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Biomedical subjects

C H Kuo

Publications and source records attributed to C H Kuo.

At least 19 recordsLinked to original sources
PubMed1992

Sonographic detection of stones in poorly opacified left intrahepatic ducts.

Intrahepatic duct (IHD) stone is a common disease in Taiwan. In some cases, left IHD stones cannot be demonstrated by endoscopic retrograde cholangiography (ERC) or even by percutaneous cholangiography (PTC). This study was designed to evaluate the efficacy of sonography in demonstrating left IHD stones in poorly opacified left IHD by either ERC or PTC. Of 109 patients with hyperechoic nodular lesions in either the dilated left IHD or atrophic left lobe of the liver, with or without acoustic shadows, 49 patients were excluded because they refused further study. Among the remainder (60 patients), 33 patients had good opacification of left IHD in ERC or PTC. Stones were seen in 31 patients, and tumor obstruction in 2 patients. Twenty-seven patients had complete or partial absence of the left IHD in cholangiograms. Stones were found at surgery in 23 patients and by CT scan in 3 patients. Mucin-producing cholangiocarcinoma was found in 1 patient. The positive predictive value of the demonstration of stones in left IHD by ultrasound was 95% (57/60). Only 15% of patients with atrophy of the left hepatic lobe and stones were demonstrated by sonogram in this series. We conclude that the detection of left IHD stones by ultrasound in patients with poor opacification of the left IHD in cholangiograms is reliable procedure.

Bile Ducts, Intrahepatic↗
PubMed1992

Topography of opsin within disk and plasma membranes revealed by a rapid-freeze deep-etch technique.

Rod outer segments in fresh rat retinas were examined by a rapid-freeze, deep-etch technique to explore how membrane proteins are organized at the macromolecular level. Cross-fractures revealed that intradiscal membranes are adherent to each other except at the rim. When an isolated fresh retina was incubated in a hypotonic solution for a few minutes, the interdiscal space was expanded and the cytoplasmic surface of the disk membrane was found to be covered with protrusions except at the rim. A few particles were scattered among the protrusions and were attached to the cytoplasmic surface. Since the distribution density of the cytoplasmic surface protrusions was similar to that of the P-face particles, which are known to reflect opsins, the protrusions were considered to be portions of opsins extending into the cytoplasm. The intradiscal surfaces in chemically-fixed retinas were rather smooth and were labelled with anti-opsin antibodies and wheat germ agglutinin. The true surfaces of the plasma membrane were found to be similar in fine structure to those of the disk. A model of the macromolecular organization of rod outer segments is proposed on the basis of these observations. The model shows apposed opsins within a disk membrane adhering to one another except at the rim. These opsins, as well as those in the plasma membrane, are minimally exposed to the extracellular surface, but protrude deeply into the cytoplasm.

Animals↗
PubMed1992

A mechanism for glutamate toxicity in the C6 glioma cells involving inhibition of cystine uptake leading to glutathione depletion.

We have demonstrated that addition of L-glutamate in millimolar amounts to a culture of C6 glioma cells induced cell death within 24 h. The glutamate-induced toxicity in the C6 glioma cells was completely suppressed by adding L-cystine (0.4-1.0 mM), while the C6 cells degenerated in L-cystine-deprived culture medium. Kinetic studies of [35S]cystine and [3H]glutamate uptake showed that cystine competitively inhibited glutamate uptake, and conversely glutamate inhibited cystine uptake competitively, suggesting that C6 cells have a cystine/glutamate antiporter (system CG or Xc) similar to that already described in the periphery. Exogenous cystine (1 mM) stimulated a release of endogenous glutamate from C6 cells in a Na(+)-independent Cl(-)-dependent fashion. Thus, the antiporter normally transports glutamate out of and cystine into the cells. With the glutamate analogues tested, there was a good correlation between cytotoxicity and inhibition of cystine uptake. The de novo synthesis of glutathione was largely dependent upon the uptake of extracellular cystine. Intracellular levels of glutathione were dramatically decreased within 8-10 h by culture in glutamate-added or cystine-free medium. Vitamin E (100 microM), an antioxidant, rescued the death of C6 cells induced by glutamate exposure or by culture in cystine-deprived medium, but did not restore the apparent decrease of intracellular glutathione. Taken together, the present data strongly indicate that glutamate-induced cell death is initially due to inhibition of cystine uptake through the antiporter Xc system; such inhibition leads to glutathione depletion exposing the cells to oxidative stress. Excess of extracellular glutamate introduced from endogenous or exogenous roots might disorder this mechanism, resulting in cell death.

