Biomedical subjects

Shih-Horng Huang

Publications and source records attributed to Shih-Horng Huang.

11 recordsLinked to original sources

PubMed2006

Impact of previous abdominal surgery on laparoscopic appendectomy for acute appendicitis.

BACKGROUND: Laparoscopic appendectomy is one of the most commonly performed laparoscopic procedures. Impact of previous abdominal surgery on laparoscopic appendectomy has not been previously reported. METHODS: From January 2001 to December 2005, 2029 patients with clinically suspected acute appendicitis underwent laparoscopic surgery in our hospital. Of these, 234 patients (11.5%) were found to have other pathology by intraoperative or histologic findings and were excluded from the study. The 1795 patients who underwent laparoscopic appendectomy for acute appendicitis were divided into three groups: group 1, patients without a history of previous abdominal surgery (n = 1652, 92%); group 2, patients with a history of upper abdominal surgery (n = 20, 1.1%); group 3, patients with a history of lower abdominal surgery (n = 123, 6.8%). Data were collected retrospectively by chart review and analyzed for conversion rate, operative time, intraoperative and postoperative complications, and hospital stay. RESULTS: Of the 1795 patients, 13 (0.7%) were converted to open appendectomy because of technical difficulty. Overall mean operative time was 57.2 (range, 20-225) min. There was no mortality or intraoperative complications. Overall postoperative complication rate was 10.7% (n = 193): rate of surgical wound infection was 8.2% (n = 147), surgical wound seroma 1.3% (n = 24), and intra-abdominal abscess 0.8% (n = 14). Overall postoperative hospital stay averaged 3.2 (range, 0-39) days. There were no significant differences between the three groups regarding the conversion rate (0.8% vs. 0% vs. 0%, p = 0.567), operative time (57.3 vs. 55.8 vs. 56.9 min, p = 0.962), postoperative complication rates (10.7 vs. 10 vs. 12.2%, p = 0.863), and hospital stay (3.2 vs. 3.6 vs. 3.1 days, p = 0.673). CONCLUSIONS: Previous abdominal surgery, whether upper or lower abdominal, has no significant impact on laparoscopic appendectomy for acute appendicitis.

Acute Disease↗

PubMed2006

Effects of PPARgamma agonists on cell survival and focal adhesions in a Chinese thyroid carcinoma cell line.

Peroxisome proliferator-activated receptor gamma (PPARgamma) agonists cause cell death in several types of cancer cells. The aim of this study was to examine the effects of two PPARgamma agonists, ciglitazone and 15-deoxy-delta(12,14)-prostaglandin J2 (15dPGJ2), on the survival of thyroid carcinoma CGTH W-2 cells. Both ciglitazone and 15dPGJ2 decreased cell viability in a time- and dose-dependent manner. Cell death was mainly due to apoptosis, with a minor contribution from necrosis. Increased levels of active caspase 3, cleaved poly (ADP-ribose) polymerase (PARP), and cytosolic cytochrome-c were noted. In addition, ciglitazone and 15dPGJ2 induced detachment of CGTH W-2 cells from the culture substratum. Both the protein levels and immunostaining signals of focal adhesion (FA) proteins, including vinculin, integrin beta1, focal adhesion kinase (FAK), and paxillin were decreased after PPARgamma agonist treatment. Meanwhile, reduced phosphorylation of FAK and paxillin was noted. Furthermore, PPARgamma agonists induced expression of protein tyrosine phosphatase-PEST (PTP-PEST), and of phosphatase and tensin homologue deleted on chromosome ten (PTEN). The upregulation of these phosphatases might contribute to the dephosphorylation of FAK and paxillin, since pre-treatment with orthovanadate prevented PPARgamma agonist-induced dephosphorylation of FAK and paxillin. Perturbation of CGTH W-2 cells with anti-integrin beta1 antibodies induced FA disruption and apoptosis in the same cells, thus the downregulation of integrin beta1 by PPARgamma agonists resulted in FA disassembly and might induce apoptosis via anoikis. Our results suggested the presence of crosstalk between apoptosis and integrin-FA signaling. Moreover, upregulation and activation of PTEN was correlated with reduced phosphorylation of Akt, and this consequence disfavored cell survival. In conclusion, PPARgamma agonists induced apoptosis of thyroid carcinoma cells via the cytochrome-c caspase 3 and PTEN-Akt pathways, and induced necrosis via the PARP pathway.

