Biomedical subjects

H Chiang

Publications and source records attributed to H Chiang.

At least 37 records · Page 2Linked to original sources

PubMed2001

Real-time dynamic telepathology through the Internet: evaluation of a new and economic technology at Taipei Veterans General Hospital.

BACKGROUND: Computer-aided, digitalized telepathology was introduced about 10 years ago and is gaining acceptance as a mode of providing pathology to remote site. The usefulness of telepathology for remote diagnosis of histology, cytology and frozen section has been evaluated in USA, Europe and Japan. In Taiwan, the use of telepathology for pathological diagnosis is still rare. In order to evaluate the potential use of this technique, we undertook the study using commercialized and low-cost microscopy, personal computer and software on routine biopsy material. METHODS: Sixty prostatic sextant transrectal needle biopsies, including 30 cases of adenocarcinoma and 30 cases of benign lesions, were retrieved retrospectively. The real-time dynamic images were transmitted to the remote site via internet and reviewed by a senior uropathologist who was unaware of the diagnosis. The diagnoses made at the remote site were correlated to the final diagnoses of the cases. RESULTS: All malignant specimens (30/30) were correctly diagnosed by this method. Only one benign case (1/31) of nonspecific granulomatous prostatitis was misdiagnosed as poorly differentiated carcinoma. CONCLUSIONS: Our results show that this method is a good way for teleconsultation. Further studies on other types of specimen worth encouragement for both intra- and inter-institutional consultation.

Biopsy, Needle↗

PubMed2000

The effect of 50 Hz magnetic field on GCSmRNA expression in lymphoma B cell by mRNA differential display.

Magnetic fields (MFs) of various characteristics can lead to plethora effects in biological system. From a molecular point of view, we hypothesized that there must be a fundamental difference in gene expression between the MF exposed and the unexposed cell. To identify the classes of genes that are regulated, 0.8 mT 50 Hz MF-induced changes in gene expression were examined in a Daudi cell culture using differential display and reverse transcriptase-polymerase chain reaction. A candidate cDNA (signatured as MF-CB) that was observed in the sham-exposed but not in MF-exposed cultures was recovered and reamplified. After verification by Northern blot, the cDNA was cloned and sequenced. It was found that 254-base pair of 5'-end MF-CB cDNA clone was identical to gcs in open reading frame (ORF) range. Based on the preliminarily sequence, the prolonged length of 5'-end MF-CB cDNA was obtained by PCR amplification and its sequence analysis showed the same results as its original fragment. In order to further determine whether MF-CB cDNA is from gcs, two Northern blots were probed with gcs and MF-CB cDNA, respectively, and the data revealed signals of the same size and expression pattern on the two probe filters, which demonstrated that MF-CB is an EST (expression sequence tag) of gcs. gcs is a gene, identified recently (GenBank accession number D89866), encoding ceramide glucosyltransferase (GCS), which has been implicated as a causal element in human cell growth and differentiation. In an additional experiment, time-dependent changes in the transcription of gcs induced by 0.8 mT MF were observed by Northern blot with a sharp and reproducible inhibition effect after 20 min exposure and a reduction after 20-24 h exposure. The study demonstrates for the first time that 50 Hz MF can lead to changes in gcs transcription, which provides a new clue to elucidate the mechanism by which MF influence cell growth and differentiation.

Amino Acid Sequence↗

PubMed2000

MIB-1 labeling index as a prognostic indicator for survival in patients with FIGO stage IB squamous cell carcinoma of the cervix.

