Design, synthesis, and evaluation of formylpiperazine analogs of Ferrostatin-1 as novel improved ferroptosis inhibitors

In this study, a series of new formylpiperazine-derived ferroptosis inhibitors were designed and synthesized based on the structure of a known ferroptosis inhibitor, ferrostatin-1 (Fer-1). The anti-ferroptosis activity of these synthetic compounds in human umbilical vein endothelial cells (HUVECs) induced by Erastin was evaluated. It was found that some of the new compounds, especially compound 26, showed potent anti-ferroptosis activity, as evidenced by its ability to restore cell viability, reduce iron accumulation, scavenge reactive oxygen species, maintain mitochondrial membrane potential, increase GSH levels, decrease LPO and MDA content, and upregulate GPX4 expression. Moreover, compound 26 exhibited superior microsomal stability than Fer-1. The present results suggest that compound 26 is a promising lead compound for the development of new ferroptosis inhibitors for the treatment of vascular diseases.

Design, synthesis, and evaluation of novel ferrostatin derivatives for the prevention of HG-induced VEC ferroptosis

Ferroptosis is a nonapoptotic, iron-catalyzed form of regulated cell death. It has been shown that high glucose (HG) could induce ferroptosis in vascular endothelial cells (VECs), consequently contributing to the development of various diseases. This study synthesized and evaluated a series of novel ferrostatin-1 (Fer-1) derivatives fused with a benzohydrazide moiety to prevent HG-induced VEC ferroptosis. Several promising compounds showed similar or improved inhibitory effects compared to positive control Fer-1. The most effective candidate 12 exhibited better protection against erastin-induced ferroptosis and high glucose-induced ferroptosis in VECs. Mechanistic studies revealed that compound 12 prevented mitochondrial damage, reduced intracellular ROS accumulation, upregulated the expression of GPX4, and decreased the amounts of ferrous ion, LPO and MDA in VECs. However, compound 12 still exhibited undesirable microsomal stability like Fer-1, suggesting the need for further optimization. Overall, the present findings highlight ferroptosis inhibitor 12 as a potential lead compound for treating ferroptosis-associated vascular diseases.

Synthesis and biological evaluation of 1-phenyl-tetrahydro-β-carboline-based first dual PRMT5/EGFR inhibitors as potential anticancer agents

Protein arginine methyltransferase 5 (PRMT5) and epidermal growth factor receptor (EGFR) are both involved in the regulation of various cancer-related processes, and their dysregulation or overexpression has been observed in many types of tumors. In this study, we designed and synthesized a series of 1-phenyl-tetrahydro-β-carboline (THβC) derivatives as the first class of dual PRMT5/EGFR inhibitors. Among the synthesized compounds, 10p showed the most potent dual PRMT5/EGFR inhibitory activity, with IC50 values of 15.47 ± 1.31 and 19.31 ± 2.14 μM, respectively. Compound 10p also exhibited promising antiproliferative activity against A549, MCF7, HeLa, and MDA-MB-231 cell lines, with IC50 values below 10 μM. Molecular docking studies suggested that 10p could bind to PRMT5 and EGFR through hydrophobic, π-π, and cation-π interactions. Furthermore, 10p displayed favorable pharmacokinetic properties and oral bioavailability (F = 30.6%) in rats, and administrated orally 10p could significantly inhibit the growth of MCF7 orthotopic xenograft tumors. These results indicate that compound 10p is a promising hit compound for the development of novel and effective dual PRMT5/EGFR inhibitors as potential anticancer agents.

Discovery of marine phidianidine-based Nrf2 activators and their potential against oxLDL- and HG-induced injury in HUVECs

One effective strategy for treating atherosclerosis is to inhibit the injury of vascular endothelial cells (VECs) induced by oxidized low-density lipoprotein (oxLDL) and high glucose (HG). This study synthesized and evaluated a series of novel Nrf2 activators derived from the marine natural product phidianidine for their ability to protect human umbilical VECs against oxLDL- and HG-induced injury. The results of in vitro bioassays demonstrated that compound D-36 was the most promising Nrf2 activator, effectively inhibiting the apoptosis of HUVECs induced by oxLDL and HG. Furthermore, Nrf2 knockdown experiments confirmed that compound D-36 protected against oxLDL- and HG-induced apoptosis in HUVECs by activating the Nrf2 pathway. These findings provide important insights into a new chemotype of marine-derived Nrf2 activators that could potentially be optimized to develop effective anti-atherosclerosis agents.

New cycloalkyl[b]thiophenylnicotinamide-based α-glucosidase inhibitors as promising anti-diabetic agents: Synthesis, in silico study, in vitro and in vivo evaluations

In the present study, a series of cycloalkyl[b]thiophenylnicotinamide derivatives against α-glucosidase were synthesized, and evaluated for their in vitro and in vivo anti-diabetic potential. Most of the synthetic analogues exhibited superior α-glucosidase inhibitory effects than the standard drug acarbose (IC₅₀ = 258.5 μM), in which compound 11b with cyclohexyl[b]thiophene core demonstrated the highest activity with an IC₅₀ value of 9.9 μM and showed higher selectivity towards α-glucosidase over α-amylase by 7.4-fold. Fluorescence quenching experiment confirmed the direct binding of 11b with α-glucosidase, kinetics study revealed that 11b was a mixed-type inhibitor, and its binding mode was analyzed using molecular docking. Moreover, analogs compounds 6a-9b, 11b, 12b did not show in vitro cytotoxicity against LO2 and HepG2 cells. Finally, compound 11b exhibited in vivo hypoglycemic activity by reducing the blood glucose levels in sucrose-loaded rats.

An Updated Overview of Synthetic α-glucosidase Inhibitors: Chemistry and Bioactivities

Diabetes mellitus (DM) is a critical global health issue, affecting nearly half a billion people worldwide, with an increasing incidence rate and mortality. Type 2 diabetes is caused by the body's inability to effectively use insulin, and approximately 95% of patients have type 2 diabetes. α-glucosidase has emerged as an important therapeutic target for the treatment of type 2 diabetes. In the past years, three α-glucosidase inhibitors have been approved for clinical use, namely acarbose, voglibose, and miglitol. However, the undesirable effects associated with these carbohydrate mimic-based α-glucosidase inhibitors have limited their clinical applications. Consequently, researchers have shifted their focus towards the development of non-carbohydrate mimic α-glucosidase inhibitors that can safely and effectively manage postprandial hyperglycemia in type 2 diabetes. Herein, this article provides an overview of the synthetic α-glucosidase inhibitors, particularly those based on heterocycles, which have been reported from 2018 to 2022. This article aims to provide useful information for medicinal chemists in further developing clinically available anti-type 2 diabetes drugs.

