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Biomedical subjects

Y Y Lee

Publications and source records attributed to Y Y Lee.

At least 19 recordsLinked to original sources
PubMed1992

Tumor necrosis factor stimulates Na+/H+ antiporter in human fibroblasts: dissociation between intracellular alkalinization and cytokine mRNA accumulation.

Several hormones and cytokines stimulate the cellular Na+/H+ antiporter and this stimulation may be a signal transduction mechanism to mediate gene expression. We find that tumor necrosis factor rapidly stimulates both the Na+/H+ antiporter and the accumulation of mRNA coding for granulocyte-macrophage colony-stimulating factor and interleukin-6 in fibroblasts. Further experiments show that these phenomena occur independent of each other.

Carrier Proteins↗
PubMed1992

A unique case of retinoblastoma masked by retinal detachment diagnosis and management.

A 4-year-old Latin American boy presented with a history of loss of vision of his left eye for 7 months. He was followed by different ophthalmologists and diagnosed with a retinal detachment. Computerized tomograms and magnetic resonance imaging demonstrated a large calcified left eye and markedly enlarged optic nerve. Based on these radiologic findings diagnosis of retinoblastoma was strongly suspected. Initially enucleation was not done because it was thought that cutting through the involved optic nerve would cause dissemination. The patient was treated with chemotherapy which resulted in marked response. Following normalization of optic nerve and after irradiation the eye was enucleated. The diagnosis of retinoblastoma was confirmed. No tumor was found in the optic nerve. The importance of imaging studies in diagnosis of retinoblastoma and the role of chemotherapy in the treatment of primary retinoblastoma are emphasized.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Infratemporal alveolar soft part sarcoma: CT, MRI and angiographic findings.

The imaging features of a rare alveolar soft part sarcoma found in a 44-year-old female are presented. Although the tumor showed hypervascularity by angiography, CT and MRI suggested slow growth. Despite this relatively benign appearance, alveolar soft part sarcoma is one of the most malignant sarcomas.

Adult↗
PubMed1992

[Aporocotyle theragrae (Trematoda: Aporocotylidae) from the blood vessel of Theragra chalcogramma].

Two fully matured specimens were collected from the blood vessel of two fish, Theragra chalcogramma, which was bought at the Emun market of Seoul in May, 1985. The blood fluke has no pharynx and suckers. Its body surface was covered with minute spines forming fan-shaped groups, 15 microns long. The intestine was H-shaped, and the ratio of esophageal length to body length was 1:6.1-6.8. Irregular shaped testes were 109-114 in number, occupying the intercecal space from cecal bifurcation to the genital pore. The present species was identified as Aporocotyle theragrae. This is the first report of the species in Korea.

Animals↗
PubMed1991

Circulating C1q-binding macromolecules and their relationship to radiographic characteristics of laryngeal cancer.

Circulating macromolecules capable of binding the first component of complement (C1qBM) may represent subcellular components of tissue/tumor debris generated from rapidly proliferating invasive disease. Thirty-eight patients were randomly selected from 74 untreated patients with laryngeal cancer on the basis of disease stage and C1qBM levels. C1qBM levels were correlated with computed tomographic evidence of tumor necrosis and/or thyroid cartilage destruction. Results show that patients with stage III/IV disease with tissue necrosis and/or cartilage invasion had demonstrably higher C1qBM levels than did individuals with similarly staged disease with no evidence of these radiographically defined characteristics (120 +/- 81 micrograms/mL vs 18 +/- 15 micrograms/mL); the strongest association was reflected by the area of necrosis within regional lymph metastases. Elevated C1qBM level in patients with stage III/IV laryngeal cancer thus reflects highly aggressive disease, which is less responsive to therapeutic intervention.

Biomarkers, Tumor↗
PubMed1991

Case report 680. Intraosseous meningioma of the sphenoid bone.

Two cases of intraosseous meningioma of the calvaria with hyperostosis are presented and compared with the appearance on plain films and CT of en plaque meningioma, metastatic disease from such primary sites as prostatic cancer, and fibrous dysplasia. It is emphasized that intraosseous meningioma in the calvaria is relatively uncommon, occurring most often in the sphenoid bone (probably because of its numerous articulations). The relationship of the development of intraosseous meningioma to the entrapment of dura containing arachnoid cells is discussed in considering the cause of such lesions, and it is stressed that calvarial fractures and cranial sutures may contribute to the entrapment of arachnoidal tissue and later the formation of a meningioma.

