[Effects of methacrylic anhydride gelatin hydrogel loaded with silver and recombinant human basic fibroblast growth factor on deep partial-thickness burn wounds in rabbits]

Objective: To investigate the effects of methacrylic anhydride gelatin (GelMA) hydrogel loaded with silver and recombinant human basic fibroblast growth factor (rh-bFGF) on deep partial-thickness burn wounds in rabbits. Methods: The experimental research method was adopted. Low-concentration GelMA materials, medium-concentration GelMA materials and high-concentration GelMA materials containing different concentrations of methacrylic anhydride (MA) were prepared, after adding photoinitiator, low-concentration GelMA hydrogels, medium-concentration GelMA hydrogels, and high-concentration GelMA hydrogels were obtained, respectively. The nuclear magnetic resonance spectroscopy was performed to detect the hydrogen nuclear magnetic resonance spectra of the above-mentioned three concentrations of GelMA materials, and to calculate the degree of substitution according to the spectrum diagram. The three-dimensional microstructure and pore size of 3 types of above-mentioned GelMA hydrogels were detected by field emission scanning electron microscopy (FESEM), with 9 samples measured. According to the selected concentration of MA, ten kinds of solutions of GelMA with different concentration of silver (silver-containing GelMA) were synthesized, and the silver-containing GelMA solution of each concentration was divided into three parts, and then exposed to ultraviolet light lasting for 20, 25, and 35 s, respectively. After adding photoinitiator,the corresponding silver-containing GelMA hydrogels were obtained. The residual degradation rate of silver-containing GelMA hydrogel with different photocrosslinking times was detected by collagenase degradation method at degradation of 12, 24, 36, and 48 h; and the time required for complete degradation was detected, and the sample number was 5. The inhibition zone diameter of GelMA hydrogel under above screened photocrosslinking times containing 10 concentrations of silver against Staphylococcus aureus was measured to reflect its antibacterial ability, and the sample numbers were all 5. The silver-containing GelMA hydrogel with statistical significance compared with the antibacterial circle diameter of the silver-containing GelMA hydrogel containing the lowest concentration (no silver) was considered as having antibacterial activity. The three-dimensional microstructure and pore size of the silver-containing GelMA hydrogels with antibacterial activity and the lowest drug concentration selected were detected by FESEM, and the sample numbers were all 9. The freeze-dried alone GelMA hydrogel and the freeze-dried silver-containing GelMA hydrogel were soaked in phosphate buffer solution for 24 h, respectively, then the swelling rate of the two GelMA hydrogel were calculated and compared by weighing method, and the sample number was 5. GelMA hydrogel containing silver and rh-bFGF, namely compound hydrogel for short, was prepared according to the preliminary experiment and the above experimental results. The appearance of the composite hydrogel was observed in general, and its three-dimensional microstructure and pore size were detected by FESEM. The deep partial-thickness burn wound was made on the back of 30 rabbits (aged 4-6 months, female half and half). Meanwhile, with the rabbit head as the benchmark, the wounds on the left side of the spine were treated as composite hydrogel treatment group, and the wounds on the right side were treated as gauze control group, and which were treated accordingly. On post injury day (PID) 3, 7, 14, 21, and 28, the healing of wounds in the two groups was observed. On PID 7, 14, 21, and 28, the wound healing area was recorded and the healing rate was calculated, with a sample number of 30. Data were statistically analyzed with analysis of variance for repeated measurement, one-way analysis of variance, and independent sample t test. Results: The substitution degree among low-concentration GelMA materials, medium-concentration GelMA materials, and high-concentration GelMA materials was significantly different (F=1 628.00, P<0.01). The low-concentration GelMA hydrogel had a loose and irregular three-dimensional spatial network structure with a pore size of (60±17) μm; the medium-concentration GelMA hydrogel had a relatively uniform three-dimensional spatial network and pore size with a pore size of (45±13) μm; the high-concentration GelMA hydrogel had the dense and disordered three-dimensional spatial network with a pore size of (25±15) μm, the pore sizes of 3 types of GelMA hydrogels were significantly differences (F=12.20, P<0.01), and medium concentration of MA was selected for the concentration of subsequent materials. The degradability of silver-containing GelMA hydrogels with different concentrations of the same photocrosslinking time was basically same. The degradation residual rates of silver-containing GelMA hydrogels with 20, 25, and 35 s crosslinking time at 12 h were (74.2±1.7)%, (85.3±0.9)%, and (93.2±1.2)%, respectively; the residual rates of degradation at 24 h were (58.3±2.1)%, (65.2±1.8)%, and (81.4±2.6)%, respectively; the residual rates of degradation at 36 h were (22.4±1.9)%, (45.2±1.7)%, and (68.1±1.4)%, respectively; the residual rates of degradation at 48 h were (8.2±1.7)%, (32.4±1.3)%, and (54.3±2.2)%, respectively, and 20, 25, and 30 s photocrosslinking time required for complete degradation of silver-containing GelMA hydrogels were (50.2±2.4), (62.4±1.4), and (72.2±3.2) h, and the difference was statistically significant (F=182.40, P<0.01), 25 s were selected as the subsequent photocrosslinking time. The antibacterial diameters of 10 types of silver-containing GelMA hydrogels against Staphylococcus aureus from low to high concentrations were (2.6±0.4), (2.5±0.4), (3.2±0.4), (12.1±0.7), (14.8±0.7), (15.1±0.5), (16.2±0.6), (16.7±0.5), (16.7±0.4), and (16.7±0.6) mm, respectively, and which basically showed a concentration-dependent increasing trend, and the overall difference was statistically significant (F=428.70, P<0.01). Compared with the silver-containing GelMA hydrogel with the lowest concentration, the antibacterial circle diameters of other silver-containing GelMA hydrogels with antibacterial ability from low to high concentration were significantly increased (with t values of 26.35, 33.84, 43.65, 42.17, 49.24, 55.74, and 43.72, respectively, P<0.01). The silver-containing GelMA hydrogel with the antibacterial diameter of (12.1±0.7) mm had the lowest antibacterial activity against Staphylococcus aureus and the lowest drug loading concentration, and the concentration of silver was selected for the concentration of subsequent materials. The microscopic morphology of the silver-containing GelMA hydrogel containing silver element with a pore size of (45±13) μm had a regular and linear strip-like structure. After soaking for 24 h, the swelling ratio of silver-containing GelMA hydrogel was similar to that of alone GelMA hydrogel. The composite hydrogel was colorless, clear and transparent, and its three-dimensional microstructure was a regular and uniform grid, with a filament network structure inside, and the pore size of (40±21) μm. On PID 3, a large amount of necrotic tissue and exudate of rabbit wound in composite hydrogel group were observed, and scattered scabs, a small amount of necrotic tissue and exudate of rabbit wound in gauze control group were observed. On PID 7, the area of rabbit wound in composite hydrogel group was significantly reduced, and adhesion of rabbit wound and gauze in gauze control group was observed. On PID 14, In composite hydrogel group, the rabbit wound surface was ruddy, and the growth of granulation tissue was observed, and in gauze control group, the rabbit wound base was pale, and the blood supply was poor. On PID 21, the rabbit wounds in composite hydrogel group healed completely, and rabbit wound in gauze control group had healing trend. On PID 28, new hair could be seen on rabbit wound surface in composite hydrogel group; oval wound of rabbit in gauze control group still remained. On PID 7, 14, 21, and 28, the wound healing areas of rabbit in composite hydrogel group were significantly larger than those in gauze control group (with t values of 2.24, 4.43, 7.67, and 7.69, respectively, P<0.05 or P<0.01). Conclusions: The medium-concentration GelMA hydrogel has good physical and chemical properties in terms of swelling and degradability. The screened silver-containing GelMA hydrogels had the lowest antibacterial activity and the lowest drug loading concentration. Composite hydrogel can significantly shorten the healing time of deep partial-thickness burn wounds in rabbits.

