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Biomedical subjects

C H Kuo

Publications and source records attributed to C H Kuo.

At least 73 records · Page 4Linked to original sources

Neuron-specific expression of a chicken gicerin cDNA in transient transgenic zebrafish.

Gicerin, a novel cell adhesion molecule which belongs to the immunoglobulin superfamily, is expressed temporally and spatially in the developing chick brain and retina. The previous in vitro experiments using transfected cells showed that gicerin can function as a cell adhesion molecule which has both homophilic and heterophilic binding activities. For the in vivo analyses of gicerin in neural development, we tried to utilize a zebrafish system, a vertebrate suitable for studying early development. We generated transient transgenic animals by microinjecting DNA constructs into zebrafish embryos. Chicken gicerin, under control of the neurofilament gene promoter, was preferentially expressed in neuronal cells and gicerin-expressing neurons exhibited a fasciculation formation with neighboring gicerin-positive axons, which may be partly due to homophilic cell adhesion activity of gicerin. These experimental results suggest that this fast and efficient transgenic animal system is useful for studying the functional roles of neuron-specific genes during the development.

Animals↗

Ca2+/calmodulin-dependent transcriptional activation of neuropeptide Y gene induced by membrane depolarization: determination of Ca(2+)- and cyclic AMP/phorbol 12-myristate 13-acetate-responsive elements.

Membrane depolarization stimuli (high potassium concentration and veratridine) increased neuropeptide Y (NPY) mRNA abundance time-dependently, without a change in beta-actin mRNA level, in NG108-15 and PC12 cells. Although the induction by veratridine was blocked completely by tetrodotoxin, the induction by potassium was suppressed minimally. Voltage-dependent Ca channel blockers and calmodulin antagonists inhibited the increases by both depolarization stimuli completely, suggesting involvement of Ca2+/calmodulin-dependent kinases (CaM kinases). Transient assay using chloramphenicol acetyltransferase reporter genes containing the rat NPY gene promoter indicated that membrane depolarization and Ca entry stimulate transcription of the NPY gene. The depolarization-induced transactivation was also blocked by CaM kinase inhibitors. The 200-bp 5'-upstream region (-344/-145) was localized as a Ca2+/ calmodulin-responsive element (CaMRE), which confers depolarization-induced transactivation. It is interesting that this CaMRE did not contain the canonical Ca-responsive elements such as CRE, SRE, NF-AT, or the C/EBP beta-binding site and was separated from a 64-bp cyclic AMP/ phorbol 12-myristate 13-acetate-responsive element (-144/-81). These findings suggested that membrane depolarization regulates the NPY gene transcription positively through the unique CaMRE by activation of CaM kinases following Ca entry through L-type Ca channels.

Animals↗

Interaction of exercise training and clenbuterol on GLUT-4 protein in muscle of obese Zucker rats.

Chronic administration of clenbuterol, a beta 2-adrenergic agonist, attenuates the exercise training-induced improvement in muscle insulin resistance of the obese Zucker rat. The present study was conducted to determine whether clenbuterol also attenuates the increase in muscle GLUT-4 protein that occurs with exercise training and whether the action of clenbuterol is related to its ability to downregulate the beta-adrenergic receptors. Female obese Zucker rats were randomly assigned to one of the following four groups: control (CON, n = 7), clenbuterol (CL, n = 8), exercise training (TR, n = 8), and clenbuterol with exercise training (CL+TR, n = 8). Rats assigned to the training groups were run on a rodent motor-driven treadmill for 6-7 wk. Rats receiving clenbuterol were intubated with 0.8 mg/kg body weight 30 min before running each day. Red quadriceps (RQ) and white quadriceps (WQ) GLUT-4 protein concentrations of TR rats were significantly greater than those of CON and CL+TR rats. The RQ GLUT-4 protein concentration of the CL+TR rats was significantly greater than that of CON rats, but this difference did not occur in the WQ. GLUT-4 protein concentrations were not different between the CON and CL rats. The patterns of RQ and WQ GLUT-4 mRNA were similar to those of their respective GLUT-4 proteins. Rats receiving daily injections of propranolol (30 mg/kg body wt), a beta-adrenergic receptor antagonist, demonstrated no increase in GLUT-4 protein in RQ or WQ after 6 wk of exercise training. These results indicate that 1) clenbuterol can attenuate the increase in muscle GLUT-4 protein associated with exercise training and 2) this effect is likely mediated by a downregulation of the beta-adrenergic receptors.

