PubMed Health⌕ Search

Biomedical subjects

N H Chow

Publications and source records attributed to N H Chow.

At least 37 records · Page 2Linked to original sources
PubMed1999

Detection of adenocarcinoma by urinary microsatellite analysis after augmentation cystoplasty.

Augmentation cystoplasty is associated with an increased risk of bladder cancer development between 10 and 20 years after augmentation. Using microsatellite analysis, we analyzed urine obtained before surgical resection of the malignant lesion from a patient who developed invasive adenocarcinoma after augmentation cystoplasty. Loss of heterozygosity was identified in both urine and tumor samples from this patient. This observation suggests that microsatellite urine analysis may be useful as a monitoring tool for patients after augmentation cystoplasty.

Adenocarcinoma↗
PubMed1998

Using 2-step PCR and restriction endonuclease digestion to detect K-ras mutation in paraffin-embedded tissues: is it reliable?

In this study, we detected the existence of both wild type and mutant K-ras DNA on the cutting board and in the solutions for tissue processing in our pathology laboratory. The detection rate of K-ras mutant DNA inversely correlated with the frequency of the solution changed, implying that DNA contaminant including K-ras mutant may be accumulated while increasing specimens were processed. The exact routes of contamination during tissue processing remain to be determined. Nevertheless, this study unveils the possibility of DNA contamination in the laboratory that can be amplified by PCR analysis, and precaution should be taken while we interpret our PCR data from paraffin-embedded specimens. The work also highlights the necessity of contamination control procedures, including specific laboratory construction, environmental control, and strict hygiene standards for laboratory equipment and personnel. Moreover, fresh specimens seem more reliable than archival materials for PCR diagnosis.

DNA Restriction Enzymes↗
PubMed1998

Potential value of urinary intercellular adhesion molecule-1 determination in patients with bladder cancer.

OBJECTIVE: Intercellular adhesion molecule-1 (ICAM-1) is known to play a role in immunity against bladder cancer and can be detected in the supernatants of cultured bladder cancer cells that constitutively express ICAM-1. This study was performed to examine the relevance of the ICAM-1 urine test in patients with bladder cancer. METHODS: A total of 53 patients with bladder carcinoma, 35 with history of bladder cancer, and 30 normal control subjects were included in this analysis. Urinary ICAM-1 (ulCAM-1) levels were measured by immunoassay and corrected for hydration status. RESULTS: Levels of ulCAM-1 were significantly elevated in patients with bladder cancer or those at tumor-free status compared with normal control subjects (P=0.001). However, there was no apparent difference between the two groups of urothelial disorders (P >0.1). ulCAM-1 did not correlate with clinicopathologic variables of bladder cancer or patient outcome (P >0.1). Six patients at tumor-free status had multiple ulCAM-1 determinations during the study period. Three of these 6 patients had elevated ulCAM-1 levels and proved to have recurrent tumors; 3 of the 6 had stable ulCAM-1 levels and were still free of disease. CONCLUSIONS: Our results suggest that urinary excretion of ICAM-1 is elevated in the early stage of bladder carcinogenesis, but is independent of biologic properties of bladder cancer. Serial monitoring of ulCAM-1 may be helpful in selecting patients who are at risk of tumor recurrence.

Adult↗
PubMed1998

Expression of fibroblast growth factor-1 and fibroblast growth factor-2 in normal liver and hepatocellular carcinoma.

This study was performed to examine the immunohistochemical expression of fibroblast growth factor-1 and fibroblast growth factor-2 in normal liver and a total of 31 cases of hepatocellular carcinoma (HCC). Reactivity for both types of angiogenic factor did not exist in any cellular component of normal liver. For HCC, variable amounts of fibroblast growth factor-1 were detected in 6 of 31 cases (19.4%). There was no apparent relationship between the expression pattern and clinicopathologic factors (P > 0.1, respectively), except a positive correlation with histologic grading (P = 0.04). No tumor showed reactivity for fibroblast growth factor-2 in their cancer cells. However, both types of peptide could be demonstrated in the pericellular stroma of HCC. With a mean follow-up at 60 months, fibroblast growth factor-1 expression did not correlate with patients' outcome (P > 0.1). Our study suggested that fibroblast growth factor-1 appears to play a certain role in hepatocarcinogenesis.

Adolescent↗
PubMed1998

Computer morphometry for quantitative measurement of liver fibrosis: comparison with Knodell's score, colorimetry and conventional description reports.