Therapeutic efficacy of humanized monoclonal antibodies targeting dengue virus nonstructural protein 1 in the mouse model

Dengue virus (DENV) which infects about 390 million people per year in tropical and subtropical areas manifests various disease symptoms, ranging from fever to life-threatening hemorrhage and even shock. To date, there is still no effective treatment for DENV disease, but only supportive care. DENV nonstructural protein 1 (NS1) has been shown to play a key role in disease pathogenesis. Recent studies have shown that anti-DENV NS1 antibody can provide disease protection by blocking the DENV-induced disruption of endothelial integrity. We previously demonstrated that anti-NS1 monoclonal antibody (mAb) protected mice from all four serotypes of DENV challenge. Here, we generated humanized anti-NS1 mAbs and transferred them to mice after DENV infection. The results showed that DENV-induced prolonged bleeding time and skin hemorrhage were reduced, even several days after DENV challenge. Mechanistic studies showed the ability of humanized anti-NS1 mAbs to inhibit NS1-induced vascular hyperpermeability and to elicit Fcγ-dependent complement-mediated cytolysis as well as antibody-dependent cellular cytotoxicity of cells infected with four serotypes of DENV. These results highlight humanized anti-NS1 mAb as a potential therapeutic agent in DENV infection.

DENV comprising four serotypes has a complicated pathogenesis and remains an unresolved global health problem. To date, supportive therapy is the mainstay for treatment of dengue patients. Despite a licensed Sanofi vaccine and ongoing clinical trials, more effective vaccines and/or licensed therapeutic drugs are required. Therapeutic mAbs are a potential tool to treat many epidemic diseases because of their high target specificity. Humanized anti-NS1 mAbs can recognize the NS1 from all four serotypes of DENV without danger of inducing ADE. In the DENV infection mouse model, we demonstrate that humanized NS1 mAbs have therapeutic benefits such as reducing DENV-induced prolonged bleeding time and skin hemorrhage. In vitro mechanistic studies showed a reduction of NS1-induced vascular permeability and an increase in cytolysis of DENV-infected cells. Our results showed that humanized anti-NS1 mAbs show strong potential for development toward clinical use.

A repeating fast radio burst source in a globular cluster

Fast radio bursts (FRBs) are flashes of unknown physical origin¹. The majority of FRBs have been seen only once, although some are known to generate multiple flashes^2,3. Many models invoke magnetically powered neutron stars (magnetars) as the source of the emission^4,5. Recently, the discovery⁶ of another repeater (FRB 20200120E) was announced, in the direction of the nearby galaxy M81, with four potential counterparts at other wavelengths⁶. Here we report observations that localized the FRB to a globular cluster associated with M81, where it is 2 parsecs away from the optical centre of the cluster. Globular clusters host old stellar populations, challenging FRB models that invoke young magnetars formed in a core-collapse supernova. We propose instead that FRB 20200120E originates from a highly magnetized neutron star formed either through the accretion-induced collapse of a white dwarf, or the merger of compact stars in a binary system⁷. Compact binaries are efficiently formed inside globular clusters, so a model invoking them could also be responsible for the observed bursts.

Effects of dietary supplementation with Taiwanese tea byproducts and probiotics on growth performance, lipid metabolism, and the immune response in red feather native chickens

Objective

This study compared the catechin composition of different tea byproducts and investigated the effects of dietary supplementation with green tea byproducts on the accumulation of abdominal fat, the modulation of lipid metabolism, and the inflammatory response in red feather native chickens.

Methods

Bioactive compounds were detected, and in vitro anti-obesity capacity analyzed via 3T3-L1 preadipocytes. In animal experiments, 320 one-day-old red feather native chickens were divided into 4 treatment groups: control, basal diet supplemented with 0.5% Jinxuan byproduct (JBP), basal diet supplemented with 1% JBP, or basal diet supplemented with 5×10⁶ colony-forming unit (CFU)/kg Bacillus amyloliquefaciens+5×10⁶ CFU/kg Saccharomyces cerevisiae (BA+SC). Growth performance, serum characteristics, carcass characteristics, and the mRNA expression of selected genes were measured.

Results

This study compared several cultivars of tea, but Jinxuan showed the highest levels of the anti-obesity compound epigallocatechin gallate. 3T3-L1 preadipocytes treated with Jinxuan extract significantly reduced lipid accumulation. There were no significant differences in growth performance, serum characteristics, or carcass characteristics among the groups. However, in the 0.5% JBP group, mRNA expression of fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) were significantly decreased. In the 1% JBP group, FAS, ACC and peroxisome proliferator-activated receptor γ levels were significantly decreased. Moreover, inflammation-related mRNA expression levels were decreased by the addition of JBP.

Conclusion

JBP contained abundant catechins and related bioactive compounds, which reduced lipid accumulation in 3T3-L1 preadipocytes, however there was no significant reduction in abdominal fat. This may be due to a lack of active anti-obesity compounds or because the major changes in fat metabolism were not in the abdomen. Nonetheless, lipogenesis-related and inflammation-related mRNA expression were reduced in the 1% JBP group. In addition, dietary supplementation with tea byproducts could reduce the massive amount of byproducts created during tea production and modulate lipid metabolism and the inflammatory response in chickens.

Identification of cis- and trans-acting factors regulating the expression of rat salivary-specific RP4 gene

The molecular basis of tissue-specific and cyclic AMP (cAMP)-inducible gene expression in salivary glands is not well understood. Previously, we cloned a salivary-specific proline-rich protein gene, RP4. To analyze the cis-regulatory element(s) that mediates the regulation of this rat salivary RP4 gene, chimeric pRP4CAT constructs containing up to 1.7 kb of the 5'-flanking region of RP4 fused to a reporter gene were transiently transfected into salivary cells. Deletion studies suggest that a 159 bp (-147/+12) fragment of the RP4 5'-flanking region is sufficient to confer salivary-specific induction by agents that can raise intracellular cAMP concentration. Further delineation of this essential sequence revealed that a segment from -136 to -109 is necessary and sufficient to confer cAMP responsiveness in a salivary-specific manner when linked to a heterologous promoter. However, this 28 bp fragment (-136/-109) does not contain an identical match to the consensus cAMP response element (CRE). DNA mobility shift binding assays establish that a sequence-specific DNA-protein complex is formed between this DNA fragment and nuclear proteins from salivary cells, but not with nuclear proteins from HeLa cells, which contain canonical CRE binding proteins (CREBs). Taken together, these data demonstrate that we have identified a 28 bp cis-regulatory element in the RP4 gene that mediates salivary-specific cAMP-inducible gene expression. We propose that the novel salivary-specific CRE binding protein (SCBP) is a key regulator for salivary cAMP-inducible gene expression.

