Single-cell RNA sequencing-guided fate-mapping toolkit delineates the contribution of yolk sac erythro-myeloid progenitors

Erythro-myeloid progenitors of the yolk sac that originates during early embryo development has been suggested to generate tissue-resident macrophage, mast cell, and even endothelial cell populations from fetal to adult stages. However, the heterogeneity of erythro-myeloid progenitors (EMPs) is not well characterized. Here, we adapt single-cell RNA sequencing to dissect the heterogeneity of EMPs and establish several fate-mapping tools for each EMP subset to trace the contributions of different EMP subsets. We identify two primitive and one definitive EMP subsets from the yolk sac. In addition, we find that primitive EMPs are decoupled from definitive EMPs. Furthermore, we confirm that primitive and definitive EMPs give rise to microglia and other tissue-resident macrophages, respectively. In contrast, only Kit+ Csf1r- primitive EMPs generate endothelial cells transiently during early embryo development. Overall, our results delineate the contribution of yolk sac EMPs more clearly based on the single-cell RNA sequencing (scRNA-seq)-guided fate-mapping toolkit.

[Effect of recombinant human thrombin for hemostasis in liver resection: a randomized controlled phase Ⅲ clinical trial]

Objective: To evaluate the hemostatic efficacy, safety and immunogenicity of recombinant human thrombin in the treatment of liver wounds that still ooze after conventional surgical hemostasis. Methods: A multicenter, stratified randomized, double-blind, placebo-controlled phase Ⅲ trial with a planned enrollment of 510 subjects at 33 centers, with a 2∶1 randomization to the thrombin group versus the placebo group. An interim analysis will be conducted after approximately 70% of the subjects have completed the observation period. The primary efficacy endpoint was the rate of hemostasis within 6 minutes at the point of bleeding that could be evaluated. Safety analysis was performed one month after surgery, and the positive rates of anti-drug antibody (ADA) and neutralizing antibody were evaluated. Results: At the interim analysis, a total of 348 subjects had been randomized and received the study drug (215 were male and 133 were female). They were aged 19-69 (52.9±10.9)years. Among them, 232 were in the thrombin group and 116 were in the placebo group, with balanced and comparable demographics and baseline characteristics between the two groups. The hemostasis rate at 6 minutes was 71.6% (95%CI:65.75%-77.36%) in the thrombin group and 44.0% (95%CI: 34.93%-53.00%) in the placebo group, respectively (P<0.001). No grade≥3 drug-related adverse events and no drug-related deaths were reported from the study.No recombinant human thrombin-induced immunologically-enhanced ADA or immunologically-induced ADA was detected after topical use in subjects. Conclusion: Recombinant human thrombin has shown significant hemostatic efficacy and good safety in controlling bleeding during liver resection surgery, while also demonstrating low immunogenicity characteristics.

Two-Dimensional Terahertz Spectroscopy of Nonlinear Phononics in the Topological Insulator MnBi_{2}Te_{4}

The interaction of a single-cycle terahertz electric field with the topological insulator MnBi_{2}Te_{4} triggers strongly anharmonic lattice dynamics, promoting fully coherent energy transfer between the otherwise noninteracting Raman-active E_{g} and infrared (IR)-active E_{u} phononic modes. Two-dimensional terahertz spectroscopy combined with modeling based on the classical equations of motion and symmetry analysis reveals the multistage process underlying the excitation of the Raman-active E_{g} phonon. In this nonlinear combined photophononic process, the terahertz electric field first prepares a coherent IR-active E_{u} phononic state and subsequently interacts with this state to efficiently excite the E_{g} phonon.

[Cone-beam CT evaluation of the Monson's spherical radius of young adults in Guangdong]

Objective: To measure and analyze the spherical radius of Monson of normal young people in Guangdong province using cone-beam CT (CBCT), and to establish a personalized measurement method of the spherical radius of Monson to provide a reference for clinical application of Monson spherical radius in occlusal reconstruction. Methods: Sixty healthy young adults from physical examination population at Stomatology Hospital of Guangzhou Medical University [30 males and 30 females, aged (22.1±2.0) years 18-26 years) were recruited, and their CBCT were taken. Three-dimensional reconstruction of CBCT data was carried out, and the reconstructed models were fixed, traced and measured. The difference of Monson spherical radius between male and female was compared by using a single sample t-test. Results: The Monson spherical radius was (100.72±4.89) mm. The Monson spherical radius of male and female were (103.48±4.19) mm and (97.97±3.93) mm respectively. The difference between male and female was statistically significant (P<0.01). Conclusions: CBCT can be used to accurately measure the spherical radius of Monson and can be used as a reference for reconstruction of occlusal plane.

P5990In vivo tracking of long-term survival of xenogeneic porcine mesenchymal stem cells seeded on tissue-engineered heart valve implanted in sheep

Background

Long-term survival of xenogeneic transplanted cells in adults requires strong immunosuppression and/or encapsulation of the cells to achieve peripheral transplant tolerance.

Purpose

The aim of our project was to seed decellularized tissue engineered heart valves (TEHV) with xenogeneic (porcine) mesenchymal stem cells (pMSCs) transfected transiently (Lipofectamine) with a positron emission tomography (PET)-reporter gene (pMSC-PETr), followed by implantation as pulmonary valve replacement into sheep without immunosuppression. The fate of the seeded pMSC-PETr was tracked via serial in-vivo non-invasive PET-computed tomography (PET-CT).

Methods

Static cultivation of TEHV scaffold led to successful ingrowth of the pMSC-PETr. For enabling quantitative assessment of viable pMSC-PETr in the TEHV scaffold after in vivo implantation, vials containing 5x104, 2x105, and 4x105 pMSC-PETr were in vitro mixed with the [18F]-FHBG PET tracer for 1 hr, then the non-bound tracer was washed out and vials were in vitro PET-CT imaged, giving reference values. TEHV-pMSC-PETr were then implanted percutaneously into the pulmonary valve position of sheep (n=4) under general anesthesia, while an additional sheep with no valve implantation served as a control. Ten mCi of [18F]-FHBGPET radiotracer was produced for each procedure and serial PET-CT imaging of the sheep was performed at 3 hr, 24 hr, 2 or 3 weeks, and 5 and 6 months after valve implantation. The study followed the Principles of laboratory animal care.

Results

PET-CT of vials containing increasing number of pMSC-PETr showed dose-dependent tracer uptake in the transfected cells in vitro (Figure). PET-CT images of the sheep 3 hr after implantation of the TEHV-pMSC-PETr showed a clear signal of transfected cells, with a mean estimated number of viable pMSC-PETr of 5.18±1.19x106. No meaningful decrease of the amount of living cells occurred at 24 hr or 2 or 3 weeks. Interestingly, 5- and 6-month follow-up PET-CT images showed clear in vivo and in vitro (after explantation) PET signals of the pMSC-PETr on TEHV, indicating spontaneous stable transfection of the PET reporter plasmid (insertional mutagenesis). Histology confirmed the survival of the pMSC-PETr at 5 and 6-month after xenogeneic transplantation. Merged immunohistochemistry and fluorescence imaging of anti-pig SLA I and anti-sheep MHC I antibodies and PET-reporter gene (HSV1-tk) suggested in vivo inter-species lateral jump gene transfer between pig MSCs and host sheep cells.

Figure 1

Conclusions

This is the first report on serial non-invasive in vivo tracking of long-term survival of xenogeneic pMSCs-PETr seeded on TEHVs and percutaneously implanted into the pulmonary position of sheep. Long-term follow-up revealed spontaneous stable transfection of the plasmid PET-reporter gene, which suggests the risk of insertional mutagenesis induced by the plasmid (transposon), and PET-reporter gene shuttle from xenogeneic pig MSCs to sheep cells.

Acknowledgement/Funding

LifeValve EU project (grant number: 242008)

Protein kinase C -activating isophthalate derivatives mitigate Alzheimer's disease-related cellular alterations

Abnormal protein kinase C (PKC) function contributes to many pathophysiological processes relevant for Alzheimer's disease (AD), such as amyloid precursor protein (APP) processing. Phorbol esters and other PKC activators have been demonstrated to enhance the secretion of soluble APPα (sAPPα), reduce the levels of β-amyloid (Aβ), induce synaptogenesis, and promote neuroprotection. We have previously described isophthalate derivatives as a structurally simple family of PKC activators. Here, we characterised the effects of isophthalate derivatives HMI-1a3 and HMI-1b11 on neuronal viability, neuroinflammatory response, processing of APP and dendritic spine density and morphology in in vitro. HMI-1a3 increased the viability of embryonic primary cortical neurons and decreased the production of the pro-inflammatory mediator TNFα, but not that of nitric oxide, in mouse neuron-BV2 microglia co-cultures upon LPS- and IFN-γ-induced neuroinflammation. Furthermore, both HMI-1a3 and HMI-1b11 increased the levels of sAPPα relative to total sAPP and the ratio of Aβ42/Aβ40 in human SH-SY5Y neuroblastoma cells. Finally, bryostatin-1, but not HMI-1a3, increased the number of mushroom spines in proportion to total spine density in mature mouse hippocampal neuron cultures. These results suggest that the PKC activator HMI-1a3 exerts neuroprotective functions in the in vitro models relevant for AD by reducing the production of TNFα and increasing the secretion of neuroprotective sAPPα.