Design, synthesis and biological evaluation of novel (E)-2-benzylidene-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)hydrazine-1-carboxamide derivatives as α-glucosidase inhibitors

In this present study, a series of novel (E)-2-benzylidene-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)hydrazine-1-carboxamide derivatives against α-glucosidase were designed and synthesized, and their biological activities were evaluated in vitro and in vivo. Most of the designed analogues exhibited better inhibitory activity than the marketed acarbose, especially the most potent compound 7 with an IC₅₀ value of 9.26 ± 1.84 μM. The direct binding of 7 and 8 with α-glucosidase was confirmed by fluorescence quenching experiments, and the kinetic and molecular docking studies revealed that 7 and 8 inhibited α-glucosidase in a non-competitive manner. Cytotoxicity bioassay indicated compounds 7 and 8 were non-toxic towards LO2 and HepG2 at 100 μM. Furthermore, both compounds were demonstrated to have in vivo hypoglycemic activity by reducing the blood glucose levels in sucrose-treated rats.

Discovery of new 2-phenyl-1H-benzo[d]imidazole core-based potent α-glucosidase inhibitors: Synthesis, kinetic study, molecular docking, and in vivo anti-hyperglycemic evaluation

In the present study, a series of 2-phenyl-1H-benzo[d]imidazole-based α-glucosidase inhibitors were synthesized and evaluated for their in vitro and in vivo anti-diabetic potential. Screening of an in-house library revealed a moderated α-glucosidase inhibitor, 6a with 3-(1H-benzo[d]imidazol-2-yl)aniline core, and then the structural optimization was performed to obtain more efficient derivatives. Most of these derivatives showed increased activity than 6a, and the most promising inhibitors were found to be compounds 15o and 22d with IC₅₀ values of 2.09 ± 0.04 and 0.71 ± 0.02 µM, respectively. Fluorescence quenching experiment confirmed the direct binding of compounds 15o and 22d with α-glucosidase. Kinetic study revealed that both compounds were non-competitive inhibitors, that was consistent with the result of molecular docking studies where they located at the allosteric site of the enzyme. Cell viability evaluation demonstrated the non-cytotoxicity of 15o and 22d against LO2 cells. Furthermore, the in vivo pharmacodynamic study revealed that compound 15o showed significant hypoglycemic activity and improved oral sucrose tolerance, comparable to the positive control acarbose.

[Eltrombopag for thrombocytopenia in 24 children after hematopoietic stem cell transplantation]

Objective: To evaluate the efficacy and safety of eltrombopag for children with thrombocytopenia after hematopoietic stem cell transplantation (HSCT). Methods: Clinical data of 24 patients with thrombocytopenia after HSCT,who were treated with eltrombopag in the Department of Pediatrics, Sun Yat-sen Memorial Hospital, Sun Yat-sen University from August 1, 2018 to April 1, 2019 were analyzed retrospectively. The response rate and adverse reactions of eltrombopag were evaluated. Patients were divided into groups by source of hematopoietic stem cells (umbilical cord blood group and peripheral stem cell group) and type of disease (malignant and non-malignant disease group) and the clinical outcomes between groups were compared. Rank Sum test was used for comparisons between groups. Results: Among 24 cases, 15 were males and 9 females, the age of starting eltrombopag was 7.7 (2.6-13.7) years, the time of eltrombopag treatment after HSCT was 27.5 (8.0-125.0) days, the time from treatment to complete response (CR) was 23.5 (6.0-83.0) days, with the treatment course 36.5 (8.0-90.0) days. The total dose of eltrombopag was 1 400(200-5 900) mg. Complete response rate was 92% (22/24),without eltrombopag related adverse reactions. Comparing with peripheral stem cell group (n=8), the course and total dose of eltrombopag in umbilical cord blood group (n=16) were significantly reduced(24.5 (8.0-81.0) vs. 65.5 (35.0-90.0) d, Z=-3.004, P=0.002; 900.0 (200.0-3 850.0) vs. 2 862.5 (1 175.0-5 900.0) mg, Z=-2.604, P=0.007), but no significant differences were found in the time from treatment to complete response, platelet count after 2 weeks of eltrombopag withdrawal or platelet count at the end point of follow-up (all P>0.05). Comparing malignant patients (n=12) and non-malignant patients (n=12), no significant differences were found in the time from treatment to complete response, course, total dose, platelet count after 2 weeks of eltrombopag withdrawal, and platelet count at the end point of follow-up in non-malignant patients (all P>0.05). Conclusion: Eltrombopag is safe and maybe effective for thrombocytopenia after HSCT, especially for umbilical cord blood transplantation.

Discovery of New α-Glucosidase Inhibitors: Structure-Based Virtual Screening and Biological Evaluation

α-Glycosidase inhibitors could inhibit the digestion of carbohydrates into glucose and promote glucose conversion, which have been used for the treatment of type 2 diabetes. In the present study, 52 candidates of α-glycosidase inhibitors were selected from commercial Specs compound library based on molecular docking–based virtual screening. Four different scaffold compounds (7, 22, 37, and 44) were identified as α-glycosidase inhibitors with IC₅₀ values ranging from 9.99 to 35.19 μM. All these four compounds exerted better inhibitory activities than the positive control (1-deoxynojirimycin, IC₅₀ = 52.02 μM). The fluorescence quenching study and kinetic analysis revealed that all these compounds directly bind to α-glycosidase and belonged to the noncompetitive α-glycosidase inhibitors. Then, the binding modes of these four compounds were carefully investigated. Significantly, these four compounds showed nontoxicity (IC₅₀ > 100 μM) toward the human normal hepatocyte cell line (LO2), which indicated the potential of developing into novel candidates for type 2 diabetes treatment.

