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Biomedical subjects

C C Huang

Publications and source records attributed to C C Huang.

At least 109 records · Page 6Linked to original sources
PubMed2001

The influence of long-term different diabetic therapies on plasma leptin in type 2 diabetic subjects.

The aim of this study was to assess the effect of the long-term different diabetic therapies on the plasma leptin level in type 2 diabetic subjects. We measured plasma leptin, body fat and fasting plasma insulin in 96 type 2 diabetic male subjects. They had received the same treatment regimen for more than one year (3.5 +/- 2.3 years, mean +/- SD) and were weight-stable over the previous three months. The distribution was as follows: diet control group: 32, oral hypoglycemic agent (OHA) group: 32, and insulin group: 32. The results showed that the plasma leptin level of the different therapy groups was all positively correlated with body fat. The fasting insulin levels were significantly higher (p < 0.0001) in the insulin group than those in the other two groups. The fasting insulin of the OHA group was also greater than that of the diet group but was not statistically significant. The leptin concentrations were significantly higher in the insulin group (p < 0.001) and OHA group (p = 0.0082) than that in the diet group. The leptin concentrations of insulin group were also significantly higher (p = 0.0021) than that of the OHA group. Stepwise multiple regression analysis revealed that the significant differences in the leptin level of whole group was mainly affected by fasting insulin (p < 0.0001), followed by fat percentage (p = 0.001), fat distribution (p = 0.009) and fasting sugar (p = 0.02), whereas there was no association of leptin with age, height, glycosylated hemoglobin A1c, lipid, or blood pressure. We concluded that long-term different diabetic therapies may affect the plasma leptin level, which is mediated mainly by insulin changes. This insulin effect is independent of body fat and may be superior to the fat effect on plasma leptin in the type 2 diabetic patients.

Adipose Tissue↗
PubMed2001

Progress in understanding the factors regulating reversibility of long-term potentiation.

Over the past two decades there has been a progressive understanding of the properties and mechanisms underlying long-term potentiation (LTP) of synaptic efficacy, a putative mechanism for learning and memory storage in the brain. Although LTP is remarkable for its stability, recent work has provided evidence that various manipulations can disrupt LTP if applied shortly after its induction. This kind of reversal of synaptic strength from the potentiated state to pre-LTP levels is termed depotentiation. Depotentiation of LTP is effectively induced by low-frequency afferent stimulation (1-5 Hz), brief periods of hypoxia, application of adenosine receptor agonists and brief cooling shocks. The examples of depotentiation described to date are input specific, and not differently expressed during development. The mechanisms responsible for this phenomenon remain to be fully characterized, although some possibilities are dependent on NMDA receptor activation, the increases in intracellular Ca2+, and altered states of protein kinases or phosphatases. In this review, we summarize the recent data concerning putative depotentiation mechanisms and the implications of this phenomenon in the mechanisms of "forgetting", and discuss the prevention of saturation of the storage capacity of a neuronal network.

Adenosine↗
PubMed2001

Treatment outcomes and costs of dental sealants among children enrolled in Medicaid.

OBJECTIVES: This retrospective cohort analysis of children enrolled in the North Carolina Medicaid program compared the likelihood of restorative treatments and associated cumulative Medicaid expenditures for teeth with or without dental sealants. METHODS: We assessed the dental experience of the cohort of 15 438 children from 1985 to 1992 on the basis of enrollment and claims files. We conducted regression analyses for outcomes (caries-related services involving the occlusal surface [CRSOs] of permanent first molars) and cumulative expenditures, controlling for characteristics of the child, the treating dentist, and the child's county of residence. RESULTS: Overall, 23% of children received at least 1 sealant and 33% at least 1 CRSO. Sealants were effective in preventing CRSOs, although the degree of effectiveness was highest for children with the greater levels of CRSOs before sealant placement. Estimated cumulative Medicaid expenditures indicated expenditure savings from sealants within 2 years of application for children with 2 or more prior CRSOs. CONCLUSIONS: Sealant placement was associated with expenditure savings to Medicaid for certain high-risk children, so Medicaid and, more broadly, society will benefit by providing for sealant placement in these children.

Child↗
PubMed2001

Intraspinal osteolipoma. Case report.