A systematic review of prediction models for prevalent pulmonary tuberculosis in adults

A systematic review was conducted to describe the quality and characteristics of prediction models for prevalent pulmonary tuberculosis (PTB) in adults at routine TB care settings. A prediction model was defined as the combination of two or more clinical predictors designed to estimate the probability of having TB. Studies using culture-confirmed PTB as reference standard were included. Models for in-patients, children or specific patient populations were excluded. PubMed, Scopus and the Cochrane Library and abstracts from the International Union Against Tuberculosis and Lung Disease, American Thoracic Society and European Respiratory Society conferences were searched. The CHARMS (Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies) checklist was used for data extraction and quality assessment. From 13 671 identified records, six were included for data extraction; three assessed smear-negative, culture-positive PTB as outcome and three focused on human immunodeficiency virus infected individuals only. Reporting of model development, performance and evaluation was poor. In four studies, predictive performance was evaluated using the development data set (apparent performance), one study did an internal validation and one study did an external validation. Results were not pooled due to heterogeneity. Existing prediction models for estimating prevalent PTB in adults at primary care level are poorly reported and validated and are not useful for TB screening. The World Health Organization symptom screen is recommended.

[Postoperative analgesia effect of different background volumes of ropivacaine in continuous tibial nerve block in patients with calcaneal surgery]

OBJECTIVE

To observe the clinical effect of different background volumes of ropivacaine in continuous tibial nerve block of postoperative analgesia after calcaneal surgery.

METHODS

This study was a prospective, randomized, controlled study. Sixty cases of calcaneal visual analogue scale (ASA) I or II undergoing elective surgery were selected and randomly assigned to two groups, thirty cases in each group. The patients received popliteal fossa posterior tibial nerve block using ultrasound guided. The continuous stimulation catheter was inserted after successful position and the 0.2% ropivacaine was injected. The background volumes of the A and B groups were 5 mL/h and 3.2 mL/h. The VAS score, the sensory block and motor block of tibial nerve and common peroneal nerve, and the satisfaction of the patients at h 12, h 24 and h 48 were recorded after catheter insertion.

RESULTS

The VAS scores at the three time points (h 12, h 24 and h 48) on the two groups of the patients were compared, and the difference was not statistically significant (P > 0.05). The difference of the sensory block and the motor block of the tibial nerve at the three time points (h 12, h 24 and h 48) on the two groups of the patients were also compared, and the difference was not statistically significant (P> 0.05). The difference of the sensory block and the motor block of common peroneal nerve at h 48 hs was statistically significant, group A was higher than the group B (P< 0.05). The difference of the patient satisfaction at the three time points (h 12, h 24 and h 48) on the two groups was not statistically significant (P> 0.05).

CONCLUSION

The use of 0.2% ropivacaine with the background volume of 3.2 mL/h in continuous tibial nerve block can provide good analgesia and reduce the incidence of the sensory block and motor block of the common peroneal nerve.

Palliative enteral feeding for patients with malignant esophageal obstruction: a retrospective study

BACKGROUND

Malignant esophageal obstruction leads to dysphagia, deterioration in quality of life, and malnutrition. Traditional bedside nasogastric (NG) tube placement is very difficult under these circumstances. However, endoscopically assisted NG tube placement under fluoroscopic guidance could be an alternative option for establishing palliative enteral nutrition. This study aimed to compare the clinical outcomes of enteral tube feeding and esophageal stenting for patients with malignant esophageal obstruction and a short life expectancy.

METHODS

Thirty-one patients were divided into 3 groups according to their treatment modality: NG tube (n = 12), esophageal stent group (n = 10), and supportive care with nil per os (NPO) (n = 9). Enteral nutrition, clinical outcomes, length of hospital stay, and median survival were evaluated.

RESULTS

There were no significant baseline differences among the groups, except in age. The tube and stent groups had significantly higher enteral calorie intake (p = 0.01), higher serum albumin (p < 0.01), shorter hospital stay (p = 0.01), and longer median survival (p < 0.01) than the NPO group. The incidence of dislodgement in the tube group was significantly higher than in the stent group (58% vs. 20%, respectively; p = 0.01). However, stenting costs more than NG tube placement.

CONCLUSIONS

Palliative enteral feeding by NG tube is safe, inexpensive, and has a low complication rate. Endoscopically assisted NG tube placement under fluoroscopic guidance could be a feasible palliative option for malignant esophageal obstruction for patients who have a short life expectancy.

The Role of Autophagy in Salivary Gland Homeostasis and Stress Responses

Autophagy is a catabolic process that has been shown to have a role in many cellular processes including the removal of excessive or damaged proteins and protein aggregates. The salivary glands play a critical role in oral health, and their secretory capacity may be critically intertwined with the autophagic process. This review describes the role of autophagy activation in normal salivary gland homeostasis and during the glandular stress responses of therapeutic radiation, ductal ligation, autoimmunity, and salivary gland adenoid cystic carcinoma.

Primary carcinoid tumor of the ovary arising in a mature cystic teratoma: a case report

Primary ovarian carcinoid tumors are rare entities, they may appear with other teratomatous components, and can be often being mistaken as part of mature cystic teratomas. Consistent with their rarity and low incidence, imaging clues that could have led to suspicion of this tumor are not well-documented. Herein, the authors present a rare case of primary ovarian carcinoid tumor in a mature cystic teratoma, who initially presented with complaints of abdominal distension for months. Contrast-enhanced computerized tomography (CT) demonstrated a multilobular mass with different density components including fat, soft tissue, and calcification materials, as well as rich vascular supply from the right ovarian vein. Serum tumor markers were within normal limits. Bilateral salpingo-oophorectomy was performed and the pathological diagnosis was mature cystic teratoma with coexisting primary ovarian carcinoid tumor, insular type. The patient has remained well with no residual disease for over one year of follow-up.

Improvements on a patient-specific dose estimation system in nuclear medicine examination

The purpose of this paper is to develop a patient-specific dose estimation system in nuclear medicine examination. A dose deposition routine to store the deposited energy of the photons during their flights was embedded in the widely used SimSET Monte Carlo code and a user-friendly interface for reading PET and CT images was developed. Dose calculated on ORNL phantom was used to validate the accuracy of this system. The ratios of S value for (99m)Tc, (18)F and (131)I computed by this system to those obtained with OLINDA for various organs were ranged from 0.93 to 1.18, which were comparable to that obtained from MCNPX2.6 code (0.88-1.22). Our system developed provides opportunity for tumor dose estimation which cannot be known from the MIRD. The radiation dose can provide useful information in the amount of radioisotopes to be administered in radioimmunotherapy.

Interferon-based therapy reduces risk of stroke in chronic hepatitis C patients: a population-based cohort study in Taiwan

BACKGROUND

Hepatitis C virus (HCV) infection has been linked to an increased risk of insulin resistance and carotid atherosclerosis.

AIM

To investigate the association between HCV infection and stroke, and the effect of interferon-based therapy (IBT) on stroke risk in chronic hepatitis C (CHC) patients.

METHODS

We conducted a retrospective cohort study that followed up 3113 subjects with a newly detected HCV infection and 12 452 age- and gender-matched subjects without HCV infection selected from a random sample of 10(6) beneficiaries from the Taiwan National Health Insurance Program up to 5 years. Use of IBT was defined as treatment with interferon alpha, pegylated interferon alpha-2a or pegylated interferon alpha-2b for at least 3 months. The hazard ratio (HR) for newly detected stroke was calculated for subjects with HCV compared to those without HCV, and for IBT-treated HCV patients compared to non-IBT-treated HCV patients while adjusting for possible confounding factors.