Adult↗
PubMed1991

Effect of pretreatment on simultaneous saccharification and fermentation of hardwood into acetone/butanol.

The effectiveness of pretreatments on hardwood substrate was investigated in connection with its subsequent conversion by simultaneous saccharification and fermentation (SSF), using Clostridium acetobutylicum. The main objectives of the pretreatment were to achieve efficient separation of lignin from carbohydrates, and to obtain maximum sugar yield on enzymatic hydrolysis of pretreated wood. Two methods have given promising results: (1) supercritical CO2-SO2 treatment, and (2) monoethanolamine (MEA) treatment. The MEA pretreatment removed above 90% of hardwood lignin while retaining 83% of carbohydrates. With CO2-SO2 pretreatment, the degree of lignin separation was lower. Under the scheme of SSF, the pretreated hardwood was converted to acetone, butanol, and ethanol (ABE) via single stage processing by cellulase enzyme system and C. acetobutylicum cells. The product yield in the process was such that 15 g of ABE/100 g of dry aspen wood was produced. In the overall process of SSF, the enzymatic hydrolysis was found to be the rate-limiting step. The ability of C. acetobutylicum to metabolize various 6-carbon and 5-carbon sugars resulted in efficient utilization of all available sugars from hardwood.

Acetone↗
PubMed1991

Outcome and patterns of failure following limited-volume irradiation for malignant astrocytomas.

Between January 1982 and June 1986, 60 consecutive patients with high-grade astrocytomas [39 glioblastoma multiforme (GBM), 21 anaplastic astrocytoma (AA)] were treated with radiation therapy after biopsy (13 patients) or resection (47 patients). Fifty-three patients were treated with limited-volume irradiation, and seven patients received whole-brain irradiation. The mean tumor dose was 65.4 Gy. In 35 patients, chemotherapy was given as part of their initial treatment. The 1- and 2-year survivals for GBM patients were 40 and 14%, respectively. Survival figures for AA patients were 76 and 52% at 1 and 2 years, respectively. The progression-free rate at 1 year was 13% in GBM and 29% in AA patients. Thirty-four of 48 patients who received limited-volume irradiation had evidence of progression on postirradiation CT scans. Six patients (3 GBM, 3 AA) had evidence of a new intracranial metastatic site on CT scan. In three patients the metastasis was within the previously irradiated volume, and in the other three patients, it was outside this volume. All six had evidence of progression of their primary tumor at the original location on CT scan prior to the discovery of the metastatic site. Twenty-one patients (15 GBM, 6 AA) had at least one postirradiation reoperation for a recurrent mass. Nineteen patients had recurrent tumors in the primary site, and two patients had necrosis but no tumor. Patients who received limited-volume irradiation for high-grade astrocytomas achieved the same survival results as patients treated previously with whole brain irradiation. New intracranial metastases did not influence the outcome, since these were always antedated by tumor progression at the primary site.

Actuarial Analysis↗
PubMed1991

A pilot clinical and pharmacokinetic study of intracarotid cisplatin and bleomycin.

Fifteen patients with progressive primary malignant or metastatic brain tumors were treated on a clinical and pharmacokinetic study with intracarotid cisplatin and bleomycin. Toxicity was tolerable and consisted mainly of nausea and vomiting. Neurologic toxicity included focal seizures (1), leukoencephalopathy (1), and motor weakness (1). Five patients had improvement in CT scans and four patients had stabilization of disease. Recommended dosage for future clinical trials are cisplatin 60 mg/m2 and bleomycin 100 units. Pharmacokinetics of intracarotid cisplatin revealed the jugular vein concentration was twice the peripheral vein level at the end of infusion. Cisplatin is a drug which has demonstrated in vitro activity against malignant gliomas (1). Clinical trials with intravenous administration of cisplatin has shown definite, although limited antitumor activity against primary brain tumors (2,3,4) and metastatic brain tumors (5,6). To enhance its antitumor effect, cisplatin has been administered by the intracarotid route (7,8,9). The results appear encouraging, but neurological and ophthalmological toxicity may occur (8). In our initial study with intracarotid cisplatin, 35 patients with malignant brain tumors (23 with primary brain tumors and 12 with brain metastases) progressing after cranial irradiation +/- chemotherapy were treated. Of 20 evaluable patients with primary tumors, 6 responded to therapy and 5 had stable disease. Five of 10 evaluable patients with brain metastases responded and 2 had stable disease. For responding primary brain tumor patients the median time to progression was 33 weeks. The recommended dose for intracarotid cisplatin was 60-75 mg/m2 administered every 3-4 weeks (7,8). Higher cisplatin doses produced more central neurological toxicity. There is limited data on the central nervous system pharmacology of cisplatin.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Quantitative and morphological changes of Langerhans cells in Bowen's disease from patients with chronic arsenicism.