Adrenergic beta-Agonists↗

Sequential evaluation of portal venous hemodynamics by Doppler ultrasound in patients with severe acute hepatitis.

OBJECTIVES: Portal hypertension may develop in patients with severe acute hepatitis. Sequential changes of portal venous hemodynamics in acute hepatitis is not well understood. This study evaluated portal hemodynamic changes and prognostic values in patients with severe, acute hepatitis. METHODS: Doppler studies, liver function tests, and virology studies were done in the inclusion, the 3rd month, and the 6th month for patients with severe, acute hepatitis. An indocyanine green clearance was done in the inclusion. Doppler portal hemodynamic studies were done in the hilar area by an average of two measurements. RESULTS: A total of 88 consecutive patients was included. Nine of them died. On initial study, fatalities were generally older patients with more delayed indocyanine green clearance, lower portal vein velocity, lower albumin values, higher bilirubin values, longer prothrombin time, and ascites. Using stepwise logistic regression, portal blood flow and prothrombin time were the two independence prognostic factors. By multiple linear regression, portal blood flow was associated with ascites, and average portal blood velocity was associated with bilirubin. During the hospital days, transient, depressed portal blood velocities followed by a hyperdynamic stage were found in survivors. The portal vein velocity changes for fatalities either were kept at a lower level or had a declining pattern. CONCLUSIONS: Doppler ultrasound detects portal hemodynamic changes for patients with severe, acute hepatitis. Sequential portal hemodynamic studies will be helpful for evaluating patients with severe, acute hepatitis.

Acute Disease↗

Expression and functional analysis of a novel isoform of gicerin, an immunoglobulin superfamily cell adhesion molecule.

We have cloned a novel cDNA of gicerin, a cell adhesion molecule belonging to the immunoglobulin superfamily. Both gicerin isoforms share the same extracellular domain, which has five immunoglobulin-like loop structures and a transmembrane domain as s-gicerin, but differ in the cytoplasmic tail domain. As the newly identified form has a larger cytoplasmic domain than the previously reported form, we refer to them as l-gicerin and s-gicerin, respectively. l-gicerin is transcribed from a distinct mRNA containing an inserted sequence not found in s-gicerin mRNA which caused a frameshift for the coding region for a cytoplasmic domain. Previous studies demonstrated that gicerin showed a doublet band of 82 and 90 kDa in chicken gizzard smooth muscle. We report that the 82-kDa protein corresponds to s-gicerin and the 90-kDa protein to l-gicerin. We also found that the two gicerin isoforms are expressed differentially in the developing nervous system. Functional analysis of these gicerin isoforms in stable transfectants revealed that they had differ in their homophilic adhesion properties, as well as in heterophilic cell adhesion assayed with neurite outgrowth factor. In addition, these isoforms have neurite-promoting activity by their homophilic adhesion, but differ in their ability to promote neurite outgrowth.

Amino Acid Sequence↗

Determination of a necdin cis-acting element required for neuron specific expression by using zebra fish.

To determine cis-acting elements required for neuron specific expression of a necdin gene, we tried to use zebra fish assay system in vivo instead of cell lines in vitro. Various expression vectors carrying upstream sequences of necdin gene fused to MEKA (lacZ) gene as a reporter were injected into fertilized zebra fish embryos and then the expression of the reporter gene was analyzed by the whole mount immunochemical method. No promoter activity was obtained with a construct carrying sequence from -63 to +63 of the necdin gene, while promoter activity with preferential skin expression was obtained with a construct having sequence from -86 to +28. Further upstream sequence from -173 to +28 exhibited neuron specific expression as well as that from -845 to +63. These results indicate that a cis-acting element responsible for neuron specific expression is located in an 87bp sequence from -173 to -87 of necdin gene.

Animals↗

Causes of increasing width of right anterior extrarenal space seen in ultrasonographic examinations.