RESULTS

The overall person-years of follow-up were 8624.11 in patients with HCV, 54,533.69 in patients without HCV, 666.65 in IBT-treated patients, and 7886.49 in nontreated patients. The multivariable-adjusted hazard ratio (HR) for newly detected stroke was 1.23 for subjects with HCV compared to the age- and sex-matched subjects without HCV (adjusted HR = 1.23, 95% CI = 1.06-1.42, P = 0.008). Moreover, use of IBT significantly reduced the risk of stroke in HCV patients (adjusted HR = 0.39, 95% CI = 0.16-0.95, P = 0.039) after adjusting for known prognostic factors.

CONCLUSIONS

Interferon-based therapy may reduce the long-term risk of stroke in patients with chronic HCV infection.

Deletion of ATG5 shows a role of autophagy in salivary homeostatic control

Autophagy is a catabolic pathway utilized to maintain a balance among the synthesis, degradation, and recycling of cellular components, thereby playing a role in cell growth, development, and homeostasis. Previous studies revealed that a conditional knockout of essential member(s) of autophagy in a variety of tissues causes changes in structure and function of these tissues. Acinar cell-specific expression of knocked-in Cre recombinase through control of aquaporin 5 (Aqp5) promoter/enhancer (Aqp5-Cre) allows us to specifically inactivate Atg5, a protein necessary for autophagy, in salivary acinar cells of Atg5(f/f);Aqp5-Cre mice. There was no difference in apoptotic or proliferation levels in salivary glands of Atg5/Cre mice from each genotype. However, H&E staining and electron microscopy studies revealed modestly enlarged acinar cells and accumulated secretory granules in salivary glands of Atg5(f/f);Aqp5-Cre mice. Salivary flow rates and amylase contents of Atg5/Cre mice indicated that acinar-specific inactivation of ATG5 did not alter carbachol-evoked saliva and amylase secretion. Conversely, autophagy intersected with salivary morphological and secretory manifestations induced by isoproterenol administration. These results identified a role for autophagy as a homeostasis control in salivary glands. Collectively, Atg5(f/f);Aqp5-Cre mice would be a useful tool to enhance our understanding of autophagy in adaptive responses following targeted head and neck radiation or Sjögren syndrome.

Role of monokine induced by interferon-γ in liver injury induced by hepatitis B virus in mice

The chemokine monokine induced by interferon-γ (Mig) is involved in the recruitment of inflammatory cells and liver injury during hepatitis B virus (HBV) infection. HBV protein X contributes to Mig expression in vitro by activation of nuclear factor (NF)-κB; however, the molecular mechanisms by which HBV induces Mig expression in vivo are unknown. In this paper, we established a mouse model for HBV study by tail vein injection of HBV genome-containing adenovirus vectors. Host immune response to the secreted hepatitis B surface antigen and e antigen was detected and serum alanine aminotransferase (ALT) was elevated at different time points. We also demonstrated that peripheral and intrahepatic Mig expression was increased after Ad-HBV infection. This was followed by inflammatory cell migration and formation of inflammatory foci in the liver. In addition, NF-κB p65 subunit translocated from the cytoplasm to the nucleus, and phosphoinositide 3-kinase/Akt, extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) were to some extent phosphorylated after HBV injection. Following tail vein injection of Mig siRNA/in vivo-jetPEI-Gal complex, Mig expression was partially suppressed, inflammatory cell migration was inhibited, serum level of ALT were reduced. In conclusion, through NF-κB activation, HBV induced Mig expression in vivo, which recruited peripheral inflammatory cells to the liver and resulted in liver damage. Phosphorylation of phosphoinositide 3-kinase/Akt, ERK and JNK but not p38 might involved in the molecular mechanisms underlying HBV induced Mig expression in vivo.

Increasing insulin resistance is associated with increased severity and prevalence of gastro-oesophageal reflux disease

BACKGROUND

The diagnosis of gastro-oesophageal reflux disease (GERD) is based on reflux symptoms. Although metabolic syndrome has been linked to erosive oesophagitis (EO), the impact of insulin resistance, the core of the metabolic syndrome, on reflux symptoms remains to be elucidated.

AIM

To assess the effects of insulin resistance on GERD, including both endoscopic findings and symptoms.

METHODS

A total of 743 sonographic noncirrhotic adult subjects, who underwent an upper gastrointestinal endoscopic examination, completed a gastro-oesophageal reflux questionnaire and had available fasting insulin data were included. Endoscopic findings were classified according to the Los Angeles classification. Homeostatic model assessment-insulin resistance (HOMA-IR) index was used to evaluate the status of insulin resistance. Univariate and multivariate approaches were used to evaluate the associations between insulin resistance and GERD.

RESULTS

Older age, male gender, smoking and alcohol consumption increased the prevalence of EO, but not GERD symptoms. A large waist circumference, high fasting blood glucose levels and high number of metabolic syndrome components were associated with increased prevalence of both EO and GERD symptoms, while high blood pressure was associated with increased prevalence of EO only. Moreover, higher scores in the gastro-oesophageal reflux questionnaire were associated with higher HOMA-IR index, and higher HOMA-IR index was associated with increased prevalence of EO (adjusted odds ratio 1.14, 95% CI 1.03-1.26, P = 0.012).

CONCLUSIONS

Our findings demonstrate clear associations between insulin resistance, metabolic syndrome and GERD. Whether reducing insulin resistance may improve GERD symptoms or EO deserves prospective study.

Inserting the tunneller during an outside-in transobturator tape procedure by syringe-needle guidance

The objective of this study was to determine the feasibility of a novel syringe-needle guidance technique (SNG), and its impact on the perioperative variables and outcomes of patients undergoing an outside-in transobturator tape procedure (TOT). Between November 2006 and May 2008, 48 consecutive women who underwent TOT with SNG were included. Another 25 women without SNG between March 2004 and October 2006 were included as a historical control. There were no significant differences in hospital stays and complication rates between the two groups. However, the operating time was shorter (mean 23.0 vs 28.3 min, p=0.008) in the SNG group than in the control group. The presence of the SNG technique was the sole predictor of the operating time (p=0.003). In conclusion, the SNG technique is a feasible method to provide help in inserting the tunneller of TOT through the transobturator foramen, and did not compromise the outcome.

Risk factors for extra-pulmonary tuberculosis compared to pulmonary tuberculosis

BACKGROUND

Tuberculosis (TB) continues to be a major global health problem. Extra-pulmonary TB (EPTB) manifests with protean symptoms, and establishing a diagnosis is more difficult than pulmonary TB (PTB).

SETTING

A university-affiliated hospital in southern Taiwan.

OBJECTIVE

To analyse the risk factors for EPTB compared with PTB.

DESIGN

This retrospective study compared patients with EPTB and PTB in southern Taiwan by analysing their demographic data and clinical underlying diseases. Risk factors for EPTB were further analysed.

RESULTS

A total of 766 TB patients were enrolled in this study, with 102 (13.3%) EPTB and 664 (86.7%) PTB cases. Of the 766 patients, 3% of PTB patients had EPTB, while 19.6% of EPTB patients also had PTB. The most frequently involved EPTB site was the bone and joints (24.5%). The incidence of EPTB vs. PTB decreased significantly for each decade increase in patient age. Multivariate logistic regression analysis showed that being female, not being diabetic, having end-stage renal disease and not smoking were independent risk factors for EPTB.

