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Biomedical subjects

Chia-Ming Liu

Publications and source records attributed to Chia-Ming Liu.

17 recordsLinked to original sources
PubMed2005

Normalization of maxillary sinus mucosa after functional endoscopic sinus surgery in pediatric chronic sinusitis.

OBJECTIVES: To observe the recovery of maxillary sinus mucosa after endoscopic sinus surgery in children with chronic maxillary sinusitis. Functional endoscopic sinus surgery (FESS) was used to perform a middle meatal antrostomy, leaving the antral mucosa intact for later observation. METHODS: Between January 1998 and December 2003, 43 children with chronic sinusitis were enrolled in the study. Pre-operative patient profiles, including a history of symptoms, signs and allergies, were collected. Phidiatap test was used to check allergy. Saccharine transit time tests were performed for each side of the nasal cavity. Under endoscopic observation, the antral mucosa was macroscopically divided into edematous and polypoid types. RESULTS: Sixty-four (76.2%) of the 84 antrums had edematous type mucosa in which 73.4% (48/64) of cases were found to have returned to normal within 8 weeks. The polypoid antral mucosa exhibited a slower recovery with 80% (16/20) returning to normal within 4 months. The preoperative saccharine transit time significantly correlated with recovery of the antral mucosa (p < 0.05), but allergy did not (p > 0.05). CONCLUSION: The antral mucosa in children with chronic maxillary sinusitis was predominantly of the edematous type. Most recovered within 2 months of having FESS. The prolonged saccharine transit time and polypoid type antral mucosa were associated with delayed mucosal recovery, warranting follow-up of more than 4 months.

Adolescent↗
PubMed2005

HMB-45 may be a more sensitive maker than S-100 or Melan-A for immunohistochemical diagnosis of primary oral and nasal mucosal melanomas.

BACKGROUND: Primary mucosal melanomas (MMs) of the head and neck are a rare entity. Melanomas with characteristic melanin-pigmented tumor cells are easy to diagnose, but those without melanin-pigmented tumor cells, amelanotic melanomas, are difficult to identify and need immunohistochemistry (IHC) to confirm the final diagnosis. In this study, we examined the expression of three melanocytic differentiation markers, HMB-45, S-100, and Melan-A in primary oral and nasal MMs. We tried to evaluate whether HMB-45, S-100, and Melan-A were useful for diagnosis of primary oral and nasal MMs and to find out which marker was the best of the three. METHODS: This study used IHC to examine the expression of HMB-45, S-100, and Melan-A in 17 formalin-fixed paraffin-embedded specimens of primary oral and nasal MMs. The staining intensities (SIs) and labeling indices (LIs) of HMB-45, S-100, and Melan-A in 17 MMs were calculated and compared between any two markers. RESULTS: Immunostaining results showed that the positive rate was 94% (16 of 17) for HMB-45, 88% (15 of 17) for S-100, and 71% (12 of 17) for Melan-A in 17 MMs. The SI of HMB-45 was significantly higher than that of S-100 (P = 0.0011) or of Melan-A (P = 0.0034). In addition, the mean LI of Melan-A (59 +/- 43%) was significantly lower than that of HMB-45 (83 +/- 28%, P = 0.0065) or of S-100 (79 +/- 33%, P = 0.0237). CONCLUSIONS: Our results indicate that both HMB-45 and S-100 show a high positive rate and LI in MMs and therefore may be good markers for immunohistochemical diagnosis of primary oral and nasal MMs. In addition, HMB-45 may be a more sensitive marker than S-100 because HMB-45 shows a significantly higher SI than S-100 in this study.

Adult↗
PubMed2005

C-C chemokine ligand 2 gene expression in nasal polyp fibroblasts: possible implication in the pathogenesis of nasal polyposis.