Lipomatous tumors can contain uncommon or rare components (such as fibrolipoma or angiolipoma) that may result in the development of symptoms. To the best of the authors' knowledge, lipoma associated with an osseous component has not been previously reported. A case of intraspinal extradural tumor composed of both adipose and bone tissue is presented. Current theories on the cause of lipoma with an osseous component are discussed. The tumor was histologically confirmed to be an osteolipoma, and the patient recovered well after resection.

Adult↗
PubMed2001

Acute flaccid paralysis in infants and young children with enterovirus 71 infection: MR imaging findings and clinical correlates.

BACKGROUND AND PURPOSE: Enterovirus 71 (EV71) infection is now considered an important cause of childhood acute flaccid paralysis. The purpose of our study was to determine whether EV71-infection-related acute flaccid paralysis in infants and young children has characteristic MR imaging patterns. METHODS: Seven infants and young children with acute paralysis of the upper or lower extremities and positive EV71 cultures underwent spinal MR studies during an outbreak of hand-foot-and-mouth disease in Taiwan in 1998. RESULTS: Acute paralysis was observed in one upper extremity in two patients, in one lower extremity in three patients, and in both lower extremities in two patients. None of the patients had sensory impairment or bulbar palsy. MR studies showed unilateral or bilateral hyperintense lesions in the anterior horn regions of the cord on T2-weighted images in six patients. No abnormal signal was present in one patient. Two of three patients who received intravenous injections of contrast material had ventral root enhancement on T1-weighted images. One of them also had enhancement of the unilateral anterior horn cells. At clinical follow-up, both patients with bilateral anterior horn abnormalities had residual motor weakness, whereas only one of the five patients with unilateral involvement had residual weakness. CONCLUSION: EV71 radiculomyelitis tends to be unilateral and to specifically involve both the anterior horn cells of the cord and the ventral roots. MR imaging allows early detection of spinal cord and root lesions.

Acute Disease↗
PubMed2001

Pyeloureteritis cystica: case report.

Pyeloureteritis cystica, characterized by multiple bubbly filling defects on urography and caused by inflammatory stimuli, is a rare disorder of the ureter. It commonly affects older people. Diagnosis is established by radiological studies. Antibiotics should be given if urinary tract infection is present. Up to now, no other specific treatment can be used to cure this disorder. We report a case of pyeloureteritis cystica associated with urinary tract infection and a ureteral stone in a young woman who presented with hematuria and bilateral flank pain. The pyeloureteritis cystica had a bead-like appearance on intravenous pyelogram and retrograde pyelogram as well as in magnetic resonance urography. The diagnosis and treatment of this disorder are discussed. Magnetic resonance urography can provide high-resolution of coronal images of the entire urinary tract without the use of contrast agents or ionizing radiation. However, the cost of the procedure is a major concern.

Adult↗
PubMed2001

Human progesterone receptor shows differential sensitivity to carboxyl group modifying agents when bound to agonist and antagonist ligands.

BACKGROUND: Modulation of human uterine progesterone receptor (PR) in relation to its binding to synthetic steroids with known agonist (R5020) and antagonist (triamcinolone acetonide, T.A.) properties was studied in the presence of the specific carboxyl group modifiers, N,N'-dicyclohexylcarbodiimide (DCCD) and 1-ethyl-3-carbodiimide hydrochloride (EDC). METHODS: Uterine cytosol was treated with DCCD or EDC. The amounts of total bound were detected using the steroid binding measurements. The formation and transformation of progesterone-receptor complexes (PRc) were analyzed using sedimentation rate analysis. RESULTS: Our studies show that the modification of the COOH group differentially influences the properties of mammalian PR binding with either R5020 or T.A. DCCD and EDC affect the steroid binding of PR by decreasing the binding sites, not by the changing the affinity. CONCLUSION: Our studies indicate the importance of the carboxyl group in steroid binding by PR. This implies that both aspartic acid and glutamic acid residues, which have the carboxyl group, may play an important role when PR binds with steroid ligands.

Cytosol↗
PubMed2001

Systemic p53 gene therapy of cancer with immunolipoplexes targeted by anti-transferrin receptor scFv.

