Incidence of ectopic beats as a function of basic rate in the ventricle.
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Animals↗
Biomedical subjects
J Han
Publications and source records attributed to J Han.
Fibrillation threshold of premature ventricular responses.
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Animals↗
[Cerebral hemorrhage with right-sided paralysis].
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Cerebral Hemorrhage↗
Antibody testing and RT-PCR results in hepatitis C virus (HCV) infection: HCV-RNA detection in PBMC of plasma viremia-negative HCV-seropositive persons.
To evaluate the concordance between viremia and antibody testing in hepatitis C virus (HCV) diagnosis, 682 serum or plasma samples collected from patients with known or suspected HCV infection were tested. An overall concordance of 77% between serological and PCR results was found, 5% was RNA positive/antibody negative and 18% antibody positive/RNA negative. The relationship between HCV infection, risk group and clinical diagnosis was studied in 116 patients: the presence of anti-HCV antibody without viremia was shown in 72.7% of asymptomatic subjects and 17.6% of chronic hepatitis subjects without interferon treatment. However, the detection of HCV-RNA in peripheral blood mononuclear cells (PBMC) in four out of 38 plasma viremia-negative HCV-seropositive subjects (10.5%), showed that HCV-RNA could persist in PBMC and could begin the viral replication again at different times. The detection of HCV-RNA in PBMC in anti-HCV-positive subjects without viremia could reduce false-negative results of HCV-RNA testing by RT-PCR in serum or plasma.
DNA Primers↗
Mobilization of calcium from intracellular stores as one of the mechanisms underlying the antiopioid effect of cholecystokinin octapeptide.
In enzymatically dissociated brain cells prepared from neonatal rats, KCl produced a significant increase in [Ca2+]i and this increase could be prevented by verapamil or nifedipine, known to block voltage-sensitive calcium channels. The opioid receptor agonists ohmefentanyl (OMF, mu agonist), [D-Pen2,D-Pen5]enkephalin (DPDPE, delta agonist), and 66A-078 (kappa agonist) produced a marked suppression of the Ca2+ influx induced by high K+ depolarization. The suppressive effect of OMF, DPDPE, and 66A-078 on the high K(+)-induced increase in [Ca2+]i was markedly reversed by their respective antagonists beta-funaltrexamine (beta-FNA), ICI174864, and nor-binaltorphimine (nor-BNI). Cholecystokinin octapeptide (CCK-8), at concentrations of 0.3, 3.0, and 30 nM, dose-dependently mobilized Ca2+ from intracellular stores. While CCK-8 30 nM did not affect significantly the increase of [Ca2+]i following high K+, it did reverse the suppression of the high K(+)-induced increase in [Ca2+]i by the mu agonist OMF and the kappa agonist 66A-078, but not that by the delta agonist DPDPE. The results suggested that while opioid ligands suppress [Ca2+]i by blocking voltage-operated Ca2+ influx, the antiopioid effect of CCK-8 seems to be operated via mobilization of Ca2+ from intracellular stores.
Animals↗
Putative oxidative metabolites of 1-methyl-6-hydroxy-1,2,3,4-tetrahydro-beta-carboline of potential relevance to the addictive and neurodegenerative consequences of ethanol abuse.
