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Biomedical subjects

C H Yang

Publications and source records attributed to C H Yang.

281 records · Page 16Linked to original sources
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Endometrium estimation in a sequence of ultrasonic images.

In this paper a novel algorithm for motion estimation of the endometrium in a sequence of ultrasonic images is presented. The algorithm used is based on the criterion that a pixel of a motion object at different times has a different gray value. The motion estimation includes motion frequency and thickness; the former one is determined by the detection of change of a pixel value in a sequence of images during a given time period, and the latter is the result of the object's dimension divided by its extended width. The algorithm has been tested on synthetic and real images, and the results are encouraging.

Algorithms↗
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Weekly and monthly regimens of paclitaxel and carboplatin in the management of advanced ovarian cancer. A preliminary report on side effects.

This preliminary study was carried out over 18 months to evaluate whether the side effects in patients with advanced ovarian cancer receiving chemotherapy using paclitaxel-carboplatin differed between weekly (98 cycles in 14 patients) and monthly (102 cycles in 15 patients) administrations. We used paclitaxel (60 mg/m2) and carboplatin (AUC of 2) in the weekly regimen and 175 mg/m2 of paclitaxel and carboplatin (AUC of 6) in the monthly regimen. All eligible patients received at least four cycles of treatment in both regimens. The results revealed significantly decreased hematological toxicity in weekly regimens relative to monthly ones, ie, 7.1% vs. 18.6% of anemia (> or = grade 2), 7.1% vs. 32.3% of grade 3/4 granulocytopenia, and 0% vs. 15.7% of >grade 2 thrombocytopenia. There was no significant difference in nonhematological toxicities between the two regimens. The incidence of unscheduled events was much less in the weekly regimen than in the monthly one; ie, delayed treatment (3 vs. 18 events), unanticipated hospitalizations (3 vs. 15 times), and supplemental support with G-CSF (7 vs. 33 times). Complete responses were observed in 6 of 14 patients in the weekly regimen and in five of 15 patients in the monthly regimen, while partial responses were seen in four and five patients in the weekly and monthly regimens, respectively. The present results demonstrate that the weekly regimen can achieve the benefits of tolerable toxicity with significantly reduced myelosuppression and improved cost-effectiveness in terms of unscheduled events.

Adenocarcinoma, Mucinous↗
PubMedDate not supplied

Gemcitabine-induced acute lipodermatosclerosis-like reaction.

Gemcitabine is considered to be a well-tolerated and safe cytostatic drug because of the relative lack of side effects. Cutaneous reactions due to gemcitabine treatment, including alopecia and maculopapular eruption, are well known. We report one patient with squamous cell carcinoma of the lung who developed a gemcitabine-induced cutaneous reaction mimicking acute lipodermatosclerosis. This case has never been reported in the literature before.

Acute Disease↗
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Morphology and function of gill mitochondria-rich cells in fish acclimated to different environments.

The objective of this study is to test the hypothesis that morphologically different mitochondria-rich (MR) cells may be responsible for the uptake of different ions in freshwater-adapted fish. Tilapia (Oreochromis mossambicus) were acclimated to high-Ca, mid-Ca, low-Ca, and low-NaCl artificial freshwater, respectively, for 2 wk. Cell densities of wavy-convex, shallow-basin, and deep-hole types of gill MR cells as well as whole-body Ca(2+), Na(+), and Cl(-) influxes were measured. Low-Ca fish developed more shallow-basin MR cells in the gills and a higher Ca(2+) influx than those acclimated to other media. However, fish acclimated to low-NaCl artificial freshwater predominantly developed wavy-convex cells, and this was accompanied by the highest Na(+) and Cl(-) influxes. Relative abundance of shallow-basin and wavy-convex MR cells appear to be associated with changes in Ca(2+) and Na(+)/Cl(-) influxes, suggesting that shallow-basin and wavy-convex MR cells are mainly responsible for the uptake of Ca(2+) and Na(+)/Cl(-), respectively.

Acclimatization↗
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Extraction of human and rabbit acrosomes: a comparison of sequential and sonication methods.

Two methods for the extraction of acrosomal membranes and enzymes from both human and rabbit spermatozoa were compared. Treatment of spermatozoa with hypotonic MgCl2 (0.05 M) solution causes removal of the plasma membrane, vesiculation, disruption and removal of the outer acrosomal membrane posterior to the equatorial segment with accompanying loss of soluble acrosomal material. Subsequent exposure to Hyamine 2389 and Triton X-100 removes acrosomal material bound to the inner acrosomal membrane with concomitant solubilization of this membrane. The MgCl2 extract from rabbit spermatozoa contained a higher yield of hyaluronidase, acrosin, and total proteinase activities, whereas the subsequent detergent extracts contained higher yields of both arylsulfatase A and B activities. By comparison, after 4 minutes of sonication to separate heads and tails, both rabbit and human spermatozoa when viewed by transmission electron microscopy showed alterations of plasma and outer acrosomal membranes with considerable loss of the acrosomal contents. Analysis of acrosomal enzymes indicates the greatest percentage of all the enzymes assayed was located in the extract obtained by sonication in contrast to either the separated head or tail fractions used for further subcellular extraction. Subsequent treatment with Hyamine and Triton yields only minimal amounts of enzyme activity.

Acrosin↗
PubMedDate not supplied

Cytology of metastatic leiomyosarcoma. A case report.

