Pediatric MR imaging with automated spine survey iterative scan technique (ASSIST)

MR imaging automated spine survey iterative scan technique (ASSIST) provides an automated subminute, submillimeter, in-plane resolution survey of the entire spine in 2 contiguous sagittal fast gradient-echo breath-hold series with computer labeling of vertebrae and disks. The technique was prospectively tested in 13 school-aged children for a wide range of clinical indications. In all cases, imaging was successful without requiring repeated sequencing. In all but 1 patient manifesting prominent scoliosis, automated labeling was concordant with neuroradiologist assignments.

Sequencing of 15 new BoLA-DRB3 alleles

The class II DR of bovine major histocompatibility complex of cattle (BoLA) plays a central role in the regulation of the immune response through their ability to present those peptides to T-cell receptors. In this work, we sequenced the exon2 of DRB3 to identify new alleles in Chinese yellow cattle, a total of 15 new BoLA-DRB3 alleles were found.

Results of biofeedback therapy together with electrical stimulation in faecal incontinence with myogenic lesions

Reports about biofeedback therapy together with electrical stimulation with faecal incontinence are rare. This study is to investigate the effectiveness of biofeedback therapy in faecal incontinence patients with myogenic lesions.

METHODS

One hundred and twenty-six patients with faecal incontinence caused by myogenic lesions were referred to this programme, comprising three sessions of supervised therapy in hospital followed by 2 months of home exercise. Biofeedback therapy methods that consist of strengthening muscles biofeedback, sensory discrimination biofeedback, synchronizing biofeedback, and electrical stimulation were selected to improve the programme. Clinical scores and outcomes of the anorectal function were assessed before and after the programme, and t test was performed for statistical analysis.

RESULTS

Before this programme, there were 19 patients with good clinical scores, 46 patients with fair and 61 patients with poor clinical scores. After therapy, 98 patients achieved good scores, 24 patients fair, and only four patients had poor clinical scores. The squeeze pressure and the sphincter electromyography amplitude were improved significantly, the rectal sensory threshold was decreased significantly, and 80 patients who previously had no external anal sphincter reflex acquired such a reflex. At the two-year follow-up, 60.2% (65/108) of patients maintained the clinical outcomes.

CONCLUSION

biofeedback therapy together with electrical stimulation is an effective method for faecal incontinence in patients with myogenic lesions. Patients should be offered this choice of therapy.

Detailed mtDNA genotypes permit a reassessment of the settlement and population structure of the Andaman Islands

The population genetics of the Indian subcontinent is central to understanding early human prehistory due to its strategic location on the proposed corridor of human movement from Africa to Australia during the late Pleistocene. Previous genetic research using mtDNA has emphasized the relative isolation of the late Pleistocene colonizers, and the physically isolated Andaman Island populations of Island South-East Asia remain the source of claims supporting an early split between the populations that formed the patchy settlement pattern along the coast of the Indian Ocean. Using whole-genome sequencing, combined with multiplexed SNP typing, this study investigates the deep structure of mtDNA haplogroups M31 and M32 in India and the Andaman Islands. The identification of a so far unnoticed rare polymorphism shared between these two lineages suggests that they are actually sister groups within a single haplogroup, M31'32. The enhanced resolution of M31 allows for the inference of a more recent colonization of the Andaman Islands than previously suggested, but cannot reject the very early peopling scenario. We further demonstrate a widespread overlap of mtDNA and cultural markers between the two major language groups of the Andaman archipelago. Given the "completeness" of the genealogy based on whole genome sequences, and the multiple scenarios for the peopling of the Andaman Islands sustained by this inferred genealogy, our study hints that further mtDNA based phylogeographic studies are unlikely to unequivocally support any one of these possibilities.

Beta-arrestins 1 and 2 are associated with nicotine dependence in European American smokers

On the basis of our previous identified linkage regions for nicotine dependence (ND), we selected seven and four single nucleotide polymorphisms (SNPs) in the beta-arrestins 1 (ARRB1) and 2 (ARRB2), respectively, to determine the associations of the two genes with ND in a total of 2037 subjects from 602 nuclear families of European American (EA) and African American (AA) origin. ND was assessed by Smoking Quantity (SQ), the Heaviness of Smoking Index (HSI) and the Fagerström Test for ND (FTND) score. Individual SNP analysis indicated that SNPs rs472112 within ARRB1 and rs4790694 within ARRB2 in the EA sample was significantly associated with HSI and FTND score, and the association of rs4790694 for ARRB2 remained significant after correction for multiple testing. Haplotype analysis revealed that haplotype C-G-C-G-G-T within ARRB1 at a frequency of 20%, formed by SNPs rs528833, rs1320709, rs480174, rs5786130, rs611908 and rs472112, was positively associated with HSI and FTND in EAs. We also found a haplotype within ARRB2, C-C-A-T at a frequency of 10.7%, formed by SNPs rs3786047, rs4522461, rs1045280 and rs4790694, that showed a significant positive association with HSI and FTND in the EA sample. No significant associations for either individual SNPs or major haplotype of both ARRB1 and ARRB2 were found in the AA sample. Further, the strength of these associations increased after removing the SQ component from HSI and FTND scores in both the EA and AA samples, suggesting that ARRB1 and ARRB2 play an important role in biological processes involved in the regulation of smoking urgency (that is time to smoke first cigarette). In summary, our results provide the first evidence of a significant association for ARRB1 and ARRB2 variants with ND in an EA sample.