The right anterior extrarenal space is composed of the perirenal fascia, the right anterior perirenal space, the right anterior pararenal space, and the liver capsule. To clarify the probable causes of an increasing width of the right anterior extrarenal space, the width was measured using ultrasonography for a period of 8 months. The right anterior extrarenal space was measured 3 cm from the superior renal pole and the smallest width obtained in several different scan planes was used. In 1,114 ultrasound examinations, 35 patients were found to have an increased width of the right anterior extrarenal space. Among the 35 cases, the common probable causes for such a condition were found in 27 cases. Eight patients had hyperchogenicity in the right pararenal space, a condition considered to be due to an acute inflammation, including acute pancreatitis, acute cecal diverticulitis, acute appendicitis, ischemic bowel, acute cholangitis, liver abscess, and penetrated duodenal ulcer. Chronic inflammations of an adjacent organ, a previous history of laparotomy, a malignancy with peritoneal metastases, and treatment with corticosteroid were considered the causes behind the condition in the 19 patients with normal echogenicity. For the remaining 8 patients, causes were not found during the follow-up period. This study indicates that life-threatening diseases, such as acute or chronic inflammatory diseases and malignancy of the abdomen, could be the cause of an increase in the width of this space.

Abdomen↗

Success of endoscopic injection therapy in correlation with maximal one-day transfusion requirement.

BACKGROUND AND STUDY AIMS: The rate of blood transfusion is related to blood flow and the diameter of the bleeding vessel. Therapeutic endoscopy is less effective in larger vessels. To determine the effect of therapeutic endoscopy with pure ethanol injection in massive peptic ulcer bleeding, we conducted a retrospective study using the maximal one-day blood requirement as an indicator of the required blood transfusion. PATIENTS AND METHODS: The maximal one-day blood requirement was defined as the total amount of blood transfusion needed within a day to keep hemodynamics stable and hemoglobin above 8.0 g% before therapeutic endoscopy. From January 1986 to May 1993, 283 patients with high-risk signs of the stigmata of hemorrhage on endoscopy, who received pure ethanol injection therapy, were included in this study. There were 214 men and 69 women with a mean age of 58.4 years (ranging from 16 to 93 years). One hundred forty-three had gastric ulcers; 125 had duodenal ulcers; and 15 had stomal ulcers. Patients whose maximal one-day blood requirement was less than 1000 ml were assigned to Group I. Patients without, and patients with, major organ diseases whose maximal one-day blood requirement was more than 1000 ml were assigned to Group IIa and Group IIb, respectively. RESULTS: In Group I, 87.1% attained permanent hemostasis; 51.3% in Group IIa; and 49.4% in Group IIb. Temporary hemostasis and failure rates were 8.9% and 4.8% in Group I; 14.5% and 33.8% in Group IIa; and 21.2% and 29.4% in Group IIb. The rate of permanent hemostasis was significantly lower in patients with massive bleeding (p < 0.001) but did not differ between patients with and without major organ diseases (p > 0.05). CONCLUSION: The success rate for pure ethanol injection therapy was lower in patients with a large maximal one-day blood transfusion requirement.

Adolescent↗

Septic acute cholecystitis.

BACKGROUND: Bacteremia occurs frequently in cholangitis, but the incidence of bacteremia in acute cholecystitis has not previously been examined. METHODS: Seventy-eight cases (46 men and 32 women; mean age, 63 +/- 10 years) of acute cholecystitis with positive blood cultures were analyzed for clinical manifestation, bacteriology, and what consequences ensued. Seventy-eight non-bacteremic cholecystitis patients, matched for age and sex, served as the control group. RESULTS: The prevalence of bacteremia in acute cholecystitis was 7.65% (78 of 1020). A single microorganism was isolated from the blood and bile in 87.2% and 27.3%, respectively. The commonest organisms were Escherichia coli and Klebsiella pneumoniae. The source of bacteremia could be identified from the infected bile in 80% of cases. Compared with the non-bacteremia group, significant increases in liver biochemical test results (aspartate and alanine aminotransferases and bilirubin, and so forth), more complications (acute renal failure and septic shock), and higher mortality (9.0%) were found in the bacteremic group. CONCLUSION: Acute cholecystitis is not often complicated by bacteremia, but when bacteremia is present, morbidity and death more consistently ensue.

Acute Disease↗

[Small cell lung cancer with liver and bone metastasis associated with hypercalcemia and acute pancreatitis--a case report].