A highly sensitive endoplasmic reticulum-targeting fluorescent probe for the imaging of endogenous H2S in live cells

Hydrogen sulfide (H₂S) as an important signaling biomolecule participates in a series of complex physiological and pathological processes. In situ and rapid detection of H₂S levels in endoplasmic reticulum (ER) is of great importance for the in-depth study of its virtual functional roles. However, the ER-targeting fluorescent probe for the detection of H₂S in live cells is still quite rare. Herein, a new ER-targeting fluorescent probe (FER-H₂S) for detecting H₂S in live cells was characterized in the present study. This probe FER-H₂S was built from the hybridization of three parts, including fluorescein-based skeleton, p-toluenesulfonamide as ER-specific group, and 2,4-nitrobenzene sulfonate as a response site for H₂S. The response mechanism of the probe FER-H₂S to H₂S is on the basis of the ring-opening and ring-closing processes in fluorescein moiety. Moreover, the probe FER-H₂S was successfully used for the imaging of exogenous and endogenous H₂S in ER of live cells.

Establishing the mechanisms underpinning solids breakthrough in UASB configured anaerobic membrane bioreactors to mitigate fouling

In this study, the mechanisms for solids breakthrough in upflow anaerobic sludge blanket (UASB) configured anaerobic membrane bioreactors (AnMBRs) have been described to establish design parameters to limit membrane fouling. As the sludge blanket develops, two periods can be identified: (i) an initial progressive enhancement in solids separation provided through sludge blanket clarification, via depth filtration, which sustains downstream membrane permeability; and (ii) sludge blanket destabilisation, which imposed solids breakthrough resulting in a loss in membrane permeability. The onset of sludge blanket destabilisation was identified earlier in the flocculent AnMBR, which was ascribed to an increased gas production, caused by hydrolysis within the sludge blanket at extended solids residence time. Whilst hydrolysis also induced higher gas productivity within the granular AnMBR, solids breakthrough was not evidently observed during this period, and was instead only observed as the sludge blanket approached the UASB overflow. However, solids breakthrough was observed earlier for both reactors when treating wastewater with lower temperatures. This was explained through characterisation of the settling velocity of discrete particles from the sludge blanket of both MBRs; solids washout was evidenced to be induced by the increase in fluid viscosity with a reduction in temperature, which lowered terminal particle settling velocity. Nevertheless, particle settling velocity was comparable for particles from both sludge blankets. We therefore propose that the enhanced stability imparted by the granular AnMBR is due to the higher inertial force of the dense granular sludge. From this study, we suggest that similarly low levels of membrane fouling can be achieved within flocculent AnMBR by managing solids retention time to constrain sludge bed height and excess hydrolysis, together with adopting an upflow velocity based on particle buoyancy at the lowest expected operating temperature.

Impact of static biocarriers on the microbial community, nitrogen removal and membrane fouling in submerged membrane bioreactor at different COD:N ratios

The polyvinyl formal (PVFM) biocarrier addition in a membrane bioreactor (MBR) was evaluated at high and low carbon/nitrogen (C/N) ratio of 20.0 and 6.7. Results indicated that static biocarrier addition could enrich nitrification and denitrification bacteria, dominating by Tauera, Amaricoccus and Nitrosospira at the genus level and slightly improved the total nitrogen removal even at a low C/N ratio. The bulk sludge characteristics (such as bigger particle size, lower SMP, lower SMP P/C) were also significantly changed in the hybrid MBR (HMBR), leading to a more sustainable membrane operation. The biocarrier addition also reduced the relative abundance of Sphingobacterials_unclassified, Ohtaekwangia and Rhodocyclaceae_unclassified at the genus level, indicating less membrane fouling in the HMBR. Consequently, HMBR with static PVFM addition could partially overcome the drawback of low C/N ratio for total nitrogen removal and membrane fouling control, providing a more resilient MBR to the undesirable environment such as low C/N ratio.

Efficient electrochemical generation of ferrate(VI) by iron coil anode imposed with square alternating current and treatment of antibiotics

Anode passivation is still a main challenge for the electrochemical generation of ferrate(VI, Fe(VI)), leading to the reduction of Fe(VI) production efficiency. In this study, cyclic voltammetry, scanning electronic microscopy, and electrochemical impedance spectroscopy were used to select better anode electrode configurations (iron wire, iron gauze, and iron coil). The results indicate that iron coil had the least degree of passivation. Different imposed current waveforms during the electrochemical generation of Fe(VI) were also investigated, and the iron coil imposed with square alternating current (AC) wave can mitigate the anode passivation, resulting in higher Fe(VI) production efficiency. The optimum conditions for the electrochemical generation of Fe(VI) were evaluated and the optimum temperature (40 ℃), current density (10 mA/cm²), AC cycle period (15 s) and electrolyte concentrations (14 M NaOH) were identified. As a result, 0.12 mol/L Fe(VI) concentration and over 50% of current efficiency can be achieved after 3 h electrolysis. The generated Fe(VI) solution was further applied to oxidize doxycycline(DOX) and sulfadiazine(SDZ) as typical antibiotics. Over 80% of DOX can be removed at a Fe(VI) to DOX molar ratio of 5:1 (pH = 4-9), whilst a higher Fe(VI) to SDZ molar ratio of 20:1 (pH = 7) was needed to obtain 75% SDZ removal.

Efficacy and safety of fosaprepitant in the prevention of nausea and vomiting following highly emetogenic chemotherapy in Chinese people: A randomized, double-blind, phase III study

The prevention of chemotherapy‐induced nausea and vomiting was one of the most challenging supportive care issues in oncology, especially to highly emetogenic chemotherapy (HEC). A total of 645 patients were randomized into fosaprepitant group (fosaprepitant/placebo 150 mg d1 in combination with granisetron and dexamethasone) or aprepitant group (aprepitant/placebo 125 mg d1; 80 mg d2‐d3 plus granisetron and dexamethasone).The primary endpoint was the percentage of patients who had a complete response (CR) over the entire treatment course (0–120 hr, overall phase [OP]). It was assessed by using a non‐inferiority model, with a non‐inferiority margin of 10%. The difference of the CR rate was compared between two groups with chi‐square analysis. Six hundred and twenty‐six patients were included in the per protocol analysis. The percentage of patients with a CR in the fosaprepitant group was not inferior to that in the aprepitant group (90.85% versus 94.17%, p = .1302) during OP. Whether the cisplatin‐based chemotherapy or not, the CR rate of the fosaprepitant group was not inferior to that of the aprepitant group. Both regimens were well tolerated. The most common adverse event was constipation. Fosaprepitant provided effective and well‐tolerated control of nausea and vomiting associated with HEC in Chinese patients.