RETRACTED: Effects of rehabilitation training on apoptosis of nerve cells and the recovery of neural and motor functions in rats with ischemic stroke through the PI3K/Akt and Nrf2/ARE signaling pathways

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief and Academic Committee of Jiangsu Normal University (ACJSNU). ACJSNU informed the journal that they were aware of PubPeer comments of data fabrication and manipulation in Fig 4A, Fig 5A, Fig 7A + C as detailed here [https://pubpeer.com/publications/D732FA0F313382B58DD725C25A8AB9#3]. ACJSNU launched an investigation and invited two independent referees to review the issues raised on PubPeer and they agreed the paper displays signs of scientific fraud. An investigation made by Tangshan People's Hospital, concluded there are no researchers called Jun-Chang Wu and Gao-Zhou Tang in the hospital. ACJSNU requested that the corresponding authors of the paper provide the original experimental records and data for verification. However, the authors have been unable to address the above concerns, and have stated that the data were obtained from a third party which was not disclosed in the article. The National Natural Science Foundation of China has also investigated this paper and others by the corresponding authors [https://www.nsfc.gov.cn/publish/portal0/tab442/info85495.htm]. The Editor-in-Chief therefore no longer has confidence in the data presented and the conclusions of the article.

Association between TXNRD1 polymorphisms and anti-tuberculosis drug-induced hepatotoxicity in a prospective study

Anti-tuberculosis drug-induced hepatotoxicity (ATDH) is a serious adverse reaction to anti-tuberculosis (TB) treatment. Thioredoxin reductase 1 (TXNRD1), encoded by the TXNRD1 gene, is an important enzyme involved in oxidant challenge. TXNRD1 plays a key role in regulating cell growth and transformation, and protects cells against oxidative damage. We investigated the association between TXNRD1 polymorphisms and ATDH susceptibility. In this prospective study, 280 newly diagnosed TB patients were followed-up for 3 months after beginning anti-TB therapy. Tag single-nucleotide polymorphisms (tag-SNPs) of TXNRD1 were selected using Haploview 4.2 based on the HapMap database of the Chinese Han in Beijing (CHB) panel. Genotyping was performed using the MassARRAY platform. Of the 280 patients enrolled in this study, 33 were lost to follow-up, 24 had ATDH, and 223 were free from ATDH. After adjusting for sex, age, smoking status, and body mass index, there were no significant differences in the allele and genotype frequency distributions of TXNRD1 SNPs between the ATDH and non-ATDH groups (all P > 0.05). The haplotype analysis showed that haplotype TCAGCC was associated with an increased risk of ATDH susceptibility [P = 0.024, OR (95%CI) = 6.273 (1.023-38.485)]. Further stratified analyses showed that the haplotype TCAGCC was associated with ATDH susceptibility in female subjects [P = 0.036, OR (95%CI) = 5.711 (0.917-35.560)] and non-smokers [P = 0.029, OR (95%CI) = 6.008 (0.971-37.158)]. Our results suggest that TXNRD1 variants may favor ATDH susceptibility in females and non-smokers. Further studies are required to verify this association.

Thermal conductivity of the diamond-chain compound Cu₃(CO₃)₂(OH)₂

Thermal conductivity (κ) of a distorted spin diamond-chain system, Cu3(CO3)2(OH)2, is studied at low temperatures down to 0.3 K and in magnetic fields up to 14 T. In zero field, the κ(T) curve with heat current along the chain direction has very small magnitudes and shows a pronounced three-peak structure. The magnetic fields along and perpendicular to the chains change the κ strongly in a way having good correspondence to the changes of magnetic specific heat in fields. The data analysis based on the Debye model for phononic thermal conductivity indicates that the heat transport is due to phonons and the three-peak structure is caused by two resonant scattering processes by the magnetic excitations. In particular, the spin excitations of the chain subsystem are strongly scattering phonons rather than transporting heat.

Control of Immune Response to Allogeneic Embryonic Stem Cells by CD3 Antibody-Mediated Operational Tolerance Induction

Implantation of embryonic stem cells (ESCs) and their differentiated derivatives into allogeneic hosts triggers an immune response that represents a hurdle to clinical application. We established in autoimmunity and in transplantation that CD3 antibody therapy induces a state of immune tolerance. Promising results have been obtained with CD3 antibodies in the clinic. In this study, we tested whether this strategy can prolong the survival of undifferentiated ESCs and their differentiated derivatives in histoincompatible hosts. Recipients of either mouse ESC-derived embryoid bodies (EBs) or cardiac progenitors received a single short tolerogenic regimen of CD3 antibody. In immunocompetent mice, allogeneic EBs and cardiac progenitors were rejected within 20-25 days. Recipients treated with CD3 antibody showed long-term survival of implanted cardiac progenitors or EBs. In due course, EBs became teratomas, the growth of which was self-limited. Regulatory CD4(+)FoxP3(+) T cells and signaling through the PD1/PDL1 pathway played key roles in the CD3 antibody therapeutic effect. Gene profiling emphasized the importance of TGF-β and the inhibitory T cell coreceptor Tim3 to the observed effect. These results demonstrate that CD3 antibody administered alone promotes prolonged survival of allogeneic ESC derivatives and thus could prove useful for enhancing cell engraftment in the absence of chronic immunosuppression.

Phytoremediation of soils contaminated with phenanthrene and cadmium by growing willow (Salix × aureo-pendula CL 'j1011')

To assess the phytoremediation potential of an autochthonous willow (Salix × aureo-pendula CL 'J1011') for phenanthrene (PHE)-contaminated soils and PHE-cadmium (PHE-Cd) co-contaminated soils, we conducted field experiments in the lower reaches of the Yangtze River, China. Ethylenediaminetetraacetic acid (EDTA) and ethyl lactate were tested for individual and combined effects on the phytoremediation efficiency. For PHE-contaminated soils, willow plus ethyl lactate resulted in significant removal of PHE from soils after 45 days, and the PHE concentration in the shoots was significantly higher with than without ethyl lactate. For PHE-Cd co-contaminated soils, both willow plus EDTA and willow plus EDTA and ethyl lactate led to a significant decrease in the concentrations of PHE and Cd in the soils after 45 days, whereas willow alone did not. The PHE and Cd concentrations in the willow shoots were significantly enhanced in the presence of EDTA alone and with ethyl lactate, except for the PHE concentration in stems with EDTA alone. Under the same treatment, the presence of Cd had no significant influence on the PHE removal from soils. The results indicate the feasibility of using this willow together with both EDTA and ethyl lactate for the simultaneous removal of PHE and Cd from soils.

Characteristics of Small Intestinal Diseases on Single-Balloon Enteroscopy: A Single-Center Study Conducted Over 6 Years in China

The small intestine has been considered inaccessible for a long term. The development of single-balloon endoscopy has greatly improved the diagnosis and treatment possibilities for small intestinal diseases.In this study, we aimed to explore the demographic characteristics and small intestinal diseases of patients who underwent single-balloon enteroscopy between 2009 and 2014 at our endoscopy center. We determined the enteroscopic findings for each small intestinal disease and the most susceptible age groups.In total, 186 patients were included in the study. Their mean age was 45.87 ± 15.77 years. Patients who underwent single-balloon enteroscopy were found to have neoplasms (most common age group: 14-45 years, most common lesion location: jejunum), lymphoma (46-59 and 60-74 years, ileum), protuberant lesions (45-59 years, jejunum), inflammation (14-45 and 46-59 years, ileum), benign ulcers (14-45 years, jejunum), diverticulum (14-45 years, ileum), vascular malformations (60-74 years, jejunum), polyps (14-45 years, jejunum), Crohn's disease (14-45 years, jejunum), hookworm infection (14-45 years, jejunum), lipid pigmentation (14-45 and 46-59 years, jejunum), undetermined bleeding (46-59 years, ileum), or undetermined stenosis (31 years, duodenum). Each small intestinal disease had distinct enteroscopic findings.