Langerhans cells (LCs) are considered to be responsible for the immunologic presentation of tumor-associated antigens and play a role in the elimination of neoplastic clones. Ultraviolet light B can cause dysfunction and loss of LCs. Both the number and dendritic morphology of LCs are known to be diminished in squamous cell carcinomas from sun-exposed skin. The effects of arsenics on LCs are unknown. Using an OKT-6 monoclonal antibody to stain intraepithelial LCs, we compared their number and morphology in Bowen's lesions and in the perilesional skin from sun-protected sites in ten patients with chronic arsenicism. There was a significant reduction in the numbers of LCs in the Bowen's lesions as compared to the perilesional skin specimens. Loss of dendrites was observed in all Bowen's lesions and in seven of the perilesional skin specimens. Ultrastructurally, the LCs showed an absence of dendrites, but the Birbeck granules were preserved. Since the specimens were not from sun-exposed skin in our study, the findings may be related to chronic arsenic intoxication. The morphologic alteration of LCs observed in the perilesional skin further suggests an arsenic-related systemic dysfunction of the LCs, which in turn may contribute to the development of skin cancers in these patients.

Aged↗
PubMed1990

Comparison of IgG subclass autoantibodies in patients with systemic lupus erythematosus and subacute cutaneous lupus erythematosus.

Circulating antinuclear antibodies and in vivo bound immunoglobulins at the dermal-epidermal junction are frequently seen in patients with lupus erythematosus. The present study was designed to examine the distribution of the IgG subclasses of in vivo skin bound IgG and circulating antinuclear antibodies (ANA) in patients with systemic lupus erythematosus (SLE) or subacute cutaneous lupus erythematosus (SCLE). Immunofluorescence studies on skin biopsies showed IgG1 to be the predominant IgG subclass in SCLE patients, present in 20 of 21 (95%) of the specimens. IgG2 was present in 4 patients (19%), IgG3 in 1 (5%), and IgG4 in 7 (33%). The frequencies of IgG2, IgG3, and IgG4 skin staining were significantly higher in the seven SLE patients who were studied: IgG1 in 7/7 (100%), IgG2 in 7/7 (100%) and IgG4 in 6/7 (86%). Immunoblot analysis for the IgG subclasses was performed on serum of 29 patients with SCLE who had antibodies to SSA/Ro antigen. Twenty-seven (93%) of these patients were positive for IgG1 anti-SSA/Ro antibody, while the frequencies for IgG2, IgG3, and IgG4 anti-SSA/Ro were very low. These studies indicate that there is a difference in the IgG subclass antibody response in patients with SLE and SCLE. The presence of more than one subclass antibody may be indicative of systemic disease.

Antibodies, Antinuclear↗
PubMed1990

Intracarotid cisplatin-based chemotherapy in patients with malignant melanoma and central nervous system (CNS) metastases.

Twenty-three patients with malignant melanoma metastatic to the central nervous system (CNS) were treated with intracarotid cisplatin-based chemotherapy. Twenty-two had failed prior cranial radiation therapy (one patient refused radiation therapy) and had progressive brain metastases documented by computerized tomography (CT). Intracarotid cisplatin 40-75 mg/m2 was administered alone (seven patients) with 1,3-bis(2-Chloroethyl)-1-nitrosourea (BCNU) (13 patients) or bleomycin (three patients). Courses were repeated monthly with CT scan. Seven patients (30%) had objective improvement in CT scans and three patients (13%) had stabilization of disease. The median time to tumor progression for responding patients was 20 weeks (range 8-34 weeks) while stable disease ranged from 9-12 weeks. In three patients the extracranial disease progressed while the brain metastases responded. Neurological and retinal toxicity were potential complications of therapy. Intracarotid cisplatin-based chemotherapy may be useful for palliation in selected patients with malignant melanoma and CNS metastases.