OBJECTIVES: Recruitment of macrophages is essential to the pathogenesis of nasal polyps (NP), since this disease is inflammation-related. In this study, the effects of tumor necrosis factor alpha (TNF-alpha) on the expression of C-C chemokine ligand 2 (CCL2) in fibroblasts derived from nasal polyps (NPFs) were investigated. The roles of cyclooxygenase (COX) 2 and prostaglandins in the mediation of TNF-alpha-stimulated CCL2 gene expression were also investigated. METHODS: Northern blot analysis was used to study the expression of CCL2 and c-Fos in cultured NPFs. An electrophoretic mobility shift assay was used to explore the interactions between activator protein 1 (AP- 1) and DNA. Immunohistochemistry was used to explore the in vivo expressions of COX-2, CCL2, and CD68 in NPs. RESULTS: The Northern blot analysis showed that TNF-alpha stimulated the expression of CCL2 and COX-2 genes, and the synthesis of CCL2 messenger RNA was COX-2-dependent. A transient elevation of c-Fos and c-Jun messenger RNAs was induced by TNF-alpha, whereas COX-2 inhibitors NS-398 and meloxicam abolished the up-regulation of c-Fos. The electrophoretic mobility shift assay revealed that TNF-alpha triggered AP-1 and DNA binding and again, NS-398 and meloxicam inhibited this reaction via reducing c-Fos synthesis. Curcumin (AP-1 inhibitor) markedly suppressed the TNF-alpha-induced CCL2 expression. The immunohistochemical staining of NP surgical specimens also revealed an intimate alignment between CCL2-positive fibroblasts and CD-68-positive macrophages. CONCLUSIONS: These data suggest that NPFs may contribute to NP development by synthesizing CCL2 to promote macrophage recruitment. Furthermore, COX-2 facilitates CCL2 transcription in NPFs via a c-Fos and AP-1 signaling pathway.

Cells, Cultured↗
PubMed2005

Clinicopathologic and immunohistochemical characteristics of fungal sinusitis.

BACKGROUND AND PURPOSE: Fungal sinusitis (FS) is a common disease in Taiwan. Histologically, there are 4 types of FS, i.e., acute invasive, chronic invasive, fungal ball and allergic FS. Among the various fungal pathogens, Aspergillus is the most important. This study analyzed results of antibody staining against Aspergillus species on tissue sections of FS to identify fungal elements and evaluated the role of Aspergillus in different types of FS. METHODS: We retrospectively reviewed 140 cases with a pathologic diagnosis of FS in our hospital from 1995 to 2003. The clinical information, hematoxylin and eosin staining, and Gomori methenamine silver staining results for each patient were analyzed. Patients were reclassified into 4 categories of FS according to histologic presentation. The causative fungi were divided into Aspergillus and non-Aspergillus groups according to the results of immunoreactivity against anti-Aspergillus antibody. RESULTS: Fungal ball was diagnosed in 126 patients (90%), 66.6% of whom were females. Only 3 patients died of underlying disease not related to the fungal infection. Immunohistochemical staining demonstrated Aspergillus infection in 108 out of 119 patients (90.7%). Thirteen patients were categorized as having acute invasive FS due to the presence of vascular and stromal invasion. All but 1 patient had underlying diseases associated with immunocompromised status and 11 out of the 13 patients died of sepsis. Immunohistochemical study revealed 5 of these patients were infected with Aspergillus species, and the other 8 were infected with non-Aspergillus fungi. Allergic FS was diagnosed in 1 patient based on the presence of allergic mucin containing numerous eosinophils and few fungal hyphae. The fungal elements were negative for anti-Aspergillus antibody. None of the patients had chronic invasive FS. CONCLUSION: Fungal ball and acute invasive FS were the 2 most common types of FS in this study from Taiwan. However, both allergic FS and chronic invasive FS are rare. Immunohistochemical staining was useful in identifying specific species of fungus in tissue sections. Aspergillus accounted for 90.7% of fungal ball infections and 38.4% of acute invasive FS infections. It is important to differentiate among the categories of FS because the clinical course, etiology, treatment and prognosis are quite different.

Adolescent↗
PubMed2004

Examination of the signal transduction pathways involved in matrix metalloproteinases-2 in human pulp cells.

OBJECTIVES: Matrix metalloproteinases (MMPs) play an important role in pulp tissue destruction. However, the mechanisms and signal transduction pathways involved in the production of MMPs in human pulp cells are not fully understood. The purpose of this study was to investigate the gelatinolytic activity in human pulp cells stimulated with various pharmacological agents. STUDY DESIGN: Human dental pulp cells were cultured using an explant technique obtained from impacted third molars with informed consent of the patients. The effects of p38 inhibitor SB203580, MEK inhibitor U0126, extracellular signal-regulated kinase (ERK) inhibitor PD098059, phosphatidylinositaol 3-kinase (PI3K) inhibitor LY294002, cyclooxygenase-2 (COX-2) inhibitor NS-398, nuclear factor kappa B (NF-kappaB) inhibitor dexamethasone, and tyrosine kinase inhibitor herbimycin A on the production and secretion of MMPs by human pulp cells were determined by gelatin zymography. RESULTS: The main gelatinase secreted by human pulp cells migrated at 72 kd and represented MMP-2. Minor gelatinolytic bands were also observed at 92 kd regions that correspond to MMP-9. After a 4-day culture period, NS-398, dexamethasone, and herbimycin A were found to depress MMP-2 production (P<.05). The inhibition decreased in an order of dexamethasone >NS-398>herbimycin A. Human pulp cells, however, treated with various pharmacological agents had no effect on the pattern of MMP-9 produced or secreted in either cell extracts or conditioned medium fractions (P>.05). CONCLUSION: These observations suggest that NS-398, dexamethasone, and herbimycin A can regulate MMP-2 produced by human pulp cells. The signal transduction pathways COX-2, NF-kappaB, and tyrosine kinase may be involved in the production of MMPs.