Electrical stimulation therapy of the lower oesophageal sphincter for refractory gastro-oesophageal reflux disease - interim results of an international multicentre trial

BACKGROUND

A previous single-centre study showed that lower oesophageal sphincter electrical stimulation therapy (LES-EST) in gastro-oesophageal reflux disease (GERD) patients improves reflux symptoms and decreases oesophageal acid exposure.

AIM

To evaluate safety and efficacy of LES-EST in GERD patients with incomplete response to proton pump inhibitors (PPIs) in a prospective, international, multicentre, open-label study.

METHODS

GERD patients, partially responsive to PPIs, received LES-EST. GERD health-related quality of life (GERD-HRQL), daily symptom diaries, quality of life scores, oesophageal acid exposure, and LES resting and residual pressure were measured before and after initiation of LES-EST. Stimulation sessions were optimised based on residual symptoms and oesophageal acid exposure.

RESULTS

Forty-four patients were enrolled and 6-month data from 41 patients are available. Hiatal repair was performed in 16 patients. One device-related, one procedure-related and one unrelated severe adverse event were reported. GERD-HRQL improved from 31.0 (IQR 26.2-36.8) off-PPI and 16.5 (IQR 9.0-22.8) on-PPI to 4 (IQR 1-8) at 3-month and 5 (IQR 3-9) at 6-month follow-up (P < 0.0001 vs. on- and off-PPI). Oesophageal acid exposure (pH < 4.0) improved from 10.0% (IQR 7.5-12.9) to 3.8% (IQR 1.9-12.3) at 3 months (P = 0.0027) and 4.4% (IQR 2.2-7.2) at 6 months (P < 0.0001).

CONCLUSIONS

These interim results show an acceptable safety record of LES-EST to date, combined with good short-term efficacy in GERD patients who are partially responsive to PPI therapy. A remarkable reduction in regurgitation symptoms, without the risk of intervention-requiring dysphagia may prove to be an advantage compared with other anti-reflux procedures. ClinicalTrials.gov Identifier: NCT01574339.

CD34+ stem cell therapy in nonischemic dilated cardiomyopathy patients

Recent trends indicate that patients with nonischemic dilated cardiomyopathy represent the largest subpopulation of heart failure patients with a significant need for alternative treatment modalities. Similar to patients with ischemic cardiomyopathy, patients with nonischemic dilated cardiomyopathy have been found to have myocardial regions with flow abnormalities, which may represent targets for neoangiogenic therapies. CD34(+) stem cells might contribute to the formation of new blood vessels from existing vascular structures in ischemic tissues by the direct incorporation of injected cells into the newly developing vasculature or by the production and secretion of angiogenic cytokines. This review summarizes the long-term clinical effects and potential underlying mechanisms of CD34(+) cell therapy in patients with nonischemic dilated cardiomyopathy.

Antitopoisomerase antibody positivity predates nailfold capillaroscopy abnormalities in scleroderma. Postulated classification of 'prescleroderma'

In a patient with early topoisomerase antibody-positive scleroderma, antinuclear antibody positivity was fortuitously observed to predate nailfold capillaroscopy changes. Using this case as a template, the prediagnostic phase of the presumed multifactorial disease may be divided into 5 temporal phases--phase 1 representing conception and intrauterine environment, phase 2 representing the extrauterine environment predating environmental exposure; phase 3 representing the early post-environmental exposure interval with no detectable perturbed body status; phase 4 representing the post-environmental exposure interval characterized by autoantibody production and microvascular changes, and phase 5, the symptomatic clinical prediagnostic interval (Raynaud's, skin, musculoskeletal, gastrointestinal, cardiorespiratory) prompting scleroderma diagnosis. Temporal classification of prescleroderma aids in both the understanding and definition of scleroderma 'onset'. If altered nailfold capillaries and autoantibodies develop at comparable rates, and if the findings from this case--that autoantibody changes precede microvascular changes--are truly representative of the preclinical disease phase, then these findings argue that the evolution of the disease is from within the vessel outwards, rather than vice versa.

Evaluation for the ecological quality status of coastal waters in East China Sea using fuzzy integrated assessment method

This research presented an evaluation for the ecological quality status (EcoQS) of three semi-enclosed coastal areas using fuzzy integrated assessment method (FIAM). With this method, the hierarchy structure was clarified by an index system of 11 indicators selected from biotic elements and physicochemical elements, and the weight vector of index system was calculated with Delphi-Analytic Hierarchy Process (AHP) procedure. Then, the FIAM was used to achieve an EcoQS assessment. As a result of assessment, most of the sampling stations demonstrated a clear gradient in EcoQS, ranging from high to poor status. Among the four statuses, high and good, owning a ratio of 55.9% and 26.5%, respectively, were two dominant statuses for three bays, especially for Sansha Bay and Luoyuan Bay. The assessment results were found consistent with the pressure information and parameters obtained at most stations. In addition, the sources of uncertainty in classification of EcoQS were also discussed.

Association of two glyoxalase I gene polymorphisms with nephropathy and retinopathy in Type 2 diabetes

BACKGROUND

Glyoxalase I (GLO1), which is the major enzyme that catalyzes the metabolism of methylglyoxal (MG), may play an important role in the pathogenesis of diabetic microvascular complications.

AIM

To investigate whether the C-7T and A419C polymorphisms of the GLO1 gene are associated with nephropathy and retinopathy in Chinese Type 2 diabetic patients.

SUBJECTS AND METHODS

A total of 364 Type 2 diabetic patients and 301 healthy controls were enroled in the study. Diabetic microvascular complications were determined by urinary albumin excretion measurements and ophthalmological examinations. Genetic analyses were performed using either Taqman PCR or direct sequencing. The effect of C-7T polymorphism on promoter activity was measured by reporter gene assays.

RESULTS

The albumin/ creatinine ratio (ACR) and prevalence of nephropathy and retinopathy were significantly higher in diabetic patients with GLO1 -7CC genotype than in patients with -7CT and -7TT genotypes (p=0.02, p=0.02, and p=0.04, respectively). The - 7CC genotype is independently associated with ACR (β=0.13, p=0.01) and the risk for retinopathy [odds ratio (OR): 2.30, 95% confidence interval (CI): 1.25-4.24, p<0.01]. The luciferase activity of the -7T promoter was higher than that of the -7C promoter (13.2±0.2 vs 11.7±0.8, p=0.04). No differences were found between ACR and the prevalence of nephropathy and retinopathy for A419C polymorphism in Type 2 diabetic patients.

CONCLUSIONS

GLO1 C-7T polymorphism alters promoter activity and confers susceptibility to nephropathy and retinopathy to Type 2 diabetic patients.

Indirect imaging of cardiac-specific transgene expression using a bidirectional two-step transcriptional amplification strategy

Transcriptional targeting for cardiac gene therapy is limited by the relatively weak activity of most cardiac-specific promoters. We have developed a bidirectional plasmid vector, which uses a two-step transcriptional amplification (TSTA) strategy to enhance the expression of two optical reporter genes, firefly luciferase (fluc) and Renilla luciferase (hrluc), driven by the cardiac troponin T (cTnT) promoter. The vector was characterized in vitro and in living mice using luminometry and bioluminescence imaging to assess its ability to mediate strong, correlated reporter gene expression in a cardiac cell line and the myocardium, while minimizing expression in non-cardiac cell lines and the liver. In vitro, the TSTA system significantly enhanced cTnT-mediated reporter gene expression with moderate preservation of cardiac specificity. After intramyocardial and hydrodynamic tail vein delivery of an hrluc-enhanced variant of the vector, long-term fluc expression was observed in the heart, but not in the liver. In both the cardiac cell line and the myocardium, fluc expression correlated well with hrluc expression. These results show the vector's ability to effectively amplify and couple transgene expression in a cardiac-specific manner. Further replacement of either reporter gene with a therapeutic gene should allow non-invasive imaging of targeted gene therapy in living subjects.

Temperature dependent pinning phenomenon in superconducting Nb films with triangular and honeycomb pinning arrays

The pinning phenomena in superconducting Nb films with triangular and honeycomb pinning arrays were explored. Special temperature dependent phenomena were found for both films. For the film with a triangular pinning array, the pronounced matching peaks in the critical currents as a function of magnetic field reduce from six to three within a narrow temperature range. This temperature dependent matching effect is explained by considering the dramatic change of coherent length with temperature when the temperature is close to T(c). In order to compare with the film with a triangular pinning array, we fabricated a film with a honeycomb pinning array with similar pinning site spacing and pinning size. Special prominent matching peaks at H = 3.5H(1) were found for this film. Molecular dynamic simulations were made to study this phenomenon. The ground state distribution of vortices obtained from simulations reasonably explains the prominent matching peaks. Pronounced temperature dependent matching effects were also found for the film with a honeycomb pinning array.