Animals↗
PubMed1992

The prognostic factors of severe amebic liver abscess: a retrospective study of 125 cases.

One hundred twenty-five cases of amebic liver abscess were diagnosed at Chang Gung Memorial Hospital in Taiwan from January 1981 to December 1989. An analysis of possible prognostic factors for severe amebic liver abscess was done retrospectively. The majority of the patients came from the southern part of Taiwan. Severe amebic liver abscess was defined as the rupture of an abscess that was resistant to 72 hr of medical treatment, or complicated by secondary bacterial infection. The results showed significant differences between patients with severe liver abscess and those with more moderate forms of amebic liver abscess in indices such as jaundice, hemoglobin and serum bilirubin levels, and dyspnea, as well as in pulmonary changes (right diaphragm elevation, right pleural effusion) seen on chest radiographs. Those patients with diabetes mellitus also had greater evidence of severe liver abscess. Moderate cases that were treated with amebicides showed excellent responses (no mortality). Severe cases required, in addition to amebicide therapy, either percutaneous or surgical drainage of pus, especially in those patients with ruptured abscesses. Those patients with abscesses that ruptured into the thoracic cavity were treated by either thoracostomy or needle aspiration, and all were cured. Three patients died of abscess rupture into the abdominal cavity, associated with secondary bacterial infection. The overall mortality rate was 2.4%. These symptoms and signs of severe liver abscess are indicators of the need for intensive treatment such as aspiration or surgical drainage.

Adult↗
PubMed1992

Liver biochemical tests and dengue fever.

The impact of dengue on liver function was studied by biochemical tests on 125 male and 145 female patients diagnosed with this disease during an outbreak that extended from November 1987 to December 1988. Abnormal levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), bilirubin, alkaline phosphatase, and gamma-glutamyl transpeptidase (G-GT) were observed in 93.3%, 82.2%, 7.2%, 16.3% and 83.0% of the patients, respectively. The elevation of transaminases was mild to moderate in most cases, but was 10-fold greater than the normal upper limit for AST and ALT in 11.1% and 7.4% of the patients, respectively. Initially, the level of AST was greater than that of ALT, increasing to maximum levels nine days after the onset of symptoms, then decreasing to normal levels within two weeks. Results of the biochemical tests did not differ significantly between the cases with and without hepatitis B or hepatitis C virus infection, but significantly higher elevations of AST, ALT, and G-GT were observed in patients with episodes of bleeding. Liver biopsies of two patients showed features of lobular hepatitis. Of the five fatal cases, three died of hepatic failure. It is concluded that dengue fever may cause hepatic injury and transaminase elevation similar to that in patients with conventional viral hepatitis. In epidemic or endemic areas, dengue fever infection should be considered in the differential diagnosis of hepatitis.

Adolescent↗
PubMed1992

Various sonographic patterns of smooth muscle tumors of the gastrointestinal tract: a comparison with computed tomography.