Liver fibrosis is currently described quite subjectively or, at best, semiquantitatively by scoring systems. In order to measure the severity of liver fibrosis quantitatively and to compare this with established methods, such as Knodell's scoring system, the colorimetric method and conventional description reports, we undertook the present study. A personal computer with an image grabber card and a microscope equipped with a computer-controlled slide-driver was used for computer morphometry. The principle behind morphometry is based on the different colours of hepatocytes and fibres following staining with Masson's trichrome stain. There were 31 patients (25 male, six female) recruited into the present study with a mean +/- SD age of 41.6 +/- 15 years (range 24-66 years). Of these patients, 16 had chronic hepatitis B, 12 had chronic hepatitis C and three were alcoholics. Colorimetric methods and Knodell's fibrosis score were performed according to established protocols. Conventional description reports were obtained from reviews of patient charts. The results from computer morphometry were highly correlated with results from the colorimetric method, with a correlation coefficiency gamma = 0.85 (P<0.0001). The results from computer morphometry also correlated with both Knodell's scoring system (gamma = 0.69; P<0.001) and conventional description reports (gamma = 0.46; P<0.01). Results from Knodell's scoring system were significantly correlated with computer morphometry, as follows: score 0, 2.7 +/- 1.4; score 1, 5.7 +/- 1.2; score 2, 7.7 +/- 2.3; score 3, 10.7 +/- 3.2; score 4, 21.8 +/- 14.1. The trend was statistically significant by the Wilcoxon rank sum test. In conclusion, our computerized morphometry system is a reliable tool for the evaluation of the severity of liver fibrosis and can be used as a tool for the objective quantification of liver fibrosis.

Adult↗
PubMed1998

Subdural empyema in 10 infants: US characteristics and clinical correlates.

PURPOSE: To investigate the ultrasonographic (US) characteristics of subdural empyema (SDE) and its differentiation from reactive subdural effusion (RSE) in infants with meningitis. MATERIALS AND METHODS: Images in 10 infants with SDE with or without RSE complicating meningitis were retrospectively reviewed and correlated with clinical findings and compared with US and magnetic resonance (MR) images in four infants with meningitis and RSE. RESULTS: At US, 15 of 16 SDEs in the 10 infants were seen as heterogeneous to hyperechoic convexity collections. Hyperechoic strands were seen in 12 SDEs. Other findings included a thick, echogenic inner membrane (n = 9), increased echogenicity of pia-arachnoid and exudates in the subarachnoid space (n = 16), mass effect (n = 16), and loculated extraaxial collections (n = 2). MR imaging findings correlated well with US and surgical results. At computed tomography, SDE was misinterpreted as RSE in one patient, due to the absence of inner membrane contrast material enhancement. Clinical outcome was related to the degree of brain damage consequent to meningitis and the chronicity of SDE. RSEs in seven infants (three with concurrent SDE) were anechoic; an inner membrane was seen in six, and increased pia-arachnoid echogenicity was seen in four. CONCLUSION: SDE has complex US features that are helpful for differentiation from anechoic RSE in infants with meningitis.

Diagnosis, Differential↗
PubMed1997

Level of transforming growth factor beta 1 is elevated in cerebrospinal fluid of children with acute bacterial meningitis.

We investigated the levels of transforming growth factor beta 1 (TGF-beta 1) in cerebrospinal fluid (CSF) in children with meningitis, with a view to prognostic relevance. CSF TGF-beta 1 levels on admission were measured by a sandwich enzyme immunoassay in children with bacterial meningitis (n = 16), aseptic meningitis (n = 12), and control subjects without evidence of central nervous system (CNS) infection (n = 16). Patients were followed up for a mean duration of 13 months, and neurodevelopmental sequelae was determined for those with bacterial meningitis. On admission, CSF TGF-beta 1 levels were significantly higher in children with bacterial meningitis (mean, standard error, 32.92, 2.36 pg/ml) as opposed to those with aseptic meningitis (25.26, 1.72 pg/ml) (P = 0.0155), or control subjects (20.53, 1.05 pg/ml) (P < 0.0001). The CSF TGF-beta 1 levels in children with aseptic meningitis were higher than those in the control group, but without significance (P = 0.02). No apparent correlation existed between CSF TGF-beta 1 levels and CSF protein or cell counts in patients with bacterial meningitis. No significant difference in CSF TGF-beta 1 levels was found between patients with or without major sequelae following bacterial meningitis.

Acute Disease↗
PubMed1997

Expression patterns of erbB receptor family in normal urothelium and transitional cell carcinoma. An immunohistochemical study.