CONCLUSION

This study defines the risk factors for EPTB compared with PTB. Awareness of these factors is essential for physicians to have a high index of suspicion for accurate and timely diagnosis.

Prediction of antibiotic resistance proteins from sequence-derived properties irrespective of sequence similarity

Increasing antibiotic resistance has become a worldwide challenge to the clinical treatment of infectious diseases. The identification of antibiotic resistance proteins (ARPs) would be helpful in the discovery of new therapeutic targets and the design of novel drugs to control the potential spread of antibiotic resistance. In this work, a support vector machine (SVM)-based ARP prediction system was developed using 1308 ARPs and 15587 non-ARPs. Its performance was evaluated using 313 ARPs and 7156 non-ARPs. The computed prediction accuracy was 88.5% for ARPs and 99.2% for non-ARPs. A potential application of this method is the identification of ARPs non-homologous to proteins of known function. Further genome screening found that ca. 3.5% and 3.2% of proteins in Escherichia coli and Staphylococcus aureus, respectively, are potential ARPs. These results suggest the usefulness of SVMs for facilitating the identification of ARPs. The software can be accessed at SARPI (Server for Antibiotic Resistance Protein Identification).

Homology-free prediction of functional class of proteins and peptides by support vector machines

Protein and peptide sequences contain clues for functional prediction. A challenge is to predict sequences that show low or no homology to proteins or peptides of known function. A machine learning method, support vector machines (SVM), has recently been explored for predicting functional class of proteins and peptides from sequence-derived properties irrespective of sequence similarity, which has shown impressive performance for predicting a wide range of protein and peptide classes including certain low- and non- homologous sequences. This method serves as a new and valuable addition to complement the extensively-used alignment-based, clustering-based, and structure-based functional prediction methods. This article evaluates the strategies, current progresses, reported prediction performances, available software tools, and underlying difficulties in using SVM for predicting the functional class of proteins and peptides.

A support vector machines approach for virtual screening of active compounds of single and multiple mechanisms from large libraries at an improved hit-rate and enrichment factor

Support vector machines (SVM) and other machine-learning (ML) methods have been explored as ligand-based virtual screening (VS) tools for facilitating lead discovery. While exhibiting good hit selection performance, in screening large compound libraries, these methods tend to produce lower hit-rate than those of the best performing VS tools, partly because their training-sets contain limited spectrum of inactive compounds. We tested whether the performance of SVM can be improved by using training-sets of diverse inactive compounds. In retrospective database screening of active compounds of single mechanism (HIV protease inhibitors, DHFR inhibitors, dopamine antagonists) and multiple mechanisms (CNS active agents) from large libraries of 2.986 million compounds, the yields, hit-rates, and enrichment factors of our SVM models are 52.4-78.0%, 4.7-73.8%, and 214-10,543, respectively, compared to those of 62-95%, 0.65-35%, and 20-1200 by structure-based VS and 55-81%, 0.2-0.7%, and 110-795 by other ligand-based VS tools in screening libraries of >or=1 million compounds. The hit-rates are comparable and the enrichment factors are substantially better than the best results of other VS tools. 24.3-87.6% of the predicted hits are outside the known hit families. SVM appears to be potentially useful for facilitating lead discovery in VS of large compound libraries.

Machine learning approaches for predicting compounds that interact with therapeutic and ADMET related proteins

Computational methods for predicting compounds of specific pharmacodynamic and ADMET (absorption, distribution, metabolism, excretion and toxicity) property are useful for facilitating drug discovery and evaluation. Recently, machine learning methods such as neural networks and support vector machines have been explored for predicting inhibitors, antagonists, blockers, agonists, activators and substrates of proteins related to specific therapeutic and ADMET property. These methods are particularly useful for compounds of diverse structures to complement QSAR methods, and for cases of unavailable receptor 3D structure to complement structure-based methods. A number of studies have demonstrated the potential of these methods for predicting such compounds as substrates of P-glycoprotein and cytochrome P450 CYP isoenzymes, inhibitors of protein kinases and CYP isoenzymes, and agonists of serotonin receptor and estrogen receptor. This article is intended to review the strategies, current progresses and underlying difficulties in using machine learning methods for predicting these protein binders and as potential virtual screening tools. Algorithms for proper representation of the structural and physicochemical properties of compounds are also evaluated.

Prediction of factor Xa inhibitors by machine learning methods

Factor Xa (FXa) inhibitors have been explored as anticoagulants for treatment and prevention of thrombotic diseases. Molecular docking, pharmacophore, quantitative structure-activity relationships, and support vector machines (SVM) have been used for computer prediction of FXa inhibitors. These methods achieve promising prediction accuracies of 69-80% for FXa inhibitors and 85-99% for non-inhibitors. Prediction performance, particularly for inhibitors, may be further improved by exploring methods applicable to more diverse range of compounds and by using more appropriate set of molecular descriptors. We tested the capability of several machine learning methods (C4.5 decision tree, k-nearest neighbor, probabilistic neural network, and support vector machine) by using a much more diverse set of 1098 compounds (360 inhibitors and 738 non-inhibitors) than those in other studies. A feature selection method was used for selecting molecular descriptors appropriate for distinguishing FXa inhibitors and non-inhibitors. The prediction accuracies of these methods are 89.1-97.5% for FXa inhibitors and 92.3-98.1% for non-inhibitors. In particular, compared to other studies, support vector machine gives a substantially improved accuracy of 94.6% for FXa non-inhibitors and maintains a comparable accuracy of 98.1% for inhibitors, based-on a more rigorous test with more diverse range of compounds. Our study suggests that machine learning methods such as SVM are useful for facilitating the prediction of FXa inhibitors.

The effect of activation treatments on the development of reconstructed bovine oocytes

The purpose of this study was to investigate the effect of different activation treatments on the development of IVM-derived and cloned bovine embryos. The effect of oocyte age (20h versus 24h after IVM) on the blastocyst rate was also investigated. No differences in the percentage of blastocyst development were observed between the oocytes matured for 20 and 24h (15% versus 27%, p>0.05). Reconstructed oocytes activated 4h after fusion (fusion before activation, FBA) had a higher blastocyst rate than those oocytes activated immediately after electrofusion (fusion and activation simultaneously, FAS) (26% versus 5%, p<0.01). Blastocyst rates were significantly greater (p<0.01) for the reconstructed oocytes activated by calcium ionophore (A23187) combined with 6-dimethylaminopurine (6-DMAP) (51.6%) than for those activated with cycloheximide (CHX) plus cytochalasin B (CB) treatment (1h, 8.2%; 5h, 14.3%). However, the blastocyst rates were similar among reconstructed oocytes activated by electric pulses and A23187 (30.5% versus 42.2%) or by A23187 and ionomycin (36.7% versus 33.3%) combined with 6-DMAP, respectively. Blastocysts that developed from reconstructed oocytes activated by A23187 and 6-DMAP resulted in three pregnancies (3/9) and one live birth from 18 embryos transferred to recipient cows. Genotypic analysis of six bovine microsatellite markers by polymerase chain reaction confirmed that the cloned calf was genetically identical to the nuclear donor. In conclusion, reconstructed oocytes that derived from oocytes exposed to activation treatment 4h after electrofusion are more likely to develop to the blastocyst stage. The best treatment to activate reconstructed bovine oocytes in this study was A23187 combined with 6-DMAP.