Ethanol is metabolized in the brain by catalase/H2O2 to yield acetaldehyde and by an ethanol-inducible form of cytochrome P450 (P450 IIE1) in a reaction that yields oxygen radicals. Within the cytoplasm of serotonergic axon terminals these metabolic pathways together provide conditions for the endogenous synthesis of 1-methyl-6-hydroxy-1,2,3,4-tetrahydro-beta-carboline (1), by reaction of acetaldehyde with unbound 5-hydroxytryptamine (5-HT), and for the oxygen radical-mediated oxidation of this alkaloid. The major initial product of the hydroxyl radical (HO.)-mediated oxidation of 1 in the presence of free glutathione (GSH), a constituent of nerve terminals and axons, is 8-S-glutathionyl-1-methyl-1,2,3,4-tetrahydro-beta-carboline-5,6-dione (6). When administered into the brains of mice, 6 is a potent toxin (LD50 = 2.9 microg) and evokes episodes of hyperactivity and tremor. Compound 6 binds at the GABA(B) receptor and evokes elevated release and turnover of several neurotransmitters. Furthermore, the GABA(B) receptor antagonist phaclofen attenuates the behavioral response caused by intracerebral administration of 6. These observations suggest that 6 might be an inverse agonist at the GABA(B) receptor site. Accordingly, it is speculated that ethanol drinking might potentiate formation of 6 that contributes to elevated release of several neurotransmitters including dopamine (DA) and endogenous opioids in regions of the brain innervated by serotonergic axon terminals. Subsequent interactions of DA and opioids with their receptors might be related to the initial development of dependence on ethanol. Redox cycling of 6 (and of several putative secondary metabolites) in the presence of intraneuronal antioxidants and molecular oxygen to produce elevated fluxes of cytotoxic reduced oxygen species might contribute to the degeneration of serotonergic pathways. Low levels of 5-HT in certain brain regions of the rat predisposes these animals to drink or augments drinking. Accordingly, 6, formed as a result of ethanol metabolism in the cytoplasm of certain serotonergic axon terminals, might contribute to the initial development of dependence on ethanol, by mediating DA and opioid release, and long-term preference and addiction to the fluid as a result of the progressive degeneration of these neurons.
Alcoholism↗
Altered pharmacokinetics and liver targetability of methotrexate by conjugation with lactosylated albumins.
To enhance the liver targetability, methotrexate (MTX) was conjugated with albumin previously substituted with varying content of lactose (L0, L5, and L24). The uptake of MTX by rat hepatocytes in vitro increased according to the increase in the lactose content on the albumin conjugates. The MTX level in the plasma and various organs was determined by counting the radioactivity of [3H]MTX and by HPLC assay, separately, to monitor the in vivo fate of MTX not only as total, regardless of forms of MTX, but also as free/intact MTX level. Conjugation of MTX with albumin alone provided the enhanced delivery of MTX to the liver, accompanied by decreased accumulation in the kidney, but by increased accumulation in other nontarget organs such lung, heart, and spleen. Lactosylation of albumin conjugates further enhanced the delivery of MTX to the liver in a lactose content-dependent manner, accompanied by decreased accumulation of MTX in the lung and heart as well as kidney. The total MTX level accumulated in the liver was 2.9-, 4.1-, and 11.0-fold higher at 1 h and 5.4-, 7.0-, and 16.5-fold higher at 4 h after injection of MTX-L0, L5, L24 albumin conjugates compared with MTX alone. MTX conjugates with lactosylated albumin provided low but prolonged level of free/intact MTX in the liver. Taken together, the pharmacokinetics and liver targetability of MTX could be favorably modulated by controlling the lactose content on the albumin conjugates. Lactosylated albumin conjugation might also provide prolonged and targeted delivery of other drugs for the treatment of liver diseases.
Animals↗
Replacement of a tracheal defect with autogenous mucosa lined tracheal prosthesis made from polypropylene mesh.
Reliable prosthetic or tissue grafts for the trachea have not, as yet, been developed for reconstruction of large, circumferential tracheal defects. Major limitations are anastomotic dehiscence and stenosis, attributed to the poor epithelialization and vascularization of the prosthetic graft. We have developed a new tracheal prosthesis that has a well vascularized and viable mucosa. The prosthesis consists of a Prolene mesh reinforced with polypropylene rings, and coated with gelatin. We lined the luminal surface of the prosthesis with transplanted autogenous oral mucosa, wrapped the prosthesis with greater omentum, and placed it in the peritoneal cavity for 2 weeks. Complete surgical resection and replacement of a segment (5 cm in length, 8 to 10 tracheal rings) of the thoracic trachea was then performed in nine adult mongrel dogs. The transplanted mucosa was well vascularized and maintained its normal histology in prereplacement analysis. Dogs with tracheal replacement regained their full activity and did not show any respiratory problems until sacrifice at 1, 2, and 6 months. After 6 months, the prostheses were completely incorporated by the host trachea in all dogs and confluent epithelialization was confirmed histologically from the upper to the lower anastomotic site of the prosthesis; furthermore, the transplanted mucosal cells had changed to ciliated columnar epithelium.