BACKGROUND: Metastasis of leiomyosarcoma is not uncommon. Determination of the primary site may be confused with the presenting symptoms and even the known pathology. CASE: A 62-year-old man presented with chest pain, a productive cough and a lung mass on radiography. Fine needle aspiration of the tumor showed pleomorphic tumor cells. The patient began to have abdominal symptoms one year after presentation. Jejunal leiomyosarcoma was proven after an emergency exploratory laparotomy for mechanical ileus. Sputum cytology disclosed tumor cells one month before death. Necropsy of the lung mass demonstrated findings similar to those of the intestinal tumor microscopically. CONCLUSION: Without laparotomy, our patient would have been diagnosed as having a primary pulmonary leiomyosarcoma by the presenting symptoms and known pathology.

Biopsy, Needle↗
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Mixed cellular population in primary and metastatic periampullary adenocarcinoma of the duodenum: report of a case.

There are numerous reports on the mixed cellular population of primary tumors, especially in the gastrointestinal tract. However, reports of mixed cellular population in metastatic foci are rare. This is a report of a case of periampullary papillary adenocarcinoma of the duodenum with 4 types of cellular population. Metastases to the regional lymph nodes also contained 4 different cell types. The histogenesis of the mixed cellular population in the primary tumor and theories proposed to explain the pathophysiologic mechanisms of mixed cellular population in the metastatic foci are discussed.

Adenocarcinoma, Papillary↗
PubMedDate not supplied

Conversion disorders in childhood and adolescence: a psychiatric consultation study in a general hospital.

From March 1986 to April 1995, 418 consecutive psychiatric consultations for patients aged 18 or below were completed. Ten of these patients met the Diagnostic and Statistical Manual of Mental Disorders, 4th. edition (DSM-IV) diagnostic criteria for a conversion disorder. The medical and psychiatric consultation records of these patients were reviewed. Chief conversion symptoms included pseudoseizure (four cases), gait disturbance (two cases), abnormal movement (one case), four limbs weakness (one case), aphonia (one case) and tunnel vision (one case). The psychosocial problems of the patients included family problems (seven cases), interpersonal problems (two case) and concurrent physical illness (one case). Six patients (60%) manifested complete remission and others showed improvement of the symptoms.

Adolescent↗
PubMedDate not supplied

Momordins inhibit both AP-1 function and cell proliferation.

The activation of Jun/Fos is a crucial factor in transmitting the tumor promoting signal from the extracellular environment to nuclear transcription machinery. One of the final steps in signal transduction is the binding of Jun/Fos to the AP-1 site in order to express gene transcription. Utilizing this concept, we screened about 100 extracts of natural plants to search for a Jun-Fos function inhibitor. The methanol extract of Ampelopsis radix reduced Jun/Foc retardation remarkably. The active principles of the extract were isolated and purified by repeated column chromatography and their structures were identified as oleanolic acid glycosides known as momordin I, Id, and Ie. These compounds reduced the Jun/Fos-DNA interaction and their activities were quantitated with liquid scintillation counting of corresponding bands. Among them, momordin I had the strongest inhibitory activity, with an IC50 value of 22.8 micrograms/ml. The methanol extract and momordin I, Id and Ie also showed cell cytotoxicity against human cancer cell lines. As expected from a gel shift assay, momordin I showed the strongest cytotoxicity and its IC50 value was from 7.280 micrograms/ml to 16.05 micrograms/ml depending on the cell line. With these data, it may be concluded that the mechanism of anticancer activity of momordin I comes from its inhibitory effect on the protein-DNA interaction. The in vivo test was done only with the methanol extract. The extract showed measurable anticancer activity against murine colon cancer. The wet tumor weight reduction rate was 17.73% at 90 mg/kg dose. We suggest that the Jun/Fos-DNA interaction results in cell cytotoxicity.

Cell Division↗
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Biochemical modulation of doxorubicin by high-dose tamoxifen in the treatment of advanced hepatocellular carcinoma.

BACKGROUND/AIMS: In vitro data have indicated that tamoxifen (> 2.5 uM) significantly enhances the cytotoxic effect of doxorubicin in hepatocellular carcinoma (HCC) cells. This clinical study was conducted to examine whether tamoxifen, at a dose sufficient to result in a plasma concentration of more than 2.5 uM, may improve the therapeutic efficacy of doxorubicin in patients with advanced HCC. METHODOLOGY: A prospective phase II study was conducted. Eligible patients had unresectable and non-embolizable HCC, objectively measurable tumors, adequate neogram with absolute granulocyte count > 2,000/mm3 and platelet count > 1 x 10/mm3, total serum bilirubin < 3.0 mg/dl, age > or = 75 year, and a Karnofsky performance status < or = 50%. The treatment included oral tamoxifen 40 mg/m2, q.i.d, Day 1 to 7, and intravenous doxorubicin 60 mg/m2, Day 4, repeated every 3 weeks. RESULTS: Between May 1994 and December 1996, a total of 38 patients were enrolled in the study. Thirty-six patients were evaluable for tumor response and treatment-related toxicities. There were 32 men and 4 women, with a median age of 49 years. They received an average of 3.8 (range:1-12) courses of chemotherapy. ECOG (Eastern Cooperative Oncology Group) Grade 3-4 leucopenia and Grade 3-4 thrombocytopenia developed in 27.2% and 12.5% courses given, respectively. Gastrointestinal toxicity was generally mild. Three patients developed symptomatic cardiac toxicity. Twelve patients (33.3%, 95% confidence interval 17-51%) had achieved a partial remission (PR), with a median progression-free survival of 7 months. Median survivals of the responders and non-responders were 10 and 3 months, respectively (p<0.05). The median Karnofsky performance status of the responders improved from 74.0+/-6.3% to a post-chemotherapy value of 93.2+/-4.6% (p<0.05) CONCLUSIONS: High dose tamoxifen appears to be an effective biochemical modulator of doxorubicin in the treatment of HCC. Prospective randomized phase III studies comparing doxorubicin alone versus doxorubicin plus high-dose tamoxifen are needed.

Adult↗