Epidemiology of Enterobius vermicularis infection among elementary school children in Hualien, Taiwan from 2007 to 2012

Enterobius vermicularis is the most common human intestinal parasite, and its control among school children is an important public health issue. The objective of this study was to document the present situation of E. vermicularis infection in school children in Hualien. The administrative divisions in Hualien county include 13 districts (3 in a mountainous area, 10 in a rural/urban area). Between 2007 and 2012, a total of 41,191 children in 13 districts in Hualien were examined using consecutive 2-day adhesive cellophane paper perianal swabs. Our results showed Enterobius egg-positive infection rates of 5.79% (452/7,089) in 2007, 6.25% (457/7,312) in 2008, 5.37% (385/7,173) in 2009, 4.98% (330/6,804) in 2010, 4.91% (301/6,133) in 2011, and 4.68% (279/5,960) in 2012. Compared to the previously reported national average in Taiwan (range, 1.53-2.23%), the prevalence of E. vermicularis in Hualien is relatively high. The infection rates were 7.55-29.10% in mountainous areas and 0.50- 12.43% in rural/urban areas. All first and fourth grade students in elementary schools in Hualien were selected as study participants. The average infection rate of the first grade students (6.71%) was higher than that of the fourth grade students (4.23%). These results indicate that enterobiasis remains an important parasitic disease among school children in Hualien, especially those in mountainous areas.

Modeling and analysis of visual digital impact model for a Chinese human thorax

OBJECTIVE

To establish a three-dimensional finite element model of the human chest for engineering research on individual protection.

METHOD

Computed tomography (CT) scanning data were used for three-dimensional reconstruction with the medical image reconstruction software Mimics. The finite element method (FEM) preprocessing software ANSYS ICEM CFD was used for cell mesh generation, and the relevant material behavior parameters of all of the model's parts were specified. The finite element model was constructed with the FEM software, and the model availability was verified based on previous cadaver experimental data.

RESULTS

A finite element model approximating the anatomical structure of the human chest was established, and the model's simulation results conformed to the results of the cadaver experiment overall.

CONCLUSION

Segment data of the human body and specialized software can be utilized for FEM model reconstruction to satisfy the need for numerical analysis of shocks to the human chest in engineering research on body mechanics.

Is endoscopic treatment beneficial in patients with clinically suspicious of common bile duct stones but no obvious filling defects during the ERCP examination?

BACKGROUND

Sometimes, no definite filling defect could be found by cholangiogram (ERC) during the endoscopic retrograde cholangio-pancreatiographic (ERCP) exam; even prior images had evidence of common bile duct stones (CBDS). We aimed in estimating the positive rate of extraction of CBDS who had treated by endoscopic sphincterotomy/endoscopic papillary balloon dilation (EST/EPBD) with negative ERC finding.

METHODS

One hundred forty-one patients with clinically suspicious of CBDS but negative ERC, who had received EST/EPBD treatments was enrolled. Potential factors for predicting CBDS, as well as the treatment-related complications were analyzed.

RESULTS

Nearly half of the patients with negative ERC, had a positive stone extraction. Only patients with high probability of CBDS were significantly associated with positive stone extraction. Moreover, patients with intermediate probability of CBDS had higher rates of overall complications, including post-ERCP pancreatitis. In addition, no significant difference of post-ERCP pancreatitis was found between EST and EPBD groups in any one group of patients with the same probability of CBDS.

CONCLUSIONS

Regarding patients with negative ERC, therapeutic ERCP is beneficial and safe for patients present with high probability of CBDS. Moreover, under the same probability of CBDS, there was no significance difference in post-ERCP pancreatitis between EST and EPBD.

Linear echoendoscope-guided ERCP for the diagnosis of occult common bile duct stones

Background

Less than 67% of patients with intermediate risk for common bile duct (CBD) stones require therapeutic intervention. It is important to have an accurate, safe, and reliable method for the definitive diagnosis of CBD stones before initiating therapeutic endoscopic retrograde cholangiopancreatography (ERCP). Few publications detail the diagnostic efficacy of linear echoendoscopy (EUS) for CBD stones.

Methods

30 patients with biliary colic, pancreatitis, unexplained derangement of liver function tests, and/or dilated CBD without an identifiable cause were enrolled in the study. When a CBD stone was disclosed by linear EUS, ERCP with stone extraction was performed. Patients who failed ERCP were referred for surgical intervention. If no stone was found by EUS, ERCP would not be performed and patients were followed-up for possible biliary symptoms for up to three months.

Results

The major reason for enrollment was acute pancreatitis. The mean predicted risk for CBD stones was 47% (28–61). Of the 12 patients who were positive for CBD stones by EUS, nine had successful ERCP, one failed ERCP (later treated successfully by surgical intervention) and two were false-positive cases. No procedure-related adverse events were noted. For those 18 patients without evidence of CBD stones by EUS, no false-negative case was noted during the three-month follow-up period. Linear EUS had sensitivity, specificity, positive and negative predicted values for the detection of CBD stones of 1, 0.9, 0.8 and 1, respectively.

Conclusion

Linear EUS is safe and efficacious for the diagnosis of occult CBD stones in patients with intermediate risk for the disease.

Upper gastrointestinal lesions in patients receiving clopidogrel anti-platelet therapy

BACKGROUND/PURPOSE

Clopidogrel is associated with a high incidence of upper gastrointestinal bleeding in high-risk patients. However, the characteristic upper gastrointestinal lesions in symptomatic clopidogrel users remain unclear. The aims of this study were to investigate the characteristics of endoscopic findings in clopidogrel users undergoing endoscopy for upper gastrointestinal symptoms and to compare the clinical characteristics and upper gastrointestinal lesions between symptomatic clopidogrel and aspirin users.

METHODS

This observational study included 215 consecutive patients receiving clopidogrel (n=106) or low-dose aspirin (n=109) therapy who underwent endoscopy for dyspeptic symptoms. The upper gastrointestinal lesions were carefully assessed, and a complete medical history was obtained by a standard questionnaire.

