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Journal of Emergency Medicine 04/2012; · 1.31 Impact Factor
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International journal of cardiology 03/2012; 155(3):506-8. · 7.08 Impact Factor
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ABSTRACT: Hypoxia is a significant perturbation that exacerbates endothelial barrier dysfunction, contributing to the disruption of vascular homeostasis and the development of various diseases such as atherosclerosis and metastasis of tumors. To date, it is not known what strategy might be used to counter the effect of hypoxia on endothelial permeability.
This study investigated the role of nitrite in regulating vascular integrity under hypoxic conditions.
We found denitrosylation and the resulting activation of caspase-3 to be critical for hypoxia-induced endothelial permeability. Nitrite treatment led to S-nitrosylation and the inactivation of caspase-3, suppressing the barrier dysfunction of endothelia caused by hypoxia. This process required the conversion of nitrite to bioactive nitric oxide in a nitrite reductase-dependent manner. Using primary human umbilical vein endothelial cells as a model, we showed that in the presence of nitrite, the S-nitrosylated and inactivated form of caspase-3 was unable to cleave β-catenin, a key component in the VE-cadherin complex. Therefore, nitrite treatment led to the maintenance of VE-cadherin-mediated adherens junctions under hypoxic conditions. In in vivo experiments using a zebrafish model, nitrite was found to protect blood vessels from hypoxia-induced vascular leakage.
These results are the first to demonstrate that nitrite plays a critical role in the protection of endothelial barrier function against hypoxic insult. Our findings show that nitrite holds great potential for the treatment of diseases associated with hypoxia-induced disorder of vascular homeostasis.
Circulation Research 12/2011; 109(12):1375-86. · 9.49 Impact Factor
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Annals of emergency medicine 10/2011; 58(4):330, 340. · 4.23 Impact Factor
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ABSTRACT: Testosterone replacement therapy has benefits for aging men and those with hypogonadism. However, the effects of exogenous testosterone on Leydig cells are still unclear and need to be clarified. In this report, we demonstrate that testosterone supplementation can reduce oxidative damage in Leydig cells. The TM3 Leydig cell line was used as an in vitro cell model in this study. Cytoprotective effects were identified with 100-nmol l⁻¹ testosterone treatment, but cytotoxic effects were found with ≥ 500-nmol l⁻¹ testosterone supplementation. Significantly reduced reactive oxygen species (ROS) generation, lipid peroxide contents and hypoxia induction factor (HIF)-1α stabilization and activation were found with 100-nmol l⁻¹ testosterone treatment. There was a 1.72-fold increase in ROS generation in the 500-nmol l⁻¹ compared to the 100-nmol l⁻¹ testosterone treatment. A 1.58-fold increase in steroidogenic acute regulatory protein (StAR) expression was found in 50-nmol l⁻¹ testosterone-treated cells (P < 0.01). Chemically induced hypoxia was attenuated by testosterone supplementation. Leydig cells treated with low-dose testosterone supplementation showed cytoprotection by decreasing ROS and lipid peroxides, increasing StAR expression and relieving hypoxia stress as demonstrated by HIF-1α stabilization. Increased oxidative damage was found with ≥ 500-nmol l⁻¹ testosterone manipulation. The mechanism governing the differential dose effects of testosterone on Leydig cells needs further investigation in order to shed light on testosterone replacement therapy.
Asian Journal of Andrology 02/2011; 13(3):432-7. · 1.52 Impact Factor
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Journal of Emergency Medicine 10/2010; 43(1):121-2. · 1.31 Impact Factor
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The American journal of medicine 04/2010; 123(4):320-1. · 4.47 Impact Factor
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Annals of the Academy of Medicine, Singapore 02/2010; 39(2):157. · 1.25 Impact Factor
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ABSTRACT: There are many combinations of treatments for pyogenic liver abscess (PLA). Different treatments are indicated for different clinical courses of PLA.