BACKGROUND: A long-standing goal in genetic therapy for cancer is a systemic gene delivery system that selectively targets tumor cells, including metastases. Here we describe a novel cationic immunolipoplex system that shows high in vivo gene transfer efficiency and anti- tumor efficacy when used for systemic p53 gene therapy of cancer. MATERIALS AND METHODS: A cationic immunolipoplex incorporating a biosynthetically lipid-tagged, anti-transferrin receptor single-chain antibody (TfRscFv), was designed to target tumor cells both in vitro and in vivo. A human breast cancer metastasis model was employed to evaluate the in vivo efficacy of systemically administered, TfRscFv-immunolipoplex-mediated, p53 gene therapy in combination with docetaxel. RESULTS: The TfRscFv-targeting cationic immunolipoplex had a size of 60-100 nm, showed enhanced tumor cell binding, and improved targeted gene delivery and transfection efficiencies, both in vitro and in vivo. The p53 tumor suppressor gene was not only systemically delivered by the immunolipoplex to human tumor xenografts in nude mice but also functionally expressed. In the nude mouse breast cancer metastasis model, the combination of the p53 gene delivered by the systemic administration of the TfRscFv-immunolipoplex and docetaxel resulted in significantly improved efficacy with prolonged survival. CONCLUSIONS: This is the first report using scFv-targeting immunolipoplexes for systemic gene therapy. The TfRscFv has a number of advantages over the transferrin (Tf) molecule itself: (1) scFv has a much smaller size than Tf producing a smaller immunolipoplex giving better penetration into solid tumors; (2) unlike Tf, the scFv is a recombinant protein, not a blood product; (3) large scale production and strict quality control of the recombinant scFv, as well as scFv-immunolipoplex, are feasible. The sensitization of tumors to chemotherapy by this tumor-targeted and efficient p53 gene delivery method could lower the effective dose of the drug, correspondingly lessening the severe side effects, while decreasing the possibility of recurrence. Moreover, this approach is applicable to both primary and recurrent tumors, and more significantly, metastatic disease. The TfRscFv-targeting of cationic immunolipoplexes is a promising method of tumor targeted gene delivery that can be used for systemic gene therapy of cancer with the potential to critically impact the clinical management of cancer.

Animals↗
PubMed2001

Klebsiella pneumoniae bacteremia: community-acquired vs. nosocomial infections.

BACKGROUND: This study attempted to determine the clinical manifestations and influential factors affecting the prognosis of patients with community-acquired and nosocomial bacteremia of Klebsiella pneumoniae (K. pneumoniae). METHODS: We retrospectively reviewed the medical records of 211 patients who had a clinically significant episode of K. pneumoniae bacteremia from January 1997 until December 1999. RESULTS: Most reports describe K. pneumoniae bacteremia as typically nosocomial, but in our study approximately 3 of 4 episodes were community-acquired. Without including "unknown origin", the most common infectious site for both community-acquired and nosocomial bacteremia was the hepatobiliary tract. The overall mortality for all 211 patients with K. pneumoniae bacteremia was 25.1%. Significantly higher mortality rates occurred in patients who were elderly (> 65 years), had a nosocomial infection, for whom the respiratory tract was the portal of entry, and ultimately fatal conditions or acute complications were due to shock or renal insufficiency. CONCLUSIONS: Patients with community-acquired and nosocomial bacteremia had different types of underlying diseases. Isolates from nosocomial infections were significantly more frequently resistant to aminoglycosides, antipseudomonal penicillin, and all three generations of cephalosporins. In this regard, an aggressive empirical therapeutic approach to infections of K. pneumoniae is suggested.

Adult↗
PubMed2000

Influence of an extracellular acidosis on excitatory synaptic transmission and long-term potentiation in the CA1 region of rat hippocampal slices.

