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Biomedical subjects

T J Chang

Publications and source records attributed to T J Chang.

71 records · Page 4Linked to original sources
PubMed1991

Clinical experience on malaria.

The 11 cases of malaria admitted to Kaohsiung Medical College Hospital in the past 10 years were analyzed to assess the characteristics of patients who acquired malaria parasite infection. Nine of the patients contracted malaria in Southeast Asia. Two men had received antimalarial chemoprophylaxis before they went abroad and another two men relapsed after antimalarial treatment. The initial symptoms and signs were nonspecific, including fever, chills, abdominal pain and hepatosplenomegaly. Seven patients responded well to the antimalarial regimens. Two persons developed meningeal malaria. Resistance to chloroquine and primaquine and even to quinine was noted in another two cases. Hypoglycemia was diagnosed in one of latter two patients who developed heavy parasitemia (26%), acute renal failure and died 5 days after treatment. Peripheral blood smear examination is a simple and quick method to make a diagnosis in any suspicious case. Resistance to chloroquine and primaquine is not uncommon, especially in those who acquired the infection in Southeast Asia. Changing to more potent agents and aggressive management in complicated cases is necessary.

Adult↗
PubMed1990

Sex hormone receptors in gastric cancer.

Gastric adenocarcinoma that originates from mucosal tissue invades submucosa, muscle, and serosa in different stages. The level of progesterone receptors (PgR), estrogen receptors (ER), and androgen receptors (AdR) in the superficial part of gastric cancer tissues (CAs) from 16 patients was determined and compared with that of the corresponding normal gastric mucosal tissues (NLm). There were PgR in all CAs (100%) with values that ranged from 20.5 to 548.4 fmol/mg protein. Eight CAs (50%) had ER values that ranged from 6.8 to 325.1 fmol/mg protein. AdR was found in two CAs with values of 14.7 and 16.4 fmol/mg protein. In NLm, 15 (93.8%) had PgR values that ranged from 7.3 to 473.2 fmol/mg protein and ten (62.5%) had ER values that ranged from 0.9 to 87.9 fmol/mg protein. AdR were present in two NLm with values of 1.5 and 73.5 fmol/mg protein. There was no statistical difference in levels of PgR and ER between CAs and NLm. There were PgR in all gastric cancers and in 93.8% of NLm. The results suggest that gastric mucosa may be the target tissues for progesterone action. Furthermore, the lack of correlation between the levels of ER and PgR in gastric cancer tissue suggests that the PgR in gastric cancers are probably estrogen independent.

Adenocarcinoma↗
PubMed1990

Absence of growth-hormone receptor in hepatocellular carcinoma and cirrhotic liver.

Hepatocellular carcinoma is a hormone-sensitive tumor. It has been reported that thyroxine and prolactin significantly stimulated hepatoma growth, whereas growth hormone failed to do so. To learn whether the growth hormone receptor is present in human hepatocellular carcinoma, we used radioreceptor assays in samples of human hepatocellular carcinoma. The liver tissues adjacent to hepatocellular carcinoma (mostly cirrhotic) and control liver tissues (taken during various surgical procedures) were also studied. The study results showed that the affinity constant and capacity of high-affinity growth hormone receptor in normal liver tissues were 6.6 +/- 2.0 x 10(10) mol/L-1 (mean +/- SE, n = 7) and 20.7 +/- 11.5 fmol/mg protein, respectively. The affinity constant and capacity of low-affinity growth hormone receptor in normal liver tissues were 8.9 +/- 3.3 x 10(9) mol/L-1 and 64.7 +/- 32.1 fmol/mg protein, respectively. The absence of growth hormone receptor in human hepatocellular carcinoma and cirrhotic liver samples may explain the absence of growth hormone in the stimulation of hepatoma growth and the decrease of somatomedin levels in cirrhosis.

Adult↗
PubMed1990

Correlation of orbital computed tomography and antibodies in patients with hyperthyroid Graves' disease.