The class I tyrosine kinase growth-factor receptors include epidermal growth factor receptor (EGFR), ErbB2 (c-erbB-2, HER-2/neu), ErbB3 and ErbB4. To elucidate their role in the regulation of homeostasis and carcinogenesis, we examined the expression of the receptors in normal urothelium and in urothelial carcinoma by immunohistochemistry. EGFR was expressed in the basal cells of normal urothelium, while ErbB2, ErbB3 and ErbB4 were present mainly in the superficial layer. A distinct reciprocal distribution was observed between the EGFR and the remaining members of the subclass (P = 0.0001). Both BCL-2 protein and Ki-67 antigen (MIB-1) showed a strong positive association with EGFR (P = 0.002) and an inverse correlation with ErbB2, ErbB3 or ErbB4 (P = 0.0004, 0.0000, and 0.001, respectively). With regard to carcinoma, there was no important relationship between receptor overexpression and tumour grading (P > 0.1), while only EGFR overexpression was correlated with muscular invasion (P = 0.02). Coexpression of EGFR-ErbB3 and ErbB3-ErbB4 was more often detected in high-grade tumours and correlated with the extent of tumour invasion. Our data indicate that class I receptors are differentially expressed in normal urothelium in vivo, but an orchestrated expression pattern does not exist during tumorigenesis.

Carcinoma, Transitional Cell↗
PubMed1997

Expression of vascular endothelial growth factor in normal liver and hepatocellular carcinoma: an immunohistochemical study.

Angiogenesis is of vital importance during the development and progression of solid tumors. To examine the role of vascular endothelial growth factor (VEGF) in hepatocarcinogenesis, we evaluated the expression of peptide in normal human liver (n = 6) and in 36 cases of hepatocellular carcinoma (HCC). Immunoreactivity for VEGF was present in the extracellular matrix of the portal tracts in the normal and nontumor part of liver, but not in hepatocytes and bile duct epithelium. For HCC, variable amounts of VEGF were expressed in 13 cases (36.1%) of tumor cells. Using a logistic regression model, expression of VEGF was significantly associated with a higher proliferative index (P = .01) and sonographic portal vein thrombosis (P = .05). However, VEGF expression did not correlate with a biochemical liver profile, alpha-fetoprotein levels, histological grading, gender, or clinical stage of cirrhosis (P > 0.1, respectively). Log-rank test showed that evaluation of VEGF did not provide more prognostic information (P > .5) than that from tumor volume and portal vein thrombosis (P < .01, respectively). In addition, VEGF was always present in the fibrovascular stroma or pericellular matrix of HCC, although no strong relationship was observed with the expression of VEGF in tumor cells (P > .5). Our data suggested that expression of VEGF may characterize a progression toward higher proliferation in hepatocarcinogenesis in vivo. The relevance of VEGF existing in the extracellular matrix of the normal liver and HCC remains to be clarified.

Adolescent↗
PubMed1997

Clinicopathological features of bladder cancer associated with chronic exposure to arsenic.

A high incidence of bladder cancer has been documented in an area of chronic arsenic (As) exposure. This study investigates the characteristics of As-associated (n = 49) and other (n = 64) bladder cancers. A higher histological grading was observed for the As-exposed tumours (P = 0.04), but no other difference in pathobiological features or prognosis was found between the two groups.

Aged↗
PubMed1997

Intracerebral injection of myelin basic protein (MBP) induces inflammation in brain and causes paraplegia in MBP-sensitized B6 mice.

Brain inflammation and paraplegia can be induced by an additional intraperitoneal (i.p.) and intracerebral (i.c.) restimulation in B6 mice after standard immunization with MBP in Freund's complete adjuvant (FCA) and Bordetella pertussis coadjuvant. Only the combination of i.p. MBP/FCA and i.c. MBP injection could induce clinical paraplegia; either one alone was not effective. Clinical symptoms would develop 2 days after the i.c. injection. The induction of paraplegia was MBP-specific, as irrelevant bovine serum albumin with the same protocol could not induce it. The i.p. restimulation was requisite and needed the MBP in FCA, as MBP in PBS was ineffective. Histopathological observation manifested cellular infiltration by leucocytes in perivascular spaces and cerebral cortex. Neutrophils were prominent at 12 h after i.c. injection, then were replaced by mononuclear cells 24 h later. There were dynamic changes in cell number and immunophenotype of VLA-4+ expression in cervical lymph node cells after i.c. injection. The cells derived from cervical lymph nodes had higher MBP-stimulated proliferation than that of distal lymph nodes. This additional i.p. and i.c. stimulation provides a new manipulation to study brain inflammation.