RESULTS

The frequencies of hemorrhagic spots, erosions and peptic ulcers in the symptomatic clopidogrel users were 25%, 39% and 39%, respectively. Among the peptic ulcer patients on clopidogrel therapy, the distributions of ulcers were 78%, 5% and 17% in the stomach, duodenum and both, respectively. Compared with the aspirin group, the clopidogrel group was older and had higher frequencies of past ulcer history and past gastrointestinal bleeding history in their clinical characteristics. By contrast, the clopidogrel users had a lower prevalence of active Helicobacter pylori infection than aspirin users (17% vs. 35%, respectively, p=0.007). Regarding to the endoscopic findings, the clopidogrel users had higher frequencies of hemorrhagic spots (25% vs. 10%) and peptic ulcer (39% vs. 24%) than aspirin users (p=0.004 and 0.027, respectively).

CONCLUSION

Most peptic ulcers in clopidogrel users are located in the stomach. The frequencies of hemorrhagic spots and peptic ulcers in symptomatic clopidogrel users are higher than those in symptomatic aspirin users.

Sequential therapy achieves a higher eradication rate than standard triple therapy in Taiwan

BACKGROUND AND AIMS

Most clinical trials concerning sequential therapy have been conducted in Italy. The efficacy of sequential therapy for Helicobacter pylori (H. pylori) eradication in Asia remains unclear. The aim of this study was to compare the efficacy of sequential therapy with standard triple therapy in Taiwan.

METHODS

From January 2005 to December 2009, 233 H. pylori-infected patients receiving either a 10-day sequential therapy (40 mg pantoprazole and 1 g amoxicillin, twice daily, for the initial 5 days, followed by 40 mg pantoprazole, 500 mg clarithromycin, and 500 mg metronidazole, twice daily, for the subsequent 5 days, n = 118) or a 7-day standard triple therapy (40 mg pantoprazole, 500 mg clarithromycin, and 1 g amoxicillin twice daily for 7 days, n = 115) were included in the retrospective study. All the patients underwent a follow-up endoscopy with a rapid urease test and histological examination or a urea breath test at 8 weeks after the end of anti-H. pylori therapy to assess H. pylori status.

RESULT

Intention-to-treat analysis demonstrated a significantly higher eradication rate for the sequential group than for the triple group (93% vs 80%, respectively, P = 0.003). Per-protocol analysis also showed similar results (93% vs 80%, P = 0.005). Both groups had similar frequencies of adverse events (29% vs 22%) and drug compliance (98% vs 97%).

CONCLUSION

Sequential therapy achieves a higher eradication rate than standard triple therapy in Taiwan. The novel treatment can be used as a first-line therapy for H. pylori infection for Taiwanese.

Attenuating effect of daidzein on polychlorinated biphenyls-induced oxidative toxicity in mouse testicular cells

The attenuating effect of daidzein (DAI) on oxidative toxicity induced by Aroclor 1254 (A1254) was investigated in mouse testicular cells. Cells were exposed to A1254 alone or with DAI. The oxidative damage was estimated by measuring malondialdehyde (MDA) formation, superoxide dismutase (SOD) activity and glutathione (GSH) content. Results show that A1254 induced a decrease of germ cell number, an elevation in thiobarbituric acid reactive substances (TBARS) but a decrease in SOD activity and GSH content. However, simultaneous supplementation with DAI decreased TBARS level and increased SOD activity and GSH content. Consequently, dietary DAI may restore the intracellular antioxidant system to attenuate the oxidative toxicity of A1254 in testicular cells.

Expression of platelet-derived growth factor-BB in liver tissues of patients with chronic hepatitis B

AIM: To study the relationship between expression of platelet-derived growth factor-BB (PDGF-BB) and fibrogenesis in chronic hepatitis B.

METHODS: Hepatic tissues from 43 patients with chronic hepatitis B were embedded in paraffin. The sections were stained with HE and picric acid-sirius red to determine inflammatory activity and fibrosis stages. PDGF-BB expression was detected by immunohistochemistry and assessed semiquantatively. Levels of serum hyaluronic acid (HA), pro-collagen III (PCIII), collagen IV (IV-C) and laminin (LN) were examined by radioimmunoassay (RIA).

RESULTS: The expression level of PDGF-BB was found to be positively correlated with inflammatory activity, fibrosis stage and grade of histological findings (τ = 0.58, 0.55, 0.55, P < 0.01). The positive correlation was also observed between tissue level of PDGF-BB expression and contents of HA, PCIII, IV-C and LN in the circulation (r = 0.52, 0.32, 0.40, 0.33, P < 0.05).

CONCLUSION: PDGF-BB may play some role in the development and progression of liver fibrosis.

Formation of a planar optical waveguide by mega-electron-volt He+ and P+ ions implanted in a BiB(3)O(6) crystal

What is believed to be the first planar optical waveguide was formed in BiB(3)O(6) (BIBO) crystal by 2.8-MeV He(+)-ion implantation with a dose of 2x10(16)ions/cm (2) and 2.8-MeV P(+)-ion implantation with a dose of 1x10(14)ions/cm (2) at room temperature. We observed 21 darks modes for the He(+)-ion-implanted BIBO waveguides and four dark modes for the P(+)-ion-implanted waveguides. The refractive-index profile of the He(+)-implanted BIBO waveguide was analyzed. The data also suggest that the BIBO waveguides formed by MeV He(+)-ion and P(+)-ion implantation differ in their developing mechanisms.

[Responses of afferent unit of the caudal nerve of diabetic hyperalgesic rats to sympathetic efferent stimulation]

Responses of afferent unit to sympathetic stimulation (SS), intravenous injection of noradrenaline (NA) and phentolamine in the caudal nerve of diabetic rats were investigated. The results showed that the discharge frequencies of C and Adelta units with spontaneous discharges were increased in diabetic hyperalgesic rats after SS, and these spontaneous discharges were eliminated by adrenergic antagonist. The C (6/21) and Adelta (19/81) units with no spontaneous discharges of diabetic hyperalgesic rat turned from silent state into active state during SS; although SS did not elicit afferent discharges of the C mechanical receptive units (C-M), it elicited afferent discharges of a part of C mechano heat units (C-MH) and C polymodal units (C-Pol); afferent discharges of some of the Adelta mechanical receptive units (Adelta-M) and Adelta mechano heat units (Adelta-MH) were also elicited by SS. The latencies of the C and Adelta units responses upon SS were not equal, but no less than 5 s. SS elicited neither afferent discharges from Abeta mechanical receptive units of diabetic hyperalgesic rat, nor receptive units of all types in the control rat. The C(3/8) and Adelta (4/12) units of diabetic hyperalgesic rat were activated by intravenous injection of NA. The present data suggest that NA released from sympathetic nerve terminals excites C and Adelta units of diabetic hypesthesic rat, which may be a peripheral factor in hyperalgesia and paresthesia of diabetic rats.