Benzoquinones↗
PubMed2004

Digital atomic force microscope moiré method.

In this study, a novel digital atomic force microscope (AFM) moiré method is established to measure the displacement and strain fields. The moiré pattern is generated by the interference between the specimen grating and the virtual reference grating formed by digital image processes. The overlapped image is filtered by the 2-D wavelet transformation to obtain clear interference moiré patterns. From moiré patterns, the displacement and strain fields can be analyzed. The experimental results show that the digital AFM moiré method is very sensitive and easy to realize in nanoscale measurements.

Algorithms↗
PubMed2003

Induction of cyclooxygenase-2 mRNA and protein expression in human gingival fibroblasts stimulated with nicotine.

BACKGROUND: Cigarette smoking is a major risk factor in the development and further progression of periodontal diseases. COX-2 is an inducible enzyme believed to be responsible for prostaglandin synthesis at site of inflammation. Currently, there is limited information on the regulation of COX-2 expression in smoking-associated periodontal disease. OBJECTIVES: The aim of the present study was to investigate the effects of nicotine on the expression of cyclooxygenase-2 (COX-2) mRNA gene and protein in cultured human gingival fibroblasts (HGFs). Furthermore, to elucidate whether induction of COX-2 may be associated with nicotine- induced cytotoxicity, NS-398 (a selective COX-2 inhibitor), was added to test its protective effect. METHODS: The quantitative reverse-transcriptase polymerase chain reaction and Western blot assays were used to investigate the effects of human HGFs exposed to nicotine. In addition, NS-398 was added to test how it modulated the effects of nicotine. RESULTS: The exposure of quiescent human HGFs to nicotine resulted in the induction of COX-2 mRNA expression. The levels of the COX-2 mRNAs increased about 1.5 and 2.5 fold after exposure to 2.5 and 15 mm nicotine for 2 h (P < 0.05), respectively. Moreover, the peak of COX-2 mRNA levels induced by nicotine was 10 mm at 2 h incubation period. Investigations of the time dependence of COX-2 mRNA expression in nicotine-treated HGFs revealed a rapid accumulation of the transcript, a signal first detectable at 30 min and diminished to control level after 8 h. In addition, 10 mm nicotine also induced COX-2 protein expression in HGFs. The kinetics of this response showed that COX-2 was detectable at 4 h and diminished nearly to control level after 24 h. NS-398 at non-cytotoxic dose is not able to prevent nicotine-induced cytotoxicity. CONCLUSIONS: Taken together, the activation of COX-2 expression by nicotine suggests a potential role for nicotine in the pathogenesis of smoking-associated periodontal disease. In addition, nicotine-induced cytotoxicity is not directly via the induction of COX-2 expression.

Cells, Cultured↗
PubMed2003

Proinflammatory cytokines induce cyclooxygenase-2 mRNA and protein expression in human pulp cell cultures.

The increased release of prostaglandins (PG) within pulpal tissues is considered to play a pathogenic role during pulpal disease progression. The rate-limiting step in the formation of PG from arachidonic acid is catalyzed by cyclooxygenase (COX). COX-2 is an inducible enzyme believed to be responsible for PG synthesis at site of inflammation. The effect of proinflammatory cytokines on human pulp cells with special reference to COX-2 expression has not been reported earlier. The aim of the present study was to investigate the effects of interleukin (IL)-1alpha and tumor necrosis factor-alpha (TNF-alpha) on the expression of COX-2 mRNA gene and protein in cultured human pulp cells. Investigations of the time dependence of COX-2 mRNA expression in proinflammatory cytokines-treated human pulp cells revealed a rapid accumulation of the transcript, a significant signal first detectable 1 h after exposure. In addition, both IL-1alpha and TNF-alpha up-regulated COX-2 protein expression by human pulp cells. The kinetics of this response showed that COX-2 was detectable in cell lysates as early as 2 h post proinflammatory cytokines challenge and remained elevated throughout the 24-h incubation period. This suggests that one of the pathogenic mechanisms of pulpal inflammation in vivo may be the synthesis of COX-2 by resident cells in response to a proinflammatory cytokines challenge. COX-2 may play an important role in the regulation of prostanoid formation in the pathogenesis of pulpal inflammation. Taken together, we propose that the use of selective COX-2 inhibitors might provide a valuable tool in the control of pulpal inflammation.