Animals↗
Do latex precautions in children with myelodysplasia reduce intraoperative allergic reactions?
Children with myelodysplasia have an increased incidence of latex allergy, which can lead to severe intraoperative allergic reactions. Despite widespread recommendations to avoid intraoperative latex exposure, little evidence exists to support the efficacy of this practice. We examined the incidence of intraoperative allergic reactions in children with myelodysplasia who underwent 1,025 operations in a 36-month period before and after institution of a standardized latex-avoidance protocol. Risk factors for an intraoperative reaction were found to be a history of latex allergy (p = 0.001) and surgery performed before institution of the latex-avoidance protocol (p = 0.01). The estimate of increased risk for allergic reaction was 3.09 times higher in cases performed without latex avoidance. Recognized violation of the protocol after its institution led to severe allergic reactions in three patients. Our experience suggests that a latex-avoidance protocol reduces intraoperative allergic reactions in children with myelodysplasia. Development of severe allergic reactions with violation of the protocol reinforces the importance of vigilance on the part of all operating room personnel in its implementation.
Child↗
Bronchiolitis in adults: pathology and imaging.
The most common high resolution CT (HRCT) findings of bronchiolitis are centrilobular nodules and branching linear structures in the secondary pulmonary lobules or areas of air trapping. These findings can be helpful in suggesting the presence of bronchiolitis. However, they are nonspecific because there are overlapping features among various kinds of bronchiolitis. Bronchiolar or peribronchiolar inflammation appears as centrilobular nodule, while bronchiolectasis filled with secretions manifests with branching linear structure on HRCT. Air trapping is secondary to bronchiolitis. Proliferative bronchiolitis with the findings of patchy areas of consolidation or ground-glass opacity can be distinguished from other bronchiolitis. Mineral dust-induced bronchiolitis and peribronchiolar lesions in sarcoidosis present with perilymphatic (centrilobular plus perilobular) micronodules in the secondary pulmonary lobule. Bronchiolitis in hypersensitivity pneumonia appears with poorly defined centrilobular nodules, associated with ground-glass opacity and air trapping.
Adult↗
Intravascular lymphomatosis of the lung: radiologic findings.
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Aged↗
Diffuse micronodular lung disease: HRCT and pathologic findings.
PURPOSE: The purpose of our study was to compare the findings seen on HRCT with those from pathologic examination in patients with diffuse micronodular lung disease (DMLD). METHOD: Forty consecutive patients with biopsy-proven DMLD (each nodule being <5 mm in diameter and occupying more than two-thirds of lung volume on chest radiograph) were included. High resolution CT (HRCT) scans were analyzed with particular attention to the location of nodules in and around the secondary pulmonary lobule (centrilobular, perilymphatic, and random) and the zonal distribution. The findings were compared to pathology. RESULTS: CT scans showed centrilobular nodules in the patients with diffuse panbronchiolitis (n = 4), infectious bronchiolitis [n = 4; Hemophilus influenzae (n = 3) and Mycoplasma pneumoniae (n = 1)], hypersensitivity pneumonia (n = 3), bronchogenic disseminated tuberculosis (n = 3), pneumoconiosis (n = 1), primary lymphoma of the lung (n = 1), and foreign body-induced necrotizing vasculitis (n = 1). They demonstrated perilymphatic nodules in the patients with pneumoconiosis (n = 5), sarcoidosis (n = 2), and amyloidosis (n = 2). They demonstrated micronodules of random distribution in the patients with miliary tuberculosis (n = 9) and pulmonary metastasis (n = 5). Upper and middle zonal predominance was seen in two of two patients with sarcoidosis and in two of six patients with pneumoconiosis. The CT location of nodules in the secondary pulmonary lobule represented the location and nature of the lesion on pathologic examination. CONCLUSION: By showing the distribution of micronodules in and around the secondary pulmonary lobule, HRCT enables the narrowing of the differential diagnosis of DMLD. CT findings reflect gross morphologic features of pathologic examination.