The purpose of this study was to elucidate the incidence of orbital changes in computed tomography, and the relationships of orbital changes with eye-muscle antibody (EMAb), thyrotrophin-binding inhibitor immunoglobulin (TBII), antithyroglobulin antibody (TgAb) and anti-thyroid microsomal antibody (MsAb), in 55 consecutive patients with hyperthyroid Graves' disease. EMAb was demonstrated by an immunoperoxidase technique. The results showed that the prevalence of orbital fat increase, extraocular muscle enlargement, lacrimal gland enlargement and optic nerve swelling were 54.5, 41.8, 21.8 and 16.5% respectively. There were 32.7% of patients without any orbital changes. The patients with extraocular muscle enlargement, lacrimal gland enlargement and optic nerve swelling had higher titres of EMAb than the patients without these orbital changes. The patients with lacrimal gland enlargement had a lower TBII index than those without. There was no difference in TgAb or MsAb between the patients with extraocular muscle enlargement, lacrimal gland enlargement, optic nerve swelling or orbital fat increase and those patients without these orbital changes. The patients with extraocular muscle enlargement, optic nerve swelling and orbital fat increase had a higher degree of exophthalmos than the patients without these orbital changes. EMAb was negatively correlated with TBII. However, there was no correlation between EMAb and TgAb or MsAb. The degree of exophthalmos was positively correlated with EMAb and negatively correlated with age. There was no correlation between exophthalmos and TBII, TgAb or MsAb. In conclusion, although the pathogenesis of orbital changes and hyperthyroidism is different, a close link between these two entities is suggested by the high incidence of orbital changes in hyperthyroid Graves' disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Content of glucocorticoid receptor and arginase in gastric cancer and normal gastric mucosal tissues.

The content of glucocorticoid receptor (GR) and arginase in human gastric cancer and the corresponding normal gastric mucosal tissues was determined. Among the 25 patients studied, the GR content in gastric cancer tissues was 33.2 +/- 10.2 fmol/mg protein versus 7.6 +/- 3.4 fmol/mg protein in gastric mucosal tissues. This difference is statistically significant (P less than 0.005). Of the 25 paired samples, 19 cancer tissues contained GR, whereas only seven of the normal mucosal tissues had GR. The level of arginase in gastric cancer tissues in 19 patients was assayed, it was 26.6 +/- 4.2 ng/mg protein which is also significantly higher than that in normal gastric mucosal tissues (13.5 +/- 1.8 ng/mg protein) (P less than 0.005). Since glucocorticoids and arginase are potent immune suppressive agents, the increased level of GR and arginase in gastric cancer tissue suggest that these glucocorticoid-related factors in gastric cancer tissue may play a partial role in regulating cellular immunity.

Aged↗
PubMed1989

A comparison of regional versus systemic drug injection. Adriamycin concentration in peripheral blood and gastric stump (post-Billroth II gastrectomy) in the dog.

Gastric stump cancer has a low resection rate and poor response to systemic chemotherapy. This study attempted to achieve higher drug concentrations in target tissues by way of regional arterial injection instead of systemic venous administration. A total of 12 male mongrel dogs that had undergone post-Billroth II gastrectomies were randomly divided into two groups: in group A, 1.27 mg/kg adriamycin (ADM) was injected through the left gastric artery; in group B, the same dose of ADM was injected into a vein in the left front leg. Blood samples were taken at various time intervals, and the dogs were sacrificed 2 h after drug administration. Tissues were removed from various parts of the gastric stump for measurement of the ADM concentration. The ADM content in the jejunum, heart, liver, spleen, and pancreas was also determined. The results were as follows: (1) the ADM concentration in the gastric stump near its lesser curvature and stomal mucosa was significantly higher in group A than in group B (P less than 0.05). (2) The ADM concentrations in the adjacent organs (heart, liver, and pancreas) were also significantly higher in group A than in group B (P less than 0.05). (3) The ADM levels in the venous blood were significantly higher in group B than in group A (P less than 0.05). These results indicate that a chemotherapeutic drug given through the left gastric artery provides a higher drug concentration in the area where gastric stump cancer frequently occurs and that a lower systemic blood level may cause fewer adverse drug effects. The high concentration of ADM in the heart may not be a good indication, but it may serve as an important signal either to select a less cardiotoxic drug or to monitor heart function cautiously during drug therapy.