Prediction of the functional class of metal-binding proteins from sequence derived physicochemical properties by support vector machine approach

Metal-binding proteins play important roles in structural stability, signaling, regulation, transport, immune response, metabolism control, and metal homeostasis. Because of their functional and sequence diversity, it is desirable to explore additional methods for predicting metal-binding proteins irrespective of sequence similarity. This work explores support vector machines (SVM) as such a method. SVM prediction systems were developed by using 53,333 metal-binding and 147,347 non-metal-binding proteins, and evaluated by an independent set of 31,448 metal-binding and 79,051 non-metal-binding proteins. The computed prediction accuracy is 86.3%, 81.6%, 83.5%, 94.0%, 81.2%, 85.4%, 77.6%, 90.4%, 90.9%, 74.9% and 78.1% for calcium-binding, cobalt-binding, copper-binding, iron-binding, magnesium-binding, manganese-binding, nickel-binding, potassium-binding, sodium-binding, zinc-binding, and all metal-binding proteins respectively. The accuracy for the non-member proteins of each class is 88.2%, 99.9%, 98.1%, 91.4%, 87.9%, 94.5%, 99.2%, 99.9%, 99.9%, 98.0%, and 88.0% respectively. Comparable accuracies were obtained by using a different SVM kernel function. Our method predicts 67% of the 87 metal-binding proteins non-homologous to any protein in the Swissprot database and 85.3% of the 333 proteins of known metal-binding domains as metal-binding. These suggest the usefulness of SVM for facilitating the prediction of metal-binding proteins. Our software can be accessed at the SVMProt server http://jing.cz3.nus.edu.sg/cgi-bin/svmprot.cgi.

Modulation spectroscopy study of the effects of growth interruptions on the interfaces of GaAsSb/GaAs multiple quantum wells

The effects of growth interruption times combined with Sb exposure of GaAsSb/GaAs multiple quantum wells (MQWs) have been investigated by using phototransmittance (PT), contactless electroreflectance (CER) and wavelength modulated surface photovoltage spectroscopy (WMSPS). The features originated from different portions of the samples, including interband transitions of MQWs, interfaces and GaAs, are observed and identified through a detailed comparison of the obtained spectra and theoretical calculation. A red-shift of the interband transitions and a broader lineshape of the fundamental transition are observed from samples grown under Sb exposure compared to the reference sample grown without interruption. The results can be interpreted in terms of both increases in Sb content and mixing of Sb in the GaAs interface layers. An additional feature has been observed below the GaAs region in the samples with Sb treatment. The probable origin of this additional feature is discussed.

Prediction of MHC-binding peptides of flexible lengths from sequence-derived structural and physicochemical properties

Peptide binding to MHC is critical for antigen recognition by T-cells. To facilitate vaccine design, computational methods have been developed for predicting MHC-binding peptides, which achieve impressive prediction accuracies of 70-90% for binders and 40-80% for non-binders. These methods have been developed for peptides of fixed lengths, for a limited number of alleles, trained from small number of non-binders, and in some cases based straightforwardly on sequence. These limit prediction coverage and accuracy particularly for non-binders. It is desirable to explore methods that predict binders of flexible lengths from sequence-derived physicochemical properties and trained from diverse sets of non-binders. This work explores support vector machines (SVM) as such a method for developing prediction systems of 18 MHC class I and 12 class II alleles by using 4208-3252 binders and 234,333-168,793 non-binders, and evaluated by an independent set of 545-476 binders and 110,564-84,430 non-binders. Binder accuracies are 86-99% for 25 and 70-80% for 5 alleles, non-binder accuracies are 96-99% for 30 alleles. Binder accuracies are comparable and non-binder accuracies substantially improved against other results. Our method correctly predicts 73.3% of the 15 newly-published epitopes in the last 4 months of 2005. Of the 251 recently-published HLA-A*0201 non-epitopes predicted as binders by other methods, 63 are predicted as binders by our method. Screening of HIV-1 genome shows that, compared to other methods, a comparable percentage (75-100%) of its known epitopes is correctly predicted, while a lower percentage (0.01-5% for 24 and 5-8% for 6 alleles) of its constituent peptides are predicted as binders. Our software can be accessed at .

The effect of electrical field strength on activation and development of cloned caprine embryos

The activation procedure used in nuclear transfer (NT) is one of the critical factors affecting the efficiency of animal cloning. The purpose of this study was to compare the effect of two electrical field strengths (EFS) for activation on the developmental competence of caprine NT embryos reconstructed from ear skin fibroblasts of adult Alpine does. The NT embryos were obtained by transfer of the quiescent fibroblasts at the fourth passage into the enucleated metaphase II (M II) oocytes. Four to five hours after electrical fusion, the NT-embryos were activated by EFS either at 1.67 or at 2.33 kV/cm and immediately incubated in 6-DMAP (2 mM) for 4 h. The cleavage rate of the NT-embryos activated with 2.33 kV/cm was greater than that activated with 1.67 kV/cm after in vitro culture for 18 h (65.6% versus 19.6%, p < 0.001). No pregnancy was found in 14 recipient does after transferring 51 NT embryos at 1-2 cell stages activated with 1.67 kV/cm. In contrast, two of the seven recipients were pregnant and gave birth to three kids after transferring 61 NT embryos at 1-2 cell stages activated by 2.33 kV/cm. The birth weights of three cloned kids were within the normal range of Alpine goats. However, one kid died 1h after birth while the remaining two are still healthy. DNA analysis by polymerase chain reaction (single-strand conformation polymorphism, SSCP) confirmed that the three kids were genetically identical to the nuclear donor.

Prediction of the functional class of lipid binding proteins from sequence-derived properties irrespective of sequence similarity

Lipid binding proteins play important roles in signaling, regulation, membrane trafficking, immune response, lipid metabolism, and transport. Because of their functional and sequence diversity, it is desirable to explore additional methods for predicting lipid binding proteins irrespective of sequence similarity. This work explores the use of support vector machines (SVMs) as such a method. SVM prediction systems are developed using 14,776 lipid binding and 133,441 nonlipid binding proteins and are evaluated by an independent set of 6,768 lipid binding and 64,761 nonlipid binding proteins. The computed prediction accuracy is 78.9, 79.5, 82.2, 79.5, 84.4, 76.6, 90.6, 79.0, and 89.9% for lipid degradation, lipid metabolism, lipid synthesis, lipid transport, lipid binding, lipopolysaccharide biosynthesis, lipoprotein, lipoyl, and all lipid binding proteins, respectively. The accuracy for the nonmember proteins of each class is 99.9, 99.2, 99.6, 99.8, 99.9, 99.8, 98.5, 99.9, and 97.0%, respectively. Comparable accuracies are obtained when homologous proteins are considered as one, or by using a different SVM kernel function. Our method predicts 86.8% of the 76 lipid binding proteins nonhomologous to any protein in the Swiss-Prot database and 89.0% of the 73 known lipid binding domains as lipid binding. These findings suggest the usefulness of SVMs for facilitating the prediction of lipid binding proteins. Our software can be accessed at the SVMProt server (http://jing.cz3.nus.edu.sg/cgi-bin/svmprot.cgi).