Adult↗
Pulmonary tuberculosis presenting as acute respiratory failure: radiologic findings.
PURPOSE: The purpose of this work was to describe the radiologic findings of pulmonary tuberculosis in patients who presented with acute respiratory failure. METHODS: We included patients who had newly diagnosed active pulmonary tuberculosis and who presented with acute respiratory failure. Initial chest radiographic (n = 17) and high-resolution CT (n = 11) findings of each patient were analyzed retrospectively. RESULTS: Of 1,010 patients with active pulmonary tuberculosis, 17 patients (1.7%) presented with acute respiratory failure. Nine (53%) of the 17 patients died. The most common initial chest radiographic findings were small nodular lesions (16/17; 94%), consolidation (13/17; 76%), and ground-glass opacity (12/17; 70%). Eleven (69%) of 16 nodular lesions, 9 of 13 (69%) consolidations, and 10 of 12 (83%) ground-glass opacities were bilateral. On HRCT (n = 11), miliary micronodular lesions were seen in 6 patients (55%), whereas bronchogenic spread of tuberculosis with disseminated centrilobular nodules and tree-in-bud appearance was seen in 5 patients (45%). Diffuse areas of ground-glass attenuation were seen in all six patients with miliary nodules and four of five patients with bronchogenic spread of tuberculosis. CONCLUSION: Patients with pulmonary tuberculosis occasionally present with acute respiratory failure. In this condition, chest radiograph most commonly shows bilateral small nodular lesions mixed with consolidation or ground-glass opacity, whereas HRCT demonstrates findings of miliary or bronchogenic disseminated tuberculosis with diffuse areas of ground-glass attenuation.
Acute Disease↗
Papillary adenocarcinoma of the lung: radiologic and pathologic findings.
We describe the radiologic and pathologic findings of papillary adenocarcinoma of the lung in three patients. The tumor appeared as a peripheral lung nodule (n = 1) or a mass (n = 2) on chest radiographs. On CT, the tumor appeared as a solitary pulmonary nodule, as a mass containing internal bubble lucencies with surrounding ground-glass opacity and satellite micronodules, and as a triangular mass with satellite micronodules. On pathology, all tumors showed distinct histologic features with papillary architecture, distortion and/or destruction of normal pulmonary architecture, and nuclear atypism.
Adenocarcinoma, Papillary↗
Spectrum of neurogenic tumors in the thorax: CT and pathologic findings.
Neurilemomas and neurofibromas appear as round soft tissue masses at CT. Variable enhancement with either homogeneity or heterogeneity is seen in neurilemomas. Attenuation of the tumors on enhanced CT depends on histology: the extent of Antoni A or B tissue and the amount of myxoid or cystic degeneration or hemorrhage. Neurofibromas are usually homogeneous low attenuation lesions on unenhanced CT. They show homogeneous enhancement or early central blush on enhanced scan. The extent of enhancement depends on the proportions of tumor components: nerve sheath cells, collagen bundles, and areas of myxoid degeneration. Malignant nerve sheath tumors show variable attenuation. Bony destruction, pleural effusion, and metastatic pulmonary nodules may also occur. Ganglioneuromas appear as oblong homogeneous low attenuation lesions on both enhanced and unenhanced CT. This low attenuation is due to their pathologic components, with an abundant amount of myxoid matrices and a relatively small amount of ganglion cells. Neuroblastomas appear as aggressive soft tissue lesions with calcification. Ganglioneuroblastomas may appear with features in between those of ganglioneuromas and neuroblastomas. The typical location of the posterior mediastinum or the aortopulmonary window and high enhancement with administration of contrast medium at CT suggest the diagnosis of paragangliomas.