Immunological mechanisms in glaucoma

Glaucoma is one of the most frequent causes of blindness worldwide. The elevated intraocular pressure does not explain glaucoma in all patients but can be considered as a risk factor of the disease. There are some evidences that autoimmune mechanisms may be involved in this disorder. This review attempts to demonstrate the findings about autoimmune mechanisms in glaucoma patients. Consistent up- and down-regulations in the autoantibody profiles against ocular antigens are present in glaucoma patients. These changes in natural autoimmunity could be found in independent study populations and might be a promising tool for glaucoma detection.

Growth hormone treatment prevents osteoporosis in uremic rats

INTRODUCTION

Growth hormone (GH) is responsible for longitudinal bone growth. GH-receptor in the growth plate was found to be decreased in chronic renal insufficiency. A therapeutic use of GH in chronic renal insufficiency is not established. The current study aims to clarify the effects of GH treatment on bone metabolism in a uremic rat model.

METHODS

Sprague Dawley rats were subjected to subtotal surgical renal ablation (SNX) or sham operation. SNX rats were randomized into 4 groups: treated with different doses of GH (1.5, 4.0, or 10.0 mg/kg) or vehicle after 10 weeks of uremia and treated for 6 weeks. Bone and renal morphology was evaluated: bone density, thickness of spongiosa, osteoblast surface, osteoid volume, osteoclast quantity, and resorptive volume.

RESULTS

GH treatment resulted in a decrease of resorption area and lower number of osteoclasts. Osteoid volume, number of osteoblasts, percentage of active osteoblasts, thickness of the growth plate and mean cortical width increased. GH receptor (GHR) protein expression increased in GH treated rats. IGF-1 expression was decreased in osteoblasts and chondroblasts of SNX-V rats and increased following GH treatment. The TGF-beta expression was down regulated in SNX+V group in osteocytes and chondroblasts as compared to sham operated animals. The down regulation was prevented in treated animals irrespective of the dose given.

CONCLUSIONS

Treatment with GH in uremic animals increased bone density to the levels of non-uremic controls. Thus GH seems to have a potential of preventing renal osteodystrophy.

Effect of lactate therapy upon cognitive deficits after traumatic brain injury in the rat

BACKGROUND

In previous studies, it has been shown that intravenous lactate therapy can improve brain neurochemistry, adenosine triphosphate (ATP) generation and outcome after traumatic brain injury (TBI) in rats. In this study, we examined: (1) four L-lactate concentrations to determine the optimal therapeutic dose post TBI in terms of cognitive function; (2) ATP production after TBI for the L-lactate concentration found to be the optimal dose; (3) the possible production of lactic acidosis with the highest L-lactate concentration tested.

METHODS

Thirty minutes following a fluid percussion injury (FPI) over the left cerebral hemisphere, the animals received an intravenous infusion of 10, 28, 100, or 280 mM L-lactate (n = 10 for each group) for 3 h at a rate of 0.65 ml/h. Shams and control injured animals received a saline infusion. At 11-15 days post injury, cognitive deficits were examined using the Morris Water Maze (MWM) test. Three groups of rats were used for ATP analysis: shams, injured + saline infusion, and injury + the optimal lactate dose as determined by the MWM (n = 4/group). Additionally, a group receiving 280 mM L-lactate (n = 5) and one receiving a saline infusion (n = 3) were monitored for arterial blood variables and blood pressures.

FINDINGS

In the MWM test, only the 100 mM L-lactate-treated injured animals showed a significant reduction in cognitive deficits when compared to saline-treated injured animals (p <or= 0.05). In the ATP study, injured animals without treatment had a 53% reduction in ATP level in the ipsilateral cortex, while animals with 100 mM lactate treatment had a 28% reduction. (p <or= 0.05). No lactic acidosis was induced by the intravenous infusion of 280 mM L-lactate.

CONCLUSIONS

This study indicates that the intravenous infusion of 100 mM L-lactate provided the optimal concentration of the substrate to ameliorate cognitive impairment, probably via the regeneration of ATP following TBI in rats.

Linkage and association studies in African- and Caucasian-American populations demonstrate that SHC3 is a novel susceptibility locus for nicotine dependence

