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Biomedical subjects

J M Chang

Publications and source records attributed to J M Chang.

At least 55 records · Page 3Linked to original sources
PubMed1995

The inhibition of DMBA-induced carcinogenesis by neoxanthin in hamster buccal pouch.

Neoxanthin, a major carotenoid pigment of spinach, is found in the Chloroplast membrane and has an unknown function in plants. Neoxanthin inhibited the production of superoxide anions in an artificial xanthine and xanthine oxidase system and depressed DNA synthesis in methylcholanthrene (MCA)-initiated C3H10T1/2 fibroblasts. in two-stage carcinogenesis experiments, neoxanthin at 0.2 micrograms/0.2 ml inhibited the formation of tumors that were induced sequentially by 7,12-dimethylbenz[a]anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA) in the buccal pouch of Syrian Golden hamsters. To assess the ongoing process of carcinogenesis, the activity of ornithine decarboxylase (ODC), required for cell proliferation, was analyzed. Neoxanthin inhibited the activity of ODC when animals were treated with neoxanthin one hour before the application of TPA in two-stage carcinogenesis. However, neoxanthin did not inhibit ODC activity when animals were treated with neoxanthin one hour before the application of DMBA in two-stage carcinogenesis, and there was no subsequent tumor formation. In a short-term anti-initiation experiment, neoxanthin inhibited the covalent binding of isotope-labeled DMBA to DNA by 53%. These results indicate that neoxanthin inhibits the initiation stage and the promotion stage in two-stage carcinogenesis. This suggests that neoxanthin may act as a potential chemopreventive agent.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1995

Carcinosarcoma of the salivary gland on CT.

Three cases of carcinosarcoma of the salivary gland, two in the submandibular gland, and one in the parotid, were investigated with CT and exhibited a variety of findings. The density of the tumors was lower than that of normal submandibular tissue. A calcification was found in one case. One case showed extensive lymphadenopathy. The parotid lesion had low central density with an enhancing margin.

Aged↗
PubMed1994

Transcatheter arterial embolization with or without cisplatin treatment of hepatocellular carcinoma. A randomized controlled study.

BACKGROUND: This randomized controlled study was objectively designed to evaluate the utility cisplatin (50 mg) in transcatheter arterial embolization (TAE) for treatment of hepatocellular carcinoma (HCC). METHODS: From May 1991 to July 1993, 46 patients were included in the study. All had a pathologic verification of HCC. Clinically, all of the patients were considered inoperable. However, these patients satisfied eligibility criteria for TAE. The patients were divided into two groups by random sampling. In group I, 22 patients received TAE with the regimen of cisplatin (50 mg) mixed with Lipiodol 5-15 ml followed by gelfoam pieces. In group II, 24 patients, as a controlled group, used the regimen of Lipiodol and gelfoam (Spongostan Film, Ferrosan, Denmark) pieces only, without adding any anticancer drug. The two groups were evaluated by a series of imaging studies and various clinical examinations before and after TAE. Subsequently, TAE was performed every 2 or 3 months for all patients until there was no visible tumor, or the patient could not sustain further TAE, or the patient died. RESULTS: In group I, TAE was administered 61 times (average 28 times for each patient), and in group II, 73 times (average 3 times for each patient). The 1-year and 2-year survival rates of group I were 52.5% and 26.2%, and group II were 72.5% and 39.5%. Statistically, there was no significant difference in survival curves and survival rates between these two groups. Tumor response rate of group I was 68% (15/22) and group II was 67% (16/24). There was no significant difference in tumor response between these two groups. The liver and renal function studies after TAE also showed no significant difference between these two groups. CONCLUSIONS: Based on this controlled study, the authors conclude that the addition of cisplatin does not enhance the therapeutic effect of TAE for treatment of HCC.

Adult↗
PubMed1994

Use of quantitative CT to predict postoperative lung function in patients with lung cancer.

PURPOSE: To evaluate the effectiveness of quantitative computed tomography (CT) for predicting postoperative lung function in patients with lung cancer. MATERIALS AND METHODS: Preoperative spirometry and conventional CT of the chest were performed in 38 patients. A postprocessing CT program was applied to quantitate the volume of whole-lung parenchyma with attenuations of -500 to -910 HU; this was defined as total functional lung volume (TFLV). The regional functional lung volume (RFLV) of the lobes or lung to be resected was quantitated separately. CT-predicted postoperative forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) were derived by multiplying the preoperative spirometry values by (1 - RFLV/TFLV). RESULTS: CT-predicted values correlated well with postoperatively measured results (FEV1: r = .93, P < .001; FVC: r = .86, P < .001) in patients who underwent pneumonectomy or lobectomy, regardless of the patient's preoperative ventilation status. CONCLUSION: This method is effective in the prediction of postoperative FEV1 and FVC in patients undergoing pulmonary resection.

