The mRNA expression and protein level of CC16 were determined by riboneuclease protection assay and Western blot separately.

RESULT

The number of Clara cells of the respiratory brochioli was lower in patients with COPD than in those without COPD (16.4% vs. 18.5%, P < 0.05). The expression of CC16 mRNA was also lower in patients with COPD than those without COPD(0.28 +/- 0.05 vs. 0.45 +/- 0.05, P < 0.05). There was no obvious difference of CC16 protein level between these two groups.

CONCLUSION

The changes of the number and function of Clara cell may be one of the factors in the development of COPD.

Imaging and visualization of 3-D cardiac electric activity

Noninvasive imaging of cardiac electric activity is of importance for better understanding the underlying mechanisms and for aiding clinical diagnosis and intervention of cardiac abnormalities. We propose to image the three-dimensional (3-D) cardiac bioelectric source distribution from body-surface electrocardiograms. Cardiac electrical sources were modeled by a current dipole distribution throughout the entire myocardium, and estimated by using the Laplacian weighted minimum norm (LWMN) algorithm from body-surface potentials. The estimated inverse solution of the current distribution was further improved by using a recursive weighting strategy for localized sources, such as origins of cardiac arrhythmias. Computer simulations were conducted to test the feasibility of the proposed approach by using a 3-D ventricle model embedded in a realistically shaped torso model. The boundary element method was used to solve the forward problem from assumed cardiac sources to the body-surface potentials. Two testing dipoles were placed in the left and right ventricles, simulating the early activation associated with ventricular arrhythmias. The LWMN inverse solution showed an equivalent source distribution over the entity of both ventricles, with spread areas of activity overlying the positions of the testing dipoles. The sharpened inverse image provides well-localized focal sources near the testing dipole positions. In summary, the present computer simulation suggests that the proposed 3-D cardiac current source imaging and localization approach appears to be a promising candidate for localizing and imaging sites of origins of cardiac activation.

[Latent adenovirus infection in chronic obstructive pulmonary disease]

OBJECTIVE

To study latent adenovirus infection in the stable stage of chronic obstructive pulmonary disease(COPD).

METHOD

The bronchial epithelial cells and alveolar macrophages from 12 patients with chronic bronchitis, 10 patients with COPD, 6 patients with asthma and 8 healthy volunteers were obtained by bronchosocpy. The adenoviral DNA was determined in the epithelial cells and macrophages. All patients were in the stable stage. The polymerase chain reaction(PCR) was used for detection of the adenoviral genome E1A.

RESULTS

The E1A region of adenovirus was found in the epithelial cells of COPD and chronic bronchitis patients (27%), not found in the patients with asthma and normal volunteers. Furthermore, E1A DNA was much more commonly in the COPD patients (50%) than in the patients with chronic bronchitis (8%) (P < 0.05).

CONCLUSIONS

Latent adenoviral infection was present in the stable stage of COPD and may be related to the pathogenesis of the disease.

A minimal product method and its application to cortical imaging

In order to reduce the spatial blurring effect due to the head volume conductor, cortical imaging technique (CIT) can be used to reconstruct the cortical potential distribution from the scalp potential measurement with enhanced spatial resolution. To overcome the ill-posed nature of the inverse problem, Tikhonov regularization (TIK) and truncated Singular Value Decomposition (TSVD) are commonly used by choosing the appropriate regularization parameter and truncation parameter, respectively. We have developed a minimal product method (MINP) to determine the regularization and truncation parameters. The present computer simulation and experimental results indicate that the MINP can be easily implemented in both TIK and TSVD with satisfactory performance, and suggest the potential applications of the MINP method in determining the corner of the L-curve.

