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Biomedical subjects

G H Kang

Publications and source records attributed to G H Kang.

52 records · Page 3Linked to original sources

Kaposi's sarcoma-associated herpesvirus in Kikuchi's disease.

Kikuchi's disease is a fairly common self-limited disorder among Orientals that usually involves the cervical lymph nodes of young individuals and occurs predominantly in females. Frequently, the disease is associated with fever or flu-like symptoms, an elevated erythrocyte sedimentation rate (ESR), neutropenia, and lymphocytosis with atypical lymphocytes in the peripheral blood, suggesting a viral origin. However, no infectious agent has been identified. The presence of Kaposi sarcoma-associated herpesvirus, known as human herpesvirus 8 (KSHV/HHV 8), was investigated by polymerase chain reaction (PCR) in archival tissue from 26 cases of Kikuchi's disease using published sequences of KSHV/HHV 8 as primers. PCR products were further characterized by Southern blot analysis. Forty reactive lymph nodes and a case of Kaposi sarcoma (KS) were included as negative and positive controls, respectively. Patients consisted of 10 men and 16 women with a mean age of 27 years. All patients were previously healthy and presented with cervical or axillary lymphadenopathy. None were positive for human immunodeficiency virus (HIV) or otherwise immunocompromised. Viral DNA was amplified by PCR in six cases of Kikuchi's disease (23%) and the control KS tissue. Southern blot analysis confirmed that the amplified products were KSHV/HHV 8. In the reactive lymph nodes, no viral genome was amplified by PCR. The presence of DNA sequences of KSHV/HHV 8 in a substantial portion of Kikuchi's disease suggests that KSHV/HHV 8 might play an important role in the pathogenesis of a subset of Kikuchi's disease.

Adolescent↗

Human herpesvirus 8 in Kaposi's sarcoma and Kaposi's sarcoma-mimicking vascular tumors.

Kaposi's sarcoma (KS) had been a rare and unusual vascular tumor until a recent epidemic of a disseminated and fulminant form of KS in AIDS patients. Infectious agents have been suspected of causing KS, and recently partial genomic DNA sequences of human herpesvirus 8 (HHV8) have been identified in AIDS-associated KS lesions. Since then, genomic DNA sequences of HHV8 have been isolated in other forms of KS. Although the partial genomic DNA sequence of HHV8 was reported to be, if rare, identified in vascular tumors other than Kaposi's sarcoma (KS), the presence of HHV8 in a very large fraction of KS indicates that detection of HHV8 by PCR is a useful auxiliary tool in differentiating KS from other KS-mimicking vascular tumors. We examined whether the 233-bp segment of the viral DNA was detected in Korean patients with KS and other KS-mimicking vascular tumors. HHV8 sequences were identified in all of nine classic type of KS but not in three epithelioid hemangioendotheliomas and seven angiosarcomas. Our results confirm the relatively restricted distribution of HHV8 and also argue against the likelihood of secondary colonization of KS cells by HHV8.

Adult↗

Primary pulmonary sarcoma with morphologic features of biphasic synovial sarcoma: a case report.

We report an unusual primary case of pulmonary sarcoma that developed in the lung of a 36-year-old woman. The tumor had histologic, immunologic and ultrastructural features identical to those of biphasic synovial sarcoma of the soft tissue. It consisted of an intimate admixture of cytokeratin and epithelial membrane antigen(EMA)-positive neoplastic epithelial cells and vimentin-positive fibroblast-like spindle cells with areas of hyalinization. The patient had a lobectomy and showed no evidence of recurrence or tumor at other sites 15 months after surgery. This case is an useful addition to the small number of published reports on pulmonary synovial sarcoma. The distinctive features of this neoplasm allow it to be different from other types of primary and metastatic malignancies in the lung.

Adult↗

Primary hepatic carcinoid tumor with a paranuclear clear zone: a case report.

Carcinoid tumors having distinct paranuclear clear zones seen on hematoxylin and eosin stain are rare and few cases have been reported in the literature. Furthermore, primary hepatic carcinoid tumor with a paranuclear clear zone is extremely rare. We recently experienced a case from a 48-year-old man who presented a large single mass, 12 cm in largest diameter, in the right lobe of the liver. Histologically, the tumor revealed characteristic organoid pattern with central hyaline degeneration. The tumor cells had a prominent paranuclear vacuolated dear zone. On immunohistochemistry, tumor cells were diffusely positive for synaptophysin and focally stained for chromogranin A. Ultrastructural examination revealed paranuclear aggregation of intermediate filaments and membrane-bound clear vesicles, which corresponded to the paranuclear vacuolated clear zone.

Carcinoid Tumor↗

Primary myxoid leiomyoma of the liver.