Aged↗
PubMed1994

Idiopathic autoimmune hemolytic anemia during pregnancy.

A case of idiopathic autoimmune hemolytic anemia occurring during the third trimester of pregnancy is presented. The hemolytic process was quite severe in the mother but responded to steroid therapy. A healthy baby without evidence of hemolysis was delivered uneventfully through the vagina. We postulate the mechanism of the discuss the clinical picture, management of the disease and the possible effect on the fetus.

Adult↗
PubMed1993

Detection of abnormal parathyroid glands in postoperative patients with recurrent hyperparathyroidism: sensitivity of MR imaging.

OBJECTIVE: The efficacy of MR imaging in identifying abnormal parathyroid glands in patients with recurrent hyperparathyroidism after surgery was investigated. SUBJECTS AND METHODS: Findings on preoperative T1- and T2-weighted MR images in 44 patients with recurrent hyperparathyroidism were prospectively evaluated and compared with surgical/pathologic results in all patients. A blinded retrospective analysis of the MR findings comparing T1- or T2-weighted images alone and in combination for detection of abnormal parathyroid glands also was performed. RESULTS: Seventy-four percent of surgically proved abnormal parathyroid glands were detected prospectively and 65% were detected retrospectively on MR images. The combination of T1- and T2-weighted images increased the sensitivity for detection. The sensitivity for detection of abnormal glands was 72% in the neck and 86% in the mediastinum. The sensitivities for detecting parathyroid adenomas (80%) and hyperplastic glands (69%) were not significantly different. There was no threshold volume for detection of lesions with MR imaging. Both intrathyroid parathyroid adenomas were missed on MR images. Abnormal glands could not be differentiated from lymph nodes on MR images in three cases. CONCLUSION: MR imaging is a useful technique for detecting abnormal parathyroid glands preoperatively in patients with recurrent hyperparathyroidism after surgery. The combination of T1- and T2-weighted images increases the sensitivity for detection.

Adult↗
PubMed1993

[Hematometra in patients with cervical cancer--its CT presentation and clinical significance].

Cervical cancer is the most common gynecologic malignancy in Chinese. Clinical staging has been traditionally used in cervical cancer, according to international Federation of Gynecology and Obstetrics (FIGO) staging classification. Computed tomography was an adjunctive modality for detecting paraaortic lymph nodes in preoperative evaluation. But CT has failed to accurately define the extent of parametrial and vaginal invasion. Here, an attempt has been made to define indirect clues alerting to invasive cervical cancer. Hematometra can be seen in CT as a dilated uterine cavity with retention of significant fluid. The incidence of hematometra was 5% (5/101) in control group, and 26% (22/84) in cervical cancer. Hematometra cannot be more specific for cervical cancer, with an accuracy of 64%, sensitivity of 82% and specificity of 61%. Hematometra was found to have a statistically high relationship with high cancer staging and uterine invasion. The Chi-square values were 14.8 (P < 0.005) in high cancer staging, and 19.8 in uterine invasion. The accuracy of hematometra was 65% in high cancer staging, and 74% in uterine invasion. Hematometra was more common in postmenopause women, with accuracy elevated to 80% for uterine invasion. This is probably related to senile atrophy or endophytic growth of the cervix into the uterus as well as to hormone replacement. These were five false positive instances of hematometra, all unrelated to cervical cancer. They presented with marked fluid and a solid mass in the uterine cavity, and included endometrial adenocarcinoma, uterine myoma and leiomyosarcoma. None of cervical cancer showed a solid mass in a dilated uterine cavity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Unusual short rib-polydactyly syndrome.

We present a case of lethal short rib-polydactyly syndrome (SRPS) that cannot be categorized into the existing classification. A nosologic discussion is presented. To our knowledge, situs inversus totalis, as in our case, has not been described before in any SRPS.

Adult↗
PubMed1992

Magnetic resonance imaging in acute and subacute mediastinal bleeding.

The appearance of intracranial hematoma on magnetic resonance (MR) images has been described. However, the appearance of hematoma on ECG-gated spin-echo images, which are used for cardiac imaging, has not been described previously. Accordingly a retrospective analysis of nine consecutive patients with acute and subacute mediastinal bleeding imaged with ECG-gated spin-echo MR images was done. The time interval between the incipient event and the date of the MR study was determined, and the signal appearance of the hemorrhage was evaluated relative to striated muscle and fat. MR findings were corroborated by other imaging modalities and surgical findings. Acute hematomas showed medium to high signal intensity, whereas subacute hematomas had areas of high signal intensity on images acquired with ECG gating to every heart beat (repetition time = R-R interval) and a short echo time (30 msec). The characteristic signal intensities of blood on ECG-gated MR images are usually distinct in comparison to other pericardial and mediastinal fluid collections. The ability of MR to specifically identify blood within the first few hours after hemorrhage was not tested in this study.

