Biomedical subjects

C Y Chen

Publications and source records attributed to C Y Chen.

At least 19 recordsLinked to original sources

PubMed1997

Optic atrophy and cerebral infarcts caused by methanol intoxication: MRI.

We present the MRI findings of cerebral and optic pathway damage in the acute and subacute stages of methanol intoxication. In the acute stage, CT and MRI showed bilateral haemorrhagic necrosis of the corpus striatum and infarcts in the anterior and middle cerebral arterial territories. MRI in the subacute stage demonstrated atrophy of the optic chiasm and prechiasmatic optic nerves in addition to the cerebral infarcts. The patient survived, with total blindness.

Adult↗

PubMed1997

Implications of Helicobacter pylori serological titer for the histological severity of antral gastritis.

BACKGROUND AND STUDY AIMS: We attempted to determine whether the serological titer of anti-Helicobacter pylori (HP) immunoglobulin (IgG) would be capable of predicting the presence of ulcer, or would correlate with the histological grading of gastritis in patients with dyspepsia. PATIENTS AND METHODS: One hundred eighty-three dyspeptic patients were prospectively included in the study after panendoscopy. Each patient underwent blood sampling for anti-HP IgG titer, and antral biopsy for both a rapid urease test (CLO) and histology. The severity of antral gastritis was semi-quantitated for acute and chronic inflammation scores (range 0-3). RESULTS: The HP findings were positive in 157 patients (85.5%), and their histological inflammation scores and serological titer were higher than those of HP-negative patients (P < 0.05). Based on the endoscopic findings, these 157 patients were classified into ulcer (n = 109) and non-ulcer dyspepsia (n = 48) subgroups. The mean chronic inflammation score in the ulcer subgroup was higher than that in the non-ulcer dyspepsia subgroup (1.77 vs. 1.28, P < 0.001). However, on the basis of only the titer itself, there was no cut-off value for serological titer to predict the presence or absence of ulcer in HP-infected patients. As the scores for either acute or chronic inflammation increased, the mean serological titer rose (acute inflammation score 0-3: 0.63, 0.78, 0.93, 1.39; chronic inflammation score 0-3: 0.18, 0.56, 0.88, 0.91). CONCLUSIONS: The titer of HP serology does not provide a method for predicting the presence of ulcer in patients with HP infection, but may indirectly offer evidence of the severity of histological changes.

Adult↗

PubMed1997

Comparison of enzyme immunoassays for antibodies to Haemophilus ducreyi in a community outbreak of chancroid in the United States.

The performance of two EIAs (adsorption EIA and lipooligosaccharide [LOS] EIA) that detect antibodies to Haemophilus ducreyi was evaluated with serum specimens obtained from 163 patients (96 with genital ulcer disease [GUD]). Paired serum specimens (initial and follow-up) were obtained from 52 of the GUD patients. By use of initial serum specimens from 82 GUD patients whose etiologic agents for their ulcers had been identified, the adsorption EIA had a sensitivity and specificity for chancroid of 53% and 71%, while the LOS EIA had a sensitivity and specificity of 48% and 89%, respectively. Sensitivity and specificity of the adsorption EIA increased to 78% and 84%, respectively, when the results of follow-up serum specimens were used to calculate optimal performance. The proportion of patients testing positive for H. ducreyi who had anti-H. ducreyi IgG antibodies, as determined by adsorption EIA, increased with the duration of infection, thus limiting the role of EIAs in the diagnosis of chancroid.

Adolescent↗

PubMed1997

Clinical assessment of the bacterial load of Helicobacter pylori on gastric mucosa by a new multi-scaled rapid urease test.