To realize the current prevalence, clinical course, trend of treatment, and prognosis of pyogenic liver abscess (PLA) in Taiwan.
We retrospectively reviewed the medical records of 126 patients with PLA. We divided them into four groups: M, MD, MS, and MDS, represented as parenteral antibiotic only, parenteral antibiotic with drainage, parenteral antibiotic with surgical intervention, and parenteral antibiotic with surgical drainage. We analyzed data by commercial statistical software (SPSS for Windows, version 11.0, SPSS Ltd., Chicago, IL). We used Student's t-test and χ(2) test for statistical analyses, and significance was set at a p value less than 0.05.
PLA patients who were treated only with parenteral antibiotics had early diagnosis of PLA with a mean fever period of 3.3 days (p = 0.043). Patients who needed surgical drainage were highly associated with shock presentation in the clinical course (35.7% versus 14.3%, p = 0.007).
The earlier we can diagnose PLA, the shorter the patient's hospital stay (20.6 days) will be. In PLA patients with shock, a higher rate of surgical intervention is mandatory to save their lives.
International Journal of Emergency Medicine 01/2010; 3(4):381-4.
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ABSTRACT: This is the case of 63-year-old mother and her 35-year-old daughter who drank herbal juice (Rhizoma Dioscoreae Nipponicae and Ficus formosana Maxim) and then developed diarrhea, cold sweating, and myoclonus. On physical examination, the mother had a normal consciousness level, a normal respiratory rate, and bilateral miosis. After the administration of 2 g of pralidoxime (PAM) and 0.5 mg of atropine, the mother felt better. The daughter only had mild symptoms of sweating and vomiting before arrival at the emergency department (ED).The poison center of our hospital was consulted, and they assured us that the herbs ingested were all non-toxic. In conclusion, the majority of emergency physicians are not familiar with herbal medicines and plants. In this instance, however, it was more important to apply appropriate early management according to the toxidrome rather than to recognize what kind of herb had been ingested.
International Journal of Emergency Medicine 01/2010; 3(2):133-4.
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Journal of Emergency Medicine 09/2009; 40(6):e115-6. · 1.31 Impact Factor
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ABSTRACT: Foreign body ingestion is not an uncommon problem encountered in clinical practice. The accidental ingestion of fish bones may sometimes lead to penetration injuries with complicating abscess formation. The ingestion of foreign bodies results in gastrointestinal perforation in about 1% of patients. Fish bones are the most commonly seen objects leading to bowel perforation. Fish bones are usually invisible on plain films. A computed tomography (CT) scan of the abdomen is helpful to determine the cause of unexplained and persistent abdominal pain. If encapsulated abscess formation cannot be completely resolved by CT-guided drainage, surgical intervention should proceed to prevent profound sepsis. We present the case of a 75-year-old man who had fever and left lower abdominal pain. CT showed a hypodense lesion with a linear foreign body in the abdomen. An intra-abdominal abscess was diagnosed and after surgical intervention, a foreign body, which proved to be a fish bone, was removed. The man could not remember swallowing this bone.
International journal of infectious diseases: IJID: official publication of the International Society for Infectious Diseases 07/2009; 14(2):e171-2. · 2.17 Impact Factor
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The American Journal of the Medical Sciences 04/2009; 337(3):205. · 1.39 Impact Factor
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ABSTRACT: We present the case of a 42-year-old female who presented to our emergency department (ED) complaining of epigastric pain for four days. She had been seen in the outpatient department and ED previously for evaluation, but continued to experience epigastric pain with fever. Emergency panendoscopy was performed and a toothpick was discovered impacted in the duodenal bulb. The gastroenterologist was unable to remove the toothpick endoscopically. Computed tomography of the abdomen revealed a long and straight hyperdense foreign body, and intra-abdominal abscess formation. An emergency laparotomy was performed. The patient recovered gradually and was discharged 11 days later. She could not remember when she swallowed the wooden toothpick, but guessed that it was while out drinking. There is an old wives' tale in Taiwan that putting a toothpick in the cup while drinking beer reduces the likelihood of abdominal distention from the carbonation of the beer.