Acute Disease↗
PubMed1992

Popliteal and tibioperoneal arteries: feasibility of two-dimensional time-of-flight MR angiography and phase velocity mapping.

To assess the feasibility of using magnetic resonance (MR) angiography and velocity-encoded cine MR imaging to evaluate morphology and function in the popliteal and tibioperoneal arteries, the profiles of blood flow velocity measured with velocity-encoded cine MR were compared with those measured with color-coded sonography. Two-dimensional time-of-flight MR angiography was performed in the popliteal and tibioperoneal arteries of 10 healthy subjects; velocity-encoded cine MR and color-coded sonography were performed above and below the trifurcation. The velocity waveforms acquired with velocity-encoded cine MR and color-coded sonography correlated well and showed a typical triphasic pattern. At peak systole in the popliteal artery, spatial maximum and spatial mean velocities measured with velocity-encoded cine MR were 42.29 cm/sec +/- 9.55 (standard deviation) and 27.7 cm/sec +/- 5.8, respectively; the peak velocity measured with color-coded sonography was 44.2 cm/sec +/- 12.3. It is concluded that use of both MR angiography and velocity-encoded cine MR should be considered for identification of arterial stenoses and assessment of the hemodynamic importance of peripheral vascular stenoses.

Adult↗
PubMed1992

Clinical analysis of surgical treatment for tuboovarian abscess.

The role of copious irrigation and drainage in the treatment of tuboovarian abscess (TOA) is crucial, especially for the patients who want to remain fertile. Some have used vaginal drainage via posterior colpotomy for patients with TOA, whereas others preferred irrigation using large-bore drains. In this study, we reported 31 cases of TOA. We found that for women who want to conceive again the best method of treatment is conservative surgery plus low pressure sump tube drainage.

Abscess↗
PubMed1992

[Acute abdomen with intraperitoneal bowel perforation-demonstration by CT scan].

Ninety-eight cases of surgically proved bowel perforation in VGH-Kaohsiung within one year were reviewed. Among them, 25 patients received abdominal CT scans before operation. Free gas or fluid could be demonstrated with CT scan in 80% of cases though sometimes the fluid was too scanty to be well recognized. Local abscess formation with or without tumor mass lesion (n = 3), local fluid accumulation (n = 1) and negative CT findings (n = 1) constituted the remaining 20% of cases. The recognition of perforation sites depended on direct evidences of perforation such as ulceration, abscess formation and tumor mass lesion (32%), or indirect evidences including hematoma formation, dependent extraluminal gas accumulation and phlegmonous reaction (12%). An inexplicable localized extraluminal fluid accumulation might also suggest a possibility of hollow organ perforation and lead to the recognition of perforation site in the absence of free gas (4%). Absence of extraluminal fluid or gas can not completely rule out the possibility of hollow organ perforation (4%). Massive free air, especially with an air-fluid level, suggested a possibility of upper abdominal perforation. The perforation hole located at the anterior wall of stomach produced more free gas than that located at posterior wall. Air-fluid levels could never be identified in the cases of lower gastrointestinal perforations. Local bowel wall thickening and the distribution of free gas contributed little to the recognition of perforation site. Extravasation of oral contrast media sometimes led to the diagnosis of gastrointestinal perforation but was not necessary to be noted around the perforation hole and did little contribution to the perforation site recognition.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen, Acute↗
PubMed1992

Intrathoracic schwannoma of vagus nerve.

Intrathoracic neurogenic tumors are relatively common mediastinal tumors generally located in the posterior mediastinum. The most common origin is the intercostal nerve or the sympathetic chain. These tumors rarely arise from vagus nerve in the anterior mediastinum. The English literature demonstrates a total of 29 cases, which are more often on the left than the right. Here, we present another case: a 41-year-old man with a history of chronic cough for 10 years, whose chest radiograph showed a homogenous mass in the right anterosuperior mediastinum. The chest CT scan revealed a well-defined mass, 4-cm in diameter, located at the right side of trachea. Marked compression and lateral displacement of the R't innominate vein were noted. The mass was heterogenous with partial area of relative lower density and only mild enhancement was noted after contrast medium infusion. Sternotomy with tumor resection from the right vagus nerve was done. The histological diagnosis was schwannoma.

Adult↗
PubMed1991

Assessment of right ventricular diastolic and systolic function in patients with dilated cardiomyopathy using cine magnetic resonance imaging.