A 67-year-old man was hospitalized with the chief complaint of diffuse abdominal pain for 3 days. Hypercalcemia and acute pancreatitis was found by laboratory examination. Abdominal CT scans showed swelling of the pancreas, multiple liver tumors and osteolytic lesions of bone. Upper mediastinal lobulated mass was suspected from chest x-ray examination, then small cell lung cancer (SCLC) was proved by bronchoscopic and pathological examination. The final diagnosis is SCLC with liver and bone metastasis associated with hypercalcemia and acute pancreatitis. After pancreatitis subsided, the patient was put on chemotherapy. Unfortunately, due to immunocompromise, he died of pneumonia and sepsis. There was no reasonable explanation regarding to the cause of acute pancreatitis except hypercalcemia, which might be due to SCLC with bone metastasis. This is the first report of such a complication in a patient with SCLC.

Acute Disease↗

Portal vein velocity by duplex Doppler ultrasound as an indication of the clinical severity of portal hypertension.

The portal vein (PV) velocity was measured by duplex Doppler ultrasound to predict the severity of portal hypertension. A total of 143 patients with liver cirrhosis were studied from January 1991 to June 1992. There were 104 males and 39 females with a mean age of 52 years old (range 23-76). The maximal PV velocity was significantly lower in patients with moderate and severe varices, cardiac varices, red-color signs on varix, esophagitis and congestive gastropathy. The patients with bleeding esophageal varices or upper gastrointestinal tract were found to have a significantly maximal PV velocity. Comparing patients without ascites or victims with controllable ascites. The maximal PV velocity in Child's C or mortality cases was also significantly lower than that in Child's A, Child's B and surviving cases. If we set the cut off value of PV velocity at 15 cm/sec, we could get the accuracy of 67.8%, 62.2%, 67.8% and 73.5% in the prediction of massive ascites, varices severity, Child C class and mortality respectively. In conclusion, PV velocity may reflect the severity of clinical portal hypertension in cirrhotic patients; it could be a prognostic factor in cirrhotic patients.

Adult↗

Tyrosine phosphorylation of a 58 kDa protein induced by morphine in SK-N-SH cells.

A 58 kDa protein which was phosphorylated on tyrosine residues with morphine was found in human neuroblastoma cells (SK-N-SH cells) by immunoblot with monoclonal anti-phosphotyrosine antibody. The tyrosine phosphorylation was induced by morphine in 5 min in a dose-dependent manner and the increment was completely inhibited by naloxone. A Delta (d) agonist, [D-Pen2,Pen5]-enkephalin (DPDPE), but not a m agonist, [D-Ala2,N-Me-Phe,Gly5-ol]-enkephalin (DAGO), stimulated the phosphorylation and treatment of the cells with pertussis toxin inhibited the phosphorylation by morphine. These data suggest that d receptor-stimulation increases tyrosine phosphorylation of the 58 kDa protein through Gi protein in SK-N-SH cells.

Cell Line↗

Role of Helicobacter pylori in cirrhotic patients with peptic ulcer. A serological study.

Helicobacter pylori was found to be a promoter factor of peptic ulcer that has an incidence higher in patients with hepatic cirrhosis. To clarify the role between H. pylori and peptic ulcer in patients with hepatic cirrhosis, a serological test (ELISA test, HEL-p, AMRAD, Australia), was used to measure the presence of H. pylori of patients with hepatic cirrhosis. Within two years, 108 cirrhotic patients who had received a panendoscopic examination were enrolled in this study. There were 79 males and 27 females with a mean age of 53.2 years. Sixty-four cases had positive serum HBsAg and 44 had negative serum. The results showed that the prevalence of Helicobacter pylori in cirrhosis was 43.5% (47/108). There was no difference of HEL-p-positive rate between peptic ulcer and normal gastroduodenal mucosa (45.2% vs 46.1%, P > 0.05). According to this study, there appears to be no relation between peptic ulcer and H. pylori in patients with hepatic cirrhosis. The etiology of peptic ulcer in cirrhotic patients need further study.

Adult↗

Gallbladder volume in patients with common hepatic duct dilatation. An evaluation of Courvoisier's sign using ultrasonography.

