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Biomedical subjects

H Chiang

Publications and source records attributed to H Chiang.

At least 55 records · Page 3Linked to original sources
PubMed1998

Ki67 labelling index correlates with stage and histology but not significantly with prognosis in thymoma.

AIMS: There have been several cell kinetic studies of thymoma, but the effectiveness of using Ki67 antibody as a tool to measure proliferative activity in this tumour was rarely evaluated. We carried out an immuno-histochemical study using this antibody to assess the clinicopathological correlation and the prognostic significance of this technique. METHODS AND RESULTS: Ninety-one cases of thymoma were collected. Double immunostaining with Ki67 and cytokeratin KL-1 antibodies was performed on paraffin sections. Ki67 labelling index (LI) was expressed as a percentage of Ki67 immunopositive nuclei by counting at least 1000 epithelial cells. The LIs were correlated with stages, histological subtypes based on both Lattes-Bernatz and Müller-Hermelink-Kirchner classifications, and length of survival. There were statistically significant differences of LIs between stage I and stage III and between stage I and stage IV tumours. Histologically, statistically significant differences were identified between predominantly epithelial thymoma and every other subtype of the Lattes-Bernatz classification and between well-differentiated thymic carcinoma and medullary or mixed thymomas of the Müller-Hermelink-Kirchner classification. Regarding the prognostic implication of Ki67 LI, although there appeared a trend that patients with tumours of higher LIs had slightly worse survival, the difference was not statistically significant in both univariate and multivariate survival analyses. CONCLUSIONS: We have demonstrated the proliferative potential in thymoma is associated with stage and histology. However, its clinical usefulness is limited on account of the overlap of LIs and lack of prognostic significance.

Adult↗
PubMed1998

Prostate cancer: local staging with endorectal magnetic resonance imaging.

BACKGROUND: Prostate cancer has received increasing attention during the past decades. Staging of tumors before treatment is imperative for planning appropriate therapy. The purpose of this study is to assess the role of endorectal magnetic resonance imaging (MRI) in local staging of prostate cancer. METHODS: Endorectal MRI was performed in 31 patients with histologically-proven prostate cancer. MRI was done three to 100 days (mean, 32.1 days) after either transrectal ultrasonography (TRUS) with biopsy or transurethral resection of the prostate (TURP). Radical prostatectomies were performed within two weeks after MRI. The diagnostic accuracy of endorectal MRI for local tumor staging, specifically for extracapsular extension (ECE) and seminal vesicle invasion (SVI), was evaluated by correlating MRI results with histopathologic findings of whole-mount specimens. RESULTS: The accuracy of endorectal MRI for the detection of tumor presence and estimation of tumor volume was 48%. Sensitivity, specificity and positive predictive value for evaluation of ECE were 88%, 69% and 80%, respectively, and for SVI, were 66%, 84% and 50%, respectively. The overall accuracy of MRI in local tumor staging (using the TMN system) was 61%. Accuracy in differentiating localized from invasive cancer was 84%. CONCLUSION: Endorectal MRI is not accurate enough to detect tumor presence or estimate tumor volume. Diagnostic accuracy for local tumor staging is unsatisfactory. However, endorectal MRI is highly accurate in differentiating localized (stage B) from invasive (stage C) cancer.

Aged↗
PubMed1997

The clinicopathological characteristics of gonadotroph cell adenoma: a study of 118 cases.

Gonadotroph cell adenoma was the most common pituitary adenoma, constituting 35% of the pituitary adenomas in our series of 339 patients with surgically removed pituitary adenomas from June 1987 to December 1995. The average age of these patients was 53 years, with a male predominance (1.5:1). The most common neurological symptoms were visual symptoms and headache. Amenorrhea and galactorrhea were recorded in 41% and 14%, respectively, of the female patients of reproductive age. Oncocytic change of varying degrees was seen in 69% of the tumors, and the average age of these patients (56 years) was older than those who had no such change (47 years) (P < .005). Five types of gonadotroph cell adenomas were recognized; they were tumors that contained (1) betaFSH, betaLH, and alphaSU, (2) betaFSH and betaLH, (3) betaFSH and alphaSU, (4) betaFSH, and (5) alphaSU. The immunostaining of betaFSH-containing cells was usually diffuse, whereas staining of betaLH- or alphaSU-containing cells was usually focal. Double immunostaining showed the immunoreactive cells containing one or any combination of the gonadotropin subunits. Increases in serum gonadotropin levels were only seen in 35% of the patients with gonadotroph cell adenoma. There was no correlation between serum hormonal levels and immunostaining results. Of the 33 recurrent cases, significant decrease or total absence of immunoreactivity of one or more hormone subunits in subsequent biopsy specimens were seen in three cases.