Cine magnetic resonance imaging (MRI) can provide clear endocardial margins of the entire right ventricle, and Simpson's algorithm can be applied to obtain the volumes at multiple phases of the cardiac cycle. Time-volume curves of the right ventricle were obtained by using cine MRI in 10 patients with dilated cardiomyopathy (DCM) and eight normal volunteers to assess right ventricular function. There were no significant differences in volumes and ejection fraction of the right ventricle between the group with DCM and the normal group. In the group with DCM the time to peak filling rate was increased (p less than 0.05) and the filling fraction was decreased (p less than 0.01). In the patients with DCM cine MRI demonstrated normal volumes and ejection fraction of the right ventricle in contradistinction to the marked increase in volumes and the decrease in ejection fraction of the left ventricle; with the use of time-volume curves of the right ventricle, impairment of diastolic function of the right ventricle was demonstrated.

Adult↗
PubMed1991

Evaluation of right ventricular early diastolic filling by cine nuclear magnetic resonance imaging in patients with hypertrophic cardiomyopathy.

Numerous studies have established abnormalities in systolic and diastolic function of the left ventricle in hypertrophic cardiomyopathy. A consistent feature of this disease is reduced diastolic function of the left ventricle, but little information is available regarding right ventricular function in this disease. Cine nuclear magnetic resonance (NMR) imaging has been found to be effective for measuring right ventricular volumes and therefore was used to assess early diastolic filling of the right ventricle in patients with hypertrophic cardiomyopathy. Right ventricular time-volume curves were obtained from cine NMR images in 10 patients with hypertrophic cardiomyopathy and 8 normal subjects. Right ventricular volume was calculated with use of Simpson's algorithm at approximately 18 phases of the cardiac cycle and, from the curve, peak filling rate and filling fraction during the first third of diastole were determined. In patients with hypertrophic cardiomyopathy, peak filling rate tended to be less (176 +/- 46 vs. 305 +/- 50 ml/s, p less than 0.01) and filling fraction decreased (39.5 +/- 13.8 vs. 74.5 +/- 13.3%, p less than 0.01) in comparison with values in normal subjects. Thus, analysis of right ventricular time-volume curves obtained by using cine NMR imaging demonstrated diastolic dysfunction of the right ventricle in hypertrophic cardiomyopathy.

Adult↗
PubMed1991

Effects on spleen colony-forming unit self-renewal after retroviral-mediated gene transfer of multi-colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, or granulocyte colony-stimulating factor.

C57BL/6 mice were established to constitutively produce multi-colony-stimulating factor (multi-CSF), granulocyte-macrophage colony-stimulating factor, or granulocyte colony-stimulating factor by transplantation with post-5-fluorouracil-treated syngeneic marrow cells infected with retroviral vectors bearing the corresponding growth factor complementary DNAs. At 2-4 weeks after transplantation, these mice had a 2-7-fold increase in spleen colony-forming unit (CFU-S) numbers when compared to control animals transplanted with MPZipNeo-infected marrow cells. Most of the CFU-S in the former animals were located in the spleen, whereas those of control mice were found in the marrow. The increase in total CFU-S content in recipients of CSF-infected mice was not due to an increase in self-renewal ability but rather to the recruitment of more primitive cells, as there were no differences in CFU-S content of spleen colonies generated from marrow cells of either group. Neither were there any differences in the cellular composition of these spleen colonies or in the size or distribution of cell types in secondary spleen colonies generated from these spleen colonies, suggesting the inability of any of the three CSFs to alter the differentiation pattern of CFU-S.

Animals↗
PubMed1989

Nonneoplastic hematopoietic myeloproliferative syndrome induced by dysregulated multi-CSF (IL-3) expression.

Post 5-fluorouracil-treated murine marrow cells were infected with a retroviral vector (MPZen) bearing a multi-potential colony stimulating factor (Multi-CSF) cDNA insert and then transplanted into lethally irradiated syngeneic recipients to study the effects of autocrine production of Multi-CSF in normal hematopoietic cells. Extremely high levels (14,000 U/mL) of Multi-CSF were detected in the sera and in media conditioned by various hematopoietic tissues of the transplanted animals. While spleen, peritoneal, and peripheral blood cellularity increased approximately 10-fold, 10-fold, and 50-fold, respectively, bone marrow cellularity decreased twofold. Progenitor numbers were depressed twofold in the bone marrow but elevated more than 100-fold in the spleen and peritoneum. The majority (80%) of transplanted mice died within 5 weeks of transplantation and showed extensive neutrophilic infiltration of the spleen, lung, liver, and muscle, often with mast cell foci; a phenomenon also seen in the skin and intestine. Neither the infected cells from hematopoietic tissues of the primary mice, nor autonomous mast cell-lines that grew from these cells in liquid culture produced any overt disease when transplanted into normal or sublethally irradiated secondary recipients. In contrast, injection into mice of autonomous FDC-P1 cells transformed by the same retroviral construct led to tumor formation in vivo within 4 weeks. Thus, dysregulated Multi-CSF expression by normal hematopoietic cells produces a fatal but nonneoplastic myeloproliferative syndrome.

Animals↗