OBJECTIVE: The goal of this study was to assess whether the MIB-1 labeling index (LI) and conventional parameters could distinguish between a good and a poor prognosis in patients with squamous cell cervical carcinoma of the same FIGO stage. METHODS: The study included 97 cases of stage IB squamous cell cervical carcinoma which were treated with radical hysterectomy between 1989 and 1991. The relation of the MIB-1 LI, conventional clinicopathologic parameters, and survival was evaluated. RESULTS: The MIB-1 LI of the entire group of tumors was 57.1 +/- 15.9 (mean +/- SD). The MIB-1 LI was significantly different only in living and dead patients, while it was not related to conventional clinicopathologic prognostic parameters. The 5- and 10-year survival rates of patients with an MIB-1 LI </=55 were 90.0 and 88.6%, respectively, which were significantly better than the survival rates of patients with LI >55, which were 73.1 and 66%, respectively. Multivariate analyses showed that MIB-1 LI >55, lymph node metastasis, and tumor size >/=40 mm were powerful predictors of shorter survival. CONCLUSIONS: Lymph node metastasis, tumor size, and MIB-1 LI were significant prognostic markers in patients with stage IB squamous cell cervical carcinoma.

Adult↗

PubMed2000

Atypical teratoid/rhabdoid tumor of the central nervous system: a comparative study with primitive neuroectodermal tumor/medulloblastoma.

Eleven atypical teratoid/rhabdoid tumors (AT/RT) and 121 primitive neuroectodermal tumors/medulloblastomas (PNET/MB) were included in this study for evaluation of the histopathological features of AT/RT and comparison between AT/RT and PNET/MB. Histopathological studies of AT/RT showed that in addition to the commonly recognized components, i.e., rhabdoid cells, small (PNET/MB) cells, spindle cells and epithelial components, there was a previously unrecognized component, sickle-shaped embracing cells, which were present in all cases and could be useful as a histological marker of this tumor. Immunohistochemical studies showed divergent differentiation of the tumor cells and among the 16 antibodies studied, vimentin, neuron-specific enolase, epithelial membrane antigen and glial fibrillary acidic protein were most commonly reactive. The frequency of AT/RT expressed as a ratio of AT/RT to PNET/MB was 1:11 in general and increased to 1:3.8 among patients younger than 3 years old. The AT/RT patients were younger than those with PNET/MB and had a female predominance. The MIB-1 labeling index of AT/RT was significantly higher than that of PNET/MB (mean 63.9 vs 40.1), which correlated with a shorter survival in patients with AT/RT than those with PNET/MB (median survival time 15.4 months vs 156.4 months).

Antigens, Nuclear↗

PubMed2000

No-scalpel vasal sperm aspiration and in vitro fertilization for the treatment of anejaculation.

OBJECTIVES: To evaluate the utility of no-scalpel vasal sperm aspiration and in vitro fertilization for the treatment of male infertility due to anejaculation. METHODS: Vasal aspiration was performed using a no-scalpel technique, and the sperm were used for conventional in vitro fertilization in 1 patient and intracytoplasmic sperm injection in 6 patients. RESULTS: The average total sperm count was 6 x 10(6), with the motility between 20% and 95%. No complications have been observed to date. A high fertilization rate (74.6%) and pregnancy rate (5 of 7) was achieved with subsequent intracytoplasmic sperm injection or in vitro fertilization. CONCLUSIONS: No-scalpel vasal sperm aspiration is a simple, effective alternative to sperm retrieval, especially for anejaculatory males.

Adult↗

PubMed2000

Lack of mutations of BCL6 and BCL10 genes in mucosa-associated lymphoid tissue lymphomas of the orbital adnexa.

Knowledge regarding the molecular pathogenesis and progression of mucosa-associated lymphoid tissue (MALT) lymphomas of ocular adnexa is limited. Eleven cases of ocular MALT lymphoma were analyzed by clonal rearrangement of antigen receptor genes using Southern blot hybridization. Polymerase chain reaction-single stranded conformational polymorphism analysis and DNA sequencing was utilized to analyze the mutations of BCL6 and BCL10 genes. Clonal rearrangement of immunoglobulin heavy genes was found in all 11 patients. No point mutation was found in BCL6 or BCL10 genes in any of the samples analyzed. We suggest that mutations of BCL6 and BCL10 genes are rare in low-grade MALT lymphoma of ocular adnexa and are unlikely to be involved in the pathogenesis of the disease. But the role of alterations of both BCL6 and BCL10 genes in the disease progression of low-grade MALT lymphoma require additional study.