To evaluate the usefulness of Courvoisier's sign in ultrasonography, gallbladder size in patients with common hepatic duct dilatation was measured using the ellipsoid method during ultrasonographic examination. During a 6-month period 24 patients with malignant obstructions (6 with carcinoma of the ampulla of Vater, 9 with pancreatic head tumors, 5 with carcinoma of the bile duct, and 4 with malignant lymphadenopathy), 50 patients with calculous obstructions, and a group of 50 normal control patients were examined in this study. Gallbladder volumes were larger in patients with biliary tract dilatation (88.8 +/- 6.8 ml) than in the control group (34.3 +/- 2.8 ml) (p < 0.01). Although the duration and total serum bilirubin level were higher in patients with malignant obstructions, the gallbladder volumes were the same in these two groups (93.0 +/- 11.3 ml versus 86.7 +/- 8.5 ml). A linear relationship was found between gallbladder volume and total serum bilirubin in patients with malignant biliary obstructions (r = 0.6, p < 0.001) and in patients with calculous biliary obstructions without gallbladder stones (r = 0.68, p < 0.001). We hypothesized that the gallbladder volume is irrelevant in differentiating the nature of the biliary tract dilatation and that the gallbladder size is dependent on the degree of biliary obstruction when the gallbladder is not afflicted by fibrosis.

Bilirubin↗

Recoverin has S-modulin activity in frog rods.

In vertebrate photoreceptors, light induces hydrolysis of cGMP by activating cGMP phosphodiesterase (PDE), which results in closure of the cGMP-activated cation channel. During light adaptation, the cytoplasmic Ca2+ concentration decreases, and this decrease is one of the underlying mechanisms of light adaptation. Sensitivity-modulating protein (S-modulin) is a Ca(2+)-binding protein involved in light adaptation in frog rods; it regulates both the light sensitivity of PDE and the lifetime of activated PDE by controlling rhodopsin phosphorylation in a Ca(2+)-dependent manner. Recoverin has been reported as a Ca(2+)-dependent regulator of guanylate cyclase in bovine rods (Dizhoor, A. M., Ray, S., Kumar, S., Niemi, G., Spencer, M., Brolley, D., Walsh, K. A. Philipov, P. P., Hurley, J. B., and Stryer, L. (1991) Science 251, 915-918). Here, we show that recoverin has similar activity as S-modulin, and the amino acid sequences of both proteins are similar. The results strongly suggest that recoverin is bovine S-modulin and regulates PDE activation.

3',5'-Cyclic-GMP Phosphodiesterases↗

Purification and characterization of three MEKA-like proteins in liver: association of a 94 kDa protein with beta gamma subunits of G-proteins.

Retinal 32 kDa MEKA protein (rMEKA) exists in the photoreceptor cells and forms a complex with beta gamma subunit of transducin. Bovine liver contained three MEKA-like proteins (94 kDa, 35 kDa-a, 35 kDa-b) which reacted with a rMEKA antibody. Each protein was purified as a single band on a SDS-PAGE and used for a reconstitution experiment with alpha and beta gamma subunits of cerebral G-proteins (Go/i). The 94 kDa protein inhibited GTP-binding ability of G alpha by forming a complex with beta gamma subunit.

Animals↗

Sonographic features of retroperitoneal neurilemoma.

Seven cases of retroperitoneal neurilemoma confirmed by histology had an ultrasound examination. There were 5 women and 2 men with a mean age of 55. Most of the cases (5/7) had a palpable mass clinically. Of the 7 cases, 4 had a mass with cystic degeneration and internal echoes on sonogram, consistent with the macroscopic findings of tumors. The internal echoes represented blood clots and residual tissue (or septa) in cyst. Of the remaining 3 cases, one showed a confluent lobulated mass, the second had a solitary homogeneous mass with small cysts, and the third one, which was the smallest (4 cm x 4 cm x 6 cm), had a hypoechoic and homogeneous pattern. The sonograms of all 7 cases were consistent with the macroscopic features of the tumors. The sonographic pattern of tumor parenchyma is either homogenously hyperechoic or hypoechoic. Because of the cystic degeneration, hemorrhage, and residual tissue of retroperitoneal neurilemoma, the sonographic pattern was variable.

Adult↗

Sequential invasions of pancreatic pseudocysts in pancreatic tail, hepatic left lobe, caudate lobe, and spleen.

A 66-year-old male patient without a history of risk factors for pancreatitis suffered from pancreatitis and developed pseudocyst. During the course of treatment and follow-up, the pseudocyst was found to have migrated through the pancreatic tail, left hepatic lobe, caudate lobe, and spleen on abdominal sonography and computed tomography scan. Finally, emergent laparotomy was done for splenic abscess and removal of infected pseudocyst in the spleen and lesser sac of the abdomen. The patient made a full recovery after operation.

Aged↗