Structural characterization of phosphorylated chitosan and their applications as effective additives of calcium phosphate cements

Chitosan was phosphorylated by P2O5 in methanesulfonic acid and the product as water-soluble phosphorylated chitosan (P-chitosans) was then characterized by phosphorus elemental analysis, IR and 31P-NMR spectroscopy. Two calcium phosphate cement (CPC) systems, i.e. (1) monocalcium phosphate monohydrate (MCPM) and calcium oxide (CaO) in 1 M phosphate buffer (pH = 7.4) and (2) dicalcium phosphate dihydrate (DCPD) and calcium hydroxide [Ca(OH)2] in 1 M Na2HPO4 solution, were chosen to improve their mechanical properties by the addition of water-soluble P-chitosans with various values for molecular weight, degree of deacetylation (DD) and degree of substitution (DS). The results show that the compressive strength (CS) and Young's modulus of both CPC formulations after setting were obviously increased and setting time was slightly prolonged by adding water-soluble P-chitosan to the liquid phases. When a suitable amount of P-chitosan was used, two improved CPC formulations were obtained with much better mechanical properties while the setting times were not longer than 15 min. The enhancement of compressive strength was due to high Ca2+-binding ability of phosphorylated chitosan, which could tightly bind the newly formed hydroxyapatite (HA) particles together by polymeric chains. It was noted that excessive addition of P-chitosan would lead to slow setting or no setting at all. The hardened CPC samples containing P-chitosan were characterized via X-ray diffraction spectra and scanning electron microscopy. Their leaching experiment was also carried out. The results indicated that P-chitosan-forced calcium phosphate cements have some good characteristics for clinical applications.

A study of equivalent source techniques for high-resolution EEG imaging

High-resolution EEG imaging has been an important topic in recent EEG research, and much work has been done on the two equivalent source imaging techniques: the equivalent distributed dipole-layer source imaging technique (EST) and the equivalent multipole source imaging technique (SAT). In this paper we first develop a forward density formula for a spherical equivalent distributed dipole layer of an arbitrary dipole in a three-concentric-sphere head model. It is clarified using the derived forward formula that the equivalent dipole-layer source and equivalent multipole source are interrelated in theory. Finally, simulation comparisons are conducted, the results of which suggest that EST has a higher spatial resolution than SAT when both of them are implemented by a truncated singular value decomposition algorithm. This is due to the different singularities of the inversion equations involved in the two techniques. An empirical VEP data study also shows that EST is better than SAT in providing higher spatial resolution EEG imaging.

Thefurrygene ofDrosophilais important for maintaining the integrity of cellular extensions during morphogenesis

The Drosophila imaginal cells that produce epidermal hairs, the shafts of sensory bristles and the lateral extensions of the arista are attractive model systems for studying the morphogenesis of polarized cell extensions. We now report the identification and characterization of furry, an essential Drosophila gene that is involved in maintaining the integrity of these cellular extensions during morphogenesis. Mutations in furry result in the formation of branched arista laterals, branched bristles and a strong multiple hair cell phenotype that consists of clusters of epidermal hairs and branched hairs. By following the morphogenesis of arista laterals in pupae, we have determined that the branched laterals are due to the splitting of individual laterals during elongation. In genetic mosaics furry was found to act cell autonomously in the wing. The phenotypes of double mutant cells argue that furry functions independently of the frizzled planar polarity pathway and that it probably functions in the same pathway as the tricornered gene. We used a P-element insertion allele as a tag to clone the furry gene and found it to be a large and complicated gene that encodes a pair of large conserved proteins of unknown biochemical function.

Estimation of intra-cranial neural activities by means of regularized neural-network-based inversion techniques

Artificial neural networks can be exploited to solve inverse problems arising from the estimation of neural activities in the brain. In this paper, we review the network inversion techniques for solving inverse problems with special attention directed towards electroencephalographic dipole localization and the improvement of positron emission tomography. In our regularized network inversion technique, for stabilizing the solution, we explicitly include the a priori knowledge by adding penalty terms to the energy function and/or build this knowledge into the architecture of the multi-layered neural networks that are used as an inverse problem solver. In the electroencephalogram analysis, the consensus term added to the energy function facilitated 3-dipole localization for visually evoked potentials. Effectiveness of our regularization is shown in improving the positron emission tomographic images and for generating metabolic images of the brain, under the constraints given by the a priori knowledge inherent to the measurement systems and physiological rules.