Animals↗
PubMed1997

Effect of thyroid hormone on urinary excretion of epidermal growth factor.

Thyroid hormones were demonstrated to upregulate the synthesis of epidermal growth factor (EGF) mRNA and proEGF in the kidneys in vivo. This prospective study was performed to examine the extent of the hypothyroid state in modulating EGF excretion in the urine (U-EGF; n = 23). Patients with thyroid cancer were serially followed up from the euthyroid status, which was retained by thyroxine supplement after thyroidectomy, to the hypothyroidism in preparing for 131I whole body scanning. Paired thyroid function panel, including triiodothyronine (T3), thyroxine (T4), thyroid-stimulating hormone (TSH), and U-EGF levels were measured on a weekly basis. Logarithmically transformed values of U-EGF were inversely correlated with TSH serum levels (p = 0.0000), but positively associated with T4 levels (p = 0.0005). No apparent correlation was observed with the T3 serum content, age and gender of the patients (p > 0.1, respectively). If the interval of measurement was taken into consideration, serum TSH was the most significant factor in association with U-EGF (p = 0.0003). Our data indicate that excretion of EGF in human urine depends substantially upon thyroid hormone support.

Adult↗
PubMed1996

Modulation of antitumor immunity of tumor-bearing mice with low-dose cyclophosphamide.

As a tumor progressively grows, the tumor-bearing host usually is under a tumor-mediated immune suppression status. Although surgical resection of the tumor may immediately eliminate most tumor-induced detrimental influences, perioperatively the antitumor immunity of the host remains temporarily suppressed. The major purpose of this study is to investigate the modulation effect of low-dose cyclophosphamide (CY) on the antitumor immunity of tumor-bearing mice (TBM). Using the C3H/He-MBT-2 murine bladder tumor model, we demonstrate that low-dose CY (100 mg/kg) intraperitoneal injection 2 days before tumor resection can significantly enhance the specific antitumor immunity of the TBM. It consequently suppresses the outgrowth of perioperative rechallenged tumor cells and improves the survival of the animals. Phenotypic analysis of cellular subset of spleen by flow cytometry revealed that low-dose CY, when given to both naive and tumor-bearing mice, causes significant reduction of both absolute number and percentage of cells with CD4-CD8- subset in the spleens of TBM. As a result of a parallel increase in the percentage of both CD4+CD8- and CD4-CD8+ subsets, the CD4+/CD8+ ratio remains unchanged. However, after short-term in vitro culture with IL-2 the percentage of the CD4-CD8- subset and CD4+/CD8+ ratio markedly decreased because of the relatively predominant proliferation of the CD4-CD8+ subset. Evidence from in vitro cytotoxicity assays on panel tumor cells and phenotypic analysis revealed that this enhancement of host antitumor immunity, following low-dose CY pretreatment, may be due to augmenting the activity of NK, LAK, and CD11b+ myeloid/macrophages in addition to cytotoxic T lymphocytes.

Animals↗
PubMed1996

Growth kinetics of colorectal adenoma-carcinoma sequence: an immunohistochemical study of proliferating cell nuclear antigen expression.

Tumorigenesis is a multistep process that begins with the abrogation of normal controls of cell proliferation. The authors examined the in vitro growth kinetics and compartment shift through the adenoma-carcinoma sequence of the human colon by determining the labelling indexes of proliferating cell nuclear antigen (PCNA) in normal mucosae (n = 10), adenomas (n = 88), and carcinomas (n = 20). Carcinoma cells had a significantly higher PCNA index than adenomas or control specimens (P = .0001). There also was a difference in the PCNA index between the histological subtypes of adenomas (P = .03), whereas no significant difference was observed for dysplastic grade, tumor size, or location (P > .1). Tubular and tubulovillous adenomas, adenomas with mild dysplasia, small (< 10 mm) adenomas, and proximally located adenomas revealed shift of cell proliferation toward the middle portion of the colonic glands. The PCNA in the villous, moderate or severe dysplastic, larger or distally located adenomas appeared to be diffuse (P = .04, 0.02, 0.07, and 0.06, respectively). In addition, the transitional mucosa neighboring carcinoma showed an elevation of the mean PCNA index together with an upward shift of cell proliferation compared with the controls (P = .03). These results suggest a stepwise increment of proliferating activity with compartment shift of the proliferating zone through the adenoma-carcinoma sequence. The information essentially supports contemporary understanding of the carcinogenic processes in the human colon.