Our previous linkage study demonstrated that the 9q22-q23 chromosome region showed a 'suggestive' linkage to nicotine dependence (ND) in the Framingham Heart Study population. In this study, we provide further evidence for the linkage of this region to ND in an independent sample. Within this region, the gene encoding Src homology 2 domain-containing transforming protein C3 (SHC3) represents a plausible candidate for association with ND, assessed by smoking quantity (SQ), the Heaviness of Smoking Index (HSI) and the Fagerström Test for ND (FTND). We utilized 11 single-nucleotide polymorphisms within SHC3 to examine the association with ND in 602 nuclear families of either African-American (AA) or European-American (EA) origin. Individual SNP-based analysis indicated three SNPs for AAs and one for EAs were significantly associated with at least one ND measure. Haplotype analysis revealed that the haplotypes A-C-T-A-T-A of rs12519-rs3750399-rs4877042-rs2297313-rs1547696-rs1331188, with a frequency of 27.8 and 17.6%, and C-T-A-G-T of rs3750399-rs4877042-rs2297313-rs3818668-rs1547696, at a frequency of 44.7 and 30.6% in the AA and Combined samples, respectively, were significantly inversely associated with the ND measures. In the EA sample, another haplotype with a frequency of 10.6%, A-G-T-G of rs1331188-rs1556384-rs4534195-rs1411836, showed a significant inverse association with ND measures. These associations remained significant after Bonferroni correction. We further demonstrated the SHC3 contributed 40.1-59.2% (depending on the ND measures) of the linkage signals detected on chromosome 9. As further support, we found that nicotine administered through infusion increased the Shc3 mRNA level by 60% in the rat striatum, and decreased it by 22% in the nucleus accumbens (NA). At the protein level, Shc3 was decreased by 38.0% in the NA and showed no change in the striatum. Together, these findings strongly implicate SHC3 in the etiology of ND, which represents an important biological candidate for further investigation.

Tumor-specific therapeutic effect induced by an oncolytic adenoviral vector containing heat shock protein 70 and prodrug activation genes

We constructed a melanoma-specific oncolytic adenoviral vector Ad.MCDIRESE1.71Hsp3, in which the cytosine deaminase and adenoviral E1A genes linked by the IRES sequence were under the control of a mouse tyrosinase enhancer/promoter transcriptional element in the E1 region of the vector. We also inserted the human heat shock protein 70 (Hsp70) gene driven by the cytomegalovirus promoter into the E3 region of this vector. The RGD-4C peptide was inserted into the HI loop of the fiber knob domain of the Ad.MCDIRESE1.71Hsp3 vector to increase the transduction efficiency of this vector to tumor cells. The Ad.MCDIRESE1.71Hsp3 vector replicates specifically in melanoma cells, and it has a melanoma-specific cytotoxic effect in the presence of 5-fluorocytosine in vitro and in vivo. Moreover, the in vivo killing of tumor cells associated with the overexpression of Hsp70 generated by the intratumoral injection of the Ad.MCDIRESE1.71Hsp3 vector into established subcutaneous tumors can lead to the suppression of tumor growth and potent melanoma-specific systemic immune responses.

A novel end-effector design for robotics in image-guided needle procedures

BACKGROUND

Robotic end-effectors are being developed to facilitate image-guided minimally invasive needle-based procedures, such as tumour ablation, biopsy, thoracentesis and blood sampling.

METHODS

A novel mechanical end-effector was designed to address the challenges associated with any major needle-based procedure, focusing on liver biopsy and ablation. In this end-effector embodiment, the distal end of a single articulating arm can grip needles and instruments and allows a fairly high number of degrees of freedom of movement during the complex motions associated with positioning and driving needles, as well as the periodic motions associated with breathing patterns. Tightening a cable that runs through the articulations fixes the arm in a rigid state, allowing insertion of the gripped needle.

RESULTS

A design is presented that will require electro-mechanical stimulation and remote joystick control. The associated forces of cranial-caudal motion of soft tissue organs affects design constraints. A simulation study defined the process with tissue phantoms with mechanical properties in the range of hepatic tissue and the overlying abdominal wall. The robotic arm coupled with our end-effector could be deployed in an image-guided interventional suite.

CONCLUSIONS

Such a switch-able and flexible mode for a robotic arm could overcome much of the current limitations for automated needle placements for mobile targets, and could mitigate risks from breathing or patient motion with a rigid needle gripper in place.

Inhibition of Na+/H+ exchanger isoform 1 attenuates mitochondrial cytochrome C release in cortical neurons following in vitro ischemia

Na+/H+ exchanger isoform 1 (NHE1) is a major acid extrusion mechanism following intracellular acidosis. We hypothesized that stimulation of NHE1 after cerebral ischemia contributes to disruption of Na+ homeostasis and neuronal death. In the present study, expression of NHE1 was detected in cultured mouse cortical neurons. Oxygen and glucose deprivation (OGD) for 3 hours followed by 21 hours of reoxygenation (REOX) led to 68 +/- 10% cell death. Inhibition of NHE1 with the potent inhibitor HOE 642 or genetic ablation of NHE1 reduced OGD-induced cell death by approximately 40% to 50% (p < 0.05). In NHE1 +/+ neurons, OGD/REOX triggered significant increases in Na+ and Ca(i)2+. Genetic ablation of NHE1 and HOE 642 treatment reduced the rise of Na(i)+ by approximately 40% to 50% and abolished the OGD/REOX-mediated Ca2+ accumulation. Moreover, mitochondrial cytochrome C release was significantly attenuated by inhibition of NHE1 activity. These results imply that NHE1 activity disrupts Na+ and Ca2+ homeostasis and contributes to ischemic neuronal damage.

Electrohydrodynamic deposition of nanostructured lead zirconate titanate

The deposition of a propanol-based lead zirconate titanate (PZT) sol using electrohydrodynamic atomization (EHDA) in the stable cone-jet mode was investigated. The droplets generated were deposited onto a copper substrate as a film, which was investigated using X-ray diffraction and scanning electron microscopy. The PZT film was shown to contain uniform nano-particles of PZT, which maintained their shape on sintering (650 degrees C, 1 hour) while forming the perovskite phase of PZT.