Apoptosis↗

PubMed2006

Macrophage activation increases the invasive properties of hepatoma cells by destabilization of the adherens junction.

Tumor-associated macrophages play an important role in tumor progression, but whether they exert a tumor-progressive effect remains controversial. Here, we demonstrated that activated macrophage-conditioned medium (AMCM) obtained from RAW macrophages (RAW/AMCM) induced epithelial-mesenchymal transition (EMT) and stimulated the migratory and invasive activities of HepG2 cells, whereas control conditioned media had no effect. Epithelial-cadherin (E-cadherin) and beta-catenin staining patterns were altered at the adherens junctions by RAW/AMCM treatment, with an approximately 50% decrease in E-cadherin and beta-catenin in the cell membrane. Importantly, levels of beta-catenin-associated E-cadherin were also decreased. Following RAW/AMCM treatment, enhanced activation of c-Src was seen prior to increased tyrosine phosphorylation of beta-catenin, and this led to the destabilization of adherens junctions. Pretreatment of HepG2 cells with the Src kinase inhibitor, PP2, completely abolished the effects of RAW/AMCM on the EMT, migration, invasion, and expression and association of E-cadherin and beta-catenin. AMCMs obtained from human THP-1 monocytes and mouse peritoneal macrophages also caused disassembly of the adherens junctions and migration of HepG2 cells. Furthermore, inhibition of the epidermal growth factor receptor (EGFR) with gefitinib partially prevented the downregulation of E-cadherin and beta-catenin at the adherens junctions and migration behavior induced by RAW/AMCM. Our results suggest that activated macrophages have a tumor-progressive effect on HepG2 cells which involves the c-Src- and EGFR-dependent signaling cascades.

Adherens Junctions↗

PubMed2006

Laparoscopic versus open appendectomy for perforated appendicitis.

The role of laparoscopic appendectomy (LA) for perforated appendicitis is under investigation. A retrospective study was conducted to compare the outcomes of laparoscopic versus open appendectomy (OA) for perforated appendicitis. From January 2001 through December 2003, 229 patients with perforated appendicitis were treated at Far-Eastern Memorial Hospital. LA was successfully completed in 91 of 99 patients. OA was performed in 130 patients. Operation time was longer in the LA group (mean +/- SD = 96.1 +/- 43.1 vs. 67.8 +/- 32.2 minutes, P < 0.01). Return of oral intake was faster in the LA group (3.2 +/- 2.4 vs. 5.0 +/- 7.0 days, P < 0.01). The intravenous antibiotic usage period was shorter in the LA group (4.4 +/- 2.8 vs. 6.3 +/- 7.1 days, P < 0.01). The postoperative wound infection rates were 15.2 % (LA group) and 30.7% (OA group). The overall infectious complication rates were 19% in the LA group and 37% in the OA group (P < 0.01). Hospital stay days were shorter for the LA group (6.3 +/- 2.9 vs. 9.3 +/- 8.6 days, P < 0.01). Our results indicated that laparoscopic appendectomy is a safe and effective procedure for treating patients with perforated appendicitis.

Adult↗

PubMed2006

Laparoscopic diagnosis and treatment of small bowel obstruction caused by postoperative intussusception.

Small bowel obstruction is a common problem, especially for patients who have had previous abdominal surgery possibly complicated by postoperative adhesions. In contrast to adhesions, postoperative intussusception is an unusual cause of small bowel obstruction. We report a case of small bowel obstruction that occurred one month after antrectomy for duodenal ulcer with massive bleeding. Laparoscopic surgery was attempted after conservative treatment failed. A segment of jejunojejunal intussusception about 50 cm below the ligament of Treitz was identified and laparoscopic reduction of the intussusception was performed. The patient had an uneventful postoperative course and remained asymptomatic at 10-month follow-up. Although not frequently encountered, postoperative intussusception should be considered a possible etiology in patients with postoperative small bowel obstruction. In experienced hands, the laparoscopic approach offers a feasible option for correct diagnosis and appropriate treatment in this situation.

Adult↗

PubMed2005

Laparoscopic appendectomy in pregnancy.