Thermostability of Cromobacterium viscosum lipase in AOT/isooctane reverse micelle

The thermostability of Cromobacterium viscosum lipase (EC 3.1.1.3) entrapped in AOT (sodium bis-[2-ethylhexyl] sulfosuccinate) reverse micelles was increased by the addition of short-chain polyethylene glycol (PEG 400). Two different approaches were considered: (1) the determination of half-life time and (2) the mechanistic analysis of deactivation kinetics. The half-life of lipase entrapped in AOT/isooctane reverse micelles with PEG 400 at 60 degrees C was 28 h, ninefold higher than that in reverse micelles without PEG 400. The lipase entrapped in both reverse micellar systems followed a series-type deactivation mechanism involving two first-order steps. The deactivation constant for the first step at 60 degrees C in PEG containing reverse micelles was 0.055 h!1, 11-fold lower than that in reverse micelles without PEG, whereas it remained almost constant for the second step. The inactivation energy of the lipase entrapped in reverse micelles with and without PEG 400 was 88.12 and 21.97 kJ/mol, respectively.

Trans-cutaneous electrogastrographic study of gastric myoelectric activity in transposed intrathoracic stomach after esophagectomy

We examined the feasibility of trans-cutaneous electrogastrography (EGG) in recording myoelectric activity of the transposed thoracic stomach after esophagectomy. Nineteen patients who had Ivor-Lewis esophagectomy were studied. The EGG signal was recorded using cutaneous electrodes placed over the lower sternum. Eleven patients who underwent total gastrectomy served as controls. Normal rhythm pattern (2.4-3.6 cpm > or = 70%) and power ratio (PR > or = 2) was observed in five and 12 patients, respectively, after esophagectomy. The observation of normal gastric rhythm was more frequent in the postprandial period in the esophagectomy group (median 42.6%vs. 7.4%, P = 0.01), and the PR was significantly higher (median 2.27 vs. 1.38, P = 0.013) than the gastrectomy group. Feeding further increased the prevalence of normal gastric slow wave in the esophagectomy group (median 14.8% to 42.6%, P = 0.002) and improved the stability of dominant frequency (median 78% to 67%, P = 0.015). We conclude that gastric myoelectric activities of thoracic transposed stomach can be detected from cutaneous sternal electrodes. This represented a preservation of gastric motility even when the stomach is pulled up to the thorax as a substitute for the esophagus.

Functional and clinical significance of hepatitis D virus genotype II infection

Hepatitis D virus (HDV) infection is one of the important etiologies of fulminant hepatitis and may aggravate the clinical course of chronic HBV infection to cirrhosis and liver failure. HDV was classified into three genotypes. Recent molecular phylogenetic analysis of HDV suggests at least seven major clades. The genotype I HDV is widely spread, genotype II is found in East Asia and genotype III HDV is prevalent in South America. The genomic size is 1682-1685 nucleotides (nt) for genotype II, and 1676 nt for genotype IV (IIb). The divergence in HDV nucleic acid sequences between genotype II and other genotypes varies from 13.8% to 35.3%. The divergences in the HDAg-coding region may range from 17.8% to 29.8% between genotype II and other genotypes. There is no genotypic or size restriction on the interactions of either the small or the large hepatitis delta antigens (HDAgs) between genotypes I and II, and there is also no genotypic incompatibility during co-package of HDAgs of different genotypes into virus like particles. There appears no apparent universal genotypic restriction of the transactivation of genotype I HDV RNA replication by small HDAg of genotype II. In contrast, there appears more genotypic restriction for genotype I small HDAgs to transactivate genotype II HDV RNA replication. Of the functional domains of HDAg, the 19 amino acids at the carboxyl-end of the large HDAg show the greatest divergences (70%-80%) between genotypes I and II. The viral packaging efficiencies of genotype I HDV isolates are usually higher than those of genotype II. The 19 amino acids at the carboxyl-end seem to be the most important determinant for viral packaging efficiencies. The editing efficiencies of the genotype I HDV are also higher than those of the genotype II. Genotype II HDV infection is relatively less frequently associated with fulminant hepatitis at the acute stage and less unfavorable outcomes [cirrhosis or hepatocellular carcinoma (HCC)] at the chronic stage as compared to genotype I. It appears that the clinical manifestations and outcomes of patients with genotype IV (IIb) HDV infection are more like those of patients with genotype II HDV infection. Persistent replication of HBV or HDV was associated with higher adverse outcomes (cirrhosis, HCC or mortality) compared to those who cleared both viruses from the sera. HBV of the genotype C is also a significant factor associated with adverse outcomes (cirrhosis, HCC or mortality) in patients with chronic hepatitis D in addition to genotype I HDV and age. However, most patients with chronic HDV infection have low or undetectable hepatitis B virus DNA levels. During longitudinal follow-up, genotype I HDV is the most important determinant associated with survival.

Responses of the antioxidant defenses of the Goldfish Carassius auratus, exposed to 2,4-dichlorophenol

Goldfish Carassius auratus were exposed to 0.1mg/l of 2,4-dichlorophenol (2,4-DCP), widely used as transportation power in China, for 2, 5, 10, 20 and 40 days, while one control group was designated for each exposure group. Antioxidant defenses consisting of contents of reduced glutathione (GSH) and glutathione disulfide (GSSG) and activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), selenium-dependent glutathione peroxidase (Se-GPx) and glutathione S-transferase (GST) in liver of freshwater fish were determined and the GSH-GSSG ratio and content of tGSH (total glutathione) were calculated. In the present study, the role of hepatic antioxidant defenses was evaluated and the possible poisoning mechanism of fish can be explained as an oxidative stress mechanism. In addition, hepatic SOD and GSH, especially tGSH, were sensitive to 2,4-DCP contamination and thus, can possibly be used in early assessment of 2,4-DCP-dominant polluted aquatic ecosystems.

Improvement in enzyme activity and stability by addition of low molecular weight polyethylene glycol to sodium bis(2-ethyl-L-hexyl)sulfosuccinate/isooctane reverse micellar system

The activity and stability of Chromobacterium viscosum lipase (glycerolester hydrolase, EC 3.1.1.3)-catalyzed olive oil hydrolysis in sodium bis (2-ethyl-l-hexyl)sulfosuccinate (AOT)/isooctane reverse micelles is increased appreciably when low molecular weight polyethylene glycol (PEG 400) is added to the reverse micelles. To understand the effect of PEG 400 on the phase behavior of the reverse micellar system, the phase diagram of AOT/ PEG 400/water/isooctane system was studied. The influences of relevant parameters on the catalytic activity in AOT/PEG 400 reverse micelles were investigated and compared with the results in the simple AOT reverse micelles. In the presence of PEG 400, the linear decreasing trend of the lipase activity with AOT concentration, which is observed in the simple AOT reverse micelles, disappeared. Enzyme entrapped in AOT/PEG reverse micelles was very stable, retaining >75% of its initial activity after 60 d, whereas the half-life in simple AOT reverse micelles was 38 d. The kinetics parameter maximum velocity (Vmax) exhibiting the temperature dependence and the activation energy obtained by Arrhenius plot was suppressed significantly by the addition of PEG 400.

Effects of water-soluble fractions of diesel oil on the antioxidant defenses of the goldfish, Carassius auratus

Larval goldfish Carassius auratus were exposed to 0.05 and 0.1 mg/L No. 20 diesel oil, widely used as transportation power in China, for 2, 4, 7, 10, 15, 25, and 40 days, while one control group was designated for each exposure group. Some fish after 25 days of exposure were transferred to diluted water until the 40th day. Hepatic antioxidant defense parameters of fish, including contents of reduced glutathione and glutathione disulfide and activities of superoxide dismutase, catalase, glutathione reductase, selenium-dependent glutathione peroxidase, and glutathione S-transferase, were determined and compared to control values. All the results indicated that the antioxidant responses of the fish to the two concentrations of oil exposure were similar on the whole. The possible defense mechanisms of fish and prospective early biomarkers for the evaluation of an oil-dominant contaminated aquatic ecosystem are discussed. In addition, after fish were removed from oil exposure, the recovery status of these antioxidant indices was explored.

Persistent retention of acetic acid is associated with complete tumour necrosis in patients with hepatocellular carcinoma undergoing percutaneous acetic acid injection

BACKGROUND

Ultrasound (US)-guided percutaneous acetic acid injection therapy (PAIT) is effective for patients with hepatocellular carcinoma (HCC). This study aimed to determine the occurrence and predictive value of persistent intra-tumoral retention of acetic acid after PAIT.