[13C] phenylalanine breath test and hepatic phenylalanine metabolism enzymes in cirrhotic rats

BACKGROUND

Stable isotope 13C-labelled phenylalanine breath test has been applied to enable the quantitative evaluation of hepatic functional reserve, but the mechanism underlying the changes in function has not been resolved. This study evaluated the correlation between expression of the mRNA of key enzymes mediating phenylalanine metabolism and the metabolism of L-[1-13C] phenylalanine (13C-phe) assessed by the excretion of 13C-CO2 in the breath of rats with, and without, chronic hepatic injury induced by administration of carbon tetrachloride (CCl4).

MATERIALS AND METHODS

Male Sprague-Dawley (SD) rats (n = 29) were given subcutaneous injections of CCl4 to induce chronic hepatic injury. L-[1-13C] phenylalanine breath tests (PheBT) were then applied to the rats to assess hepatic function. Expression of phenylalanine hydroxylase (PHH) and tyrosine transaminase (TYT) mRNA in liver was detected by real-time fluorescence quantification RT-PCR, using TaqMan as the probe. It was then determined whether the PheBT results correlated with PHH and/or TYT mRNA expression. In addition, immunohistochemical labelling was used to visualize PHH protein expression in the control and injured liver tissue.

RESULTS

There were significant decreases in PheBT and PHH mRNA expression in the cirrhotic rats relative to the uninjured controls and these two measures of liver function were correlated. However, TYT mRNA expression was not changed by CCl4-induced liver injury. The immunohistochemical analysis revealed that PHH protein was expressed predominantly in the cytoplasm of liver cells.

CONCLUSIONS

The results of the PheBT were consistent with the changes in PHH gene expression following liver injury. The present findings indicate that decreased expression of the rate-limiting enzyme PHH, but not of TYT, might underlie the functional deficits detected as decreased PheBT. The 13C excretion rate constant per mass liver (PheBT-k/LW) was the most sensitive index that could be used to evaluate the PHH mRNA expression in the liver.

Differential gene expression in liver of inbred chickens and their hybrid offspring

Differential display of mRNA was used to analyse the differences of gene expression in liver between chicken hybrids and their parents in a 4 x 4 diallel crosses in order to study the molecular basis of heterosis in chickens. The results indicated that patterns of gene expression in hybrids differ significantly from their parents. Four patterns of differential gene expression were revealed, which included: (i) bands only detected in the hybrid F1s (UNF1); (ii) bands only absent in the hybrid F1s (ABF1); (iii) bands only detected in the parental P1 or P2 lines (UNP1 and UNP2) and (iv) bands absent in the parental P1 or P2 lines (ABP1 and ABP2). In addition, correlations between patterns of gene expression and heterosis percentages of nine carcass traits of 8-week-old chickens were evaluated. Statistical results showed that negative correlations between heterosis percentages and the percentage of F1-specific bands (UNF1) were significant at P < 0.01 for breast muscle yield, leg muscle yield, wing weight, eviscerated weight and eviscerated weight with giblet of 8-week-old chickens, and at P < 0.05 for intermuscular fat width. Heterosis percentage was negatively correlated with ABP (bands present in the hybrid F1s and one parental line but absent in the other parental line, ABP1 and ABP2) for breast muscle yield, leg muscle yield, wing weight, eviscerated weight and eviscerated weight with giblet of 8-week-old chickens (P < 0.01). Bands detected only in the hybrid F1s but not in either of the parental lines (UNF1) and bands absent in parental P1 or P2 lines (which includes ABP1 and ABP2) may play important roles in chicken heterosis.

Pure motor mononeuropathy with distal conduction block: an unusual presentation of multifocal motor neuropathy with conduction blocks

OBJECTIVE

To report an hitherto undescribed presentation of Motor Neuropathy with Multifocal Conduction Block (MMNCB).

METHODS

Description of two patients presenting with complete paralysis of the 3 heads of the trapezius muscle (case one) and progressive weakness of finger extension (case 2).

RESULTS

Nerve conduction studies (NCS) established that the corresponding nerves were distally inexcitable. In the affected muscles, no voluntary activity was elicited in both patients with spontaneous activity noted in patient 2. Systematic NCSs documented an asymptomatic, partial conduction block (CB) in a median nerve forearm segment in both patients. Neurophysiological follow-up after a dramatic response to intravenous immunoglobulins demonstrated recovery of the initially unobtainable motor responses.

CONCLUSIONS

This indicates that a complete, distal CB of the motor fibers destined to the trapezius muscle in patient 1, and to the extensor indicis proprius in patient 2, had caused the heralding deficits.

SIGNIFICANCE

These findings underscore the possibility of distal CB in this disorder and the need for extensive NCSs, including asymptomatic nerves, for an accurate diagnosis.

