Search PubMed⌕ Search

Biomedical subjects

C C Hsu

Publications and source records attributed to C C Hsu.

At least 127 records · Page 7Linked to original sources
PubMed1996

Advanced glycosylation end products stimulate the growth but inhibit the prostacyclin-producing ability of endothelial cells through interactions with their receptors.

The influence of advanced glycosylation end products (AGE) on endothelial cells was investigated. When human umbilical endothelial cells were cultured with AGE-bovine serum albumin, viable cell number as well as DNA synthesis was significantly stimulated, whereas prostacyclin production by the endothelial cells was decreased. Antisense oligodeoxyribonucleotides against mRNA coding for AGE receptor were found to reverse both the AGE-induced growth stimulation and the inhibition of prostacyclin production in endothelial cells. These results thus suggest that AGE ligand-receptor interactions in endothelial cells can promote angiogenesis and thrombogenesis, leading to the development of diabetic vascular complications.

6-Ketoprostaglandin F1 alpha↗
PubMed1996

Use of sonography in the evaluation of the gastroesophageal junction.

To demonstrate the gastroesophageal junction with a real-time, transabdominal sonography through the window of left lobe of liver, the normal sonographic pattern and the thickness of the wall of abdominal esophagus were determined. The detection rate of the normal pattern in 30 control subjects was 93%, the normal thickness of the wall being 3.8 +/- 1.2 mm (range 2 mm to 5 mm). In 7 patients with severe acute esophageal inflammation, the thickness was 7.6 +/- 2.1 mm (range 5 mm to 10 mm). In 6 patients with an invading lesion in the gastroesophageal junction due to malignancy, the thickness of the wall was more than 10 mm in each case. This preliminary study indicates that the sonographic detection of gastroesophageal junction through the liver window can be included in routine abdominal sonography. An increased thickness of the wall needs further study to find the cause of the thickening.

Acute Disease↗
PubMed1996

L ferritin accumulation in macrophages infiltrating the lung during rat Angiostrongylus cantonensis infection.

A 22-kDa protein was increased quantitatively, as measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis techniques, in lung microsomes prepared from Angiostrongylus cantonensis-infected rats. However, it was almost absent in normal rats. The protein was purified by sequential chromatography on Superdex 200 columns and identified chemically and immunologically as ferritin. Using isoelectric focusing and anion exchange chromatography, it was identified as L ferritin. Distribution of this 22-kDa protein in the lung tissue of A. cantonensis-infected rate was studied by immunocytochemistry. Positively stained cells were mainly infiltrated macrophages. Our results suggest that L ferritin accumulation in the macrophages may be related to the proliferation of connective tissue elements and the inflammatory response to A. cantonensis dwelling in the pulmonary arteries of the rat.

Angiostrongylus cantonensis↗
PubMed1996

Design and application of a low-temperature Peltier-cooling microscope stage.

A light microscopy system has been designed for freezing and lyophilization studies of protein pharmaceuticals. The system consists of a cascade of four Peltier thermoelectric modules in the lyophilization cell to freeze samples to -60 degrees C, controllers to regulate temperature and pressure conditions, and a video camera to record the events under study. Specific demonstration of the system was conducted using recombinant CD4-IgG and human growth hormone (hGH) as model proteins. Observations of recrystallization during warming of frozen CD4-IgG solution and lyophilization of hGH solution are discussed. These examples demonstrate that the system is a useful tool for the fundamental understanding of freezing and lyophilization of protein pharmaceuticals.

CD4 Antigens↗
PubMed1996

Endoscopic features of metastatic tumors in the upper gastrointestinal tract.

BACKGROUND AND STUDY AIMS: Metastatic tumors in the upper gastrointestinal tract are rare. The tumors that most frequently metastasize to the upper gastrointestinal tract are reported to be melanoma, lung cancer, and breast cancer. We describe here our experience in relation to the clinical manifestations and endoscopic findings of metastatic tumors in the upper gastrointestinal tract. PATIENTS AND METHODS: Excluding leukemia, lymphoma, and direct tumor invasion, eight cases of metastatic tumor in the upper gastrointestinal tract from five identified primaries were observed over a period of eight years. The histological nature of the lesions was verified by endoscopic biopsy. RESULTS: The primary tumors in the eight cases were lung cancer (two cases), renal transitional-cell carcinoma (two cases), colonic cancer (two cases), melanoma (one case) and testicular embryonal cell carcinoma (one case). Acute upper gastrointestinal bleeding and anemia were the most common features of the clinical presentation, and the stomach and duodenum were the organs most often involved. Endoscopically, submucosal tumors and polypoid masses, with either erosion or ulceration, were the usual morphological findings. CONCLUSIONS: Panendoscopy with histological examination is a way of identifying metastatic tumors to the upper gastrointestinal tract when patients have a known primary cancer and symptoms relating to the upper gastrointestinal tract. However, there is no specific information allowing the origin of a lesion to be predicted.