Adaptor Proteins, Signal Transducing↗

PubMed2000

Chronic oral mucosal ulceration in a 54-year-old female.

Pemphigus vulgaris most often begins in the mouth but is often overlooked in the differential diagnosis of chronic, multiple oral ulcerations and erosions. Accurate diagnosis requires perilesional biopsy including intact epithelium, submitted for hematoxylin and eosin as well as direct immunofluorescence staining. Early and aggressive treatment with moderate to high dose prednisone in combination with steroid sparing drugs such as azathioprine and mycophenolate allow complete remission in most patients.

Chronic Disease↗

PubMed2000

EEG correlates of finger movements as a function of range of motion and pre-loading conditions.

OBJECTIVES: The present study was designed to obtain additional data regarding the differential influence of kinematic parameters and different nominal force levels upon components of movement-related cortical potentials (MRP) during index finger flexion. METHODS: The absolute nominal force level of discrete movements was varied while the rate of force development remained constant within a given task. This was accomplished by utilizing a pre-loading experimental design at different ranges of index finger motion (25, 50 and 75 degrees), so that the movement kinematic profiles (velocity and acceleration) and rate of force development remained constant within each given range of motion. Time-domain averaging of EEG single trials was applied in order to extract 3 movement-related potentials (BP(-600 to -500), BP(-100 to 0) and N(0 to 100)) preceding and accompanying 25, 50 and 75 degrees of unilateral finger movement with no pre-load (0 g), small pre-load (100 g) and large pre-load (200 g). RESULTS: The range of motion differentially influenced the amplitude of early (BP(-600 to -500)) and late (BP(-100 to 0)) MRP components spatially localized over frontal, central and parietal areas. The amplitude of the N(0 to 100) component localized over parietal and frontal areas was also sensitive toward experimental manipulations of the range of motion. Overall, the amplitude of N(0 to 100) localized over the central area was the only MRP component that was sensitive to the amount of pre-loading. However, within a given range of motion, none of the pre-loading conditions (0, 100 or 200 g) influenced the amplitude of MRP components. CONCLUSIONS: The central finding was that an increase in nominal force production within a given range of motion did not influence MRP components when the rate of force development was held constant. It becomes especially apparent with strict control of kinematic and kinetic movement parameters that different methods of adding weight to the index finger performing the same movement patterns have different consequences for EEG correlates as reflected in the amplitude and spatial distribution of MRP. The range of motion of index finger flexion was the primary kinematic variable that consistently influenced MRP components both preceding and accompanying movement execution.

Adult↗

PubMed2000

Tubulocystic clear cell adenocarcinoma arising within the prostate.

Neoplasms resembling ovarian common epithelial-type tumors, including clear cell adenocarcinomas, rarely occur in the lower urinary tract of men. When they do, they develop in the urethra or urinary bladder. We report a case of such a tumor arising within the prostate of a 47-year-old man. The tumor was a cystic mass in the left posterolateral region of the prostate. Histologically, the tumor was chiefly composed of tubulocystic and papillary glands lined by glycogen-rich, cuboidal or hobnail cells with clear to eosinophilic cytoplasm. The tumor cells were strongly positive for pan-cytokeratin, low molecular weight cytokeratin, and epithelial membrane antigen, and focally positive for high molecular weight keratin. The tumor did not immunohistochemically express prostate-specific antigen (PSA) and prostatic acid phosphatase. Serologically, the patient had increased levels of CA125 instead of PSA. The clinical as well as the pathologic features are consistent with a clear cell adenocarcinoma as seen in the female genital tract rather than a typical prostatic adenocarcinoma.