An asthma-associated genetic variant of STAT6 predicts low burden of ascaris worm infestation

Th-2 immune mechanisms are involved in the pathology of asthma and in the protective immune response to parasitic worms. Common upregulating genetic variants of Th-2 immune signalling are risk factors for asthma, and we tested whether they may confer a counteradvantage in protecting against parasitic worms. We examined the intensity of infection by the parasitic worm, Ascaris lumbricoides, by microsopic counting of ascaris eggs in the stool of 614 schoolchildren from an area of endemic ascaris infection in China. We investigated the relationship between the intensity of ascaris infection and common, asthma-associated genetic variants of Th-2 and Th-1 immune signalling. Ascaris egg counts per gram of stool (epg), mean 1068 epg, ranged from barely detectable (<240 epg) to heavy (approximately 9600 epg) in a skewed distribution. Logistic regression, after exploratory discriminant analysis, showed a major association between a common genetic variant of the 3'-UTR regulatory elements of the signal transducer and transactivating factor (STAT6) (P=0.0002) and egg counts, at the 77 th centile. Linear regression after log transformation of egg counts confirmed a highly significant association with this STAT6 variant (P=0.001). Thus, a common, asthma-associated, genetic variant of the pivotal transduction and transactivating factor for Th-2 immune signalling, STAT6, predicts increased resistance to ascaris worm infection. The evolution of enhanced resistance to parasitic worm infection, through human genetic variation in Th-2 immune signalling, may represent one origin for asthma.

Cytokine-induced enhancement of autoimmune inflammation in the brain and spinal cord: implications for multiple sclerosis

Multiple sclerosis and experimental autoimmune encephalomyelitis (EAE) are autoimmune inflammatory diseases in which cytokines are intimately involved. Here we test the hypothesis that injection of pro-inflammatory cytokines, tumour necrosis factor-alpha (TNFalpha) and interferon gamma (IFNgamma) into the brain of animals in the prodromal phase of EAE significantly enhances inflammation in the central nervous system (CNS). We were particularly interested to learn whether a local increase in cytokines influenced the pathology locally, or more extensively, within the CNS. EAE was induced in female adult Lewis rats. Eight days post-inoculation, TNFalpha or INFgamma was injected into one cerebral hemisphere. Days 11 and 13 post-inoculation (3 and 5 days after the injection of cytokine) inflammation was quantified by the number of perivascular cuffs and the degree of major histocompatibility complex (MHC) class II expression by microglia. Normal animals injected with cytokines, and EAE animals with saline injection served as controls.

RESULTS

microglial activation was increased three- to fourfold in the brain and eightfold in the spinal cord (P </= 0.05); lymphocyte invasion was increased sixfold in the brain and three- to fourfold in the spinal cord (P </= 0.01) following injections of TNFalpha or INFgamma in EAE animals compared with controls. Significant axonal damage was observed in white matter associated with the perivascular cuffs.

CONCLUSION

local changes in the release of pro-inflammatory cytokines within the brain in EAE results in the widespread enhancement of autoimmune inflammation within the brain and cord, and exacerbation of clinical symptoms.

129IN UTERO TRANSPLANTATION OF HUMAN HEMATOPOIETIC STEM CELLS (HSC) INTO FETAL GOATS OFFERS A NEW APPROACH TO STUDIES OF HSC EXPANSION AND DEVELOPMENT

In utero transplantation of xenogeneic stem cells into animals (such as mouse, sheep, goats) is a new approach to the studies of the engraftmen, expansion and development of foreign cells in vivo. In addition, such an approach is able to offer a model to clinical potential for correcting or replacing damaged tissues in a variety of disorders, including many that are inherent as well as acquired. Recently, we generated a human/goat hematopoietic stem cell (HSC) xenogeneic model to investigate the engraftment, expansion and development of human hematopoietic cells at an in vivo level. Human HSCs (lin-cells) were isolated and purified from fresh cord blood, and then injected intraperitoneally into pre-immune fetal goats at 55–65 gestation days (term: 145 days). A total of 50 fetal goats were injected. The growth and development of the recipient goats were monitored by B-type ultrasound scan. Ten goats suffered miscarriage due to GVH response; 39 recipients survived a complete gestation and were born alive. All these live-born goats were healthy and grew very well. They could produce offspring normally. In order to determine whether human cells were present longterm in the circulatory blood of the recipient goats, FACS, real-time PCR, RT-PCR, and Southern-blot hybridization as well as FISH were used to analyze the genotype and phenotype up to 11 months after birth. The results showed that hematopoietic chimerism (on average, &gt;108 human cells per goat) was documented in 90% (35/39) of live-born goats that had been originally transplanted with 105 human HSCs. The regenerated human cells included myeloid, B-lymphoid and erythroid lineages as well as more primitive cells as shown by specific positive staining for human CD14, CD20, glycophorin A (GPA) and CD34, and the detection of human-specific DNA sequences and human GPA and CD34 transcripts in the blood of the transplanted goats. No human T or NK-lineage cells were detected. These studies demonstrate the feasibility of using in utero-transplanted fetal goats as a new approach for evaluating the longterm engraftment potential, expansion and development of human hematopoietic cells in vivo.