METHODS

We prospectively studied 60 (52 M, mean age 68 +/- 10 years) patients with 72 HCC nodules (45 < or = 3 cm) treated with PAIT. The presence of post-treatment persistent retention of acetic acid, defined as a homogeneous and highly hyperechoid mass in US appearance 3 days after completion of the treatment, was correlated with the treatment response.

RESULTS

The mean size of the treated tumour was 2.9 +/- 1.0 cm (range 1.5-5 cm). Thirty (42%) HCC nodules showed complete tumour necrosis demonstrated by contrast-enhanced dynamic CT. Complete response was found in 22 (69%) of 32 nodules showing persistent intra-tumoral retention of acetic acid (P < 0.001). Small (< or = 3 cm) tumour size was also significantly associated with complete tumour necrosis (P = 0.001). There were no significant differences of the injection volume and treatment sessions between those with and without complete tumour necrosis in either small or large (> 3 cm) HCC (P > 0.1). Multivariate logistic regression analysis showed that persistent retention of acetic acid (odds ratio (OR) 10.4, 95% confidence interval (CI) 3.1-34.7; P < 0.001) and tumour size < or = 3 cm (OR 6.8, 95%, CI 1.8-25.8; P = 0.002) were independent factors predicting complete tumour necrosis.

CONCLUSIONS

The presence of persistent retention of acetic acid is associated with a favourable response and may predict complete tumour necrosis after PAIT.

Reliability of contemporary radiology to measure tumour size of hepatocellular carcinoma in patients undergoing resection: limitations and clinical implications

BACKGROUND

Preoperative radiology has been widely used to detect and measure hepatocellular carcinoma (HCC). However, its accuracy and reliability are unclear. This study aimed to assess the ability of current radiology to measure tumour size in patients undergoing resection.

METHODS

We evaluated 212 HCC patients undergoing curative resection. Tumour size measured in the pathological examination was correlated with that obtained in preoperative ultrasound (US) and contrast-enhanced dynamic computed tomography (CT). Accuracy and association with tumour recurrence were investigated.

RESULTS

The mean size of the tumour was 4.5 +/- 2.6 cm and was accurate in both US and CT in only 6 (3%) patients. Cirrhosis (P = 0.015), absence of tumour stain (P = 0.002) and small (< or = 4 cm) tumour (P < 0.001) were the significant factors associated with size deviation using both US and CT. Ninety-four (44%) patients developed tumour recurrence within 17 +/- 11 months of resection. Recurrence rate was 52%, 52% and 67% in patients with underestimation in US (relative risk [RR]: 2.0, 95% confidence interval [CI]: 1.2-3.4, P = 0.01), CT (RR: 2.1, 95% CI: 1.1-4, P = 0.022) and both modalities (RR: 2.5, 95% CI: 1.4-4.2, P = 0.001), respectively, compared to 30% recurrence in patients with accurate estimation of tumour size.

CONCLUSION

The accuracy of radiology in measuring tumour size was poor, and may lead to inappropriate treatment. The finding that underestimation of tumour size was associated with a higher tumour recurrence rate is consistent with the hypothesis that HCC may recur from pre-existing tumour foci which could not be identified from the current imaging modalities.

Comparison of percutaneous acetic acid injection and percutaneous ethanol injection for hepatocellular carcinoma in cirrhotic patients: a prospective study

BACKGROUND

Ultrasound-guided percutaneous ethanol injection (PEI) and percutaneous acetic acid injection (PAI) are effective in the treatment of hepatocellular carcinoma (HCC). We conducted a prospective study to compare the therapeutic efficacy of both these methods.

METHODS

Sixty-three patients were treated by PAI using 50% acetic acid and 62 by PEI using pure ethanol. There were no significant baseline differences in age, sex, Child-Pugh class, tumour size and number, or other clinico-biochemical parameters between the two groups.

RESULTS

During a follow-up period of 24 +/- 9 (range 6-38) months, 19 (30%) of the PAI group and 21 (34%) of the PEI group died (P = 0.704). The 1- and 3-year survival rates were 84% and 51% for the PAI group and 81% and 46% for the PEI group (P = 0.651). The corresponding tumour recurrence rates were 51% and 74% for the PAI group, and 54% and 64% for the PEI group (P = 0.787). The treatment sessions were 3.9 +/- 1.6 and 6.2 +/- 2.3 for the PAI and PEI groups, respectively, in each treatment cycle (P = 0.008). A multivariate analysis using the Cox regression model revealed that ascites (relative risk (RR) 3.1, 95% confidence interval (CI) 1.5-6.3, P = 0.002), large (>3 cm) or multinodular HCCs (RR 2.4, 95% CI 1.1-5.4, P = 0.04), and development of tumour recurrence (RR 7.0, 95% CI 3.1-16.0, P < 0.001) were independent, poor prognostic factors in both groups.

CONCLUSIONS

PAI and PEI are equally effective in the treatment of HCC. PAI has the advantage of fewer treatment sessions in each treatment course. Careful pretreatment patient selection may improve survival.

D1 receptor alleles predict PET metabolic correlates of clinical response to clozapine

A goal of pharmacogenetics is to clarify associations between allelic variation and risk factors in psychiatric illness. We report changes in regional brain metabolism based on dopamine alleles. Treatment-resistant schizophrenic subjects were positron emission tomography scanned with 18F-fluorodeoxyglucose after 5 weeks each of placebo and clozapine treatment. Significant regional brain metabolic effects were found for the D1 receptor genotypes (P < 0.05), adjusted for multiple comparisons. Metabolic decreases for the 2,2 genotype but not the 1,2 genotype were observed in all major sectors of the brain, with the exception of the ventral parts of the caudate and putamen. Frontal, temporal, parietal, and occipital neocortices showed decreased metabolism as did the cingulate juxta-allocortex and the parahippocampal allocortex. Decreases were also observed in the thalamus, amygdala, and cerebellum bilaterally. No significant metabolic differences by genotype were observed for D3, 5HT(2A), and 5HT(2C) polymorphisms. In terms of clinical response, the DRD1 2,2 genotype significantly improved with clozapine treatment, demonstrating a 30% decrease in the Brief Psychiatric Rating Scale positive symptoms in contrast to a 7% worsening for the 1,2 genotype (P < 0.05). In this preliminary study, brain metabolic and clinical response to clozapine are related to the D1 receptor genotype.

Hepatitis C viral genotype influences the clinical outcome of patients with acute posttransfusion hepatitis C

Most patients with an acute infection of hepatitis C virus (HCV) will develop chronic hepatitis, and only about 15-20% of the cases will resolve spontaneously. The mechanism for the different outcomes in patients with acute HCV infection remains unclear. HCV genotype has been recognized as an important factor affecting the clinical course and outcome of chronic hepatitis C patients. In order to evaluate the role of HCV genotype in the clinical course and outcome of acute posttransfusion hepatitis C, 67 patients with acute posttransfusion hepatitis C from a prospective study of posttransfusion non-A, non-B hepatitis were enrolled. Thirty-nine patients (58.2%) were HCV genotype 1b. Among the 67 patients with acute posttransfusion hepatitis C, 53 (79.1%) progressed to chronic hepatitis. Significantly more patients with genotype 1b than non-1b genotypes developed chronic hepatitis (89.7% vs. 64.3%; P = 0.019). There was no significant difference in gender, mean age, amount of transfused blood, hepatitis symptoms, jaundice, incubation period, peak serum alanine transaminase, or serum HCV RNA titer between patients with HCV genotype 1b and non-1b infections. Patients who developed chronic hepatitis had a significantly greater incidence of genotype 1b infection (66.0% vs. 28.6%; P = 0.013) and a longer incubation period (7.3 weeks vs. 5.4 weeks; P = 0.052) than patients whose infection was resolved. Patients with a genotype 1b infection that resolved itself spontaneously all had an incubation period of less than 6 weeks. Multivariate logistic regression analysis revealed that genotype 1b and an incubation period > or = 6 weeks were significant predictive factors for the development of chronic hepatitis. Therefore, the HCV genotype can influence the outcome of patients with acute HCV infection.

Dysfunction of oesophageal motility in Helicobacter pylori-infected patients with reflux oesophagitis

BACKGROUND

Helicobacter pylori infection has been suggested to be protective against gastro-oesophageal reflux disease. However, a significant proportion of patients with gastro-oesophageal reflux disease are infected by H. pylori.

AIM

To study oesophageal motor function in H. pylori-infected patients with reflux oesophagitis.

METHODS

Patients with erosive reflux oesophagitis were recruited prospectively for stationary oesophageal manometry and 24-h ambulatory oesophageal pH monitoring. H. pylori status was determined by biopsy urease test. Non-reflux volunteers were recruited as controls.