Adenoma↗
PubMed1997

Polydactyly of the foot: manifestations and treatment.

Polydactyly of the foot is not an uncommon foot problem. However, it is not well understood and not often reported. Its clinical manifestations vary, as do treatment methods and results. During the period of 1979 to 1994, 54 children with polydactyly of 65 feet were treated in our clinic. Bilateral involvement was seen in 11 patients, and six had accompanying polydactyly of the hand. By Blauth and Olason's classification, duplication of the fifth ray (43 feet) was most common, followed by first ray duplication (20 feet) and other ray duplication (2 feet). A rudimentary form was found in one foot. Polysyndactyly was present in 18 feet. Hallux varus was the most common associated problem and was present in seven feet. Surgery for both cosmetic and functional purposes was performed in 38 patients (44 feet). Treatment included excision of the extra toe and reconstruction of the soft tissue around the remaining toe, of which the alignment was restored in cases of deviation. Results were evaluated with Phelps-Grogan's protocol; 39 feet (88%) were classified as having excellent results, two (5%) had good, and three (7%) had poor results. Postoperative complications included residual hallux varus in three feet with polydactyly of the first ray, and unpleasant surgical scars in another two. We conclude that polydactyly of the foot should be treated individually, depending on classification. Special attention should be paid to complex first ray polydactyly.

Adolescent↗
PubMed1997

The effects of 50 Hz magnetic field exposure on dimethylbenz(alpha)anthracene induced thymic lymphoma/leukemia in mice.

Several epidemiological investigations have suggested an increased incidence of lymphoma, leukemia, and brain tumor in residents living near power transmission lines. However, some observers failed to confirm such a positive correlation. To evaluate the effects of extremely low frequency (ELF) magnetic fields on leukemogenesis, an experimental animal model was used, in which thymic lymphoma/leukemia was induced by dimethylbenz(alpha)anthracene (DMBA) injected subcutaneously into the interscapular region of newborn mice within 24 h after birth. Beginning at the second week of age, 165 mice were exposed to 50 Hz magnetic field at 1 mT, 3 h/day, 6 days/week for 16 weeks, and 155 animals exposed to sham conditions. All surviving animals were killed by cervical dislocation at the age of 32 weeks and were examined pathologically. The results showed that the incidences of advanced thymic lymphoma, complicated with lymphomatous leukemia, were 21.8 and 23.9% in the two groups, respectively, without statistically significant differences. But dense metastatic infiltration by lymphoma cells into liver in the field exposure group greater (50%) than that in the sham-exposure group (16.2%) was observed (chi 2 = 9.847, P < 0.01). To determine whether ELF acts as a tumor promoter, further experiments are required.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1997

Squamous cell carcinoma of esophagus with diffuse mucin-secreting component: a clinicopathologic study.

BACKGROUND: Primary esophageal squamous cell carcinomas with a diffuse mucin-secreting component are not common, and the cases reported are few. The nomenclature for this group of tumors is complex and the histogenesis of these tumors is confused. Therefore, further investigation is needed. METHODS: Twelve cases have been collected from pathology files of Veterans General Hospital-Taipei from 1965 to 1995. Clinicopathologic relationship, histopathological and immunohistochemical features of these cases were analyzed and compared with the reported literature concerning this entity. RESULTS: The age, sex and prognosis for patients of this group, and the size and site of the tumors were not different from that of pure squamous cell carcinoma. The tumors continuously connected with esophageal squamous epithelium, and intraepithelial dysplasia were present in 83% cases. Positive anticarcinoembryonic antigen staining was also demonstrated in squamous epithelium, dysplastic epithelium and tumor cells with either squamous or adenomatous differentiation. CONCLUSIONS: It is believed that esophageal squamous cell carcinoma with diffuse mucin-secreting component is close to the squamous cell carcinoma.