Extraordinary refractive-index increase in lithium niobate caused by low-dose ion implantation

Multienergy Cu(+) ions with total dose of ~10(14) ions/cm(2) were implanted into LiNbO(3) crystals to form a nearly homogenous damage profile from the sample surface to the end of the ions' track. The extraordinary refractive-index enhancement was found in the damage region by observation of the dark mode. The extraordinary index showed an increasing trend until the ion dose reached a critical value. The largest index enhancement was ~0.0132. By use of low-dose ion implantation, we determined that the decreased spontaneous polarization caused the extraordinary index increase.

Determination of low-level mercury based on a renewable-drops sensing technique

The design and characteristics of a novel drop-based fluorescence-detection technique for the determination of mercury(II) are described. The method, using a flow injection technique, is based on the renewable-drops of 3,3',5,5'-tetramethylbenzidine(TMB), which are formed at the bottom tip of a silica capillary tube connected to the end of the flow system. An excitation beam from a high-pressure Hg lamp directly illuminates the drops, the fluorescence emission is conducted to a photodiode (PD) to convert the photocurrent into a voltage signal (mV). Optimum analytical conditions for Hg(II) assays have been established. In NaAc/HAc buffer at pH 3.09 this assay has a wide linear range for Hg(II) from 8.0 x 10(-8) to 2.0 x 10(-5) mol/L with a detection limit of 2.0 x 10(-8) mol/L. The use of renewable drops allowing a fresh reaction surface for each sample is of particular value to solving the problems of irreversible reactions. Besides its high sensitivity, the method permits a simple, fast, and inexpensive measurement with only micro-quantities of reagent consumption. The technique described provides a simple and sensitive way to fabricate sensors of feasible prospects and commercial advantages.

Management of scrap computer recycling in Taiwan

It is estimated that approximately 300,000 scrap personal computers are generated each year in Taiwan [S.-L. Chang, A Study on the Scrap Computer Treatment Cost, Environment Protection Administration of Taiwan, December 1998 (in Chinese)]. The disposal of such a huge number of scrap computers presents a difficult task for the island due to the scarcity of landfills and incineration facilities available locally. Also, the hazardous materials contained (i.e., phosphor coatings of cathode ray tubes (CRTs), batteries, polychlorinated biphenyl capacitors, mercury-containing parts, liquid crystal display, high-lead content CRT funnel glass, and plastic containing flame-retardant bromine, etc.) in the scrap computers may seriously pollute the environment if they are not properly disposed of. Therefore, the EPA of Taiwan declared scrap personal computers the producer's recycling responsibility as of July 1997. Under this decree, the manufacturers, importers and sellers of personal computers have to properly recover and recycle the scrapped computers which they originally sell. On June 1, 1998, a producer responsibility recycling program for scrap computers was officially implemented in Taiwan. Under this program, consumers can bring their unwanted personal computers to the designated collection points and receive reward money. Currently, only six computer items are mandated to be recycled in this recycling program. They are notebooks, monitors, hard disks, power supplies, printed circuit boards and main frame shells. This article outlines the current scrap computer recycling system in Taiwan.

Annealing behavior of barriers in ion-implanted LiNbO3 and LiTaO3 planar waveguides

We formed planar waveguides in LiNbO(3) and LiTaO(3) crystals by megaelectron volt He-ion implantation. The dark modes of both waveguides are measured and their refractive-index profiles are described according to the parameterized index profile reconstruction method. The extraordinary indices of both ion-implanted waveguides exhibit quite different profiles. We compare the thermal stability of barriers in ion-implanted LiNbO(3) and LiTaO(3) waveguides by annealing at different temperatures. The results show that the barrier in a LiTaO(3) planar waveguide has higher thermal stability than that in a LiNbO(3) waveguide. The experiments also show that annealing at a temperature higher than 400 degrees C results in recrystallization of the barrier.

Planar optical waveguide in Cu-doped potassium sodium strontium barium niobate crystal formed by mega-electron-volt He-ion implantation

The first planar optical waveguide to the authors' knowledge has been formed in Cu-doped potassium sodium strontium barium niobate crystal by mega-electron-volt He(+) implantation. Both TE and TM modes are observed. The profiles of the ordinary and the extraordinary refractive indices are deduced from dark-line mode spectroscopy. The results show that the mega-electron-volt He implantation results in a decrease in refractive index in barriers for both n(o) and n(e), but for n(e) there is an obvious increase in the waveguide region. From an experiment in photorefractive two-wave mixing, it is found that the erasure time for two-wave mixing is prolonged by ion implantation.

[Effects of sympathetic efferent in diabetic hyperalgesia in rat]

While sympathetic efferents and prostaglandins (PGs) play an important role in hyperalgesia of partial injury of peripheral nerves and inflammation, whether these are also involved in diabetic hyperalgesia is unknown. With intraperitoneal injection of 6-hydroxydopamine (6-OHDA) to eliminate effects of sympathetic postganglionic neurons (SPGNs) terminals, a model of diabetic rats with infused 6-OHDA could be set up by injection of streptozotocin (STZ). Nociceptive paw-withdrawal threshold (NPWT) and tail flick latency (TFL) in 6-OHDA/diabetic rats were not changed significantly in the following four weeks. However, in diabetic group rats, pain threshold was decreased significantly and accompanied by development of hyperalgesia. NPWT was significantly decreased with noradrenaline (NA) in diabetic hyperalgesic rats and increased with phentolamine or yohimbine, but not by prazocin. In the control rats, NPWT are not changed significantly by NA or phentolamine, and in 6-OHDA/diabetic rats, neither NA nor phentolamine also affected on NPWT significantly. However, NPWT may be significantly decreased by PGE1, PGE2 and PGD2 in both the control and the diabetic hyperalgesic rats. The above results suggested that SPGNs terminals are involved in hyperalgesia of diabetic rats, NA accelerated synthesis of PGs and released by way of presynaptic effect on alpha 2-adrenergic receptors at the SPGNs terminals, PGs, in turn, directly acted on the primary afferent nociceptors, producing hyperalgesia.