RESULTS

Seventy-four patients with erosive oesophagitis (34 H. pylori-positive, 40 H. pylori-negative) and 48 non-reflux patient controls (22 H. pylori-positive, 26 H. pylori-negative) were recruited. There was no difference in severity of oesophagitis (median grade, 1; P=0.53) or oesophageal acid exposure (total percentage time oesophageal pH < 4, 7.6% vs. 6.8%; P=0.57) between H. pylori-positive and H. pylori-negative groups. Compared to H. pylori-negative patients, H. pylori-positive patients had significantly lower basal lower oesophageal sphincter pressure (12.2 mmHg vs. 15.3 mmHg; P=0.03) and amplitude of distal peristalsis (56.9 mmHg vs. 68.4 mmHg; P=0.03). Ineffective oesophageal motility (14% vs. 7%; P=0.02) and failed oesophageal peristalsis were also significantly more prevalent in H. pylori-positive patients.

CONCLUSIONS

Among patients with a similar degree of reflux oesophagitis, H. pylori-infected patients have more severe oesophageal dysmotility and lower oesophageal sphincter dysfunction. Oesophageal motor dysfunction probably plays a dominant role in the development of gastro-oesophageal reflux disease in patients with H. pylori infection.

The spatial distribution of macular pigment in humans

PURPOSE

To estimate the distributions in width as well as in density of macular pigment (MP) in humans at different ages, imaging fundus reflectometry was employed as a tool to reach our aim.

METHODS

Imaging fundus reflectometry was used to measure the macular pigment distribution in human eyes with a modified fundus camera to which a cooled CCD camera was attached. The fundus images were taken at 460 nm and 560 nm after the retina was light-adapted to completely bleach rhodopsin. The density of macular pigment was estimated using a model described in the text. The variation in density with retinal eccentricity was fit to Gaussian distribution. The width of MP in retinal eccentricity was estimated by 95% covering area of the distribution profile. A total of 54 normal people served as subjects. They were divided into three groups with ages of 24.8 +/- 2.6 years (N = 24), 40.2 +/- 8.3 years (N = 13) and 67.5 +/- 7.1 years (N = 17) respectively. Statistical t-tests were employed to evaluate the differences in MP density, the half width of MP distributed (HWMPD) in retina with respect to age between the groups. Linear regression was also applied to reveal the relationships of HWMPD distribution with respect to age.

RESULTS

The results indicate that the average MP densities are 0.23 +/- 0.08, 0.22 +/- 0.06 and 0.23 +/- 0.06 density unit (DU) for the young to old age groups. The average MP density is 0.23 +/- 0.07. No statistical significant difference is found in the peak MP density between the groups (all p > 0.05). This result pretty agrees with the data that obtained from others by using optical methods. For the young to old age groups, the average estimated HWMPD are 2.6 degrees +/- 0.5 degrees, 3.1 degrees +/- 0.5 degrees and 4.1 degrees +/- 0.6 degrees respectively. The differences between loci of HWMPD in the three groups are statistically significant with p = 0.0059, p < 0.0001 and p = 0.0001 for young vs. mid-age, young vs. old and mid-age vs. old respectively. Linear regressions for the HWMPD vs. age (r = 0.734, p < 0.001) implies that the macular pigment can gradually accumulate and spread out to the periphery of retina through our life span with an increase rate of approximately 0.03 degrees /year.

CONCLUSIONS

The accumulation of MP is reflected by the broader area in the macula lutea due to age, but no significant change is observed in peak density. The cause of the extension in the macular area with respect to age is unknown.

Clinical neurochemical implications of sleep deprivation's effects on the anterior cingulate of depressed responders

The antidepressant and cerebral metabolic effects of total sleep deprivation (TSD) or partial sleep deprivation (PSD) for one night has been studied with functional neuroimaging in seven publications from five different groups. Despite the variations in methods and techniques, the over-all findings were relatively consistent. First, before sleep deprivation, responders have significantly elevated metabolism compared with non-responders and normal controls, in the orbital medial prefrontal cortex, and especially the ventral portions of the anterior cingulate cortex. Second, after sleep deprivation, these hyperactive areas normalize in the responders. One functional imaging study suggested that synaptic dopamine release was associated with the antidepressant effects of TSD. The neurochemical implications of these findings are explored. Possible dopaminergic and serotonergic mechanisms are discussed.

Long-term evaluation of recombinant interferon alpha2b in the treatment of patients with hepatitis B e antigen-negative chronic hepatitis B in Taiwan

The effect of interferon (IFN) on hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) has not been fully investigated in Chinese patients. We enrolled 58 HBeAg-negative CHB Chinese patients with hepatitis B viremia in Taiwan to evaluate the response to IFN. 30 patients received recombinant IFN 5 million units 3 times weekly for 6-10 months, and 28 patients who refused IFN treatment served as controls. Rates of virological response and biochemical response were higher in the treated group at the end of treatment (57% vs 18%, P = 0.006, and 73% vs 29%, P = 0.002, respectively). Both effects were superior in the treated group at 6 months after IFN withdrawal (virological: 30% vs 7%, P = 0.06; biochemical: 47% vs 7%, P = 0.002). Improvement of liver histological activities with persistently biochemical response was found in 65% of the treated patients. After a mean of 32 months' follow-up, virological response was rarely maintained (17% vs 4%, P = 0.228) but biochemical response was better in the treated group (27% vs 4%, P = 0.039). None of the treated patients but five controls developed severe complications of CHB during the follow-up period. A larger total IFN dosage or a younger age (< or = 40 years) were associated with 'sustained' virological response. Younger age and higher baseline alanine transaminase values (> or = 120 Ul(-1)) were related to 'sustained' biochemical response.

Hereditary hemorrhagic telangiectasia: demonstration of portosystemic venous shunts using power Doppler sonography and sonographically guided percutaneous transhepatic portovenography

Hereditary hemorrhagic telangiectasia is a rare autosomal dominant inherited disease associated with vascular abnormalities, which may occur in any organ. Cases of hereditary hemorrhagic telangiectasia accompanied by intrahepatic portosystemic venous shunts, however, have rarely been described. We report a case of hereditary hemorrhagic telangiectasia in which intrahepatic portosystemic shunts were detected using power Doppler sonography and portovenography with percutaneous transhepatic contrast agent injection. On gray-scale sonography, the common hepatic artery was dilated, and dilated tubular structures mimicking dilated biliary tracts were found. Power Doppler sonography demonstrated the continuity of tortuous vascular channels connecting a branch of the right portal vein to a branch of the right hepatic vein. The dilated vascular channels and tributaries of the right hepatic vein showed a monophasic waveform pattern on spectral analysis. Portovenography showed a tangle of vascular structures connecting with a branch of the right hepatic vein.

Noninvasive optical imaging of firefly luciferase reporter gene expression in skeletal muscles of living mice

The ability to monitor reporter gene expression noninvasively offers significant advantages over current techniques such as postmortem tissue staining or enzyme activity assays. Here we demonstrate a novel method of repetitively tracking in vivo gene expression of firefly luciferase (FL) in skeletal muscles of mice using a cooled charged coupled device (CCD) camera. We first show that the cooled CCD camera provides consistent and reproducible results within +/-8% standard deviation from mean values, and a detection sensitivity (range tested: 1 x 10(4) - 1 x 10(9) plaque form-ing units (pfu)) of 1 x 10(6) pfu of E1-deleted adenovirus expressing FL driven by a cytomegalovirus promoter (Ad-CMV-FL). The duration and magnitude of adenoviral mediated (1 x 10(9) pfu) FL gene expression were then followed over time. FL gene expression in immunocompetent Swiss Webster mice peaks within the first 48 hours, falls by 98% after 20 days, and persists for >150 days. In contrast, FL activity in nude mice remains elevated for >110 days. Finally, transduced Swiss Webster and nude mice were sacrificed to show that the in vivo CCD signals correlate well with in vitro luciferase enzyme assays (r(2)=0.91 and 0.96, respectively). Our findings demonstrate the ability of the cooled CCD camera to sensitively and noninvasively track the location, magnitude, and persistence of FL gene expression. Monitoring of gene therapy studies in small animals may be aided considerably with further extensions of this technique.