Removal of natural organic matter from water using a nano-structured photocatalyst coupled with filtration membrane

A study of the characteristics of a novel photocatalyst indicated that it consisted of 17.3 nm nano size (average) TiO2 in the anatase phase and porous Fe2O3. SEM results revealed that nano size TiO2 was uniformly deposited onto the surface of Fe2O3 to form a bulk photocatalyst, as TiO2/Fe2O3. The porous TiO2/Fe2O3 catalyst had a BET surface area of 168 m2/g, which is three times higher than that of commercial TiO2. The experimental results indicated that the suspended TiO2/Fe2O3 photocatalyst in a photocatalytic oxidation (PCO) reactor was effective in removing TOC at 61.58% and color400 at 93.25% at 180 min illumination time, under 0.4 g/l catalyst loading and pH 7. Experimental results also revealed that pH at 7 and TiO2/Fe2O3 loading at 0.4 g/l was the optimum condition for removal of humic acids using a PCO reactor. Experimental results clearly indicated that the permeate flux rate of the ultrafiltration (UF) membrane was improved and the filtration membrane fouling phenomenon was reduced with the addition of TiO2/Fe2O3 photocatalysts to the UF membrane system. It was found that increasing the filtration time from 40 min to 185 min, the improvement to the permeate flux rate was from 57 to 83 L/hr x m2.

Increasing cell membrane potential and GABAergic activity inhibits malignant hepatocyte growth

Increasing hepatocyte membrane potentials by augmenting GABAergic activity inhibits nonmalignant hepatocyte proliferative activity. The objectives of this study were to document 1) potential differences (PDs) of four malignant hepatocyte cell lines, 2) GABAA receptor mRNA expression in the same cell lines, and 3) effects of restoring malignant hepatocyte PDs to levels approximating those of resting, nonmalignant hepatocytes. Hepatocyte PDs were documented in nonmalignant and malignant (Chang, HepG2, HuH-7, and PLC/PRF/5) hepatocytes with a fluorescent voltage-sensitive dye and GABAA receptor expression by RT-PCR and Western blot analyses. Compared with nonmalignant human hepatocytes, all four malignant cell lines were significantly depolarized (P < 0.0001, respectively). Only PLC/PRF/5 cells had detectable GABAA-beta3 receptor mRNA expression and all cell lines were negative for GABAA-beta3 receptor protein by Western blot analysis. Stable transfection of Chang cells with GABAA-beta3 receptor cDNA resulted in significant increases in PD and decreases in proliferative activity as manifest by decreased [3H]thymidine and bromodeoxyurieine incorporation rates, 4-[3-(4-lodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate activity, a lower mitotic index, prolongation of cell-doubling times, and attenuated growth patterns compared with cells transfected with vector alone. Colony formation in soft agar and the number of abnormal mitoses were also significantly decreased in GABAA-beta3 receptor transfected cells. The results of this study indicate 1) relative to healthy hepatocytes, malignant hepatocytes are significantly depolarized, 2) GABAA-beta3 receptor expression is absent in malignant hepatocyte cell lines, and 3) increasing the PD of malignant hepatocytes is associated with less proliferative activity and a loss of malignant features.

Cutaneous stimulation improves function of a chronic patient with cerebellar damage

The prognosis of cerebellar hemorrhage with brain stem compression is known to be poor, and patients who can usually survive are severely disabled with limited benefit from conventional rehabilitation. An innovative cutaneous stimulation was administered to a chronic patient (2 years after the incidence) who has severe ataxia, gait imbalance and limb spasticity caused by cerebellar hemorrhage. After 8 months of intervention, patient's function as evaluated by two functional measures has improved by 40%. In addition, the patient's ataxia and hypotonia have improved significantly in which he has regained the abilities to grasp objects, sit upright, control his equilibrium, and monitor an electric wheelchair. The present case study demonstrated a significant improvement of a chronic severely disabled patient who received the intervention 2 years after the accident, suggesting that the cutaneous stimulation may be a possible effective neurologic intervention.

Fouling and cleaning of microfiltration membrane in municipal wastewater reclamation

This paper presents an investigation on fouling and cleaning of a tubular microfiltration membrane for municipal wastewater reclamation. A bi-level complex model, namely channel clogging and pore plugging, was introduced to elucidate the fouling mechanism. Based on 135 days of microfiltration of activated sludge, a preventive method for channel clogging was reasonably proposed and proven to be effective. Without channel clogging, the operation period was observed a five-fold increase on average, reaching 3-4 weeks. To remove pore plugging, a multi-step chemical cleaning was employed and further optimized in terms of temperature and alkaline concentration. Generally, the chemical cleaning could restore the membrane permeability to higher than 90%.

Control of phospholipase A(2) activity in cockroach (Periplaneta americana) fat body trophocytes by hypertrehalosemic hormone: the role of calcium

Recently, synthetic HTH-I and HTH-II have been shown to increase the formation of free fatty acids in cockroach (Periplaneta americana) fat body. In this study we show that HTH-II increases PLA(2) activity in dispersed trophocytes, thus implying that phospholipid is a potential source of the fatty acids. The increase in HTH-induced PLA(2) activity is triggered by an increase in [Ca(2+)](i) but extracellular Ca(2+) is also required for a maximal Ca(2+) signal: an effect that can be blocked by the introduction of BAPTA into the trophocytes. Treating trophocytes with ryanodine blocks the increase in PLA(2) activity that follows treatment of the cells with HTH-II. This indicates that the Ca(2+) release channels are distinct from those that respond to inositol trisphosphate. Thapsigargin, which releases Ca(2+) to the cytosol from an intracellular store, increases PLA(2) activity. The data show that the enzyme is translocated from the cytosol to the plasma membrane.