The effects of extracellular acidification on the synaptic function and neuronal excitability were investigated on the hippocampal CA1 neurons. A decrease of extracellular pH from 7.4 to 6.7 did not alter either the resting membrane potential or the neuronal membrane input resistance. Extracellularly recorded field excitatory postsynaptic potentials (fEPSPs) and population spikes (PSs) were significantly reduced by acidosis. Additionally, the amplitude of presynaptic fiber volley was also reduced. The sensitivity of postsynaptic neurons to N-methyl-D-aspartate, but not to alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid, was depressed by acidosis. Lowering of extracellular pH did not significantly affect the magnitude of paired-pulse facilitation (PPF) of synaptic transmission. Acidosis also reversibly limited the sustained repetitive firing (RF) of Na(+)-dependent action potentials elicited by injection of depolarizing current pulses into the pyramidal cells. The limitation of RF by extracellular acidification was accompanied by the reduction of the maximal rate of rise (;V(max)) of the action potentials and the amplitude of afterhyperpolarization. Neither the Na (+)/H (+) antiporter blocker 5-(N -ethyl -N -isopropyl)-amiloride nor the selective adenosine A (1) receptor antagonist 1,3-dipropyl -8-cyclopentylxanthine, however, affected the acidosis -induced synaptic depression. It was also found that acidosis did not affect either the induction r maintenance of long -term potentiation (LTP) at Schaffer collateral -CA 1 synapses. These results suggest that the extracellular acidosis -induced synaptic depression is likely to result from an inhibition of presynaptic Na (+) conductance, thereby decreasing the amplitude of action potentials in individual afferent fibers or the number of afferent fiber activation to stimuli and then indirectly affecting the signaling processes contributing to trigger neurotransmitter release.

Acidosis↗
PubMed2000

Unicentric Castleman's disease associated with hydronephrosis.

We describe a patient with an unusual case of unicentric Castleman's disease, which bore a malignant appearance and was located in the pararenal space. She initially presented with hydronephrosis. Two years after surgical removal of the tumor, no recurrence was evident. To our knowledge, only 2 additional cases of this uncommon disease entity associated with hydronephrosis have been reported. Furthermore, our patient was the first to receive conservative surgery. On the basis of our experience, owing to the benign clinical course of this tumor and its excellent response to limited resection, radical surgery may be avoided.

Abdominal Neoplasms↗
PubMed2000

Effect of Staphylococcus enterotoxin B on the concurrent CD8(+) T cell response to influenza virus infection.

Bacterial superantigens have potent in vivo effects. Respiratory viral infections are often associated with secondary bacterial infections, raising the likelihood of exposure to bacterial superantigens after the initiation of the anti-viral immune response. In this study, the general and V beta-specific effects of exposure to Staphylococcal enterotoxin B (SEB) during influenza virus infection on both the ongoing acute and the subsequent recall CD8(+) T cell responses were analyzed, using the well-characterized murine influenza model system and tetrameric MHC/peptide reagents to directly identify virus-specific T cells. The results show that although superantigen exposure during the primary viral infection caused delayed viral clearance, there was remarkably little effect of SEB on the magnitude or TCR repertoire of the ongoing cytolytic T cell response or on the recall response elicited by secondary viral infection. Thus, despite the well-characterized immunomodulatory effects of SEB, there was surprisingly little interference with concurrent anti-viral immunity.

Acute Disease↗
PubMed2000

Vascular endothelial junction-associated molecule, a novel member of the immunoglobulin superfamily, is localized to intercellular boundaries of endothelial cells.

During the process of lymphocyte homing to secondary lymphoid organs, such as lymph nodes and tonsils, lymphocytes interact with and cross a specialized microvasculature, known as high endothelial venules. There is a great deal of information available about the first steps in the homing cascade, but molecular understanding of lymphocyte transmigration through the intercellular junctions of high endothelial venules is lacking. In analyzing expressed sequence tags from a cDNA library prepared from human tonsillar high endothelial cells, we have identified a cDNA encoding a novel member of the immunoglobulin superfamily. The protein, which we have termed VE-JAM ("vascular endothelial junction-associated molecule"), contains two extracellular immunoglobulin-like domains, a transmembrane domain, and a relatively short cytoplasmic tail. VE-JAM is prominently expressed on high endothelial venules but is also present on the endothelia of other vessels. Strikingly, it is highly localized to the intercellular boundaries of high endothelial cells. VE-JAM is most homologous to a recently identified molecule known as Junctional Adhesion Molecule, which is concentrated at the intercellular boundaries of both epithelial and endothelial cells. Because the Junctional Adhesion Molecule has been strongly implicated in the processes of neutrophil and monocyte transendothelial migration, an analogous function of VE-JAM during lymphocyte homing is plausible.

Amino Acid Sequence↗
PubMed2000

Serological survey and first finding of Neospora caninum in Taiwan, and the detection of its antibodies in various body fluids of cattle.