To evaluate the sonographic patterns of smooth muscle tumors of the gastrointestinal tract, we analyzed 25 patients with histologically confirmed smooth muscle tumors. Sonography revealed no abdominal mass in seven patients (sonogram-negative), and abdominal masses in 18 patients (sonogram-positive). The mean size of tumors in the sonogram-negative group (4.5 +/- 1.5 cm) was smaller than that in the sonogram-positive group (11.4 +/- 3.5 cm). We classified the various sonograms into three patterns. Comparing the sonograms with the computed tomographic pictures of each pattern, we theorized that the different patterns on sonograms may be caused by tumor necroses of different sizes with or without gas in the necrotic cavity. For the necrotic tumors, the size of the necrotic area did not correspond to the size of the tumor. However, the tumors with necroses were significantly larger than those without necroses. A central necrosis was found in cases exhibiting both leiomyosarcoma and leiomyoma. On comparing the sonogram-positive and sonogram-negative groups, we found that the size and location of a tumor may affect the detection rate of that tumor by sonography.

Adult↗
PubMed1992

Toxic effect of bile acid ingestion in rats.

Ingestion of raw bile from some grass carp fish has been reported to be associated with impairment of renal function in some Chinese people. 5 alpha-cyprinol, the main bile alcohol in these fish, has been suggested as the toxic compound causing electrolyte imbalance. In this study, we attempted to determine whether oral administration of pure bile acids also affects the electrolyte balance in rats. Twenty-four female Long-Evans rats weighing 200-250 g were used. Conscious cannulated animals were prepared and studied with gastric intubation of 15%, 4.8 mL/kg of sodium cholate (SC), sodium deoxycholate (SD), and water; there were three groups of eight rats in each. A drastic drop in blood pressure, elevation of the ST segment of the EKG, increases in plasma potassium, hydrogen, blood urea nitrogen, and oxygen partial pressure were found. All rats treated with bile acids died within 24 hours. Six SD rats and three SC rats died within eight hours after oral administration of bile acid. It is concluded that the effects of feeding rats bile acids are very similar to the toxic action seen after ingestion of grass carp bile.

Animals↗
PubMed1991

Induction of immunoreactive proliferating cell nuclear antigen (PCNA) in goldfish retina following intravitreal injection with tunicamycin.

Effects of a photoreceptor-specific biotoxin, tunicamycin (TM), injected intravitreally into the goldfish eye at one side, were explored on electroretinograms (ERGs) and proliferating cell nuclear antigen-immunoreactive (PCNA-ir) nuclei, representing the mitotic activity of rod precursors, in the retina at both sides. The eye-cup preparations were made for ERG recording, and the retinas were isolated and processed as cryosections or wholemounts by a routine immunohistochemical method for visinin (cones), opsin (rods), tyrosine hydroxylase (dopaminergic cells) and proliferating cell nuclear antigen (PCNA), at various intervals after intravitreal injection with TM (1.0 micrograms/eye). On some thin sections, autoradiographic study was combined following intravitreal injection with [3H]thymidine (TdR, 0.1 microCi/eye). The dose of TM used heavily destroyed cones and rods only in the treated retinas 2-15 days after injection, the photoreceptors being renewed for further 15-20 days. Approximately in parallel, ERGs were largely impaired 2-10 days after TM injection and recovered for 10-20 days. However, intravitreal TM altered the distribution and density of PCNA-ir nuclei in both treated and untreated retinas. The density of PCNA-ir nuclei reduced at first (on days 1 and 2), and then clustered and rapidly increased on days 3-5 and maintained at high levels with diffuse distribution over the whole area, particularly in the treated retinas, up to 60 days after TM injection; the maximum peak of 3.7 and 20 times the initial level was seen on day 20 in the outer nuclear layer (ONL) and inner nuclear layer (INL), respectively. PCNA-ir nuclei were found to be abundant in the ONL even after the photoreceptors and ERGs had been restored in the treated retinas on day 20, suggesting a kind of overproduction of retinal cells. The autoradiographic study provided comparable results to those obtained with PCNA immunohistochemistry. The mechanism by which damage to the treated retina causes rod precursor cells to proliferate in the untreated retina remains unresolved.

Animals↗
PubMed1991

Purification and characterization of an 82-kD membrane protein as a neurite outgrowth factor binding protein: possible involvement of NOF binding protein in axonal outgrowth in developing retina.