Aged↗
PubMed1996

Presence of human herpesvirus-like DNA sequence in oral Kaposi's sarcoma. A preliminary PCR study.

DNA sequences closely related to herpesvirus-like sequences have been found in AIDS-associated Kaposi's sarcoma. Subsequent studies indicate that these DNA sequences may be consistently found in AIDS Kaposi's sarcoma and non-AIDS Kaposi's sarcoma from different geographic regions. Oral Kaposi's sarcoma is rare and the specificity of this viral DNA in oral Kaposi's sarcoma and in other oral neoplasms has not been examined. A total of 77 oral neoplasms, including 3 Kaposi's sarcoma specimens from 2 patients with AIDS, were analyzed by polymerase chain reaction for the presence of this herpesvirus-like DNA sequence with the 330-233 primers. All three specimens of oral AIDS-Kaposi's sarcoma from two patients were positive for this DNA sequence. All of the other intraoral lesions including hemangioma, pyogenic granuloma, and various types of epithelial neoplasms, however, had negative reactions. Our results further confirm that oral Kaposi's sarcoma appears to be associated with this herpesvirus-like DNA sequence.

AIDS-Related Opportunistic Infections↗
PubMed1996

Adenosquamous carcinoma and schneiderian papilloma-like lesion in a mature cystic teratoma of the ovary: a case report.

Malignant transformation is uncommon in the mature cystic teratoma of ovary, in which adenosquamous carcinoma is even rarer. It seldom combines with papillary lesion, like schneiderian papilloma of upper airway. We report such a rare case of mature cystic teratoma undergoing malignant change, with the pictures of both adenosquamous carcinoma and schneiderian papilloma.

Carcinoma, Adenosquamous↗
PubMed1996

Malakoplakia of the prostate forming a fistulous tract to rectum: a case report.

Malakoplakia is a rare lesion of granulomatous inflammation which mainly affects urinary bladder but may involve other parts of the body. Differentiation from neoplastic process is often difficult due to its tumorous gross appearance and similarity to carcinoma microscopically. Malakoplakia of the prostate is even rare. We present a case of prostatic malakoplakia masquerading as a rectal tumor due to formation of a fistulous tract to the rectal muscular layers accompanied with ulceration of the rectal mucosa. Its clinical course is different from those of most reported cases, while the outcome is as satisfactory as in usual cases.

Diagnosis, Differential↗
PubMed1995

Pulsed magnetic field from video display terminals enhances teratogenic effects of cytosine arabinoside in mice.

Eighty-nine Swiss Webster mice were randomly divided into four groups: a control group, a pulsed magnetic field (PMF) group, a cytosine arabinoside (ara-C, a teratogen) group, and a combined PMF + ara-C group. Mice in the PMF and PMF + ara-C groups were irradiated with a PMF (a sawtooth waveform with 52 microseconds rise time, 12 microseconds decay time, and 15.6 kHz frequency) at a peak magnetic flux density of 40 microT for 4 hours daily on days 6-17 of gestation. The mice in the ara-C and the PMF + ara-C groups were injected intraperitoneally on day 9 of gestation with 10 mg/kg of ara-C. The incidence of resorption and dead fetuses was not affected by PMF but was increased by ara-C injection. The malformation incidence of cleft palate (CP) and/or cleft lip (CL) was significantly higher in all three of the treated groups than in the control group (P < 0.05). If, however, statistical analyses had been done on litters rather than on individual fetuses, they would show that the incidence of CP and/or CL in the PMF group is not significantly greater than that in the control group. A significantly higher incidence of CP and/or CL was found in the PMF + ara-C group (49%) than the ara-C alone group (26.1%). These data suggest that PMF might enhance the development of ara-C-induced CP and/or CL. The incidence of minor variations in skeletal development, including reduction of skeletal calcification and loss of skeleton, was not statistically significant in the PMF group.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Drug-Induced↗
PubMed1995

Effect of orchiectomy on the alpha adrenergic contractile response of dog prostate.