[Sulfation of polysaccharides isolated from Indocalamus tesselatus and their anticytopathic effect on human immunodeficiency virus type I]

For preparation of sulfated polysaccharides isolated from bamboo leaves (Indocalamus tesselatus) with chlorosulfonic acid-pyridine, the experimental conditions as the molar ratio of reactants and temperature and time of reaction were discussed. A homogeneous sulfation method with good yield of more than 80% was obtained and the sufur content was found to be 21.9%. Conformation change in sulfated polysaccharide with changes of intrinsic viscosity, polarimetery and CD spectra were found to be related to the negative charge. The polysaccharide sulfates were shown to have better activity to inhibit cytopathic effect of human immunodeficiency virus(HIV) infection than native polysaccharides. The effective concentration was 10 micrograms.ml-1 while the cytotoxic concentration was 2.5 mg.ml-1.

Traumatic brain injury induced cell proliferation in the adult mammalian central nervous system

Recent studies indicate the existence of progenitor cells and their potential for neurogenesis in the subventricular zone (SVZ) and the hippocampus of the normal adult mammalian brain. However, the proliferative response and the specific cell types generated following traumatic brain injury have not been examined. This cellular response to CNS injury was investigated using the fluid percussion injury (FPI) model, a widely accepted rat model that simulates moderate head injury sustained in humans. Forty-eight hours following moderate FPI, adult rats received intraperitoneal injections of the thymidine analogs, 5-bromodeoxyuridine (BrdU) or tritiated thymidine (3H-thymidine), which are markers for mitotic activity. Injured and control animals receiving BrdU were used to determine the total number of cells induced to proliferate. To determine the cellular identity of these proliferating cells, animals receiving 3H-thymidine were sacrificed and sections through the injured area were immunostained with markers for immature and mature astrocytes, activated microglia, neural precursors and mature neurons. These studies showed that the total number of proliferating cells was significantly increased in the injury group for both the SVZ and the hippocampus. However, the proliferating cells in the SVZ did not express any of the cellular markers used, suggesting that they have not yet begun to differentiate. In contrast, there was a significant increase in the number of immature astrocytes and activated microglia, but not neurons, at this early time point in the hippocampus. Taken together, these experiments demonstrate the compensatory capacity of the adult brain to injury and should lead to a new generation of studies aimed at enhancing the neuronal proliferative response.

Regulation of phospholipase A(2) activity in cockroach (Periplaneta americana) fat body by hypertrehalosemic hormone: evidence for the participation of protein kinase C

Phospholipase A(2) (PLA(2)) associated with the membrane fraction of trophocytes from Periplaneta americana fat body increases by as much as 100% when the cells are incubated with hypertrehalosemic hormone (HTH-II). Activation with HTH-II is approximately halved by inclusion of the PKC inhibitor sphingosine in the incubation medium. Because activation of PLA(2) by HTH-II is blocked by the GDP analogue GDP-beta-S, and the unactivated enzyme is activated by the GTP analogue GTP-gamma-S it is likely that a G protein is involved in activation of the enzyme. Activation of PLA(2) was also achieved by treating the trophocytes with the synthetic diacylglycerol 1-oleoyl-2-acetylglycerol in the presence of thapsigargin. This supports the view that protein kinase C is also involved in the activation process.

Electrochemical impedance spectroscopy study of high-palladium dental alloys. Part II: behavior at active and passive potentials

Electrochemical impedance spectroscopic (EIS) analyses were performed on three high-palladium alloys and a gold-palladium alloy at active and passive potentials in five electrolytes that simulated body fluid and oral environmental conditions. All four alloys were previously found to have excellent corrosion resistance in these in vitro environments. Before performing the EIS analyses, alloy specimens were subjected to a clinically relevant heat treatment that simulated the firing cycles for a dental porcelain. It was found that the EIS spectra varied with test potential and electrolyte. Diffusional effects, related to the dealloying and subsequent surface enrichment in palladium of the high-palladium alloys, along with species adsorption and passivation, were revealed at both active and passive potentials, although these effects were more evident at the passive potentials.

Electrochemical impedance spectroscopy study of high-palladium dental alloys. Part I: behavior at open-circuit potential

Electrochemical impedance spectroscopy (EIS) was used to study the in vitro corrosion of three representative high-palladium alloys and a gold-palladium alloy for comparison. The corrosion resistances (measured as the charge transfer resistance R(CT) from an equivalent circuit) of the high-palladium alloys and the gold-palladium alloy were comparable in simulated body fluid and oral environments, and under simulated dental plaque. The great similarity in corrosion behavior for the three high-palladium alloys is largely attributed to their substantial palladium content and passivity in the laboratory test media, and possibly to their similar structure at the submicron level. Differences in composition and microstructure at the micron level and greater, including the effects of heat treatment simulating the firing cycles for dental porcelain, do not have noteworthy effects on the in vitro corrosion of the three high-palladium alloys. Good accuracy and convenience of extracting corrosion characteristics from equivalent circuit modeling, along with the capability of providing intrinsic information about the corrosion mechanism, enable EIS to be an excellent alternative method to conventional potentiodynamic polarization for evaluating the corrosion behavior of noble dental alloys.