We describe a case of hepatic leiomyoma in a 41-year-old woman who complained of abdominal discomfort due to a right upper quadrant abdominal mass. A computed tomographic scan revealed a large hepatic mass with unusual cystic change. Light and electron microscopic findings and an immunohistochemical study demonstrated diffuse and scattered proliferation of smooth muscle cells in a myxoid matrix. In contrast to previously reported cases of primary leiomyoma of the liver, the present tumor developed in a patient without an immunosuppressive condition. To the best of our knowledge, this is the first reported case of primary "myxoid" leiomyoma of the liver.

Adult↗

An experimental study of embolic effect according to infusion rate and concentration of suspension in transarterial particulate embolization.

RATIONALE AND OBJECTIVES: The authors evaluate the embolic effect according to infusion rate and concentration of particulate suspension, focusing on arterial occlusion level. METHODS: The renal arteries of 14 rabbits were embolized with 150 to 250 microns polyvinyl alcohol (PVA) particles, divided into four groups according to two different infusion rates (1 mg/second and 0.1 mg/second) and two different concentrations of suspension (10 mg/mL and 2.5 mg/mL). Arteriograms obtained immediately and a week after embolization were assessed for occlusion level. For the nephrograms obtained a week after embolization, the opacifying areas were graded from 0 to 4. Median coronal sections of each kidney specimen were investigated for the presence of peripheral infarct grossly and for the presence of PVA particles in the small artery microscopically. RESULTS: Arteriograms showed various occlusion levels. Using a 0 to 4 grading system, the opacifying area of the nephrogram obtained 1 week after embolization was noted to be smaller in the low infusion rate group (P < 0.05). In gross and microscopic pathologic examination, the number of cases with peripheral infarct or PVA particles in the small artery (< 300 microns) was greater in the group with the low infusion rate and low concentration (P < 0.05). CONCLUSIONS: In transarterial particulate embolization, slower infusion of more diluted suspension provides for a more distal arterial occlusion.

Animals↗

In-vivo study on the harmful effect of the extremely low frequency unipolar pulsating magnetic field in mice.

We studied the biological effect of a magnetic field on murine brain and kidney. Magnetic field we used was generated by Magno-DR apparatus (Hanil Co., Korea) which produced a high density unipolar square pulsating magnetic field, about 0.3 approximately 0.5 Tesla at 7 Hertz. Animals were placed in the chamber of the machine for various times from 4 hours to 24 hours. Histological sections of brain and kidney were made after perfusion fixation with paraformaldehyde. The light microscopic examination showed eosinophilic change of cytoplasm and positive immunohistochemical reaction to amyloid precursor protein in the neurons of the cerebral cortex. However, the thalamus and brain stem were less affected. The changes in the brain was seen in the mouse exposed more than 12 hours. The renal tubular epithelium showed degenerated tubules scattered in cortical area but little change was noted in glomeruli in the cortex and collecting tubules in the medulla. Immunohistochemistry of the kidney showed weakly positive reaction for the amyloid precursor protein in the distal tubular epithelium after 4 hours of exposure. These data suggest that strong pulsating magnetic fields could induce deleterious effect on the murine brain tissue and renal cortical tubules.

Amyloid beta-Protein Precursor↗

Thin glomerular basement membrane disease: light microscopic and electron microscopic studies.

Benign recurrent hematuria usually indicates a good prognosis. This condition is associated with abnormally thin glomerular basement membranes. Of 680 renal biopsy cases in which lower urinary tract disease had been excluded by careful study, 25 cases from seven children and eighteen adults met the criteria for thin glomerular basement membrane disease, placing the incidence of the disease at 3.7%. The mean patient age was 32.4 years and the male to female ratio was 1 to 5.3. The primary finding was microscopic hematuria in eighteen patients and gross hematuria in five patients. Among eighteen patients who had microscopic hematuria, one patient also exhibited proteinuria and one patient suffered from acute renal failure due to acute drug-induced interstitial nephritis. Proteinuria was only found in one patient. All of the patients had normal renal function, with the exception of one who suffered from acute renal failure. The duration of hematuria from the time of detection to the date of biopsy ranged from 3 months to 30 years with a mean interval of 56.6 months. No apparent evidence of familial hematuria in any patient was noted. Under light microscopy most glomeruli were normal. However, five cases showed focal global sclerosis. Under immunofluorescence microscopy seventeen cases were negative for all immunoglobulins, for complement, and for fibrinogen. Eight cases showed nonspecific mesangial deposition of fibrinogen and/or IgM. Ultrastructurally, extensive diffuse thinning of the GBM was a constant finding. The mean thickness of the GBM was 203.2 +/- 28.3 nm (n = 25); the thickness in adult (201.4 +/- 27.5 nm; n = 18) did not differ from that in children (208.1 +/- 32.0 nm; n = 7).

Adolescent↗

Genetic evidence for the multicentric origin of synchronous multiple gastric carcinoma.