Adult↗
PubMed1990

Loculated intracranial leptomeningeal metastases: CT and MR characteristics.

Studies of twenty-five patients with loculated leptomeningeal tumor metastases diagnosed by CT and/or MR were analyzed retrospectively. Medulloblastoma was the most frequent primary tumor (8/25, 32%). Four subgroups of loculated patterns were identified. Type A included mass(es) limited to the subarachnoid space without obvious direct parenchymal infiltration; this pattern occurred in 12 patients, of whom five had associated diffuse pattern. Type B was characterized by mass(es) still predominantly in the subarachnoid space but with minor transpinal parenchymal infiltration; this pattern was found in five patients. Type C comprised subarachnoid mass(es) with marked transpinal extension mimicking parenchymal lesion; this pattern was observed in three patients. Type D consisted of subarachnoid mass(es) growing along the perineural CSF space; this pattern was noted in two patients. Additionally, two patients presented with combined A and C patterns, and one patient had a combined B and C pattern. More than half the patients (14/25, 56%) presented with a single lesion. The most frequent locations were the suprasellar cistern, ventricular walls, and lateral recesses of the fourth ventricle, Gd-DTPA-enhanced T1-weighted MR images appeared best for demonstrating the site and extent of disease. Recognition of the loculated patterns of leptomeningeal metastases, which are less common than the diffuse pattern, is important to radiologists and clinicians for correct diagnosis and proper management of patients with this disease.

Carcinoma, Squamous Cell↗
PubMed1990

Lymphoma of the head and neck.

Lymphoma is the second most common neoplasm of the head and neck region and should be considered in the differential diagnosis of any lesion in this region, especially if the typical factors for squamous cell carcinoma are not present. The head and neck is the second most common site for extranodal lymphoma. It can involve virtually any region, including the orbit, paranasal sinuses, Waldeyer's ring, salivary glands, or thyroid. Communication with the surgeon and pathologist is essential to prevent an incorrect or delayed diagnosis. One should consider the diagnosis of lymphoma especially when multiple, large, nonnecrotic lymph nodes are present or multiple sites of disease are identified in extranodal tissue.

Head and Neck Neoplasms↗
PubMed1989

Superselective intra-arterial chemotherapy of advanced paranasal sinus tumors.

Twenty-four patients with advanced paranasal sinus tumors were treated with combined superselective intra-arterial and systemic chemotherapy, yielding an immediate satisfactory tumor response rate of 91%, significantly better than previously reported. Eight patients had craniofacial surgery circumvented because of complete or near complete response. Repetitive uncomplicated catheterization of the pterygoid segment of the internal maxillary artery using a coaxial system is the cornerstone of successful induction chemotherapy. Strenuous screening of medical status is mandatory for this aggressive introduction chemotherapy.

Adult↗
PubMed1989

Comparison of IgG subclasses and complement binding activity of autoantibodies from patients with bullous pemphigoid and pemphigus.

Bullous pemphigoid and pemphigus are autoimmune disorders of skin of unknown etiology and are characterized by the presence of immunoreactants in the skin and circulating autoantibodies to skin components. The distribution of IgG subclass antibodies to intercellular substance (ICS) of pemphigus and basement membrane zone substance (BMZ) of bullous pemphigoid was analyzed by using monoclonal antibodies to human IgG subclasses. IgG4 type anti-BMZ antibody was found in the majority of patients with bullous pemphigoid (88% in skin and 96% in serum). One third to one half of bullous pemphigoid patients had IgG1 and IgG2 anti-BMZ antibodies. The majority of bullous pemphigoid skin (92%) had complement in skin, however only one third of their sera had complement binding activity in vitro. IgG1 anti-ICS antibody was the predominant one in patients with pemphigus (86% in skin and 80% in circulation). IgG4 anti-ICS antibody was seen in two thirds of specimens from pemphigus patients. IgG3 subclass antibody was more frequently seen in pemphigus than in bullous pemphigoid patients. Two-thirds of pemphigus sera were capable of activating complement in vitro. The complement binding activity was directly associated with IgG1 and/or IgG3 subclass antibodies. The possible mechanisms for the restricted IgG4 subclass antibodies in bullous pemphigoid and pemphigus are discussed.

Antibody Specificity↗