[Responsive properties of afferent units of the superficial branch of radial nerve in diabetic neuropathic patients]

By means of intraneural microrecording (INMR), changes of mechanical threshold and conduction velocity (CV) of A beta mechanical receptive units and A delta units of the superficial branch of the radial nerve and their response to sympathetic efferent were studied in 8 diabetic neuropathic patients. The results showed that the CV of these units was significantly decreased, and so was the mechanical threshold of A delta units. During the aftermath of excitation of the skin sympathetic nerve by mental arithmetics, 3/12 A delta units were turned to the active state with decreased mechanical threshold.

[Responsive property of afferent units in the caudal nerve of streptozotocin-diabetic rats]

In the present study, the responsive properties of afferent units in caudal nerve of streptozotocin (STZ) induced diabetic rats were investigated. It was found that some of the C and A delta units spontaneously discharged and their mechanical threshold was decreased significantly in diabetic rats. The response of the C units of diabetic and control rats to a 1 min sustained mechanical stimulus of threshold strength was similar, whereas, discharge frequencies during sustained suprathreshold mechanical stimulus were significantly greater in the C units of diabetic rats. After removal of threshold or suprathreshold mechanical stimulus, after discharges were also greater in C units of diabetic rats. Conduction velocity of C units, A delta units and A beta mechanical receptive units were also decreased in diabetic rats. However, there was no significant difference in the subunits of all kinds of receptive units between diabetic and control rats. The present data suggested that the C and A delta units with lowered mechanical threshold contribute to the decrease of the behavioral nociceptive threshold of diabetic rats and abnormal discharge of the C and A delta units may be a peripheral factor in hypersensitivity to painful stimuli and paresthesia of diabetic rats.

Potassium ion-selective optodes based on the calix[6]arene hexaester and application in human serum assay

Plasticized PVC membranes incorporating the hexaester of calix[6]arene, potassium tetrakis(4-chlorophenyl) borate and a neutral H+-selective chromo-ionophore (ETH 5294) have been used as reversible sensing devices for optical determination of potassium ion in pH-buffer solutions. At pH 9.0, the absorbance response of the optode shows a good correlation with the theoretically derived formula in the range from 1 x 10(-6) to 1 x 10(-2) mol l(-1) potassium ion. Typical response times (t95) in the samples are 3 min, the relative standard deviation for repeated measurements being within 0.5%. The selectivity of this potassium-selective membrane allows its application for the reversible optical detection of potassium concentration in human serum samples.

[Physiological properties of A delta and C fibres of superficial branch of radial nerve in human]

By means of intraneural micro recording (INMR) and intraneural microstimulation (INMS), properties of receptive units innervated by A delta and C fibers of the superficial branch of the radial nerve were measured on humans. Thresholds of 24 A delta units to mechanical stimulation varied significantly; their receptive fields ranged from a single point to 75.4 mm2, with one to four receptive sensitive zones. A delta units by INMS evoked tingling with projected fields varying between 1.2 and 97 mm2. Receptive fields and projected fields of these units overlapped each other and showed a proximodistal size gradient (P < 0.05). The results suggest that A delta units have accurate localizing capacity. Eleven nociceptive units had higher threshold to mechanical stimulation. INMS of C nociceptive units evoked burning pain. Both the receptive fields and projected fields of most of these units showed overlapping indicating that C nociceptive units, to some extent, can localize noxious stimulation.

Construction of a genomic DNA library of the Toxoplasma gondii ZS2 strain, screening of specific clones, and DNA diagnosis of toxoplasmosis

We have constructed a genomic DNA library of the Toxoplasma gondii ZS2 strain and isolated a specific cloned DNA sequence from this organism. The restriction map of this cloned 1.1-kb DNA fragment was analyzed. Southern and dot-blot analyses showed that the 32P-labeled DNA fragment hybridized to parasite DNA, to DNAs from peripheral blood leukocytes and the thymus of baby pigs that were artificially infected with T. gondii, and to DNAs of T. gondii-positive anencephalic and hydrocephalic fetuses. It did not hybridize with DNA from controls, (i.e., normal human and baby pig peripheral blood leukocytes, spleen of normal mice, Plasmodium falciparum, Pneumocystis carinii, and pBR322). As few as 100 T. gondii parasites or 500 pg of purified DNA from T. gondii can be detected by dot-blot hybridization. This probe method was specific and sensitive, and has been used successfully in detecting various clinical cases of toxoplasmosis with T. gondii.

T-lymphocyte specificity differences to horse cytochrome c in different lymphoid cell compartments

T-lymphocyte proliferative responses were determined with peripheral blood lymphocytes (PBL), peritoneal exudate lymphocytes (PEL) and lymph node lymphocytes (LNL) of guinea pigs immunized with horse cytochrome c (HCytc). The proliferative response of PBL activated by peptide 81-104 from animals immunized with HCytc was equal to or better than HCytc while the proliferative response activated by peptide 1-65 was small and no reactivity was seen when peptide 66-80 was tested. In contrast, the proliferative responses of PEL and LNL stimulated by peptide 1-65 approached those activated by HCytc, while peptide 81-104 was far less effective. The differences in the proliferative responses of PBL and PEL activated by peptide 81-104 and peptide 1-65 suggest that different lymphoid compartments may have T-cells directed to different T-cell epitopes displayed on the same antigen. The possible roles of different T-cell clones, antigen processing, and differential induction of suppressor cells are discussed in relation to these findings.

Rainbow holography of 3-D diffuse objects with HOE/MEHL

A new technique of one-step rainbow holography with a multiexposure holographic lens (MEHL) is described. The synthesization of the slitlike function in the object wave can be performed with the specially fabricated holographic lens. The MEHL can also be applied to the oriented speckle encoding of images in white-light optical image processing. Successful experimental results are presented.