BACKGROUND: Laparoscopic appendectomy (LA) is a safe, effective, and beneficial procedure for the treatment of acute appendicitis. However, limited data are available regarding the safety and feasibility of LA during pregnancy. METHODS: Between January 2001 and August 2004, 1235 patients with clinically suspected appendicitis underwent laparoscopic surgery at our hospital. Eleven patients (0.9%) were pregnant women (mean age, 25 years; age range, 19-37 years; range of gestational age, 4-30 weeks). Clinical data collected retrospectively included demographic information; preoperative, procedural, and postoperative information; and outcome of the pregnancy. RESULTS: All 11 pregnant women underwent laparoscopic surgery without need of conversion. Ten patients underwent LA and were found to have acute appendicitis on histologic analysis. One patient had torsion of the right fallopian tube and a healthy-looking appendix; she underwent detorsion of the fallopian tube and incidental appendectomy. Mean operative time was 50.5 minutes (range, 20-135 minutes). Length of postoperative hospital stay averaged 4.2 days (range, 1-11 days). One patient had a surgical wound infection, which was managed conservatively. Mean follow-up period was 14 months (range, 2-46 months). Seven pregnant women delivered healthy term infants, 2 had planned abortions, and 1 experienced fetal loss due to uterine infection and premature contractions 1 month after LA. Another patient had normal results at prenatal examination. CONCLUSION: Our data support the accumulating evidence that LA is a safe and feasible procedure for the treatment of acute appendicitis in all trimesters of pregnancy. Close maternal and fetal monitoring is essential during and after the operation.

Adult↗

PubMed2005

Laparoscopic diagnosis and treatment of acute small bowel obstruction resulting from a congenital band.

Acute small bowel obstruction is a common problem, especially for those patients with previous abdominal surgery that can cause postoperative adhesions. Acute, non-postoperative small bowel obstruction is less common and has various etiologies. We report a case of acute small bowel obstruction without previous abdominal surgery. The patient underwent laparoscopic exploration, and a congenital band was found to cause direct compression of the ileum and entrapment of a segment of bowel loop. There was evidence of bowel strangulation. The color and peristalsis of the entrapped bowel loop recovered gradually after division of the band, and segmental bowel resection was avoided. He has remained asymptomatic since the procedure. We suggest early and aggressive surgical intervention for patients with acute, non-postoperative small bowel obstruction to avoid possible complications of bowel strangulation and gangrene. A laparoscopic approach may be a safe, feasible, and favorable option for correct diagnosis and appropriate treatment in this situation.

Acute Disease↗

PubMed2004

Signaling pathway of magnolol-stimulated lipolysis in sterol ester-loaded 3T3-L1 preadipocyes.

The aims of the present study were to examine the effect of magnolol on lipolysis in sterol ester (SE)-loaded 3T3-L1 preadipocytes and to determine the signaling mechanism involved. We demonstrate that magnolol treatment resulted in a decreased number and surface area of lipid droplets, accompanied by release of glycerol. The lipolytic effect of magnolol was not mediated by PKA based on the facts that magnolol did not induce an elevation of intracellular cAMP levels, and protein kinase A (PKA) inhibitor KT5720 did not block magnolol-induced lipolysis. Calcium/calmodulin-dependent protein kinase (CaMK) was involved in this signaling pathway, since magnolol-induced a transient rise of intracellular [Ca(2+)] and Ca(2+) influx across the plasma membrane, and CaMK inhibitor significantly abolished magnolol-induced lipolysis. Moreover, magnolol increased the relative levels of phosphorylated extracellular signal-related kinases (ERK1 and ERK2). In support of the involvement ERK, we demonstrated that magnolol-induced lipolysis was inhibited by PD98059, an inhibitor of mitogen-activated protein kinase kinase (MEK), and PD98059 reversed magnolol-induced ERK phosphorylation. Further, the relationship between CaMK and ERK was connected by the finding that CaMK inhibitor also blocked magnolol-induced ERK phosphorylation. Taken together, these findings suggest that magnolol-induced lipolysis is both CaMK- and ERK-dependent, and this lipolysis signaling pathway is distinct from the traditional PKA pathway. ERK phosphorylation is reported to enhance lipolysis by direct activation of hormone sensitive lipase (HSL), thus magnolol may likely activate HSL through ERK and increase lipolysis of adipocytes.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed2003

Effects of 18beta-glycyrrhetinic acid on the junctional complex and steroidogenesis in rat adrenocortical cells.