Animals↗
PubMed1989

Steroid hormone receptors in meningiomas of Chinese patients.

Meningioma is a hormone-related intracranial tumor. Brain tumor samples were collected from 32 Chinese patients, 20 of whom had meningiomas. Estrogen receptors were present in 6 of 17 meningiomas, 1 hemangioblastoma, 1 gemistocytic astrocytoma, and 1 neurilemoma. Of the 26 samples assayed for progesterone receptors, measurable bindings were found in 14 of 17 meningiomas, 1 of 2 astrocytomas, 1 malignant lymphoma, 1 hemangioblastoma, 1 ganglioglioma, 1 glioblastoma multiforme, 1 anaplastic ependymoma, 1 small cell sarcoma, and 1 neurilemoma. Androgen receptors were found in 8 of 19 meningiomas, but not in the 11 other brain tumors examined. Measurable glucocorticoid receptors were found in 15 of 19 meningiomas, 1 malignant lymphoma, 1 hemangioblastoma, 2 craniopharyngiomas, 1 neurilemoma, 1 of 2 glioblastomas, and 1 of 2 astrocytomas. Of the 10 samples examined for tyrosine aminotransferase activity, measurable enzyme activity was found in 7 of the 8 meningiomas, but not in the single hemangioblastoma nor in the single craniopharyngioma. In accordance with other published studies, the results from this study also suggest that the growth of meningiomas may be regulated by hormones, and that the role steroid hormones and their receptors play in the meningioma is worthy of further investigation.

Adult↗
PubMed1988

Glucocorticoid receptors in hepatocellular carcinoma and adjacent liver tissue.

Glucocorticoid and progesterone receptors, tyrosine aminotransferase, gamma-glutamyltransferase and alpha-fetoprotein levels were determined in human hepatocellular carcinoma (HCC) and adjacent liver tissues. Glucocorticoid receptor was present in seven of ten HCC samples, values ranged from 1.9 to 66.8 fmol/mg protein. Progesterone receptor was present in two of ten HCC samples with values of 1.7 and 7.2 fmol/mg protein, respectively. In the adjacent liver tissues, no measurable progesterone receptor was found and only one sample had glucocorticoid receptor with a value of 3.0 fmol/mg protein. The increase of glucocorticoid receptor in HCC samples was coincident with a decreased level of tyrosine aminotransferase and an increased level of gamma-glutamyltransferase. No correlation was found among glucocorticoid receptor level, serum or tissue alpha-fetoprotein levels. The presence of glucocorticoid receptors in HCC suggest that hormones may play an important role in the formation of hepatoma, and hormonal therapy may be useful for patients with HCC.

Carcinoma, Hepatocellular↗
PubMed1985

[Antibacterial properties of some spice plants before and after heat treatment].

This study was carried out to understand the antibacterial properties of some spice plants before and after heat treatment in boiling water. The samples included the core and the outer layers of onion, the white and the green parts of green onion, garlic bulb, ginger, ginger root, sweet pepper, chili pepper, brown pepper, and mustard. The test microorganisms included Escherichia coli, Salmonella typhimurium, Vibrio parahaemolyticus, Pseudomonas aeruginosa, Proteus vulgaris, Staphylococcus aureus, Mycobacterium phlei, Streptococcus faecalis, Bacillus cereus, and Micrococcus luteus. Raw garlic bulb could inhibit all of the test strains. The antibacterial activities of green onion are slightly weak than that of onion. However, green onion could inhibit P. aeruginosa and M. luteus, but onion could inhibit E. coli, P. vulgaris, S. faecalis, and B. cereus. Ginger and ginger root could only inhibit M. luteus. Chili pepper could inhibit V. parahaemolyticus and P. vulgaris. Brown pepper could also inhibit P. vulgaris. Sweet pepper and mustard showed no antibacterial activity to all of the test strains. In general, antibacterial components in the spice plants were heat labile. All the spices tested lost their antibacterial activities within 20 min at 100 degrees C.