Neurite outgrowth factor (NOF) is a glycoprotein isolated from an extract of gizzard that induces neurite outgrowth from cultured retinal or ciliary ganglionic (CG) neurons. We have reported that a glycoprotein of approximately 82 kD solubilized from gizzard muscles binds to NOF (ligand blotting) and inhibits the neurite promoting activity of NOF (inhibition assay). The 82-kD protein (NOF binding protein) was purified from gizzard muscle membranes as a doublet band on SDS-PAGE and a polyclonal antibody was raised against it. An NOF binding protein in developing retina exhibited the same physicochemical properties as that of the gizzard muscle. Quantitative decrease in NOF binding protein in embryonic retinas was observed after day 11 by the inhibition assay, ligand blotting, and immunoblotting, its decrease being parallel with reduction of NOF-induced neurite outgrowth of embryonic retinas. In an immunohistochemical study, the antibody stained only the optic fiber layers of the retinas of 8-d embryos, and this staining was no longer detectable in retinas of 18-d embryos. These results suggest that the 82-kD protein is a novel membrane protein that behaves as an NOF receptor and that the loss of neuritic response of the retinal neurons to NOF reflects a decrease in NOF receptor molecules.

Animals↗
PubMed1991

Bacteremia in patients with cirrhosis of the liver.

Infections are frequent in patients with liver cirrhosis, as their defenses against infectious agents are altered. But bacteremia occurring in cirrhotic patients has seldom been reported in the literature. From 1981 to 1986, we collected 197 cases with 228 episodes of bacteremia for this retrospective study. The incidence of bacteremia in cirrhotic patients was 8.8%; no significant difference was noted between cirrhotic patients with variant etiologies of HBV(+), HBV(-) and alcohol. But the incidence increased with the severity of the disease (1%, 4.8%, 17.1% in Child's A, B, C groups, respectively). Gram-negative bacteria were the predominant microorganisms of bacteremia (75.6%). Among them, Escherichia coli, Klebsiella pneumoniae and Aeromonas hydrophilia were the three most commonly detected microorganisms. Gram-positive bacterias were detected in 21.2% of patients with bacteremia, with predominance of the Streptococcus group and Staphylococcus aureus. In about 26.3% of cases the infectious sources were the same by bacteria cultures as from blood. The most common sources were spontaneous bacterial peritonitis, urinary tract infection, pneumonia and biliary tree infection. In cirrhotic patients with and without bacteremia, the mortality rate increased significantly in the bacteremia group (54.8% vs 23.2%, P less than 0.05). By Child's classification, the mortality of patients with classes B and C increased significantly after onset of bacteremia. There was no significant difference in mortality between bacteremic patients in the HBV(+), HBV(-) and alcohol groups. In conclusion, bacteremia is a severe complication of liver cirrhosis and a sign of a poor prognosis.

Bacteremia↗
PubMed1991

Upper gastrointestinal bleeding in dengue fever.

Twenty-six virologically and serologically confirmed Dengue patients with signs of upper gastrointestinal tract bleeding (13.1%) were studied during the 1987 outbreak in southern Taiwan. Within a 1-yr period from 1987 to 1988 in Kaohsiung Chang Gung Memorial Hospital, there were 198 patients with Dengue fever confirmed. Viral isolation and serological studies indicated that type I Dengue was the cause. There was no evidence of sequential secondary infection among them. The 26 patients were evaluated gastroduodenoscopically. Most of the Dengue patients who developed upper gastrointestinal bleeding had gastric ulcers or duodenal ulcers; superficial and hemorrhagic gastritis are the other relevant endoscopic findings. Thirteen patients (50%) had a past history of peptic ulcer symptoms, whereas the other 13 did not. Dengue infection is a precipitating factor in inducing peptic ulcer bleeding because of hemostatic derangements. Supportive therapy and blood transfusions alone were adequate treatment, except for one patient who required surgery due to massive bleeding of a duodenal ulcer. No mortality was observed in this study.

Adult↗
PubMed1990

Isolation and analysis of the human MEKA gene encoding a retina-specific protein.