Adult↗
Halo sign on high resolution CT: findings in spectrum of pulmonary diseases with pathologic correlation.
The halo sign in a pulmonary nodule refers to the condition in which soft tissue attenuation of a pulmonary nodule is surrounded by peripheral ground glass attenuation on high resolution CT. The halo sign can be caused by several pathologic processes: hemorrhagic pulmonary nodules, tumor cell infiltration, and nonhemorrhagic inflammatory lesions. Hemorrhagic pulmonary nodules may occur in infectious diseases including invasive pulmonary aspergillosis, mucormycosis, and candidiasis and noninfectious diseases including Wegener granulomatosis and primary and metastatic hemorrhagic tumors. Tumor cell infiltration in bronchioloalveolar carcinoma, pulmonary lymphoma, and pulmonary metastatic neoplasm may appear with the halo sign. Eosinophilic lung disease and organizing pneumonia are representative of inflammatory lesions showing the sign.
Hemorrhage↗
Squalene-induced extrinsic lipoid pneumonia: serial radiologic findings in nine patients.
PURPOSE: The purpose of this work was to demonstrate the initial and follow-up radiologic findings of squalene-induced extrinsic lipoid pneumonia. METHOD: Follow-up chest radiographs (n = 9) and high-resolution CT scans (n = 3) as well as initial radiographs (n = 9) and CT scans (n = 8) were obtained in nine patients with squalene-induced extrinsic lipoid pneumonia. The serial radiologic findings were analyzed retrospectively by three chest radiologists, focusing on the pattern and distribution of parenchymal abnormalities. RESULTS: The most frequent pattern of parenchymal abnormalities on chest radiograph was areas of ground-glass opacity (n = 9, bilateral 6), followed by consolidation (n = 7, bilateral 3) and poorly defined small nodules (n = 4, bilateral 2). The abnormalities were distributed in the right lower lung (n = 9), left lower lung (n = 6), and right middle lung (n = 6) zones. Initial CT scans (n = 8) demonstrated bilateral areas of ground-glass attenuation (n = 8), poorly defined centrilobular nodules (n = 8), crazy paving (n = 6), and consolidation (n = 3). The abnormalities were distributed in the right middle lobe (n = 8) and in both lower lobes (n = 5). Follow-up chest radiograph (n = 9) showed complete disappearance (n = 2) and decrease (n = 7) in the extent of the parenchymal abnormalities. Follow-up CT scans (n = 3) demonstrated decrease (n = 2) and no change (n = 1) in the extent of the abnormalities. CONCLUSION: Squalene-induced extrinsic lipoid pneumonia most commonly appears as areas of ground-glass attenuation mixed with poorly defined centrilobular nodules and crazy paving on CT, being distributed mainly in the right middle and both lower lobes. The lesions are indolent and remain after cessation of squalene ingestion.
Adolescent↗
Thoracic involvement of systemic lupus erythematosus: clinical, pathologic, and radiologic findings.
Thoracic involvement occurs more frequently in systemic lupus erythematosus than in any other connective tissue diseases, and more than half of patients with the disease suffer from the involvement. Primary intrathoracic manifestations include pleural disease (effusions and/or thickening), acute lupus pneumonitis, subacute interstitial lung disease including bronchiolitis obliterans organizing pneumonia and non-specific interstitial pneumonia with fibrosis, chronic interstitial lung disease of usual interstitial pneumonia, pulmonary hemorrhage, pulmonary vascular disease, small airway disease of bronchiolitis obliterans, and pulmonary arterial hypertension. Secondary intrathoracic manifestations include atelectasis due to diaphragmatic dysfunction, opportunistic pneumonia, drug and oxygen toxicity, aspiration, and pleuropulmonary consequences of cardiac and renal failure.
Biopsy↗