Cell Culture Techniques↗
PubMed2003

Induction of cyclooxygenase-2 mRNA and protein expression in human pulp cells stimulated with black-pigmented bacteroides.

Cyclooxygenase-2 (COX-2) is induced after the activation of cells by a variety of proinflammatory agents. Recently, evidence has shown that COX-2 may play a role in the pathogenesis of pulpal inflammation. However, little is known regarding the mechanism of pulpal inflammation at the site of bacterial infection. The purpose of this study was to determine the effects of the supernatants from black-pigmented Bacteroides (Porphyromonas endodontalis, Porphyromonas gingivalis, and Prevotella intermedia) on the COX-2 expression in primary human pulp cells in vitro. Investigations of the time dependence of COX-2 mRNA expression in black-pigmented Bacteroides-treated human pulp cells revealed a rapid accumulation of the transcript, a significant signal first detectable after 1 h of exposure. In addition, black-pigmented Bacteroides also up-regulated COX-2 protein expression in human pulp cells. Data from our in vitro experiment showed that black-pigmented Bacteroides were capable of stimulating COX-2 expression in human pulp cells. These results indicate that black-pigmented Bacteroides species may play an important role in the pathogenesis of pulpal inflammation. The activation of COX-2 may be one of the distinct host degradative pathways in the pathogenesis of microbial-induced pulpal/periapical inflammation.

Blotting, Western↗
PubMed2003

Primary sinonasal non-Hodgkin's lymphoma masquerading as chronic rhinosinusitis: an issue of routine histopathological examination.

Primary non-Hodgkin's lymphoma (NHL) of the sinonasal tract is uncommon. Morphologically and radiographically, sinonasal lymphomas are difficult to distinguish from other malignant neoplasms or non-neoplastic processes. However, there is no general consensus about the need of routine histopathological examination for nasal polyps among otolaryngologists. We present a case of primary sinonasal NHL mimicking chronic rhinosinusitis and debate the issue of routine histopathological examination. We suggest that all tissues removed from the sinonasal tract during surgery must be submitted for histopathological examination. Failure to do so may miss diagnosis and delay appropriate treatment.

Diagnosis, Differential↗
PubMed2002

Inducible cyclooxygenase and interleukin 6 gene expressions in nasal polyp fibroblasts: possible implication in the pathogenesis of nasal polyposis.

BACKGROUND: Inflammation is believed to be related to the pathogenesis of nasal polyp (NP). Inducible cyclooxygenase (COX-2) and interleukin (IL) 6 are important mediators of inflammation. However, no information is available regarding the expression of these mediators in nasal polyp fibroblasts (NPFs). The inductive effects of proinflammatory cytokines (IL-1alpha or tumor necrosis factor alpha) alone or in combination with prostaglandin E(2) on IL-6 and COX-2 messenger RNA (mRNA) synthesis in NPFs were investigated. DESIGN: The expressions of IL-6 and COX-2 mRNAs in NPFs and in 34 surgical specimens of NP were detected by Northern blot and in situ hybridization. RESULTS: Significant amounts of constitutive IL-6 and COX-2 mRNAs were produced in NPFs. Cytokines induced IL-6 and COX-2 mRNA synthesis in NPFs. Meloxicam (a specific COX-2 inhibitor) suppressed the induction of cytokines on IL-6 mRNA levels, and these effects could be reversed by exogenous prostaglandin E(2). In situ hybridization revealed that IL-6 and COX-2 mRNAs were detected primarily in fibroblasts, macrophages, and plasma cells. Aggregation of plasma cells as well as collagen deposition in vicinity to IL-6 mRNA-producing fibroblasts was found. Rich vascularity around COX-2 mRNA(+) fibroblasts was also identified. CONCLUSIONS: The pathogenesis of nasal polyposis involves NPFs through synthesizing IL-6 to modulate the activation of immune responses (plasma cell formation) and synthesis of stroma. Inducible cyclooxygenase also contributes to NP development by promoting vasodilatation and modulating the cytokine-induced IL-6 gene expression in NPFs.

Antineoplastic Agents↗
PubMed2002

Influence of cosolvents and in situ forming hydroxyapatite on the mechanical characteristics of collagen films.