Adenocarcinoma, Clear Cell↗

PubMed2000

Preferentially deleted chromosome region 9p21 in large hepatocellular carcinomas.

The role of somatic deletions in chromosome 9 and chromosome 22 loci in hepatocellular carcinomas (HCC) was studied. Twenty-one paired HCC and adjacent tumor-free liver tissue samples were examined for loss of heterozygosity at six chromosome 9 and ten chromosome 22 loci. Among informative cases, the highest LOH rates were observed at 9p21 (40% or 4/10 at IFNA) and 9q23 (23% or 3/13 at D9S318). Our observed LOH rate at 9p21 was significantly higher than the background level previously reported for the same tumor type. Clinical data indicate that chromosome 9p21 deletions occurred preferentially in larger tumors (>5 cm diameter). However, a sequence analysis of the MTS1 gene coding region in cases of 9p21 LOH did not reveal any change, suggesting another tumor suppressor gene as the LOH target.

Aged↗

PubMed2000

Spuriously high CK-MB isoenzyme activity mimicking acute myocardial infarction in a patient with adenocarcinoma of the rectum.

A 58-year-old Chinese male presented with precordial distress and was found to have elevated creatine kinase (CK)-myocardial bound (MB) (determined by the Kodak Ektachem Clinical Chemistry Slide method) activity and an abnormal electrocardiogram. Eventually, the patient was diagnosed with an annular ulcerative tumor 10 cm above the anal orifice. The tumor was an adenocarcinoma of the rectum and was immunoreactive for CK-BB (brain type). CK isoenzyme electrophoresis disclosed both BB and MM (muscle type) bands. We concluded that the level of CK-MB determined using the Kodak Ektachem Clinical Chemistry Slide method was spuriously elevated in our patient with adenocarcinoma of the rectum, without evidence of myocardial injury. Institutions using the Kodak Ektachem Clinical Chemistry Slide system for CK should be aware of this possibility.

Adenocarcinoma↗

PubMed2000

Desmoplastic small round cell tumor--report of 3 cases and review of the literature.

Desmoplastic small round cell tumor (DSRCT) is a rare neoplasm with distinctive histological features, characterized by extensive stromal tissue around islands of small and undifferentiated cells revealing the desmoplastic appearance. It was first described by Gerald and Rosai. It mainly the peritoneum and is found predominently in adolescents and young adults, and it is much more common in males than in females. The histological and immunhistochemical features are very distinct but may be misdiagnosed as other undifferentiated neoplasm if the pathologist has no idea of this entity. We report the experience of three cases here. The first case was diagnosed as malignant neuroendocrine neoplasm orginally and revised to DSRCT later. Case 2 had been diagnosed as Atypical carcinoid and received surgery and chemotherapy. It was revised as DSRCT 5 years later by an other pathologist. Case 3 carried the characteristic feature whereby diagnosis could be made even in frozen section.

Adolescent↗

PubMed1999

p53 gene mutations and rearrangements in non-Hodgkin's lymphoma.

BACKGROUND: Alterations of the p53 gene have been associated with the progression of certain human malignancies. To establish further the correlation between p53 gene alterations and progression of non-Hodgkin's lymphomas (NHLs), the authors analyzed both mutations and rearrangements of the p53 gene in a cohort of 84 NHLs. METHODS: Eighty-four NHLs were analyzed for p53 gene alterations. Point mutations of exons 5-9 were studied by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), and DNA rearrangements were studied by Southern blot analysis. RESULTS. Point mutations and DNA rearrangements of the p53 gene were detected in 6 (7.2%) and 3 (3.6%) patients, respectively. All p53 gene abnormalities were found exclusively in B-cell NHLs. Taken together, patients with p53 gene alterations had poorer survival than other patients (P = 0.024). However, of the three patients with p53 gene rearrangements, the two who appeared to have one normal allele showed a relatively better response to chemotherapy and had longer survival (27 and 47 months). In contrast, the remaining patient who had rearranged bands much stronger than the germline, and thus appeared to have both alleles rearranged, was refractory to chemotherapy and had poorer survival (6 months). CONCLUSIONS: Patients with NHLs of intermediate and high grades who carried point mutations or rearrangements of p53 genes had worse outcomes than other patients. Patients with one abnormal p53 allele and one residual normal allele had a more favorable prognosis than those with two abnormal alleles.