The present study tests the efficacy of the multi-scaled urease test (MUT) in detecting Helicobacter pylori infection and determines whether the MUT can predict the bacterial density on histology. A total of 111 sets of gastric specimens were obtained from patients with dyspepsia but without recent bleeding. Two biopsies were taken as closely as possible in each set. One sample was used for the MUT (Hp fast; GI Supply, Camp Hill, PA, USA), while the other was used to determine the histological density of H. pylori by modified Giemsa stain (grade 0-5). The results of MUT were interpreted as negative if the colour was yellow or bright green (reaction score 0) and positive if the colour was green, light blue, or blue (reaction score 1, 2 and 3, respectively). The reaction scores of MUT were recorded sequentially at 15 and 30 min and 1, 4 and 24 h. On the basis of histological confirmation, MUT had a sensitivity of 89.6%, a specificity of 88.2%, a positive predictive value of 94.5% and a negative predictive value of 78.9%. Focusing on specimens with the presence of bacteria under histology, 77 specimens were divided into five subgroups by grades of density of H. pylori (HPD1-5). The reaction scores had become sequentially elevated from 30 min through to 24 h in each subgroup. For subgroups HPD4 and 5, the positive rates of MUT were 70.6 and 66.6%, respectively, as early as 30 min and progressed to 100% within 4 h. In contrast, the positive rate for the HPD1 subgroup was 16.6% at 4 h and increased to only 62.5% at 24 h. In subgroups HPD 2 and 3, the positive rates were less than 30% at 30 min, but became more than 66.6% at 4 h and were 100% at 24 h. The early (i.e. mean value of reaction scores before 4 h) and late (24 h) mean reaction scores disclosed two elevated trends as the density of H. pylori increased (early: 0.2, 0.7, 0.8, 1.5, 1.2; late: 1.4, 2.3, 2.6, 3.0, 3.0; P < 0.05). In conclusion, MUT is a reliable method for the diagnosis of H. pylori infection. It can also indirectly predict the density of H. pylori on histology.

Biopsy↗

PubMed1997

Case report: life-threatening haematochezia from a jejunal leiomyoma.

Leiomyoma is a common benign intestinal tumour. Melaena is not rare in this tumour. Recently, rectal haematochezia has been considered as one of the very rare manifestations of leiomyoma. We report a case of jejunal leiomyoma showing life-threatening rectal bleeding. This 76-year-old man was admitted to hospital because of continuous rectal bleeding for 2 days. Haemorrhagic shock occurred and transfusion of 27 units of packed red blood cells failed to correct the shock. Emergent superior mesenteric angiography revealed a distal jejunal tumour showing evidence of active oozing. Segmental intestinal resection was performed to remove this jejunal tumour. Final pathological examination disclosed a jejunal leiomyoma with a ruptured artery responsible for the life-threatening bleeding. The patient recovered after tumour resection. Our presenting case was probably the second case of jejunal leiomyoma showing haematochezia. The diagnostic priority is discussed.

Aged↗

PubMed1997

Plasmid virulence gene expression induced by short-chain fatty acids in Salmonella dublin: identification of rpoS-dependent and rpo-S-independent mechanisms.

The Salmonella plasmid virulence spvABCD genes are growth phase regulated and require RpoS for maximal expression in stationary phase. We identified a growth phase-independent expression of spv which is mediated by short-chain fatty acids. During this fatty acid-mediated expression of spv, RpoS is required for induction only during exponential phase. In stationary phase, an rpoS-independent mechanism is responsible for expression of spv.

Bacterial Proteins↗

PubMed1997

Competition between negative acting YY1 versus positive acting serum response factor and tinman homologue Nkx-2.5 regulates cardiac alpha-actin promoter activity.

Transcription of sarcomeric alpha-actin genes is developmentally regulated during skeletal and cardiac muscle development through fine-tuned control mechanisms involving multiple cooperative and antagonistic transcription factors. Among the cis-acting DNA elements recognized by these factors is the sequence CC(A/T)6GG of the serum response element (SRE), which is present in a number of growth factor-inducible and myogenic specified genes. We recently showed that the cardiogenic homeodomain factor, Nkx-2.5, served as a positive acting accessory factor for serum response factor (SRF) and together provided strong transcriptional activation of the cardiac alpha-actin promoter. In addition, Nkx-2.5 and SRF collaborated to activate the endogenous murine cardiac alpha-actin gene in 10T1/2 fibroblasts, by a mechanism that involved coassociation of SRF and Nkx-2.5 on intact SREs of the alpha-actin promoter. Here, we show that the second SRE of the avian cardiac alpha-actin promoter served as a binding site for Nkx-2.5, SRF, and zinc finger containing GLI-Kruppel-like factor, YY1. Expression of YY1 inhibited cardiac alpha-actin promoter activity, whereas coexpression of Nkx-2.5 and SRF was able to partially reverse YY1 repression. Displacement of YY1 binding by Nkx-2.5/SRF complex occurs through mutually exclusive binding across the CaSRE2. The interplay and functional antagonism between YY1 and Nkx-2.5/SRF might constitute a developmental as well as a physiologically regulated mechanism that modulates cardiac alpha-actin gene expression during cardiogenesis.