International journal of infectious diseases: IJID: official publication of the International Society for Infectious Diseases 01/2009; 13(5):e264-6. · 2.17 Impact Factor
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ABSTRACT: Xanthogranulomatous pyelonephritis (XGPN) is an unusual suppurative granulomatous reaction to chronic infection. It often occurs in the presence of chronic obstruction from a calculus, stricture or tumor. XGPN clinically presents with abdominal mass, pain, weight loss, anemia and pyuria. Here, we report a case of a 50-year-old woman who had extensive XGPN complicated by a rarely seen unusual devascularization of the transverse and descending colon resulting in ischemic colitis owing to compression by a large mass. The abdominal mass was the largest to be reported to date worldwide. The etiologies, symptoms and signs, complications, diagnosis and treatment are also reviewed in this article.
International journal of infectious diseases: IJID: official publication of the International Society for Infectious Diseases 11/2008; 13(3):e89-91. · 2.17 Impact Factor
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ABSTRACT: In the majority of pneumoperitoneum cases we diagnose perforated viscus. We present herein a case of ruptured hepatic abscess mimicking perforated viscus.
A 40-year-old man presented to the emergency room with fever and right upper quadrant abdominal pain. The fever had been on/off for a period of 1 month. On physical examination, diffuse abdominal pain with rebounding tenderness was noted. Blood tests showed leukocytosis with left shift, hyperglycemia, and elevated liver function tests. A chest X-ray showed a subdiaphragmatic region air-fluid level, indicating a hepatic abscess. Pneumoperitoneum was also seen. Owing to the status of peritonitis, computed tomography (CT) of the abdomen was performed and revealed an air-containing liver abscess in the right lobe of the liver. Perforation of a hollow organ was also suspected because of the pneumoperitoneum. An emergent laparotomy was immediately performed for the suspicion of a hollow organ perforation. No perforation of the hollow viscus was found. The ruptured hepatic abscess was attributed to the pneumoperitoneum. A blood culture grew Klebsiella pneumoniae four days later, and the same organism was also found in a surgical specimen culture of the abscess.
For a ruptured hepatic abscess, surgical intervention with draining of the abscess and cleaning of the abdominal cavity are essential to save patient lives.
International journal of infectious diseases: IJID: official publication of the International Society for Infectious Diseases 10/2008; 12(6):e95-7. · 2.17 Impact Factor
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ABSTRACT: Acute abdomen is an emergent condition in the emergency department, and it is mandatory to evaluate it immediately and treat it without delay. Pneumoperitoneum is usually attributed to perforation of the gastrointestinal tract. However, intra-abdominal, gynecologic, urologic, and miscellaneous pathogenesis not related to a perforated gastrointestinal tract had never been described in the past. Approximately 10% of pneumoperitoneum is not associated with hollow organ perforation. There are many imitators of pneumoperitoneum including subphrenic abscess, colon volvulus, Chilaiditi syndrome, and so on. In our case, the gas-forming bacterial peritonitis accounted for the pneumoperitoneum. We presented an 85-year-old man who received laparotomy due to peritonitis, and radiographic subphrenic free air was seen. However, a large amount of ascites was found rather than perforated bowels during the surgical exploration, and the culture of ascites was positive for Pseudomonas aeruginosa.
The American journal of emergency medicine 10/2008; 26(7):838.e3-5. · 1.54 Impact Factor
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ABSTRACT: We sought to evaluate the effects of clonidine on type-2 cationic amino acid transporter (CAT-2) transcription in endotoxin-activated murine macrophages.