A serological survey for antibodies against Neospora caninum in cattle, goats and farm dogs in Taiwan was carried out. Sera of 613 cattle from 25 dairy farms, 24 goats from six goat farms and 13 dogs from six dairy cattle farms were tested for antibodies against N. caninum using indirect fluorescence antibody test (IFAT). The same sera were also tested for antibodies against Toxoplasma gondii using latex agglutination test. Of the 613 cattle sera, 44.9% (275/613) were found to have antibodies against N. caninum. Among these 275 positive cattle, 77 also possessed antibodies against T. gondii. Nevertheless, 92 cattle which were negative for N. caninum showed antibodies against T. gondii. Of the 24 goat sera tested, none was found to be positive for N. caninum but 50% (12/24) were positive for T. gondii. Of the 13 farm dogs tested, three were found to possess antibodies against N. caninum, two of which tested negative for T. gondii antibodies. Besides sera, antibodies to N. caninum in cattle could be observed in the milk, vaginal secretion and saliva. However, the order of higher frequency of antibodies detection is in sera, milk, vaginal secretion and saliva. This is the first demonstration of the presence of antibodies to N. caninum in vaginal secretion and saliva of cattle. A 50microm cyst was observed in the brain of one of the 13 prednisolone-treated SPF ICR mice which had been peritoneally inoculated 4 months earlier with the brain homogenate of a serologically N. caninum positive but T. gondii negative cattle. Thus, we have confirmed for the first time the presence of N. caninum in Taiwan and also observed that it is widespread among dairy cattle and farm dogs.

Animals↗
PubMed2000

Multimerization potential of the cytoplasmic domain of the human immunodeficiency virus type 1 transmembrane glycoprotein gp41.

We previously demonstrated that an envelope mutant of human immunodeficiency virus type 1 lacking the entire cytoplasmic domain interferes in trans with the production of infectious virus by inclusion of the mutant envelope into the wild-type envelope complex. We also showed that the envelope incorporation into virions is not affected when the wild-type envelope is coexpressed with the mutant envelope. These results suggest that an oligomeric structure of the cytoplasmic domain is functionally required for viral infectivity. To understand whether the cytoplasmic domain of human immunodeficiency virus type 1 transmembrane protein gp41 has the potential to self-assemble as an oligomer, in the present study we fused the coding sequence of the entire cytoplasmic domain at 3' to the Escherichia coli malE gene, which encodes a monomeric maltose-binding protein. The expressed fusion protein was examined by chemical cross-linking, sucrose gradient centrifugation, and gel filtration. The results showed that the cytoplasmic domain of gp41 assembles into a high-ordered structural complex. The intersubunit interaction of the cytoplasmic domain was also confirmed by a mammalian two-hybrid system that detects protein-protein interactions in eucaryotic cells. A cytoplasmic domain fragment expressed in eucaryotic cells was pulled down by glutathione-Sepharose 4B beads via its association with another cytoplasmic domain fragment fused to the C terminus of the glutathione S-transferase moiety. We also found that sequences encompassing the lentiviral lytic peptide-1 and lentiviral lytic peptide-2, which are located within residues 828-856 and 770-795, respectively, play a critical role in cytoplasmic domain self-assembly. Taken together, the results from the present study indicate that the cytoplasmic domain of gp41 by itself is sufficient to assemble into a multimeric structure. This finding supports the hypothesis that a multimeric form of the gp41 cytoplasmic domain plays a crucial role in virus infectivity.

ATP-Binding Cassette Transporters↗
PubMed2000

MRI in acute neuropathic Gaucher's disease.

We present the cranial MRI findings in a 6-month-old girl with biopsy-proven acute neuropathic Gaucher's disease, which include unilateral cerebral atrophy and dural thickening with contrast enhancement.

Acute Disease↗
PubMed2000

Steroid-sensitive anemia in a boy on dialysis--an association with Kimura disease.

The cause of hypereosinophilia (EO) in hemodialysis (HD) patients is multifactorial and is felt to be a benign laboratory abnormality related to dialysis or uremia. Kimura disease (KD) is an angiolymphoid proliferative disorder of unknown etiology. Many cases are associated with nephrotic syndrome in children; however, it has seldom been reported in children on dialysis. We report here a 13-year-old boy who developed persistent EO and subsequent anemia after maintenance HD; he later developed KD. The atypical clinical manifestation of KD and its relationship to HD and erythropoietin hyposensitive anemia in this patient are discussed.

Adolescent↗