Actins↗

PubMed1997

Rapid spongiform degeneration of the cerebrum and cerebellum in Creutzfeldt-Jakob encephalitis: serial MR findings.

We report the cerebral MR imaging findings in a patient with pathologically proved Creutzfeldt-Jakob disease in whom predominant gray and white matter degeneration was seen within 1 year of symptom onset. The initial MR signal abnormalities in the basal ganglia were subtle. A follow-up MR examination revealed diffuse cerebral and cerebellar atrophy and demyelination.

Atrophy↗

PubMed1997

Surgical treatment and its long-term result for caustic-induced prepyloric obstruction.

OBJECTIVE: To present our long-term results of the treatment of caustic-induced prepyloric obstruction, and to set out guidelines for the management of such patients. DESIGN: Retrospective study. SETTING: General hospital (medical centre), Taiwan. SUBJECTS: 30 patients (8 male and 22 female, mean age 34 years, range 13-62) who developed prepyloric obstruction out of 271 treated for caustic injuries of the upper gastrointestinal tract. INTERVENTIONS: Gastrojejunostomy (n = 24), antrectomy and Billroth I reconstruction (n = 4), and antrectomy and Billroth II reconstruction (n = 2). Four patients required second operations: oesophageal reconstruction for stricture (n = 3), and gastrojejunostomy for restenosis of Billroth I anastomosis (n = 1). MAIN OUTCOME MEASURES: Morbidity and mortality. RESULTS: No patient died postoperatively, and there were three complications--wound infection, internal bleeding, and stenosis of the Billroth I anastomosis. 21 patients were able to enjoy their normal diet postoperatively, 5 required periodic dilatation of oesophageal strictures, and 4 required further operations. CONCLUSIONS: Gastrojejunostomy gives good long term results as long as there is no oesophageal stricturing, and morbidity and mortality are low. The long term outcome is dependent on the degree of oesophageal involvement.

Adolescent↗

PubMed1997

Hyperbaric oxygen in the treatment of diabetic foot infection.

BACKGROUND: Although hyperbaric oxygen therapy to treat diabetic foot lesions has been approved for insurance reimbursement in Taiwan, its clinical application has not yet been well accepted. This study evaluated multiple healing predictive factors in patients with diabetic foot infections to determine the usefulness of adjunctive hyperbaric oxygen in the treatment of such patients. METHODS: From March 1995 to May 1996, we treated 31 diabetic patients presenting with infected foot lesions with a regimen of adequate metabolic control, frequent wound debridement and hyperbaric oxygen therapy. Age, gender, leukocyte count, total lymphocyte count, hemoglobin, erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), glycosylated hemoglobin Alc (HbAlc), albumin, ankle-brachial index, types of bacterial cultures and number of debridements were compared between successful and failed treatments. Independent t-test and Fisher's exact test were used to identify the prognostic factors associated with outcome of treatment. RESULTS: The mean age of the patients was 63.0 +/- 9.7 years (range 43 to 81). The mean number of hyperbaric oxygen therapies was 35.3 +/- 21.8 treatments (range 5 to 83). Of the 31 patients, 6 received below knee amputation, and 25 had their foot preserved or achieved a lower level of amputation. Elevated leukocyte count and low ankle-brachial index were significantly related to poor outcome. CONCLUSIONS: In the treatment of diabetic foot infection, adjunctive hyperbaric oxygen therapy seems to be a useful tool to enhance wound healing provided that there are preserved circulation and controlled infection.

Adult↗

PubMed1997

Optimal surgical strategy for potentially curable serosa-involved gastric carcinoma with intraperitoneal free cancer cells.