Collagen was processed into films in mixtures containing various ratios of water, propylene glycol, and ethanol. An experimental mixture design was applied to characterize the effects of individual solvents and their interactions on the mechanical properties of collagen films. Scanning electron microscopy (SEM) was used to examine the surface properties of collagen films. The ultimate tensile strength (UTS) and related characteristics of collagen films were also evaluated with dynamic mechanical analysis. The effect of in situ forming hydroxyapatite (HAP) within collagen films at a concentration of 10 mM on the physical characteristics of these films was evaluated by the same methods. With X-ray and SEM examinations, it was confirmed that HAP was formed inside the collagen film. However, the UTS of collagen films without HAP was 4-5 times higher than that with HAP. This was probably due to the discontinuity of the film structure caused by HAP in the collagen films. The results of a statistical analysis of the experimental design revealed the influence of the solvent mixtures on the mechanical properties of the collagen films with and without HAP, showing similar responses for the UTS and modulus of elasticity. Both parameters showed a maximal response in the solvent range containing a lower percentage of ethanol with the desired percentage of propylene glycol to plasticize the collagen films.

Biocompatible Materials↗
PubMed2002

Videostrobolaryngoscopy of mucus layer during vocal fold vibration in patients with laryngeal tension-fatigue syndrome.

The mucus layer on the vocal folds was examined by videostrobolaryngoscopy in patients with laryngeal tension-fatigue syndrome, a chronic functional dysphonia due to vocal abuse and misuse. Besides the findings in previous reports (such as abnormal glottal closure, phase or amplitude asymmetry, and the irregular mucosal wave), the vocal folds during vibration had an uneven mucus surface. The occurrence of an uneven mucus layer on vocal folds was significantly greater in subjects with this voice disorder (83% or 250 of 301 patients in this series) than in those without voice disorders (18.5% or 5 of 27). The increase of mucus viscosity, mucus aggregation, and the formation of rough surfaces on the vocal folds alter the mechanical properties that contribute to vibration of the cover of the vocal folds, and thereby worsen the symptoms of dysphonia in patients with laryngeal tension-fatigue syndrome.

Adult↗
PubMed2002

Increased epithelial cell proliferation in nasal polyps.

BACKGROUND AND PURPOSE: The mucociliary function of the sinonasal mucosa is an innate defense mechanism of the human nasal airway. Epithelial cell proliferation is required for cell renewal and repair of the sinonasal mucosa. In this study, the MIB-1 monoclonal antibody, which can detect the S-phase nuclear protein Ki-67, was used to evaluate the proliferation of the sinonasal mucosa in patients with various inflammatory conditions of the sinonasal mucosa. METHODS: Specimens from the inferior turbinates of patients with nasal allergy (n = 12), vasomotor rhinitis (n = 20), nasal polyps (n = 22), and control subjects undergoing rhinoplasty (n = 5) and mucosa of chronic sinusitis patients [inferior turbinates (n = 10), middle turbinates (n = 10), and maxillary sinus (n = 9)] were fixed in neutral formalin and embedded in paraffin. MIB-1 monoclonal antibody was used to detect proliferation of epithelial cells. RESULTS: Significantly increased epithelial cell proliferation was noted in nasal polyps compared to sinonasal mucosa. There was no difference among various sinonasal inflammatory conditions between patients and controls. CONCLUSIONS: Increased epithelial cell proliferation in nasal polyps may play an important role in covering the epithelial defects caused by the rupture of the epithelium and prolapse of connective tissue in nasal polyps.

Adolescent↗
PubMedDate not supplied

A rare complication of functional endoscopic sinus surgery: maxillary atelectasis-induced spontaneous enophthalmos.

BACKGROUND: The first case report of spontaneous enophthalmos due to maxillary atelectasis as a late complication of FESS is presented. METHODS: Chart review of a 24-year-old male who developed a left progressive enophthalmos within three months post bilateral functional endoscopic sinus surgery. RESULTS: The preoperative computed tomography showed a normal left maxillary sinus. The postoperative computed tomography revealed a left maxillary atelectasis with a descending orbital floor. The subject received revised endoscopic sinus surgery and his enophthalmos was stable without further progression after the operation. CONCLUSIONS: This may have been caused by an ostium occlusion with retention of secretions inducing sinus inflammation, osteolytic activity, and osseous remodeling of the sinus walls. A negative pressure may develop. When the pressure gradient exceeds the sinus wall tension, maxillary atelectasis and enophthalmos occur. Prevention of this complication of FESS should include making a patent naso-antral window, minimizing mucosal trauma, and careful postoperative sinoscopic treatment. A "functional" sinus is the goal.

Adult↗