Adolescent↗

PubMed1999

Rapid progression of squamous cell carcinoma of the cervix after hyperbaric oxygenation.

The role of hyperbaric oxygenation in the treatment of radiation-induced sequelae and chronic ulcer is well established. On the contrary, a possible cancer-causing or growth-enhancing effect by hyperbaric oxygenation was highly controversial. Herein, we present a 55-year-old Chinese woman with recurrent squamous cell carcinoma of the cervix on her left inguinal area. She received concurrent chemoradiation therapy followed by radical inguinal lymphadenectomy due to persistent tumor mass. The patient was complicated with severe radiation fibrosis and unhealed wounds, so she was treated with hyperbaric oxygenation (HBO). However, the patient died of complications of the disease after completing HBO therapy I month later and autopsy of the patient showed carcinomatosis of the abdominal cavity and lower abdominal wall. Because previous studies have been inconclusive regarding the effect of HBO on tumor cells, we reviewed the possible relation between the HBO and tumor cells.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1999

Effects of 50 Hz magnetic fields on gap junctional intercellular communication.

To explore whether the extremely low frequency (ELF) electromagnetic fields (EMFs) may act as cancer promoters or be synergistic with 12-O-tetradecanoylphorbol-13-acetate (TPA) in cancer promotion, an experiment was conducted on the effects of 50 Hz magnetic fields (MFs) on gap junctional intercellular communication (GJIC) of Chinese hamster lung (CHL) cells. Lucifer dye was loaded into CHL cells by iontophoretic injection, and the number of dye-coupled cells (DCC) 5 min after the injection was adopted as the index of GJIC. The effects of TPA at different concentrations and magnetic fields at different intensities, combined with 5 ng/ml TPA, were studied. The results showed that the suppression of TPA on GJIC was dependent on TPA concentration; the threshold concentration of TPA for CHL cells was between 1 and 5 ng/ml. After exposure to 0.8 mT magnetic field for 24 h, the number of DCC decreased to 6.08 +/- 1.59, whereas the number of DCC in the control group was 9.84 +/- 2.27 (P < .05). When the cells were exposed at 0.2, 0.4, and 0.8 mT for 24 h, combined with 5 ng/ml TPA treatment during the last 1 h, the number of DCC decreased to 5.52 +/- 1.53, 5.00 +/- 1.22, and 4.00 +/- 1.29, respectively, which were significantly lower than the values for the group treated with 5 ng/ml TPA alone (6.38 +/- 1.39). It is suggested that certain intensities of 50 Hz magnetic field might act as cancer promoters, be additive with other promoters in cancer promotion, or both.

Animals↗

PubMed1999

Immunohistochemical analysis of nm23-H1 protein in bladder cancer.

BACKGROUND: The nm23 gene was first identified from murine K-1735 melanoma cell lines and possesses metastasis-suppressor activity. However, conflicting results concerning the metastasis-suppressor activity of nm23-H1 gene product have been reported in human solid tumors. The significance of nm23-H1 protein in bladder cancer remains to be determined. Therefore, we examined nm23-H1 protein expression immunohistochemically in bladder cancer. METHODS: Formalin-fixed, paraffin-embedded tissue specimens were obtained from 39 patients with primary bladder cancer who had undergone radical cystectomy between 1987 and 1994. The specimens were examined immunohistochemically using a monoclonal antibody to nm23-H1, and the results of immunostaining were compared with clinicopathologic factors and patient survival. RESULTS: Positive nm23-H1 protein expression was confined primarily to the cytoplasm of bladder cancer cells. A higher frequency of nm23-H1 positive expression was seen in higher stage tumors. There was a positive trend for the expression of nm23-H1 protein with the progression of the tumor (p < 0.025). No relationship was found between nm23-H1 protein expression and patients' clinicopathologic factors including age, tumor size, tumor morphology and tumor grade. Furthermore, nm23-H1 protein expression was not correlated with patient survival. CONCLUSIONS: These results suggest that in bladder cancer nm23-H1 protein expression may play an important role in tumor progression rather than in metastasis suppression.