PURPOSE: To investigate the effect of androgen deprivation on the alpha-adrenergic contractile response of the dog prostate using both in vitro and in vivo methods. MATERIALS AND METHODS: In vitro muscle bath study: One month after surgery, responses to KCl (120 mM.) and norepinephrine (10(-8) to 10(-3)M.) of prostatic tissue strips (of the same size) from castrated (n = 6) and sham-operated (n = 6) adult mongrel dogs were determined. In vivo study: Before and 1 month after surgery, the intraprostatic urethral pressure response to intravenous norepinephrine administration of 6 castrated and 5 sham-operated adult dogs was examined. RESULTS: (1) Before castration the serum level of testosterone was 1.24 +/- 0.2 ng./ml.; 1 month after castration, it had dropped to an undetectable level. (2) Histological examination of the prostates from castrated animals revealed profound atrophy of glandular tissue with a relatively increased stromal tissue component in each section. (3) In vitro study: The contractile responses to KCl and norepinephrine of individual prostate strips (same size) from castrated animals were significantly higher than control. However, if the response to norepinephrine was normalized to the response to KCl, there was no significant difference in response to norepinephrine between the 2 groups. In addition, the ED50 of the norepinephrine-stimulated contractile response was not changed by castration. (4) In vivo study: There was no significant change in intraprostatic urethral pressure response to intravenous norepinephrine administration after orchiectomy. CONCLUSIONS: The results of this study show that the sensitivity of the alpha-adrenergic contractile response of the dog prostate is not affected by androgen deprivation, nor is alpha-adrenergic contractile activity of the dog prostate regulated by androgen.

Adrenergic alpha-Agonists↗
PubMed1995

A multivariate analysis of prognostic factors in thymoma.

BACKGROUND: Considering the prognostic factors of thymoma, the clinical stage is the most important, while controversies exist about other clinicopathologic factors. A multifactorial study was carried out to clarify the relationship between prognosis and sex, age, tumor size, presence of myasthenia gravis, staging, epithelial subtyping, lymphocyte/epithelial cell ratio (L/E ratio) and other adjuvant pathological features. METHODS: One hundred and thirty-seven cases were collected in Veterans General Hospital-Taipei from 1961 to 1993. The aforementioned features were studied. Kaplan-Meier's actuarial survival analysis was adopted, with Logrank test, to determine the significance of overall heterogeneity and trend. Cox proportional hazard model was also used for multivariate analysis. RESULTS: Among all tested prognostic factors, staging had the highest significance (relative risk = 3.00, p < 0.001) and age had only a moderate one (relative risk = 1.04, p = 0.011). No other clinicopathological factor showed any statistical significance for prognosis. CONCLUSIONS: Staging remains of greatest usefulness in predicting the biological behavior of thymoma. The effect of age requires more investigation. Other clinicopathological features have no definite influence in survival expectancy.

Adolescent↗
PubMed1995

Papillary carcinoma of thyroglossal duct cyst: a case report.

We report a papillary carcinoma of thyroglossal duct cyst. Thyroglossal duct carcinoma is rare: only about 160 cases have been reported. Preoperative diagnosis of malignancy is even rare, except for a few cases by fine needle aspiration cytology or biopsy. A primary lesion or metastasis from the thyroid gland is widely discussed. However, the prognosis is good.

Carcinoma, Papillary↗
PubMed1995

Polyethylene glycol method is superior to ammonium sulfate and protein-A sepharose-4B method in fractionating thyroid stimulating immunoglobulin in Graves' disease.