Antigenic determinant of trichosanthin peptide fragments

Purified plant protein, Trichosanthin (TCS), was partially digested with chymotrypsin to produce peptide fragments. Two large fragments, I and II, have been isolated and identified as C-terminal peptides located at sequence positions between 79-234 and 107-234. Their molecular weights determined by electrophoretic mobility on SDS gel were 16,000 and 14,000 daltons. Studies using fluorescence quenching measurements by titrating anti-TCS Fab with TCS and fragment I and II showed that four epitopes were present in intact TCS and one each epitope in fragment I and II. One of the epitopes is therefore located between sequence positions 107 and 234.

A study on the receptive field of acupoints and the relationship between characteristics of needling sensation and groups of afferent fibres

We have recorded the afferent unit discharges and using it as an index, measured the locations and the volumes of nine acupoints, such as Neiguan and Shaoshang, which are innervated by median nerve. We have also investigated the relationships between electric needling sensations and afferent fibres of different groups as well as manual needling sensations by means of analysing power-spectrum of the unit discharges with FFT. It has been found that the fibres of Group II and Group IV convey numbness and soreness, respectively. The fibres of Group III relates to the conduction of heaviness and distention closely.

Antibody subpopulation in antihorse cytochrome c serum

A specific antibody subpopulation(s) in antihorse cytochrome c serum was detected for peptide fragment 81-104 of cyanogen bromide (CNBr) cleaved horse cytochrome c (HCytc). This antiserum was made in the rabbit against polymeric horse cytochrome c. The presence of the peptide-specific antibody subpopulation(s) was demonstrated utilizing HCytc, CNBr-peptide 81-104 and isolated chymotrypsin-digested HCytc fragments 60-67, 83-97 and 98-104 to compete with radio-labeled peptide 81-104 and antiHCytc serum in a competitive radioimmunoassay (RIA). This antibody subpopulation(s) in antiHCytc serum was demonstrated to be specific for peptide 81-104. At the 50% inhibition level in competitive RIA, 100- and 1000-fold molar excesses of HCytc and its peptide 1-65, respectively, were required to affect an equivalent binding to that of the HCytc peptide 81-104. Competitive RIAs have been performed utilizing three different kinds of antigen to compete with HCytc peptide 81-104 and antihorse cytochrome c sera. These three kinds of antigens are: endopeptidase digests of HCytc, cytochrome c peptides 81-104 of several species and several isolated chymotryptic peptide fragments of HCytc. The results have indicated that this peptide-specific antibody subpopulations(s) in antiHCytc serum is similar to antibodies made against peptide 81-104-BSA. Regions of antigenicity have been identified at positions 92, 100, 103 and 104 with both antisera.

Specificity of rabbit antisera for peptide 81-104 of horse cytochrome c is dominated by C-terminal residues

Sera have been prepared in rabbits against the carboxy terminal cyanogen bromide fragment of horse cytochrome c (81-104) conjugated to bovine serum albumin (BSA). The specificity of these sera has been studied by radioimmunoassay and reveals that only peptide 81-104 binds the antibody. Neither whole cytochrome c nor peptides 1-65 and 66-80 displace 125I-81-104 from specific antibody, while cold peptides 81-104 is active in this regard, as expected. Fine specificity studies with isolated heterologous peptides 81-104 from the bovine, rabbit, canine, chicken, pigeon and tuna species of cytochrome c reveal that a major antigenic determinant is influenced by sequence positions 100 and 103 while a minor antigenic determinant is influenced by residue 92. These results are exactly mirrored and supported by inhibition studies with the isolated chymotryptic fragments 98-104 and 83-97. Studies with tryptic, chymotryptic and peptic digests of horse cytochrome c reveal that these natural proteases can generate peptides with the appropriate peptide sequences to react with antibodies produced against the peptide 81-104-BSA conjugate.

Sympathetic ophthalmia: a comparison of the histopathological features from a Chinese and American series

The importance of this comparison between two large series of cases of sympathetic ophthalmia lies in its confirmation of our previous findings, which differ somewhat from the classical pathological description. Sympathetic ophthalmia remains a clinicopathological diagnosis, relying on a history of perforating injury to one eye, followed after a variable incubation period by inflammation in the fellow eye. The inflammatory changes in both eyes consist of a diffuse, granulomatous proliferation throughout the uveal tract, which involves the choriocapillaris and the retina late in its course. The infiltrate is composed predominantly of lymphocytes and plasma cells, with a variable number of epitheloid and giant cells. Corticosteroid therapy may modify this picture. The epithelioid cells contain phagocytosed pigment granules, but there is not sign of necrosis. Eosinophils appear early in the course of the disease and disappear late. The granulomatous inflammation may spread to involve the optic nerve sheath, the nerve itself, the scleral emissaria, and the scleral stroma. Dalén-Fuchs nodules appear early peripherally, and it is over these nodules that retinal granulomas, when present, usually are found. In the Shanghai series, it was found that corticosteroid therapy and prompt enucleation of the exciting eye reduced the number of exacerbations experienced by these patients but did not improve visual prognosis. The MEEI data, while they did show a bimodal distribution to the visual result, seemed to indicate that prompt enucleation of a blind eye combined with aggressive corticosteroid therapy may improve visual prognosis.

Uveal melanoma in China

We reviewed 65 cases of uveal melanoma from the Shanghai Eye, Ear, Nose, and Throat Hospital between 1956 and 1979. These 65 cases occurred at a rate of 4.5 cases per 10,000 inpatients on the ophthalmology service. Uveal melanoma is more frequently encountered in China than previous reports have suggested. In China, as in the United States, uveal melanoma is the most frequently occurring primary intraocular neoplasm in adults. We observed a strikingly younger age distribution of our cases; almost 20 percent of cases in our series involved patients between the ages of 19 and 30. The largest number of cases was seen in the fifth decade. However, only 5 cases (8 percent) were seen in the sixth decade. Fundus lesions, which were observed to stimulate choroidal melanoma, are similar to those encountered in the United States. One contrast was the importance of inflammatory lesions in the differential diagnosis of choroidal melanoma. Management of cases was surgical in all instances. A lower percentage of spindle cell tumors and a higher percentage of epitheloid tumors were seen than in most Western series.