Adenoma↗
PubMed1996

Implications of urinary basic fibroblast growth factor excretion in patients with urothelial carcinoma.

1. Angiogenesis occurs in response to wounding, and is of vital importance for tumour growth and metastasis. Basic fibroblast growth factor, a well-known angiogenic factor, has been suggested to be a urine marker for urothelial carcinoma. However, the relevance of its detection has not been evaluated in a large number of patients. 2. Immunoassay of basic fibroblast growth factor was performed on urine samples from different aetiologies of urothelial disorder. Expression of basic fibroblast growth factor in the corresponding tumour was correlated with the urine level. 3. The excretion of basic fibroblast growth factor (ng/g creatinine) was significantly elevated in both inflammatory and neoplastic urological diseases compared with normal individuals (P < 0.05), while it was normalized in tumour-free subjects (P < 0.01). Receiver operating characteristic plotting revealed a sensitivity of 40% for tumour diagnosis at the cut-off point of 3.29 ng/g creatinine. The sensitivity of the test in predicting tumour recurrence was only 14%. The basic fibroblast growth factor level in urine showed a positive association with increasing age of cancer patients (P = 0.02) and with tumour grading (P = 0.05). However, no important relationship was observed regarding tumour stage, size, number, shape or degree of local inflammatory reaction (P > 0.01). Pairwise analysis of the basic fibroblast growth factor level in urine and its expression in corresponding tumours did not reveal a conspicuous correlation (r = -0.097, P = 0.43). 4. Our results suggested that estimation of urinary basic fibroblast growth factor cannot be satisfactory as a tumour marker. The measurement may represent one of the tissue responses to injury or the host-tumour interactions. A longitudinal study is required to elucidate the role of basic fibroblast growth factor in order to select the appropriate treatment strategy for urothelial carcinoma.

Adult↗
PubMed1996

Prognostic factors of primary transitional cell carcinoma of the upper urinary tract.

OBJECTIVES: We presented and analyzed our results in order to determine the relationship between patient survival and tumor grade and/or stage. In addition, a retrospective tumor DNA ploidy study was done to evaluate its possible role in predicting future tumor recurrence in the bladder. METHODS: A total of 112 patients with upper urinary tract transitional cell carcinomas (TCCs) were recorded at our hospital. Of these, 68 patients without concurrent bladder tumors (ages ranged from 36 to 80, mean 62.4 years; male:female = 1:1.2) were treated by nephroureterectomy and bladder cuff resection. They were followed up for 14-79 months (average 38.2 months). Eight (36.4%) of the 22 patients who had stage C or D tumors had received adjuvant systemic methotrexate, vinblastine, epirubicin, cisplatin chemotherapy after surgery. DNA flow cytometry using paraffin-blocked tumor specimens was performed on the tumors of 52 patients. RESULTS: Their pathologic stages and grades were 11 at stage 0, 15 at stage A, 20 at stage B, 14 at stage C, 8 at stage D; 9 of grade I, 41 of grade II, and 18 of grade III. Postoperatively, 13 patients (19.1%) subsequently developed bladder tumors with a latent period ranging from 2 to 37 months (average 14.9 months). The difference of the tumor DNA ploidy distribution pattern among tumors of high versus low stages and/or grades is not statistically significant (p > 0.05). Overall, the 5-year survival rates for patients with low- and high-stage tumors were 100 and 66.7%, respectively; for patients with grade I-II and III tumors they were 93.6 and 28.3%, respectively. CONCLUSIONS: Patient survival was mainly related to both tumor stages (p = 0.0037) and grades (p = 0.0001), rather than to tumor DNA ploidy. For patients with grade II upper urinary tract tumors, tumor DNA ploidy seems to provide no additional predictive value on subsequent tumor recurrence in the bladder.

Adult↗
PubMed1996

Eosinophilic gastroenteritis with esophageal involvement.

Eosinophilic gastroenteritis is an unusual disease entity characterized by eosinophilic infiltration of the gut with gastrointestinal disturbance. The disease commonly involves the stomach and small bowel. Esophageal involvement is rarely reported. We present a patient with simultaneous achalasia, pyloric stenosis, and ascites. Macroscopically, the esophagus, stomach and small intestine were involved. Microscopically, the mucosa was involved to the serosa. The patient has remained well under low dose prednisolone treatment for 7 years since his condition was diagnosed.

Ascites↗