Cellular mechanisms in the development of the Drosophila arista

Epidermal cells of Drosophila form a variety of polarized structures during their differentiation. These polarized structures include epidermal hairs, the shafts of sensory bristles, larval denticles and the arista laterals. The arista is the terminal segment of the antenna and consists of a central core and a series of lateral extensions. Here we describe the cellular mechanisms involved in the development of the arista and the morphogenesis of the laterals. We found that the development of the arista is a complex process that involves coordinated cell shape changes, elongation of the central core, apoptosis, nuclear migration, the formation of polyploid cells and the outgrowth of the laterals. This developmental program is highly conserved in the development of the arista in the housefly (Musca domestica). Altering arista cell number in Drosophila by stimulating or inhibiting apoptosis results in an altered number of laterals. Interestingly, the increased number of laterals that result from the inhibition of apoptosis in Drosophila results in an arista whose morphology is reminiscent of the Musca arista. Previous experiments have shown that both the actin and microtubule cytoskeletons have important functions in the cellular morphogenesis of hairs and bristles. Inhibitor studies reported here show that this is also the case for the formation of the arista laterals, arguing that the actin and microtubule cytoskeletons have similar functions in the morphogenesis of all of these cell types. We conclude that the arista laterals are a valuable complementary cell type system for studying the morphogenesis of polarized cellular extensions in Drosophila.

[Effects of five different polar extracts from Herba pogostemonis being gotten rid of volatile oil on gastrointestinal tract]

The effects of the five extracts from Herba pogostmonis being gotten rid of volatile oil on gastrointestinal tract were studied. The results showed that the five extracts could increase gastric secretion of acid and activity of pepsin, reduce the incidence of diarrhea induced by Folium sennae and relieve the gripping pain induced by abdominal administration of acetic acid. The extract of ethyl acetate could also inhibit the normal and neostigmine induced mice intestinal propellant movement. The effect of extract of ethyl acetate was consistent with clinical application. The above results indicated that the clinical effect of Herba pogostmonis may be comprehensive action of above five different polar extracts.

Localization of the site of origin of cardiac activation by means of a heart-model-based electrocardiographic imaging approach

We have developed a new approach to solve the inverse problem of electrocardiography in terms of heart model parameters. The inverse solution of the electrocardiogram (ECG) inverse problem is defined, in the present study, as the parameters of the heart model, which are closely related to the physiological and pathophysiological status of the heart, and is estimated by using an optimization system of heart model parameters, instead of solving the matrix equation relating the body surface ECGs and equivalent cardiac sources. An artificial neural network based preliminary diagnosis system has been developed to limit the searching space of the optimization algorithm and to initialize the model parameters in the computer heart model. The optimal heart model parameters were obtained by minimizing the objective functions, as functions of the observed and model-generated body surface ECGs. We have tested the feasibility of the newly developed technique in localizing the site of origin of cardiac activation using a pace mapping protocol. The present computer simulation results show that, the present approach for localization of the site of origin of ventricular activation achieved an averaged localization error of about 3 mm [for 5-muV Gaussian white noise (GWN)] and 4 mm (for 10-muV GWN), with standard deviation of the localization errors of being about 1.5 mm. The present simulation study suggests that this newly developed approach provides a robust inverse solution, circumventing the difficulties of the ECG inverse problem, and may become an important alternative to other ECG inverse solutions.

A mechanism for androgen receptor-mediated prostate cancer recurrence after androgen deprivation therapy

The development and growth of prostate cancer depends on the androgen receptor and its high-affinity binding of dihydrotestosterone, which derives from testosterone. Most prostate tumors regress after therapy to prevent testosterone production by the testes, but the tumors eventually recur and cause death. A critical question is whether the androgen receptor mediates recurrent tumor growth after androgen deprivation therapy. Here we report that a majority of recurrent prostate cancers express high levels of the androgen receptor and two nuclear receptor coactivators, transcriptional intermediary factor 2 and steroid receptor coactivator 1. Overexpression of these coactivators increases androgen receptor transactivation at physiological concentrations of adrenal androgen. Furthermore, we provide a molecular basis for this activation and suggest a general mechanism for recurrent prostate cancer growth.