Cellular junctions play important roles in cell differentiation, signal transduction, and cell function. This study investigated their function in steroid secretion by adrenal cells. Immunofluorescence staining revealed the presence of gap junctions and adherens junctions between adrenal cells. The major gap junction protein, connexin43, was seen as a linear dotted pattern of the typical gap junction plaques, in contrast to alpha-, beta-, and gamma-catenin, which were seen as continuous, linear staining of cell-cell adherens junction. Treatment with 18beta-glycyrrhetinic acid, a gap junction inhibitor, reduced the immunoreactivity of these proteins in a time- and dose-dependent manner, and caused the gap junction and adherens junction to separate longitudinally from the cell-cell contact sites, indicating the structural interdependency of these two junctions. Interestingly, 18beta-glycyrrhetinic acid stimulated a two- to three-fold increase in steroid production in these adrenal cells lacking intact cell junctions. These data raise the question of the necessity for cell communication for the endocrine function of adrenal cells. Pharmacological analyses indicated that the steroidogenic effect of 18beta-glycyrrhetinic acid was partially mediated by extracellular signal-related kinase and calcium/calmodulin-dependent kinase, a pathway distinct from the protein kinase A signaling pathway already known to mediate steroidogenesis in adrenal cells.

Adrenal Cortex↗

PubMed2003

Factors affecting long-term survival of Taiwanese patients with medullary thyroid carcinoma.

BACKGROUND AND PURPOSE: Long-term survival of patients with postoperative recurrence of medullary thyroid carcinoma (MTC) is not uncommon. This study assessed whether local or distant recurrence after operation is a significant factor affecting long-term survival in Taiwanese patients with MTC. The benefit of family screening for MTC patients on survival was also evaluated. METHODS: A total of 54 patients with a diagnosis of MTC by pathology or cytology during the period from 1977 to 2000 were included in the study. Survival curves were compared between different groups according to age, gender, tumor size, metastasis, recurrence after surgical intervention, or diagnosis before and after the performance of family screening for MTC patients. RESULTS: The 5-year survival rate using the Kaplan-Meier method was 84.1% (95% confidence interval, 73.9% to 94.2%), and the 10-year survival rate was 77.6% (95% confidence interval, 64.9% to 90.3%). Patients with lymph node metastasis and distant metastasis before operation had significantly shorter survival. Surprisingly, recurrence was not associated with shorter survival. Patients diagnosed after the start of family screening in 1991 had fewer lymph node metastases before operation, and lived longer. CONCLUSIONS: Patients with lymph node or distant metastasis before operation had poor prognosis. However, local or distant recurrence after operation did not influence survival. Efforts to obtain early diagnosis and surgical intervention before tumor metastasis, such as family screening, resulted in improved survival.

Adolescent↗

PubMedDate not supplied

Three-dimensional cytomorphology in fine needle aspiration biopsy of parathyroid lesions.

OBJECTIVE: To elucidate three-dimensional (3-D) cytomorphology in fine needle aspiration biopsy (FNAB) of parathyroid lesions. STUDY DESIGN: Ultrasound-guided FNAB was performed on parathyroid lesions from 10 patients with hyperparathyroidism. The aspirates were stained and observed under a light microscope (LM). The aspirates were also fixed, dehydrated, critical point dried, spattered with gold ions and observed with a scanning electron microscope (SEM). Findings under SEM were correlated with the appearances under LM as well as with serum parathyroid hormone (PTH) concentrations. RESULTS: Under LM, nine cases displayed isokaryosis and one case, anisokaryosis. These appearances corresponded to isocytosis or anisocytosis under SEM. Under SEM, 3-D cytomorphology of parathyroid lesions displayed isocytotic, scattered cells in five cases, uniform cellular arrangements in four cases and anisocytotic, scattered cells in one case. The cell surface was rather smooth in five cases. The other five cases had significant granules on the cell surfaces; these all had serum PTH concentrations > or = 268 pg/mL. CONCLUSION: 3-D cytomorphology in FNAB of parathyroid lesions was a rather smooth cell surface in cases with low serum PTH and a granular cell surface in cases with significantly increased serum PTH. These characteristics and the absence of microvilli might be helpful in the differential diagnosis between parathyroid and follicular thyroid lesions.

Adenoma↗