Adult↗

PubMed1998

MIB-1 labeling index in nonpilocytic astrocytoma of childhood: a study of 101 cases.

BACKGROUND: The prognosis of pediatric patients with nonpilocytic astrocytoma, and in particular those with anaplastic astrocytoma, is somewhat unpredictable. This study used MIB-1 monoclonal antibody, a proliferative marker that can be used in formalin fixed paraffin embedded tissues, to study nonpilocytic pediatric astrocytoma. METHODS: Astrocytoma, anaplastic astrocytoma, and glioblastoma specimens excised from a total of 101 pediatric patients during the period from January 1975 to September 1996 were retrieved from the authors' surgical pathology file. Histologic grading of the specimens was performed based on a modified Ringertz system. The proliferative potential of the tumors was estimated by using the MIB-1 labeling index (LI), which was evaluated with morphologic grades of tumors and survival of the patients. RESULTS: Of the 101 patients, 34 had astrocytoma, 33 had anaplastic astrocytoma, and 34 had glioblastoma. Their mean survival times were 165.2+/-14.9 months (mean+/-standard error; SE), 46.1+/-9.9 months, and 21.8+/-5.6 months, respectively. The mean MIB-1 LI of different tumor grades were as follows: astrocytoma, 3.9+/-4.3 (mean+/-standard deviation; range, 0.0-21.6); anaplastic astrocytoma, 24.3+/-15.6 (range, 1.7-62.8); and glioblastoma, 35.9+/-16.4 (range, 7.36-63.3). The mean survival of the entire group of patients with LIs < or = 11 was 173.2+/-12.2 months (mean+/-SE), and the mean survival of those with LIs > 11 was 20.3+/-4.1 months. The survival of anaplastic astrocytoma patients with LIs < or = 11 was similar to that of astrocytoma patients, whereas the survival of anaplastic astrocytoma patients with LI > 11 was similar to that of patients with glioblastoma. CONCLUSIONS: The results of the current study show that histopathologic grading can predict the outcome for patients with astrocytomas and glioblastomas, whereas MIB-1 LI can separate better and worse prognostic groups in patients with anaplastic astrocytoma.

Adolescent↗

PubMed1998

Expression of E-cadherin and alpha- and beta-catenins in thymoma.

Expression of the cell adhesion molecules including E-cadherin and its cytosolic binding proteins, alpha- and beta-catenins, has been widely studied in a variety of tumours, but not, to date, in thymic epithelial tumours. To observe the expression pattern of these adhesion molecules, immunohistochemical stains for E-cadherin (E-CD) and alpha- and beta-catenins were performed on 89 cases of thymoma which were classified as cortical (57 cases), mixed (18 cases), and medullary (14 cases), based on the classification of Marino and Müller-Hermelink. The majority of cortical thymomas showed diffuse and homogenous membrane immunoreactivity for these molecules (88 per cent for E-CD; 86 per cent for alpha-catenin; 91 per cent for beta-catenin) and the remaining cases showed heterogeneous immunoreactivity, whereas almost all mixed and medullary thymomas revealed decreased expression or were negative. In each histological subtype of thymoma, the expression did not correlate with invasion or with the presence of myasthenia gravis. These results indicate that the expression of E-CD and alpha- and beta-catenins is more closely associated with the histological subtypes of thymoma than with their biological behaviour.

Adult↗