To determine the effects of clonidine on CAT-2 transcription, confluent murine macrophages (RAW264.7 cells) were treated with 1x phosphate buffered saline, clonidine (1000 microM), lipopolysaccharide (LPS, 100 ng/mL), or LPS plus clonidine (10, 100, or 1000 microM). After reacting with LPS for 18 hours or a comparable duration in groups without LPS, cell cultures were harvested and the CAT-2 mRNA concentration was assayed. To determine the stability of CAT-2 mRNA, confluent macrophages were treated with LPS or LPS plus clonidine (100 microM). After reacting with LPS for 6 hours, CAT-2 transcription was terminated and the stability of CAT-2 mRNA was determined.
The CAT-2 mRNA concentration of cell cultures receiving LPS plus clonidine (100 microM) or LPS plus clonidine (1000 microM) were significantly higher than that of the cell cultures receiving LPS alone, whereas the CAT-2 mRNA concentrations of cell cultures receiving LPS plus clonidine (10 microM) was comparable to that of cell cultures receiving LPS alone. The data indicated that clonidine significantly enhanced LPS-induced CAT-2 transcription. The estimated half-life of CAT-2 mRNA of cell cultures receiving LPS was similar to that of cell cultures receiving LPS plus clonidine. These results indicated that clonidine did not affect CAT-2 mRNA stability.
Clonidine enhances CAT-2 transcription in endotoxin-activated murine macrophages.
Acta Anaesthesiologica Taiwanica 10/2008; 46(3):118-23.
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ABSTRACT: Effects of dexmedetomidine on regulating endotoxin-induced upregulation of inflammatory molecules were elucidated.
Murine macrophages (RAW264.7 cells) were treated with lipopolysaccharide (LPS, 100 ng/mL), LPS plus dexmedetomidine (0.01, 0.1, 1, 10, or 100 microM), LPS plus dexmedetomidine plus yohimbine, or LPS plus dexmedetomidine plus idazoxan. The dosages of dexmedetomidine were chosen to correspond to 1, 10, 100, and 1000 times of clinically relevant dosages (i.e., 0.01-0.1 microM). The levels of inducible nitric oxide synthase (iNOS)/nitric oxide (NO), cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), IL-6, and IL-10 were measured.
Dexmedetomidine at 0.01 microM did not affect iNOS expression and NO production in activated macrophages. At 1 microM, dexmedetomidine significantly inhibited iNOS expression (up to 20.8% +/- 4.7%) and NO production (up to 26.2% +/- 6.8%). In contrast, dexmedetomidine at 100 microM significantly enhanced iNOS expression (up to 31.5% +/- 7.5%) and NO production (up to 34.9% +/- 5.6%). The effects of dexmedetomidine on COX-2 expression and the production of PGE2, TNF-alpha, IL-1beta, IL-6, and IL-10 paralleled the effects of dexmedetomidine on iNOS. Moreover, these effects were significantly reversed by both of the alpha2-adrenergic receptor antagonists, yohimbine, and idazoxan.
Dexmedetomidine at clinically relevant dosages did not significantly affect the expression of inflammatory molecules in activated macrophages. In contrast, dexmedetomidine at dosages higher than clinically relevant ones posted small but significant biphasic effects (inhibiting, then enhancing) on regulating the expression of inflammatory molecules, possibly through the alpha2-adrenergic receptors. However, as the magnitude of changes was relatively small, these effects may not be clinically significant.
Journal of Surgical Research 09/2008; 154(2):212-9. · 2.25 Impact Factor
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ABSTRACT: Most patients with appendicitis had elevated white blood cell count. It is rarely seen with leukopenic presentation in acute appendicitis. Physicians in the emergency department easily miss these cases that had normal white blood cell count and leukopenic presentation. We presented a case of a 38-year-old man who had right lower quadrant abdominal pain with fever. White blood cell count was only 1800/microL. Computed tomography showed thickening with fluid contained in the lumen of distended appendix, and emergent appendectomy was done. Accurate diagnosis of acute appendicitis is still based on the clinical history and physical examination adjuvant with imaging studies.
The American journal of emergency medicine 08/2008; 26(6):735.e3-4. · 1.54 Impact Factor