PEARLS: Program for Energetic Analysis of Receptor−Ligand System

Analysis of the energetics of small molecule ligand-protein, ligand-nucleic acid, and protein-nucleic acid interactions facilitates the quantitative understanding of molecular interactions that regulate the function and conformation of proteins. It has also been extensively used for ranking potential new ligands in virtual drug screening. We developed a Web-based software, PEARLS (Program for Energetic Analysis of Ligand-Receptor Systems), for computing interaction energies of ligand-protein, ligand-nucleic acid, protein-nucleic acid, and ligand-protein-nucleic acid complexes from their 3D structures. AMBER molecular force field, Morse potential, and empirical energy functions are used to compute the van der Waals, electrostatic, hydrogen bond, metal-ligand bonding, and water-mediated hydrogen bond energies between the binding molecules. The change in the solvation free energy of molecular binding is estimated by using an empirical solvation free energy model. Contribution from ligand conformational entropy change is also estimated by a simple model. The computed free energy for a number of PDB ligand-receptor complexes were studied and compared to experimental binding affinity. A substantial degree of correlation between the computed free energy and experimental binding affinity was found, which suggests that PEARLS may be useful in facilitating energetic analysis of ligand-protein, ligand-nucleic acid, and protein-nucleic acid interactions. PEARLS can be accessed at http://ang.cz3.nus.edu.sg/cgi-bin/prog/rune.pl.

Prediction of transporter family from protein sequence by support vector machine approach

Transporters play key roles in cellular transport and metabolic processes, and in facilitating drug delivery and excretion. These proteins are classified into families based on the transporter classification (TC) system. Determination of the TC family of transporters facilitates the study of their cellular and pharmacological functions. Methods for predicting TC family without sequence alignments or clustering are particularly useful for studying novel transporters whose function cannot be determined by sequence similarity. This work explores the use of a machine learning method, support vector machines (SVMs), for predicting the family of transporters from their sequence without the use of sequence similarity. A total of 10,636 transporters in 13 TC subclasses, 1914 transporters in eight TC families, and 168,341 nontransporter proteins are used to train and test the SVM prediction system. Testing results by using a separate set of 4351 transporters and 83,151 nontransporter proteins show that the overall accuracy for predicting members of these TC subclasses and families is 83.4% and 88.0%, respectively, and that of nonmembers is 99.3% and 96.6%, respectively. The accuracies for predicting members and nonmembers of individual TC subclasses are in the range of 70.7-96.1% and 97.6-99.9%, respectively, and those of individual TC families are in the range of 60.6-97.1% and 91.5-99.4%, respectively. A further test by using 26,139 transmembrane proteins outside each of the 13 TC subclasses shows that 90.4-99.6% of these are correctly predicted. Our study suggests that the SVM is potentially useful for facilitating functional study of transporters irrespective of sequence similarity.

Prediction of functional class of novel plant proteins by a statistical learning method

In plant genomes, the function of a substantial percentage of the putative protein-coding open reading frames (ORFs) is unknown. These ORFs have no significant sequence similarity to known proteins, which complicates the task of functional study of these proteins. Efforts are being made to explore methods that are complementary to, or may be used in combination with, sequence alignment and clustering methods. A web-based protein functional class prediction software, SVMProt, has shown some capability for predicting functional class of distantly related proteins. Here the usefulness of SVMProt for functional study of novel plant proteins is evaluated. To test SVMProt, 49 plant proteins (without a sequence homolog in the Swiss-Prot protein database, not in the SVMProt training set, and with functional indications provided in the literature) were selected from a comprehensive search of MEDLINE abstracts and Swiss-Prot databases in 1999-2004. These represent unique proteins the function of which, at present, cannot be confidently predicted by sequence alignment and clustering methods. The predicted functional class of 31 proteins was consistent, and that of four other proteins was weakly consistent, with published functions. Overall, the functional class of 71.4% of these proteins was consistent, or weakly consistent, with functional indications described in the literature. SVMProt shows a certain level of ability to provide useful hints about the functions of novel plant proteins with no similarity to known proteins.

Comparison of the severity of illness scoring systems for critically ill cirrhotic patients with renal failure

BACKGROUND

Mortality rates of cirrhotic patients with renal failure admitted to the medical intensive care unit (ICU) are high. End-stage liver disease is frequently complicated by disturbances of renal function. This investigation is aimed to compare the predicting ability of acute physiology, age, chronic health evaluation II and III (APACHE II and III), sequential organ failure assessment (SOFA), and Child-Pugh scoring systems, obtained on the first day of ICU admission, for hospital mortality in critically ill cirrhotic patients with renal failure.

METHODS

Sixty-seven patients with liver cirrhosis and renal failure were admitted to ICU from April 2001-March 2002. Information considered necessary for computing the Child-Pugh, SOFA, APACHE II and APACHE III score on the first day of ICU admission was prospectively collected.

RESULTS

The overall hospital mortality rate was 86.6%. Liver disease was most commonly attributed to hepatitis B viral infection. The development of renal failure was associated with a history of gastrointestinal bleeding. Goodness-of-fit was good for SOFA, APACHE II and APACHE III scores. The APACHE III and SOFA models reported good areas under receiver operating characteristic curve (0.878 +/- 0.050 and 0.868 +/- 0.051, respectively).

CONCLUSION

Renal failure is common in critically ill patients with cirrhosis. The prognosis for cirrhotic patients with renal failure is poor. APACHE III and SOFA showed excellent discrimination power in this group of patients. They are superior to APACHE II and Child-Pugh scores in this homogenous group of patients.

Dyspeptic symptoms and water load test in patients with functional dyspepsia and reflux disease

OBJECTIVE

Hypersensitivity to gastric distension has been reported in functional dyspepsia (FD). The aim of this study was to assess the perception to gastric distension and its relationship to specific symptoms using the water load test (WLT) in FD and gastroesophageal reflux disease (GERD).

MATERIAL AND METHODS

A 5-min WLT was used to evaluate sensitivity of gastric distension in 47 FD and 61 GERD subjects, and 49 healthy controls (HC). A visual analogue scale (VAS) measuring symptom severity was obtained from all subjects and its relationship with the maximal ingested volume was determined. The maximal ingested volume was registered and the subjective symptoms were assessed at baseline and 30 min after the WLT.

RESULTS

The maximal ingested volume by HC was 597 +/- 33 ml, which was statistically greater than that of FD (422 +/- 22 ml, p < 0.001) and GERD (504 +/- 23 ml, p < 0.02) subjects. The maximal ingested volume did not differ significantly between FD and GERD. The maximal ingested volume correlated well with nausea (r = -0.49, p < 0.01) and fullness (r = -0.33, p < 0.05) in FD. Male subjects ingested more water than females in the HC (p < 0.01) and GERD groups (p < 0.05), but not in FD (p = NS).

CONCLUSIONS

Both FD and GERD subjects have altered perception to gastric fullness induced by the WLT compared to healthy controls. Good correlations have been observed between the WLT and dyspeptic symptoms such as early satiety and postprandial fullness, but not in GERD.