Adult↗
PubMed1996

Coamplification of the ZFX and ZFY genes for sex identification in preimplantation embryos.

Knowledge of the sex of an embryo may be particularly useful for couples who have a high risk of producing offspring with inherited genetic disorders. We present a rapid and reliable nested polymerase chain reaction strategy to simultaneously amplify the ZFX and ZFY genes at the single cell level. Forty single blastomeres isolated from six triploid preembryos were subjected to coamplification of ZFX and ZFY genes. The results obtained from the preembryo were consistent with the assigned genotype. The amplification rate was 80% for ZFX and 84% for ZFY. Our strategy can be applied to preimplantation diagnosis of single gene disorders, and is especially useful for preimplantation diagnosis and prevention of X-linked diseases in in vitro fertilization programs.

Blastocyst↗
PubMed1996

Sonographic signs of complete rotator cuff tears.

BACKGROUND: To evaluate the usefulness of high resolution ultrasound (HRUS) in the examination of complete rotator cuff tear (RCT). METHODS: A prospective study of 157 patients with sonographic examination of shoulder was performed. All of them complained of chronic shoulder pain and were referred by clinician for suspicion of RCT. Their age ranged from 30 to 76 years. The ultrasonic scanners we used were Acuson 128 XP 10 with 7MHz linear transducer, or Diasonics VST master series using 10MHz linear transducer. Examination positions included external rotation of shoulder for scanning biceps tendon and subscapularis tendon, and internal rotation for supraspinatus tendon and lateral scan of infraspinatus tendon and teres minor tendon. Sonographic criteria of complete RCT included 1. complete absence of rotator cuff (RC); 2. focal thinning of RC; 3. focal hypoechoic cleft of RC; 4. focal depression of RC; and 5. heterogeneous hypoechoic RC with subdeltoid bursa fluid. Arthrography was performed after sonography examination on the same day. RESULTS: Among 49 complete RCTs diagnosed by sonography, 46 were proved to be complete RCT by arthrography; only 3 were false positive. In 108 patients with normal rotator cuff diagnosed by sonography, 104 had compatible results with arthrography; only 4 patients turned out to be complete RCT. The sensitivity, specificity, positive predictive values, negative predictive values and accuracy were 92%, 97.2%, 93.9%, 96.3% and 95.5%, respectively. CONCLUSIONS: HRUS can directly demonstrate the morphological changes of RC. It has a high sensitivity and specificity in the diagnosis of complete RCT, and can be used as a firstline screening modality for complete RCT in patients with chronic shoulder pain.

Adolescent↗
PubMed1995

Receptor-mediated toxicity to pericytes of advanced glycosylation end products: a possible mechanism of pericyte loss in diabetic microangiopathy.

The influence of advanced glycosylation end products (AGE) on bovine retinal pericytes was investigated. When pericytes were cultured with AGE-bovine serum albumin (BSA), pericyte growth was significantly retarded in a dose-dependent manner. They also exhibited an immediate toxicity to pericytes. However, MRC-5 human fibroblasts were totally resistant to AGE-BSA. Moreover, antisense oligonucleotides complementary to mRNA coding for AGE receptor were found to reverse the AGE-induced decrease in viable pericyte number, although the mRNA level was about one order of magnitude lower in pericytes than in the fibroblasts. These results indicate that pericytes may possess a peculiar sensitivity to AGE, and that AGE ligand-receptor interactions may play an important role in the pathogenesis of pericyte loss, the principal change in diabetic microangiopathies.

Animals↗
PubMed1995

Interference with uterine blood flow by clomiphene citrate in women with unexplained infertility.

OBJECTIVE: To investigate the effect of clomiphene citrate on the uterine blood flow in women with unexplained infertility. METHODS: Twenty-one women who had normal uterine blood flow (pulsatility index [PI] less than 3 from the LH peak to the middle luteal phase of a natural ovulatory cycle) were enrolled in this study. Patients were given clomiphene citrate (100 mg/day) from days 5-9 of the next ovulatory cycle. The PI values measured in the natural and clomiphene citrate-treated cycles were compared using repeated measures analysis of variance. Their correlations with the estradiol (E2) and progesterone concentrations in the treatment cycle were calculated using the Pearson correlation coefficient. RESULT: In the natural cycles of those with normal uterine blood flow, the highest impedance of uterine blood flow was detected at the late follicular phase, then blood flow increased during the luteal phase. In the clomiphene citrate-treated cycles, a statistically significant decrease in uterine blood flow also occurred during the early luteal phase (P < .05). No significant correlation of E2 or progesterone serum concentrations with PI values of the uterine artery could be found in either natural or clomiphene citrate-treated cycles. CONCLUSION: The use of clomiphene citrate decreases the uterine blood flow during the early luteal phase, a periimplantation stage.