BACKGROUND: Radical gastrectomy with systematic lymphadenectomy (RG) remains controversial in the treatment of gastric carcinoma. On the other hand, the prognosis of gastric carcinoma, in the presence of intraperitoneal free cancer cells, is poor. The optimal surgical strategy for serosa-involved gastric carcinoma with intraperitoneal free cancer cells remains undefined. STUDY DESIGN: A prospective study of intraperitoneal cytologic washing was conducted on 134 patients with potentially curable serosa-involved gastric carcinoma who underwent RG. During the same period, 28 patients with resectable tumors who received palliative simple gastrectomies because of the presence of gross incurable conditions (eg, multiple hepatic metastases, peritoneal carcinomatosis, or extra-abdominal metastasis) were used as controls. RESULTS: Intraperitoneal free cancer cells were found in 26 patients (19.4 percent). Compared with the remaining 108 patients without free cancer cells, there were no significant differences in the clinicopathologic characteristics and pathologic stages. No patients died after palliative resection, but five patients died after RG. The patients with free intraperitoneal free cancer cells had a poorer long-term prognosis after RG than those without free cancer cells (p < 0.0001). The prognosis for such patients was similar to the prognosis of those who underwent palliative resection. CONCLUSIONS: A peritoneal washing cytologic examination is mandatory before resection for potentially curable serosa-involved gastric carcinoma. When free cancer cells appear in the washing fluid, the cancer is incurable. Simply gastrectomy without additional lymphadenectomy is the optimal strategy for treatment.

Aged↗

PubMed1997

Utilization of Chinese medicine in Taiwan.

This article examines the use of Chinese medicine in Taiwan. Based on a national sample survey, the authors investigated how Chinese medicine is being used and factors that are associated with its use among the Taiwanese. Results of the study suggest that Chinese medicine use among this population depends on health conditions, and that having a regular source of care for Chinese medicine as well as a preference for Chinese medicine are two predictors for its use. Policies on the integration of Chinese medicine or other traditional medicine into the modern healthcare system are recommended.

Adolescent↗

PubMed1996

Separate pathways for p53 induction by ionizing radiation and N-(phosphonoacetyl)-L-aspartate.

The tumor suppressor gene product, p53, appears to be a significant participant in signaling pathways that mediate cellular responses to cytotoxic stresses. In particular, p53 appears to be a critical determinant of whether the cell lives or dies and how it progresses through the cell cycle after the cytotoxic exposure. Many of the molecular details for these signaling pathways remain to be elucidated, and whether all cytotoxic signals utilize the same pathway to increase p53 expression is not clear. Here, we demonstrate the existence of cell types in which the induction of p53 and associated G1 arrest by the antimetabolite, N-(phosphonoacetyl)-L-aspartate (PALA), is defective, whereas p53 induction and G1 arrest induced by ionizing radiation are intact. These observations demonstrate the existence of genetic defects that can alter p53 induction and associated cellular outcomes after some, but not all, cytotoxic insults and suggest distinct pathways of p53 induction by PALA and ionizing radiation.

Antimetabolites, Antineoplastic↗

PubMed1996

Co-existence of atrial tachycardia and common atrial flutter: electrophysiological characteristics and radiofrequency catheter ablation.

Four patients, who had no prior atrial surgery, underwent radiofrequency ablation for clinically documented typical atrial flutter. In addition to typical atrial flutter re-entrant atrial tachycardia was initiated during electrophysiological study in these four patients. We used earliest atrial endocardial activation and concealed entrainment pace mapping with short stimulus-P interval (< 40 ms) to identify the exit site of slow conduction are of atrial flutter were located at the posteromedial right atrium between the coronary ostium and the tricuspid annulus and those of slow conduction area of atrial tachycardia were located at high lateral right atrium in all four patients. Radiofrequency energy applied to these exit sites successfully eliminated both atrial flutter and atrial tachycardia in these four patients. Typical atrial flutter and re-entrant atrial tachycardia with two distinct re-entrant circuits concomitantly occurring in patients without prior atrial surgery are rare. Radiofrequency ablation can abolish both atrial tachyarrhythmias in the same ablation session.

Aged↗

PubMed1996

Phosphorylation of Bcl-2 protein and association with p21Ras in Ras-induced apoptosis.

p21Ras mediates mitogenic responses and also renders cells susceptible to apoptosis after inhibition of protein kinase C (PKC) activity. Ras-induced apoptosis can be blocked by the proto-oncogene bcl-2, but the biochemical or functional nature of Bcl-2 regulation of Ras-induced apoptosis is not understood. We demonstrate that Bcl-2 and p21Ras molecules can be co-immunoprecipitated in Jurkat cells. The level of this association is enhanced when an apoptotic stimulus (inhibition of PKC activity) is delivered. Bcl-2/p21Ras association is coincident with new phosphorylation of the Bcl-2 protein. Inhibition of this phosphorylation prevents protection from apoptosis by Bcl-2, providing a functional correlation to the phosphorylation event. The Bcl-2/p21Ras association cannot be competed by exogenous glutathione S-transferase-Ras fusion protein, suggesting that the endogenous complex may be formed before cell lysis. These results provide a possible mechanism of regulation of Ras-induced apoptosis by Bcl-2.