Seasonal variability of the QT dispersion in healthy subjects

We studied the seasonal variability of QT dispersion in 25 healthy subjects, aged 36 +/- 5 (25 to 46) years. Four seasonal 12-lead rest electrocardiograms (ECGs) recorded at a double amplitude were performed at 25 mm/s at intervals of roughly 3 months. To avoid possible confusion from the circadian rhythm of QT dispersion, subsequent ECGs were recorded within 30 minutes of the reference summer one. The QT dispersion was calculated as the difference between the longest and the shortest mean QT intervals. There was a seasonal variability in the QT dispersion (P =.001), with the largest QT dispersion occurring in winter (66 +/- 21 ms) and the smallest one in spring (48 +/- 18 ms). In conclusion, there exists a seasonal variability of QT dispersion in healthy subjects and such variability should be taken into consideration in comparison of the QT dispersion.

Incidence of gastroesophageal malignancy in patients with dyspepsia in Hong Kong: implications for screening strategies

BACKGROUND

A "test-and-treat" strategy for H pylori infection has been recommended in Europe and North America as safe and cost-effective for management of patients with dyspepsia. The primary aim of this study was to determine the frequency of gastroesophageal cancer in 2 groups of patients with dyspepsia: those 45 years of age or younger without "alarm" symptoms (low-risk group) and patients over 45 years of age or any patient with "alarm" symptoms (high-risk group). A secondary aim was to determine the frequency of gastric cancer among patients in the low-risk group with or without a positive serology for H pylori.

METHODS

Patients with persistent dyspepsia were recruited from 4 regional hospitals in Hong Kong. Those in the low-risk group were evaluated for H pylori by using a whole blood serology test; they underwent endoscopy within 1 week. Those in the high-risk group and those taking nonsteroidal anti-inflammatory drugs (NSAIDs) underwent endoscopy promptly. Alarm symptoms were as follows: weight loss (10 or more pounds over 8 weeks), recurrent vomiting, dysphagia, bleeding, or anemia.

RESULTS

Of 2627 patients enrolled, 1017 were in the low-risk group and 1610 in the high-risk group. Twenty-three patients (0.9%) had gastroesophageal cancers (20 gastric, 3 esophageal). Four patients with cancer (17.4%) were in the low-risk group (3 gastric, 1 esophageal); all except the patient with esophageal cancer had a positive serology test. In the high-risk group, 19 patients had cancer (17 gastric, 2 esophageal).

CONCLUSION

Gastric cancer is relatively frequent among young patients with dyspepsia who have no alarm features in Hong Kong. This finding raises concerns as to the safety of the "test-and-treat" strategy for the management of patients with dyspepsia in Asia.

RNA folding pathway functional intermediates: their prediction and analysis

The massively parallel genetic algorithm (GA) for RNA structure prediction uses the concepts of mutation, recombination, and survival of the fittest to evolve a population of thousands of possible RNA structures toward a solution structure. As described below, the properties of the algorithm are ideally suited to use in the prediction of possible folding pathways and functional intermediates of RNA molecules given their sequences. Utilizing Stem Trace, an interactive visualization tool for RNA structure comparison, analysis of not only the solution ensembles developed by the algorithm, but also the stages of development of each of these solutions, can give strong insight into these folding pathways. The GA allows the incorporation of information from biological experiments, making it possible to test the influence of particular interactions between structural elements on the dynamics of the folding pathway. These methods are used to reveal the folding pathways of the potato spindle tuber viroid (PSTVd) and the host killing mechanism of Escherichia coli plasmid R1, both of which are successfully explored through the combination of the GA and Stem Trace. We also present novel intermediate folds of each molecule, which appear to be phylogenetically supported, as determined by use of the methods described below.

Brain metabolic and clinical effects of rivastigmine in Alzheimer's disease

In-vivo metabolic measures with positron emission tomography using (18)F-fluorodeoxyglucose (FDG-PET) have demonstrated hypometabolism in temporal, frontal, and hippocampal areas during the early stages of Alzheimer's disease (AD). Progression of the dementia in AD involves compromised cholinergic functioning. Cholinesterase inhibitors have demonstrated efficacy in improving cognition and behaviour in AD. In this study, we demonstrate the usefulness of FDG-PET in measuring the progression of untreated AD and its modification by treatment with rivastigmine (Exelon, Novartis Pharmaceuticals, East Hanover, New Jersey, USA), a centrally selective cholinesterase inhibitor of the carbamate type. Patients with mild to moderate probable AD (Mini-Mental Status Exam scores of 10-26, inclusive) were enrolled in a double-blind, placebo controlled comparison of three fixed daily doses of rivastigmine (3, 6, or 9 mg/d) or placebo for 26 wk. FDG-PET scans were obtained on 27 patients at baseline and following 26 wk of treatment using the Snodgrass Picture Naming activation task. A total of 71.4% of the patients treated with placebo deteriorated clinically compared to only 25.0% of the patients treated with rivastigmine (chi2 = 4.8; p & 0.03). Rivastigmine-responders (i.e. those who clinically improved or remained clinically stable as measured by the Clinicianaposs Interview-Based Impression of Change-plus) showed a marked increase in brain metabolism (p <0.01) involving, but not limited to, structures comprising the memory-related cortices and the prefrontal system. These metabolic changes were not observed in the placebo-treated patients or the rivastigmine non-responders. Of note is that responders increased hippocampal metabolism by 32.5% (p < 0.03) compared to a non-significant decrease in the non-responders (6.4%) and placebo-treated patients (4.1%). These results are consistent with the literature suggesting that FDG-PET can sensitively measure the progression of AD and its improvement with cholinesterase inhibitors. Rivastigmine prevented the expected deterioration in clinical status and dramatically increased brain metabolic activity in a majority of patients.

Correlations between theoretical and experimental determination of heat of formation of certain aliphatic nitro compounds

Heats of formation of energetic materials were calculated by Dewar's AM1 and Stewart's PM3 methods. In order to compare the theoretical results with the experimental ones, some correlation models were proposed in this study. Correlations were evaluated by multivariable linear regression method, considering the number of nitro groups and the use of quadratic relations involving the number of carbon, hydrogen, nitrogen, and oxygen atoms. Results indicated very precise correlations. Based on these correlations, heats of formation of some aliphatic nitro compounds can be predicted at 95% predictive interval without experimental analysis.

Trauma inhibits erythroid burst-forming unit and granulocyte-monocyte colony-forming unit growth through the production of TGF-beta1 by bone marrow stroma

OBJECTIVE

To examine the effect of trauma plasma on clonogenic progenitor cultures.

SUMMARY BACKGROUND DATA

Severely injured trauma patients often experience altered hematopoietic functions, manifested by an increased susceptibility to infection and the development of a persistent anemia. Experimental and clinical data suggest that trauma results in the release of cytokines into the plasma that have hematopoietic regulatory function, but few studies have examined human bone marrow.

METHODS

Plasma was obtained from 42 severely injured patients admitted to the surgical intensive care unit from days 1 to 15 after injury. Bone marrow and normal plasma were obtained from volunteers. Bone marrow mononuclear cells were isolated and plated for granulocyte-monocyte colony-forming unit (CFU-GM) and erythroid burst-forming unit (BFU-E) growth. Parallel cultures were incubated with 2% (v/v) trauma or normal plasma. Additional cultures were plated with neutralizing concentrations of antibodies to transforming growth factor (TGF)-beta1 and MIP-1alpha. Circulating plasma TGF-beta1 was determined by bioassay. mRNA from bone marrow stromal cultures was extracted and probed for TGF-beta1 and macrophage inflammatory protein (MIP)-1alpha.

RESULTS

Trauma plasma suppressed CFU-GM and BFU-E colony growth by 40% to 60% at all time periods after injury compared with cultures incubated with normal plasma. Using a noncontact culture system, the authors showed that this inhibition of BFU-E and CFU-GM colony growth was mediated by bone marrow stroma. The inhibition appeared to be due to soluble plasma-induced bone marrow stromal products that did not require direct cell-cell contact. The addition of anti-TGF-beta1 antibodies reversed the suppressive effect of trauma plasma on CFU-GM and BFU-E colony growth during the early but not late time points after injury. Trauma but not normal plasma induced TGF-beta1 mRNA in bone marrow stroma.

CONCLUSIONS

Trauma plasma inhibits bone marrow BFU-E and CFU-GM colony growth for up to 2 weeks after injury. This inhibition is mediated through the interaction of trauma plasma with bone marrow stroma. TGF-beta1 production by bone marrow stroma appears to plays an important role in the early but not late bone marrow suppression after injury.

Quantitative PET findings in patients with posttraumatic anosmia

OBJECTIVE

To investigate quantitative positron emission tomography (PET) findings, particularly from orbitofrontal cortex, in patients with posttraumatic anosmia.

SETTING

Neuropsychology outpatient clinic and university brain imaging center.

SUBJECTS

Eleven patients with head injury resulting in severe anosmia and 11 controls matched for age. All 11 head-injured patients had their head injuries at least 2 years before involvement in the study.