Allium↗
PubMed1984

Comparison of the genomes of pseudorabies (Aujeszky's disease) virus strains by restriction endonuclease analysis.

The DNA of pseudorabies virus (PRV) strains from the United States and Taiwan and attenuated vaccine strains from Romania were compared by restriction endonuclease analysis. Electrophoretically separated PRV DNA fragments of KpnI and BamHI digests demonstrated cleavage pattern variations which clearly distinguished the 3 Taiwan isolates from all other strains, as well as from each other. One type of variation involved the loss or gain of restriction endonuclease cleavage sites. Examples of this type of variation were clearly observed in fragment patterns of the Taiwan isolates. Another type of variation that occurred at higher frequency for fragments mapping in the repeat and repeat-unique joint regions of the PRV genome involved sequence additions or deletions from existing fragments. This second type of variation occurred in most of the strains analyzed.

Animals↗
PubMedDate not supplied

Can synthetic bone models approximate the mechanical properties of cadaveric first metatarsal bone?

The authors evaluated the value of plastic foam models for approximating the mechanical properties of cadaveric bone. Three mechanical tests (3-point bending, cantilevered load to failure, screw push-out) were performed to evaluate the performance of fresh (nonpreserved) human metatarsals, plastic solid foam anatomic models, and modified anatomic models. The test results indicate that plastic models may simulate the mechanical properties of natural bone in tests in which only elastic deformation is achieved. However, under circumstances where load is applied until material failure, the mechanical properties vary dramatically. These tests indicate that specific goals should be established with these results in mind, when planning mechanical testing studies with either plastic or cadaveric models.

Biomechanical Phenomena↗
PubMedDate not supplied

Up-regulation of beta-actin, cyclophilin and GAPDH in N1S1 rat hepatoma.

Beta-actin, cyclophilin and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) are all constantly expressed proteins that regulate cellular structures and endogenous cytoarchitectural functions. In this study, we used an in vivo N1S1 rat hepatoma model to examine changes in the expression levels of these housekeeping genes in normal and tumor liver samples. The beta-actin, cyclophilin and GAPDH genes were all up-regulated in tumor groups as compared to the controls. Our results suggest that up-regulation of beta-actin, cyclophilin and GAPDH genes may be essential for oncogenesis in hepatoma.

Actins↗
PubMedDate not supplied

Abnormal transcripts of FHIT gene in Chinese brain tumors.

FHIT located at chromosome 3p14.2 was discovered and proposed as a candidate tumor suppressor gene in several cancers. To determine whether the FHIT gene at 3p14.2 is altered in Chinese brain tumors, we examined 13 brain tumors for deletions within FHIT locus. Evaluation of the FHIT gene in the panel of brain tumors led to a comprehensive mutation analysis. The complete sequence of the FHIT gene was determined and deletions between exon 5-8 were found in all 13 cases. In addition, single point mutation of amino acid from two glioblastoma and one atypical meningioma cases and multiple amino acid mutations from one pituitary tumor were observed. Our results support the hypothesis that FHIT gene alteration is involved in tumorigenic development of human neoplasms.

Acid Anhydride Hydrolases↗
PubMedDate not supplied

Abnormal transcripts of FHIT gene in thyroid cancer.

Abnormalities of the FHIT gene were found in many carcinoma cell lines and human tumors as reported which suggest an etiological function in tumorigenesis. To investigate whether the FHIT gene is a target of thyroid tumor specific 3p alterations, we screened the FHIT gene for alteration in thyroid tumors and found that the tumors exhibited aberrant FHIT gene expression. The complete sequence of the FHIT gene in seven cases was determined and deletions between exon 2-9 in different regions were found. Goiter samples as control had normal FHIT transcripts while both normal and aberrant transcripts of FHIT were found not only in the tumor samples but also in the adjacent non-tumorous portion of the thyroid tumor. Our results support the hypothesis that FHIT gene alteration is involved in tumorigenetic development of human neoplasms in thyroid glands.

Acid Anhydride Hydrolases↗