BACKGROUND: The purpose of this study is to compare the performance of three methods, i.e., ammonium sulfate, polyethylene glycol (PEG) and protein A sepharose 4B in fractionation of thyroid stimulating immunoglobulin. METHODS: Twelve patients with Graves' disease and twelve age-, sex-matched normal controls were recruited. 0.9 ml of saturated ammonium sulfate was added slowly to 1.1 ml of sera of all subjects and was stirred until reaching 45% saturation. The precipitation was allowed to form at 4 degrees C overnight. The solution was centrifuged at 10,000 x g for 5 minutes. The precipitate was washed twice with 45% ammonium sulfate, dissolved in 0.55 ml of distilled water equal to half of the initial volume of the serum and dialyzed against 200 volumes of phosphate-buffered saline (PBS) for 48 hours. Another 0.5 ml of serum sample from the same patients was mixed with 1.5 ml of 20% polyethylene, followed by centrifugation at 2,800 g for 20 minutes. The pellet was dissolved in 0.6 ml of Hanks' medium without NaCl containing 1.5% bovine serum albumin, 20mM HEPES: 1 ml of sera was applied to 0.75 g of protein A sepharose-4B in PBS buffer and eluted with glycine, pH 2.3. By adding immunoglobulin (Ig) from the different methods to the FRTL-5 tissue culture, we determined the cAMP generation. RESULTS: Patients with Graves' disease were found to have higher serum thyroxine and triiodothyronine concentrations (p < 0.001) and significantly higher free thyroxine concentration than normal subjects. Ig elicited stronger response in cyclic AMP generation when prepared with PEG method, as compared with the other two methods (p < 0.001). With sepharose-4B Ig preparation, 10 out 12 patients (83.33%) showed positive thyroid stimulating immunoglobulin (TSI) while with ammonium sulfate precipitation, nine out 12 patients (75%) showed positive TSI. On the other hand, all patients showed positive TSI with PEG precipitation. When the degree of thyrotoxicosis was classified in terms of thyroid hormone concentrations, there was no correlation between TSI titers and thyroid hormone concentration. CONCLUSIONS: Polyethylene glycol is superior to both ammonium sulfate and protein A sepharose-4B in fractionating TSI in terms of sensitivity and convenience in operation.

Adult↗
PubMed1995

Mesoblastic nephroma: a case report.

Mesoblastic nephroma is a rare tumor of kidney characterized by interlacing bundles of spindle mesenchymal cells. The tumor usually occurs in the newborn, and scarcely in the old child. In this article, the authors report a case of an unusual age, a 12-year-old boy, with mesoblastic nephroma which was found by routine physical examination.

Child↗
PubMed1995

Pseudomelanosis duodeni: report of eight cases.

Pseudomelanosis duodeni is an uncommon endoscopic sign characterized by diffuse small black spots on the first and second portions of the duodenum. It occurs predominantly in female and elderly patients and is linked to chronic illnesses and related medications. Between 1988 and 1994, the authors saw eight patients with pseudomelanosis duodeni. To evaluate the nature of the pigments, special staining was performed in seven cases. Iron stain was strongly positive in three cases. Electron microscopy was performed in two cases. This revealed amorphous bodies within macrophage lysosomes in one case and angular crystals in another case. These tests suggest that in pseudomelanosis duodeni iron metabolism may be impaired and iron is pooled within macrophages.

Aged↗
PubMed1994

Effects of 2.45-GHz microwave radiation and phorbol ester 12-O-tetradecanoylphorbol-13-acetate on dimethylhydrazine-induced colon cancer in mice.

The purpose of this study was to investigate the effects of 2.45 GHz microwave (MW) radiation on dimethylhydrazine (DMH)-induced colon cancer in mice. The subjects were 115 Balb/c mice 4 weeks of age. The animals were divided into group A (control), group B (DMH), group C (DMH+MW), and group D [DMH + 12-O-tetradecanoylphorbol-13- acetate (TPA)]. Radiation (10 mW/cm2) was delivered dorsally with the E field parallel to the mouse's long body axis in an anechoic chamber. Radiations were administered 3 hr daily, 6 days per week, over a period of 5 months. The average SAR was estimated to be 10-12 W/kg. During the course of radiation treatments, DMH was injected once per week. The tumor promoter TPA was administered once per week for 10 weeks, from the third week on, after the initial treatment. The incidence of tumors did not significantly differ between the three test groups (groups B, C, and D; P > 0.25). However, the number of tumors, the size of the tumors, and the incidence of protuberant and infiltrative types in tumor-bearing animals were higher in group D compared to groups B and C (P < 0.05). No difference was found between groups B and C (P > 0.25). The study indicates that 2.45 GHz microwave radiation at 10 mW/cm2 power density did not promote DMH-induced colon cancers in young mice. The study also showed that TPA could accelerate colon tumor production if a tumor was initiated.

Adenomatous Polyps↗