MoViES: molecular vibrations evaluation server for analysis of fluctuational dynamics of proteins and nucleic acids

Analysis of vibrational motions and thermal fluctuational dynamics is a widely used approach for studying structural, dynamic and functional properties of proteins and nucleic acids. Development of a freely accessible web server for computation of vibrational and thermal fluctuational dynamics of biomolecules is thus useful for facilitating the relevant studies. We have developed a computer program for computing vibrational normal modes and thermal fluctuational properties of proteins and nucleic acids and applied it in several studies. In our program, vibrational normal modes are computed by using modified AMBER molecular mechanics force fields, and thermal fluctuational properties are computed by means of a self-consistent harmonic approximation method. A web version of our program, MoViES (Molecular Vibrations Evaluation Server), was set up to facilitate the use of our program to study vibrational dynamics of proteins and nucleic acids. This software was tested on selected proteins, which show that the computed normal modes and thermal fluctuational bond disruption probabilities are consistent with experimental findings and other normal mode computations. MoViES can be accessed at http://ang.cz3.nus.edu.sg/cgi-bin/prog/norm.pl.

Transfer function analysis of heart rate variability in response to water intake: correlation with gastric myoelectrical activity

We utilized transfer function analysis of heart rate variability (HRV) and respiration to investigate the effect of water intake on gastric myoelectrical activity and its relationship to vagal activity. The electrogastrography (EGG) and HRV were recorded simultaneously before and after drinking 500 ml of water in 10 healthy subjects. We observed good linearity between lung volumes and HRV signals at a ventilatory rate between 0.2 and 0.4 Hz before and after water intake. The EGG power of 3 cycles/min increased remarkably after the water intake. We found that there was a significant increase in the magnitude of the respiration-HRV transfer function after water intake (P < 0.05). The EGG 3 cycles/min power was positively correlated with the transfer magnitude throughout the study (r = 0.54, P = 0.01). These results confirm that transfer function analysis of HRV sensitively identifies subtle changes in the respiratory sinus arrhythmia that occurs with water intake. The present findings suggest that transfer function analysis of HRV and respiration after water intake can be used to evaluate vagal nervous activity in the human gut.

Randomization of heavily damaged regions in annealed low energy Ge+-implanted (0 0 1)Si

Apparent growth of amorphous layers during low temperature annealing was observed in low energy Ge(+)-implanted (001)Si by high-resolution transmission electron microscopy. The occurrence of abnormal growth is due to the randomization of heavily damaged regions beneath the original amorphous/crystalline interfaces. The randomization process is attributed to the strain, incurred by the presence of a high density of large Ge atoms in the heavily damaged Si substrate, relaxation to lower the free energy of the systems. The randomization upon annealing may be fruitfully applied to minimize the transient enhanced diffusion in shallow junction formation.

Hydrogen peroxide increases the activity of rat sympathetic preganglionic neurons in vivo and in vitro

Reactive oxygen species (ROS) have been shown to modulate neuronal synaptic transmission and have also been implicated in cardiovascular diseases such as hypertension. The hypothesis that H(2)O(2) acting on sympathetic preganglionic neurons (SPNs) affects spinal sympathetic outflow was tested in the present study. H(2)O(2) was applied intrathecally via an implanted cannula to the T7-T9 segments of urethane-anesthetized rats. Blood pressure and heart rate were used as indices to evaluate the spinal sympathetic effects of H(2)O(2) in vivo. Intrathecal H(2)O(2) (100-1000 nmol) dose-dependently increased both the mean arterial pressure and heart rate. Reproducible pressor effects of H(2)O(2) (1000 nmol) applied consecutively at intervals of 30 min were observed. The pressor effects of intrathecal H(2)O(2) (1000 nmol) were attenuated by pretreatment with intrathecal administration of catalase (500 units), or N-acetyl-cysteine (1000 nmol). The pressor effects of intrathecal H(2)O(2) (1000 nmol) were also antagonized dose-dependently by prior intrathecal injection of AP-5 (DL-2-amino-5- phosphonovaleric acid, 10 and 30 nmol), or 6-cyano-7- nitroquinoxaline-2,3-dione, 10 and 30 nmol. In vitro electrophysiological study in spinal cord slices showed that superfusion of 1 mM H(2)O(2) for 3 min, which had no effect on membrane potential, caused an increase in amplitude of excitatory postsynaptic potentials in SPNs, but had little effect on that of inhibitory postsynaptic potentials. Taken together, these results demonstrated that oxidative stress in spinal cord may cause an increase in spinal sympathetic tone by acting on SPNs, which may contribute to ROS-induced cardiovascular dysfunction.

Structural evolution in amorphous silicon and germanium thin films

The structural evolution in amorphous silicon and germanium thin films has been investigated by high-resolution transmission electron microscopy (HRTEM) in conjunction with autocorrelation function (ACF) analysis. The results established that the structure of as-deposited semiconductor films is of a high density of nanocrystallites embedded in the amorphous matrix. In addition, from ACF analysis, the structure of a-Ge is more ordered than that of a-Si. The density of embedded nanocrystallites in amorphous films was found to diminish with annealing temperature first, then to increase. The conclusions also corroborate well with the results of diminished medium-range order in annealed amorphous films determined previously by a variable coherence microscopy method.

Sympathoinhibitory action of nociceptin in the rat spinal cord

1. Whole-cell patch recordings were made from antidromically identified sympathetic preganglionic neurons (SPN) of immature rat spinal cord slices. Bath application of nociceptin (0.1-1 micromol/L) suppressed excitatory postsynaptic potentials (EPSP) and hyperpolarized a population of SPN; these effects were naloxone (1 micromol/L) insensitive. 2. Nociceptin suppressed the amplitude of EPSP without causing a concomitant change in glutamate-induced depolarizations, suggesting a presynaptic inhibitory action. 3. Analysis of current-voltage relationships showed that nociceptin hyperpolarized SPN by increasing an inwardly rectifying K+ current. 4. Intrathecal injection of nociceptin (3, 10 and 30 nmol) to urethane-anaesthetized rats dose-dependently reduced the mean arterial pressure and heart rate; these effects were not prevented by prior intravenous injection of naloxone (1 mg/kg). 5. Results from our in vitro and in vivo experiments suggest that nociceptin suppresses spinal sympathetic outflow either by attenuating excitatory synaptic responses or hyperpolarizing SPN.

Pneumocystis carinii pneumonia in systemic lupus erythematosus: a report of two cases

Patients with systemic lupus erythematosus (SLE) have increased susceptibility to infection by Pneumocystis carinii, but this condition has rarely been reported in Taiwan. Here, we describe two cases of patients with SLE who developed Pneumocystis carinii pneumonia (PCP). The first patient was a 39-year-old woman presenting with fever and dyspnea that had lasted 2 weeks. Chest roentgenography disclosed bilateral interstitial and alveolar infiltrates. The second patient was a 22-year-old woman presenting with a 4-day history of malaise, cough, dyspnea, and fever. She had concomitant Mycobacterium tuberculosis infection. Both patients had been treated with varying doses of corticosteroids and/or cytotoxic drugs within 4 months before presentation. Diagnosis was established based on the findings of bronchoalveolar lavage (BAL) and transbronchial lung biopsy (TBLB). Both patients received trimethoprim-sulfamethoxazole (20 mg.kg-1.d-1 trimethoprim), but finally died of nosocomial septicemia (Acinetobacter baumanni and Pseudomonas aeruginosa bacteremia in one, P. aeruginosa bacteremia in the other). These two cases demonstrate that PCP should be included in the differential diagnosis of patients with SLE presenting with pneumonic processes. In addition, a second opportunistic pathogen should be suspected. Bronchoscopic examination should be performed if the diagnosis is not clear and should include TBLB and BAL.