Apoptosis↗

PubMed1996

Osa protein encoded by plasmid pSa is located at the inner membrane but does not inhibit membrane association of VirB and VirD virulence proteins in Agrobacterium tumefaciens.

The osa gene of IncW plasmid pSa encodes a 21-kDa protein that completely abolishes the oncogenic activity encoded by virulence genes in Agrobacterium tumefaciens. osa is the last gene of a four-gene operon in pSa, the expression of which appears to be highly regulated since the Osa protein is absent when either pSa or the osa operon is present in the Agrobacterium cell. When the osa gene alone or together with upstream genes within the operon are expressed under the control of a constitutive promoter. Osa protein is produced, enabling us to determine its subcellular location. Immunoblot analyses located Osa protein at the inner membrane of both A. tumefaciens and Escherichia coli. Because Osa inhibits oncogenicity of A. tumefaciens, and because alterations of the products of the virB and virD genes affect oncogenicity, studies were conducted to determine if there are changes in their specific association with the membranes in the presence Osa. Immunoblot analyses of VirB2, VirB3, VirB4, VirB9, and VirD4 in the presence and absence of Osa revealed no differences between the two treatments in these Vir protein associations with the membranes. These results indicate that both virB and virD gene products are produced in the presence of Osa; that they appear unaffected in their association with the membranes; and that Osa is associated with the inner membrane, where VirB2, VirB4, and VirD4 proteins are also located.

Agrobacterium tumefaciens↗

PubMed1996

Molecular epidemiology of cytomegalovirus infection in kindergarten children.

This study was conducted to determine the source of cytomegalovirus (CMV) excretion in children who had persistent viruria. A total of 287 children, ages 3-5 years, enrolled in two kindergartens were followed for 9 months, and 28.8% of 139 CMV-infected children were found to have shed virus persistently in urine for > or = 3 months. A polymerase chain reaction (PCR)-based method provided direct evidence to demonstrate differences in CMV strains shed by 32 persistent shedders selected at random. The glycoprotein B (gB) nucleotide regions of CMV were amplified and analyzed by restriction enzyme digestion. The CMV strains shed by most of these children showed different restriction profiles compared with strains from their playmates. It is considered that persistent reactivation of endogenous CMV is the most plausible explanation.

Antibodies, Viral↗

PubMed1996

Ultrasound-guided fine-needle aspiration biopsy of lung cancers.

One hundred eighty-eight patients with 191 lung cancers were collected retrospectively to evaluate the diagnostic results and to determine the accuracy of cytologic diagnoses obtained from ultrasound-guided fine-needle aspiration biopsy (US-guided FNAB), and to discuss the necessity of large-bore tissue core needle biopsy. All 188 patients underwent US-guided FNAB, and 20 patients with 21 lung tumors also underwent US-guided tissue-core needle biopsy. Using US-guided FNAB alone, the positive cytologic results and correct cytologic diagnoses were 91% (174 of 191) and 71% (37 of 52). If both US-guided FNAB and selected US-guided tissue core needle biopsy (n = 21) were evaluated, the positive cytologic or histologic results and correct cytologic or histologic diagnoses were 94% (180 of 191) and 80% (45 of 57), respectively. Analyzing the disagreement between the cytologic results and histologic diagnoses (n = 15), we found that the disagreement usually occurred in the specimens with poorly differentiated carcinomas (nonspecific cell type) (53% [8 of 15]); of these, two patients (13% [2 of 15], small cell carcinoma) would have a change in treatment. The complications of US-guided FNAB were pneumothorax (n = 3), hemoptysis (n = 1), hemothorax (n = 1), and suspected tract metastasis (n = 1). We conclude that US-guided FNAB has a high diagnostic yield in lung cancers, and US-guided tissue core needle biopsy is only necessary in patients whose cytologic results are negative or who have poorly differentiated carcinomas.

Adult↗