MEASURES

Regional cerebral glucose metabolism was measured with PET.

RESULTS

Quantitative evaluation of PET findings for anosmic patients as a group showed orbitofrontal hypometabolism compared with controls. Decreased activity was also noted in mesial temporal lobe. Activity in subcortical white matter was essentially identical between groups.

CONCLUSIONS

Findings strongly suggest that posttraumatic anosmia is closely associated with hypometabolism in the orbitofrontal cortex and the medial prefrontal cortex. The results also underscore the importance of posttraumatic anosmia as a clinical sign of orbitofrontal damage, as has been shown previously with neuroSPECT (single photon emission computed tomography).

Transcriptional regulation of the ovine follicle-stimulating hormone-beta gene by activin and gonadotropin-releasing hormone (GnRH): involvement of two proximal activator protein-1 sites for GnRH stimulation

Previous studies from our laboratory demonstrated that a transgene consisting of the promoter for the ovine FSH beta-subunit gene and a luciferase reporter (wt-oFSHbetaLuc) was expressed and regulated like the FSHbeta gene in vivo and in vitro. In the present study pituitary cultures were prepared from these transgenic mice as well as mice carrying mutated oFSHbetaLuc lacking two functional activator protein-1 (AP-1) sites at -120 and -83 bp (mut-oFSHbetaLuc). These AP-1 sites were reported necessary for induction of oFSHbetaLuc by GnRH in a HeLa cell system. To examine the importance of the two AP-1 sites in mediating GnRH and activin effects in primary gonadotropes, pituitary cultures derived from transgenic mice were pretreated with follistatin to remove activin or activin-like factors present in the cultures. Follistatin lowered luciferase expression in cultures carrying both wt-oFSHbetaLuc and mut-oFSHbetaLuc transgenes by 74-86%, and subsequent addition of activin induced luciferase expression of both wt- and mut-transgenes by 4- to 14-fold within 4 h, suggesting that these AP-1 sites are not involved in activin stimulation of FSHbeta gene transcription. When GnRH was added along with activin, the wt-oFSHbetaLuc transgene was induced 200% compared with activin alone, but this effect was not observed with the mut-oFSHbetaLuc transgene. These data confirmed the HeLa cell studies showing that GnRH signals through two AP-1 sites to increase oFSHbeta transcription in gonadotropes. However, as the mutation of both AP-1 sites had no apparent effect on the expression and regulation of the transgene in vivo (basal, castration, GnRH down-regulation, cycle stage, and GnRH immunoneutralization), it appears that these AP-1 sites have little influence over the major effect of GnRH observed in vivo. These data also showed that activin plays a major role in transcriptional regulation of the FSHbeta gene, and the oFSHbeta promoter contains the activin response element(s) that is as yet undefined.

The promoter for the ovine follicle-stimulating hormone-beta gene (FSHbeta) confers FSHbeta-like expression on luciferase in transgenic mice: regulatory studies in vivo and in vitro

Transgenic mice harboring the ovine FSHbeta (oFSHbeta) promoter plus first intron (from -4741 to +759 bp) linked to a luciferase reporter gene (oFSHbetaLuc) were generated to determine whether this promoter can direct tissue-specific expression in vivo and serve as a model for studying hormonal regulation of the FSHbeta gene. Of six lines of transgenic mice analyzed, luciferase was detected uniquely in the pituitaries of five of them. Pituitary luciferase activity was decreased 51-99% by chronic GnRH treatment (Lupron depot). Orchidectomy caused a 2- to 8-fold increase, and ovariectomy caused a 2- to 27-fold increase in pituitary luciferase activity. Furthermore, pituitary luciferase expression was consistently higher on estrus than on diestrus (3- to 20-fold). These data strongly suggested that the transgene was expressed specifically in pituitary gonadotropes and regulated in the same way as the endogenous mouse FSHbeta gene. Using primary pituitary cell cultures prepared from these transgenic mice, basal luciferase expression was maximal on day 3 and then decreased by day 6 of culture, a pattern reflected by endogenous mouse FSH secretion. In these pituitary cultures, basal oFSHbetaLuc expression was decreased 61-82% by follistatin or 59-79% by inhibin. Similarly, mouse FSH secretion was decreased 71% by follistatin or 65% by inhibin. Progesterone inhibited oFSHbetaLuc expression by 44-51%, but it had no effect on endogenous mouse FSH secretion. Estradiol lowered FSH secretion by 21%, but did not decrease oFSHbetaLuc expression significantly. In conclusion, these data demonstrated the ability of the oFSHbeta promoter to direct expression of a reporter gene specifically to pituitary gonadotropes in transgenic mice. Studying oFSHbetaLuc expression in vivo and in cell cultures derived from pituitaries of these transgenic mice should prove useful for understanding many features of FSHbeta regulation.

A novel role for bone morphogenetic proteins in the synthesis of follicle-stimulating hormone

FSH is produced in pituitary gonadotropes as an alpha/beta heterodimer, and synthesis of the beta-subunit is the rate-limiting step in overall FSH production. Synthesis of FSHbeta can be regulated by activin and inhibin, both of which are members of the transforming growth factor-beta superfamily. Bone morphogenetic proteins (BMPs) also belong to the transforming growth factor-beta family and are multifunctional growth factors involved in many aspects of tissue development and morphogenesis, including regulation of FSH action in the ovary. Here we report a novel function for BMP-7 and BMP-6 in regulating FSH synthesis in the pituitary. Using primary pituitary cell cultures derived from transgenic mice that carry the ovine FSHbeta promoter linked to a luciferase reporter gene (oFSHbetaLuc), BMP-7 or BMP-6 was found to stimulate oFSHbetaLuc expression by 6-fold. Transient expression of the oFSHbetaLuc in a transformed gonadotrope cell line, LbetaT2, was induced 4-fold by BMP-7 or BMP-6 treatment. More importantly, BMP-7 and BMP-6 increased endogenous FSH secretion by 10- and 14-fold, respectively, from LbetaT2 cells, demonstrating for the first time that a functional signaling BMP system is present in gonadotropes. Two bioneutralizing antibodies to BMP-7, which cross-react with BMP-6, but not with activin A, decreased basal oFSHbetaLuc expression and FSH secretion from transgenic mouse pituitary cultures by 83-88% and 47-48%, respectively, suggesting an autocrine or paracrine role for BMP-7 or BMP-6 in FSH synthesis. Neither bioneutralizing antibody to activin A or activin B decreased basal oFSHbetaLuc expression or mouse FSH secretion significantly. Dose-dependent inhibition of FSH synthesis by anti-BMP7 was also observed in rat and sheep pituitary cultures. These results combined with the fact that the messenger RNAs for BMP-7 and BMP-6 were detected in mouse pituitaries and LbetaT2 cells indicate that BMP-7 and/or BMP-6 can function as FSH stimulators and may be significant physiological factors maintaining basal FSH expression in vivo.

Stimulation of hyaluronan synthesis by interleukin-1beta involves activation of protein kinase C betaII in fibroblasts from patients with Graves' ophthalmopathy

Hyaluronan accumulation in the retroorbital connective tissue is one of the pathological features of Graves' ophthalmopathy. Interleukin-1beta (IL-1beta) is known to stimulate hyaluronan synthesis in orbital fibroblasts. In the present study, the intracellular signal transduction pathways involved in this stimulatory effect were investigated in cultured human retroorbital fibroblasts from patients with Graves' ophthalmopathy. IL-1beta-induced hyaluronan synthesis was significantly inhibited by pretreatment of the cells with two protein kinase C (PKC) inhibitors, chlerythrine chloride and H-7. In addition, treatment with phorbol 12-myristate 13-acetate (PMA), a direct PKC activator, also resulted in increased hyaluronan production. IL-1beta- or PMA-stimulated hyaluronan synthesis was blocked by the protein synthesis inhibitor, cycloheximide. Moreover, the intracellular Ca(2+) concentration of the orbital fibroblasts was also involved in the IL-1beta induced transduction pathway, the effect being completely inhibited by BAPTA, an internal calcium chelator. In addition, A23187, a calcium ionophore, increased hyaluronan synthesis in unstimulated cells. These results suggest that the Ca(2+)-dependent PKC signal transduction pathway plays an important role in the IL-1beta-induced hyaluronan synthesis. Moreover, IL-1beta treatment resulted in increased PKC activity and the rapid translocation of PKC betaII from the cytoplasm to the plasma membrane. These results indicate that cytosolic Ca(2+) and PKC betaII are involved in IL-1beta-induced hyaluronan synthesis in cultured orbital fibroblasts from patients with Graves' ophthalmopathy.