Analysis of gene expression induced by irritant and sensitizing chemicals using oligonucleotide arrays

Chemical-induced allergy continues to be an important occupational health problem. Despite decades of investigation, the molecular mechanisms underlying chemical-induced hypersensitivity and irritancy remain unclear because of the complex interplay between properties of different chemicals and the immune system. In this study, gene expression induced by toluene diisocyanate (TDI, a primarily IgE-inducing sensitizer), oxazolone (OXA, a cell-mediated hypersensitivity inducing sensitizer), or nonanoic acid (NA, a non-sensitizing irritant) was investigated using gene arrays. Female BALB/c mice were dermally exposed on the ears once daily for 4 consecutive days. On day 5, the lymph nodes draining the exposure sites were collected and used for RNA extraction and subsequent hybridization to Affymetrix Mu6500 oligonucleotide arrays. Of the 6519 genes on the arrays, there were 44, 13, and 51 genes in the TDI-, OXA-, and NA-exposed samples, respectively, that displayed a minimum of twofold change in expression level relative to the vehicle control. There were 32, 19, and 19 genes that were differentially expressed (with a minimum of twofold change) between TDI and OXA, TDI and NA, OXA and NA, respectively. The differentially expressed genes include immune response-related genes, transcriptional factors, signal transducing molecules, and Expressed Sequence Tags. Based on the gene array results, candidate genes were further evaluated using RT-PCR. There was only about 47% concordance between the gene array and RT-PCR results.

High-resolution EEG: a new realistic geometry spline Laplacian estimation technique

BACKGROUND

A new realistic geometry (RG) spline Laplacian estimation technique has been developed for high-resolution EEG imaging.

METHODS

Estimation of the parameters associated with the spline Laplacian is formulated by seeking the general inverse of a transfer matrix. The number of spline parameters, which need to be determined through regularization, is reduced to one in the present approach, thus enabling easy implementation of the RG spline Laplacian estimator.

RESULTS

Computer simulation studies have been conducted to test the feasibility of the new approach in a 3-concentric-sphere head model. The new technique has also been applied to human visual evoked potential data with a RG head model.

CONCLUSIONS

The present numerical and experimental results demonstrate the feasibility of the new approach and indicate that the RG spline Laplacian can be estimated easily from the surface potentials and the scalp geometry.

The SH integral membrane protein of the paramyxovirus simian virus 5 is required to block apoptosis in MDBK cells

In some cell types the paramyxovirus simian virus 5 (SV5) causes little cytopathic effect (CPE) and infection continues productively for long periods of time; e.g., SV5 can be produced from MDBK cells for up to 40 days with little CPE. SV5 differs from most paramyxoviruses in that it encodes a small (44-amino-acid) hydrophobic integral membrane protein (SH). When MDBK cells were infected with a recombinant SV5 containing a deletion of the SH gene (rSV5DeltaSH), the MDBK cells exhibited an increase in CPE compared to cells infected with wild-type SV5 (recovered from cDNA; rSV5). The increased CPE correlated with an increase in apoptosis in rSV5DeltaSH-infected cells over mock-infected and rSV5-infected cells when assayed for annexin V binding, DNA content (propidium iodide staining), and DNA fragmentation (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling assay). In rSV5DeltaSH-infected MDBK cells an increase in caspase-2 and caspase-3 activities was observed. By using peptide inhibitors of individual caspases it was found that caspase-2 and caspase-3 were activated separately in rSV5DeltaSH-infected cells. Expression of caspase-2 and -3 in rSV5DeltaSH-infected MDBK cells appeared not to require STAT1 protein, as STAT1 protein could not be detected in SV5-infected MDBK cells. When mutant mice homologous for a targeted disruption of STAT1 were used as a model animal system and infected with the viruses it was found that rSV5DeltaSH caused less mortality than wild-type rSV5, consistent with the notion of clearance of apoptotic cells in a host species.