Adult↗
PubMed1995

Surface denaturation at solid-void interface--a possible pathway by which opalescent particulates form during the storage of lyophilized tissue-type plasminogen activator at high temperatures.

During protein lyophilization, it is common practice to complete the freezing step as fast as possible in order to avoid protein denaturation, as well as to obtain a final product of uniform quality. We report a contradictory observation made during lyophilization of recombinant tissue-type plasminogen activator (t-PA) formulated in arginine. Fast cooling during lyophilization resulted in a lyophilized product that yielded more opalescent particulates upon long term storage at 50 degrees C, under a 150 mTorr nitrogen seal gas environment. Fast cooling also resulted in a lyophilized cake with a large internal surface area. Studies on lyophilized products containing 1% (w/w) residual moisture and varying cake surface areas (0.22-1.78 m2/gm) revealed that all lyophilized cakes were in an amorphous state with similar glass transition temperatures (103-105 degrees C). However, during storage the rate of opalescent particulate formation in the lyophilized product (as determined by UV optical density measurement in the 360 to 340 nm range for the reconstituted solution) was proportional to the cake surface area. We suggest that this is a surface-related phenomenon in which the protein at the solid-void interface of the lyophilized cake denatures during storage at elevated temperatures. Irreversible denaturation at the ice-liquid interface during freezing in lyophilization is unlikely to occur, since repeated freezing/thawing did not show any adverse effect on the protein. Infrared spectroscopic analysis could not determine whether protein, upon lyophilization, at the solid-void interface would still be in a native form.

Calorimetry, Differential Scanning↗
PubMed1995

Follow-up of skin manifestations in Yu-Cheng children.

We report an 11-year follow-up study on the dermatological manifestations of Yu-Cheng children born to mothers who were poisoned by polychlorinated biphenyl (PCB)-contaminated cooking oil between 1977 and 1979. Eighty-eight children born to these mothers, and 86 matched controls, were examined by one dermatologist. Chloracne scars were found in one patient, and there were nail abnormalities in about one-third of the exposed patients. Transverse grooves, irregular depressions, and koilonychia/nail flattening were significantly more frequent than in the control group, based on Fischer's exact test. This study indicates that in Yu-Cheng children the nail changes are the most persistent abnormality after PCB intoxication, and their occurrence may indicate developmental retardation of the fetal nail matrix. Such a finding might also suggest that PCBs remaining in the mother could exert an effect on nail growth in children born several years after the intoxication event.

Adolescent↗
PubMed1995

CPEO and carnitine deficiency overlapping in MELAS syndrome.

Mitochondrial myopathy, encephalopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome is one of the mitochondrial encephalomyopathies that has distinct clinical features including stroke-like episodes with migraine-like headache, nausea, vomiting, encephalopathy and lactic acidosis. We report a 27-year-old woman who presented with partial seizure, stroke-like episodes including hemiparesis, hemianopia and hemihypethesia, sensorineural hearing loss, migraine-like headache, and lactic acidosis. Brain computed tomographic scan showed encephalomalacia in the right parieto-occipital area and recent hypodensity in the left temporoparieto-occipital area with cortical atrophy. Muscle biopsy revealed ragged-red fibers and paracrystaline inclusions in the mitochondria. Genetic study revealed an A to G point mutation at nucleotide position (np) 3243 of mitochondrial DNA. External ophthalmoplegia and ptosis were also found during two exaggerated episodes in this patient. Therefore, the overlapping syndrome of chronic progressive external ophthalmoplegia in the MELAS syndrome is considered in this case. Furthermore, we also found carnitine deficiency in this patient and she was responsive well to steroid therapy. Muscle biopsy also revealed excessive lipid droplets deposits. Therefore, the carnitine deficiency may occur in MELAS syndrome with the A to G point mutation at np 3243. We recommend the steroid or carnitine supplement therapy be applied to the MELAS syndrome with carnitine deficiency.

Adult↗
PubMed1995

Growth abnormalities in the population exposed in utero and early postnatally to polychlorinated biphenyls and dibenzofurans.