Stimulation of trehalose efflux from cockroach (Periplaneta americana) fat body by hypertrehalosemic hormone is dependent on protein kinase C and calmodulin

Protein kinase C and calmodulin play key roles in cockroach fat body during activation of phosphorylase and trehalose efflux by HTH-II. The data support the view that an increase in cytosolic Ca2+ is prerequisite for enhanced activity of protein kinase C and calmodulin. Chelation of Ca2+ (i) with BAPTA blocks HTH-II-induced trehalose efflux from the fat body whereas thapsigargin, which raises [Ca2+]i to the same level as HTH-II, produces only a small, yet significant increase in trehalose efflux. Sphingosine, an inhibitor of protein kinase C, inhibits HTH-II-induced trehalose efflux in a concentration-dependent manner. Trehalose efflux is not activated by the protein kinase C activators OAG or PMA alone but in the presence of thapsigargin both agents increase trehalose efflux to a level comparable to that obtained with HTH-II. Thapsigargin has only a moderate activating effect on phosphorylase but in combination with OAG produces an activation indistinguishable from that provoked by HTH-II. Each of the structurally different calmodulin inhibitors, trifluoperazine, W-7, and calmidazolium, blocks completely the action of HTH-II on trehalose efflux, thus confirming the importance of calmodulin in HTH-II initiated trehalose efflux.

Characterization of cockroach (Periplaneta americana) fat body phospholipase A(2) activity

A phospholipase has been identified in the fat body of the American cockroach, Periplaneta americana, which removes fatty acid from the sn-2 acyl position of an artificial substrate. The enzyme has been characterized using a crude preparation obtained by low-speed centrifugation of the homogenized tissue. With 1-hexadecanoyl-2-(1-pyrenedecanoyl)-sn-glycero-3-phosphocholine as the substrate, the K(m) has been estimated to be 1.17 microM and the v(max) 113.5 pmol/min/mg protein. The phospholipase has a pH optimum close to 7 and shows maximal activity at 50 degrees C. Activity of the phospholipase has been determined in cytosolic and plasma membrane fractions. The specific activity of the latter fraction is approximately twice that of the cytosol. The enzyme in both fractions is Ca(2+)-independent. Arch.

Characterization of genomic DNA encoding cecropins from an Aedes albopictus mosquito cell line

We used cDNA probes from Aedes albopictus mosquito cecropins AalCecA, B, and C to obtain genomic DNA copies and flanking DNA. Two gene copies (AalCecA1 and A2, AalCecB1 and B2, AalCecC1 and C2) encoding each of the three mature cecropin peptides were recovered. All these genes had a similar organization, into two exons interrupted by a single short intron. AalCecA1 and AalCecA2 encode mature protein products that differ by one amino acid residue, while AalCecB1 and AalCecB2, AalCecC1 and AalCecC2 encode identical mature cecropin peptides, respectively. The AalCecB and C gene pairs each share a common intergenic region of approximately 1 kb, with the two coding regions transcribed in opposite directions. With the exception of small insertions/deletions, the intergenic spacer region was highly conserved between the B1/C1 and B2/C2 clones. In transfected cells, 0.8 kb of upstream sequence was sufficient for inducible expression of AalCecA1. Within this region, a 28 bp sequence at positions -192 to -165 upstream of the transcription initiation site was found to contain a potential regulatory element. In electrophoretic mobility shift assays, synthetic double-stranded DNA containing this 28 bp sequence retarded protein in cytoplasmic and nuclear extracts from C7-10 cells.

Solvothermal Syntheses and Characterizations of Two Isomorphous One-Dimensional Chain Complexes Constructed by Orotic Acid

Solvothermal reactions of M(OAc)2 (M = Ni, Co) with orotic acid (2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid, H3L) in H2O/MeOH (1 : 1) gave rise to two new isomorphous polymeric complexes, [M(HL)(H2O)3]n [M = Ni, (4); Co, (5)], with one-dimensional chain structures. Both complexes crystallize in the orthorhombic space group P212121, with a 7.7438(7), b 7.7610(7), c 14.6528(12) �, Z 4 for (4), and a 7.7005(3), b 7.8725(3), c 14.6997(10) �, Z 4 for (5). X-Ray diffraction analysis shows that the metal ion is coordinated by nitrogen and oxygen atoms of an orotate ligand (HL2–) and water molecules in a distorted octahedral geometry. The hydrogen-bond interactions between chains leads to the formation of three-dimensional network structures.

Quadruplex-interactive agents as telomerase inhibitors: synthesis of porphyrins and structure-activity relationship for the inhibition of telomerase

The cationic porphyrin 5,10,15,20-tetra-(N-methyl-4-pyridyl)porphyrin (TMPyP4) binds to quadruplex DNA and is thereby an inhibitor of human telomerase (Wheelhouse et al. J. Am. Chem. Soc. 1998, 120, 3261-3262). Herein the synthesis and telomerase-inhibiting activity of a wide range of analogues of TMPyP4 are reported, from which rules for a structure-activity relationship (SAR) have been discerned: (1) stacking interactions are critical for telomerase inhibition, (2) positively charged substituents are important but may be interchanged and combined with hydrogen-bonding groups, and (3) substitution is tolerated only on the meso positions of the porphyrin ring, and the bulk of the substituents should be matched to the width of the grooves in which they putatively lie. This SAR is consistent with a model presented for the complexation of TMPyP4 with human telomeric quadruplex DNA.