Multiple gastric cancers, which constitute 4% to 10% of all gastric cancers, occur in older people and are associated with more extensive intestinal metaplasia. With regard to the genesis of multiple gastric cancers, multicentricity (independent origin) rather than multifocality (local or lateral spread of one cancer) has been the favored theory. Conventional morphologic study, however, has not been able to provide convincing evidence in support of multicentricity. The purpose of this study was to verify the multicentric origin of multiple gastric cancers at a genetic level. For this purpose, immunohistochemical and molecular techniques were used to define the mutation pattern of APC, MCC and p53 in multiple lesions of synchronous multiple gastric cancers. The study was based on a total of 30 gastric tumors from 13 patients, including 10 double tumors, 2 triple tumors, and 1 quadruple tumor. Single-strand conformation polymorphism and polymerase chain reaction direct sequencing were carried out for exons 5 to 8 of p53, and loss of heterozygosity was detected on the basis of polymerase chain reaction amplification of polymorphism in exon 10 of MCC and in exon 11 of APC. Twelve of 13 cases showed alteration in one or more genetic markers. Of these, three demonstrated a discordant mutation pattern of p53 in individual lesions, and another two revealed allelic loss of MCC in one lesion and p53 mutation in the other. In six other cases, only one lesion showed alteration of APC, MCC, or p53, and in the remaining case, one lesion carried p53 and MCC mutations and the other carried MCC loss of heterozygosity only. The results of this study showed discordance of the mutation pattern of APC, MCC, and p53 in individual lesions of multiple gastric cancers, providing genetic evidence for a multicentric origin of synchronous multiple gastric carcinomas. Collectively, these findings supported the theory of field cancerization in gastric carcinogenesis.

Adenocarcinoma↗

Adamantinoma of tibia with predominant features of fibrous dysplasia--a case report.

We report a case of adamantinoma of the tibia resembling fibrous dysplasia. The patient was a 55-year-old male, and complained of pain in the right lower leg. Roentgenographs showed a well demarcated osteolytic lesion with small foci of calcification and septation within the diaphysis of the distal tibia. The cortex was partially disrupted. Histologically, initial biopsy specimen showed fibrous connective tissue and trabeculae of immature woven bone, strongly suggestive of fibrous dysplasia. The lesion recurred and the second biopsy revealed nests of spindle cells and tubular epithelial structures embedded in granulation type-fibrous tissue. Immunohistochemically, both the nests of spindle cells and the tubular structures gave a positive reaction for cytokeratin. The present case emphasizes once again that histological diagnosis of fibrous dysplasia of the tibia should be made carefully with exclusion of the possibility of adamantinoma.

Ameloblastoma↗

Congenital tuberculosis--report of an autopsy case.

An autopsy case of congenital tuberculosis is described in a 41-day-old female infant who was born to a mother having active pulmonary tuberculosis. The primary complex was seen in the liver and portal lymph nodes, and there was a generalized miliary dissemination including lung, liver, spleen, pancreas, adrenals, thyroid, thymus, kidneys, brain, and bowel. The organism was confirmed to be Mycobacterium tuberculosis. The tubercles were histopathologically of various chronicity and characterized by massive caseation and fairly poor peripheral lymphohistiocytic reaction. Giant cell response was also minimal. It should be stressed that although rare, tuberculosis is still an important disease in Korea that can involve fetus or newborn infants if pregnant women are untreated or unnoticed for her tuberculosis.

Female↗

Nodular regenerative hyperplasia of the liver in Budd-Chiari syndrome: CT and MR features.

We report the imaging findings of spiral computed tomography (CT), magnetic resonance (MR) imaging, and MR angiography in a patient with nodular regenerative hyperplasia of the liver associated with Budd-Chiari syndrome. Spiral CT showed multiple enhancing nodules during the hepatic arterial and portal venous phases. MR images showed multiple hyperintense nodules on T1-weighted images and hypointense or isointense nodules on T2-weighted images. MR angiography showed thrombotic occlusion of three hepatic veins, suggesting Budd-Chiari syndrome.

Adolescent↗

A spindle cell tumor of unknown origin and diffuse bone marrow involvement in a patient with hypercalcemia.

BACKGROUND: Metastasis of unknown origin in bone marrow is infrequent, although, when it occurs, adenocarcinoma is the most common histologic type. Involvement of bone marrow by a spindle cell tumor and presentation with hypercalcemia are very rare. METHOD: This report describes a 21-year-old man with diffuse bone marrow involvement from a spindle cell tumor. RESULTS: The patient presented with low back pain, anemia, thrombocytopenia, azotemia, and hypercalcemia. Bone marrow biopsy revealed a spindle cell tumor that was positive for vimentin staining but whose primary site could not be identified. A bone marrow scan revealed absence of uptake, which suggested systemic disease. We treated this case as a type of sarcoma by giving combined chemotherapy consisting of vincristine, actinomycin-D and cyclophosphamide. The patient showed a clinical response for seven months, but the disease progressed despite chemotherapy and he died one year after diagnosis. CONCLUSIONS: We have documented a rare case of spindle cell tumor involving bone marrow without evidence of the tumor's primary site.

Adult↗