This article reviews the findings in children exposed to various levels of polychlorinated biphenyls (PCBs) and related compounds in utero and early postnatally. Yu-Cheng ("oil-disease") mothers were Taiwanese women exposed to PCBs and their heat-degradation products from the ingestion of contaminated rice oil in 1979. Children of these mothers were born growth retarded, with dysmorphic physical findings, and delayed cognitive development compared with unexposed children. In this article, findings in Yu-Cheng children born between 1978 and 1985 are summarized and compared with two other well-documented cohorts of children prenatally exposed to different levels of PCBs. Results of the investigation in Yu-Cheng children will provide important information about the toxicities, health effects, and mechanisms of PCB/PCDF exposure and demonstrate that the developing human is more sensitive than the adult to the toxic effects of these chemicals.

Adult↗
PubMed1995

Rebleeding rate of various stigmata of recent hemorrhage in peptic ulcer bleeding with different severity.

The stigmata of recent hemorrhage (SRH) have been used as a factor for predicting peptic ulcer rebleeding. In previous studies, the rebleeding rate of the visible vessel varied. A hypothesis had been proposed stating that the evolution of the color of the stigmata depends on the point in the healing process of the blood clot on the bleeding ulcer. This retrospective study evaluates the rebleeding rates associated with various colors of stigmata of recent hemorrhage. Of a total of 623 cases of peptic ulcer bleeding (474 male and 149 female, with a mean age of 59 years old), there were 232 gastric ulcers, 369 duodenal ulcers, and 22 stomal ulcers. Stigmata of recent hemorrhage were found in 387 cases (62%). The overall rebleeding rate for those with gastric ulcers was higher than for those with duodenal ulcers (24.2% versus 16.3%, p<0.05), especially for oozing and sentinel clots, the rebleeding rates for active bleeding, blood clots, sentinel clots, and others were 35%, 24.8%, 17%, and 11.3% respectively. The red clot of stigmata of recent hemorrhage had a slightly higher rebleeding rate than the black clot, but the difference was not statistically important. Furthermore, the 5 duodenal ulcers with white sentinel clots experienced no rebleeding. When comparing the rebleeding rates between groups with massive and minor bleeding, a significantly higher rebleeding rate was found in the massive bleeding group (50.5% versus 6.6%, p < 0.001). It can thus be seen that the different types of stigmata of recent hemorrhage represent different stages in the healing process of a bleeding ulcer. A white sentinel clot had a change of not rebleeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Chi-Square Distribution↗
PubMed1994

An integral membrane protein form of brain L-glutamate decarboxylase: purification, characterization and its relationship to insulin-dependent diabetes mellitus.

A new and novel form of L-glutamate decarboxylase (GAD; EC 4.1.1.15) was purified from whole porcine brain to apparent homogeneity by a combination of column chromatographies on DE-52, ultragel AcA 34, hydroxylapatite and Sephadex G-200, and native gel electrophoresis. The purified GAD was established as an integral membrane protein based on hydrophobic interaction chromatography and membrane extraction studies. This membrane GAD (MGAD) has a native molecular weight of 120 +/- 5 kDa and is a homodimer of 60 +/- 2 kDa. Immunoprecipitation and immunoblotting tests using the sera from insulin-dependent diabetes mellitus (IDDM) patients revealed the presence of antibodies against this newly identified MGAD in IDDM. The role of MGAD in the pathogenesis of IDDM and related autoimmune disorders is also discussed.

Diabetes Mellitus, Type 1↗
PubMed1994

Purification and characterization of a novel form of brain L-glutamate decarboxylase. A Ca(2+)-dependent peripheral membrane protein.

L-Glutamic acid decarboxylase (GAD) catalyzes the one-step biosynthesis of gamma-aminobutyric acid (GABA), which is widely accepted as the major inhibitory neurotransmitter in the mammalian brain. In this paper, we report the identification and purification of a new and novel form of peripheral membrane GAD (MGAD) referred to as MGADIII, using a combination of chromatography on DE52, AcA 34, hydroxylapatite and Sephadex G-200, and native gel electrophoresis. The purified MGADIII migrated as a single protein band on a native 5-25% gradient polyacrylamide gel electrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis with an apparent molecular mass of 118 +/- 6 and 60 +/- 4 kDa, respectively, suggesting that it is a homodimer of 60 kDa. MGADIII was established as a Ca(2+)-dependent peripheral membrane protein based on Triton X-114 phase partitioning assay, liposome binding experiment, and membrane extraction studies. Several lines of evidence are presented to show that the association of MGADIII with membranes occurs during depolarization of nerve terminal and that this is a reversible process. Based on these results and previous findings that GAD associates with synaptic vesicles and is regulated by phosphorylation, a model for regulation of GAD in the nerve terminal is proposed.

Animals↗