We have isolated and sequenced a human gene encoding photoreceptor cell-specific MEKA protein. The protein coding region was separated into three exons, which encoded 246 amino acid residues with a molecular weight of 28,311. The coding region of the human gene exhibited the homologies of 90.7% nucleotides and 88.5% amino acids with those of the bovine cDNA. Southern blot analysis revealed that the human MEKA gene has a single copy number. However, the anti-bovine MEKA stained both rod and cone photoreceptor cells in the human retina.

Amino Acid Sequence↗
PubMed1990

Visinin: a novel calcium binding protein expressed in retinal cone cells.

Visinin is a retinal cone cell-specific protein (molecular weight 24,000, pI 5.1). To investigate its function, visinin cDNA was isolated from a chick retinal lambda gt11 cDNA library, using anti-visinin serum. The beta-galactosidase-visinin fusion protein was used for purifying epitope-selected antibody. The purified visinin antibody reacted only with a 24 kd protein in retinal cone cells. Visinin mRNA was expressed only in the retinal photoreceptor layer. The nucleotide sequence of the cDNA revealed that visinin has three E-F hand structures and is a Ca2+ binding protein. Visinin protein expressed in E. coli exhibited Ca2+ binding activity. These results suggest that visinin is a photoreceptor-specific Ca2+ binding protein and may be involved in phototransduction in the cone cells.

Amino Acid Sequence↗
PubMed1990

Retroperitoneal neurilemoma: clinical features in 10 cases.

Neurilemoma is a rare tumor in the retroperitoneal cavity. Up to 1984, less than 50 cases had been reported in the English literature. We observed 10 cases of retroperitoneal neurilemoma with histologic proof at our hospital. The major symptoms were abdominal pain (80%) and body weight loss (40%). Physically palpable abdominal masses were found in 90% of the cases. The laboratory data were all within normal limits, except for a mild elevation of the eosinophil count in 4 cases. Radiologic examination demonstrated the tumor in most cases. Abdominal ultrasonography was very effective in the detection of these tumors. Surgical resection was the treatment of choice. Some patients suffered from leg numbness after the operation. Recurrent rate was high, up to 20% therefore, long-term follow-up is mandatory.

Adult↗
PubMed1989

Developmental changes of MEKA protein and opsin in normal and rd mice.

Antisera raised against photoreceptor-specific MEKA and opsin proteins were provided for immunohistochemical studies on the retinas of normal (BJ57BL/6) and retinal degeneration (rd, C3H/He) mice. The expression of MEKA protein began at postnatal day 6 (P6) in the photoreceptor cells and gradually increased until P10 in both normal and rd mice. Thereafter the MEKA proteins in the photoreceptor cells of rd mice gradually decreased and disappeared at P18, whereas those of normal mice were increasing until P18. The time course of MEKA proteins in the photoreceptor cells of normal and rd mice was almost similar to that of opsin protein, except that the MEKA protein disappeared earlier than opsin.

Aging↗
PubMed1989

Identification of a retina-specific MEKA protein as a 33 K protein.

A photoreceptor-specific MEKA protein was purified from bovine retinal soluble fraction. The purified sample was eluted as a single peak of 74 kDa protein from a Superose column, which was dissolved into three components, MEKA protein (32 kDa), beta-(36 kDa) and gamma-(10 kDa) subunits of transducin on a SDS-PAGE. From several lines of evidence, we concluded that MEKA protein is identical with a 33k phosphoprotein reported by Lee et al (1).

Animals↗
PubMed1989

Translocation of a photoreceptor-specific MEKA protein by light.

Light-or dark-adapted retinal sections from bovine chick and mouse were provided for immunohistochemistry with antiserum against a MEKA protein which is specific to photoreceptor cells. In dark-adapted retinal sections, the anti-MEKA serum heavily stained outer segments of photoreceptor cells and lightly stained inner segments. The reverse staining pattern was observed in light-adapted retinal sections. These results indicate that the translocation of MEKA protein in a photoreceptor cell is regulated by light dark.

Animals↗