Search PubMed⌕ Search

Biomedical subjects

L H Kim

Publications and source records attributed to L H Kim.

12 recordsLinked to original sources
PubMed2003

The immunophenotypic patterns of follicle centre and mantle zone in Castleman's disease.

BACKGROUND: Castleman's disease is an uncommon disease and the histopathogenesis is poorly understood. This study aims to investigate their clinicopathological and immunophenotypic profile. MATERIALS AND METHODS: Castleman's disease was reconfirmed in biopsy tissue from 10 patients in a period of 17 years. Immunohistochemical staining was performed on the archival materials, with antibodies to lymphoid antigens and oncogene products, Bcl-6 and Bcl-2. Six reactive hyperplastic lymph nodes and three tonsils were used for comparative study of the phenotypic expression. RESULT: There were three cases of plasma-cell and seven of hyaline-vascular variant. The ages of patients ranged from eight to 60 years (median 30 years). The three patients with plasma-cell variant were older, all females. Two of the plasma-cell variant had multicentric lesions associated with systemic disease. All patients with hyaline-vascular variant had localised disease. Atrophic follicle centres were present in all the diagnostic tissue of both subtypes, with loss of Bcl-6 follicular centre B-cells and presence of relatively few CD57 T-cells. These follicle centres stained strongly with anti-CD21. In the mantle zone, CD5 expression was observed in only two cases and Bcl-2 expression similar to reactive follicles was present in six. CONCLUSION: Loss of Bcl-6 B-cells in the atrophic follicle centres, characteristic CD21 network patterns, low rate of CD5 and Bcl-2 expression in the mantle-zone lymphocytes are present in both variants of Castleman's disease, differ distinctly from reactive follicles. The phenotypic similarity in these two variants suggests possibility of closely related pathogeneses.

Adolescent↗
PubMed2001

TARC, a CC chemokine, is frequently expressed in classic Hodgkin's lymphoma but not in NLP Hodgkin's lymphoma, T-cell-rich B-cell lymphoma, and most cases of anaplastic large cell lymphoma.

Thymus and activation-regulated chemokine (TARC) has been identified as a lymphocyte-directed CC chemokine that attracts activated T-helper type 2 (Th2) cells in humans. Recent studies showed that the T cells surrounding Reed-Sternberg cells in Hodgkin's lymphomas (HL) are Th2 type. Anaplastic large cell lymphomas (ALCL), T-cell-rich B-cell lymphoma (TCRBCL) can mimic HL in some instances. This study aimed to establish the pattern of TARC expression in these diseases. Immunohistochemical stain using a polyclonal goat anti-human antibody to TARC was performed on 119 cases of confirmed HL; 99 were classical type (43 mixed cellularity, 43 nodular sclerosis, 5 lymphocyte depleted, 4 lymphocyte rich, 4 unclassifiable) and 20 lymphocyte predominant HL. Additional 27 ALCL (9 T-, 18 null-cell phenotype), 16 T-cell and 8 B-cell non-Hodgkin's lymphoma (NHL) were studied. A total of 85.8% of the classical HL, one case of ALCL, and one case of large cell B-cell lymphoma with anaplastic morphology showed positive TARC expression in the tumor cells. The expression was paranuclear and/or diffuse in the cell cytoplasm. The tumor cells in all cases of lymphocyte predominant HL, TCRBCL, null ALCL, and T-NHL did not express TARC. The high frequency of TARC expression in the Reed-Sternberg cells of classical HL may explain the characteristic T-cell infiltrate in this disease. The absence in other types that may be morphologically similar indicates that staining for TARC may aid in differential diagnosis.

Chemokine CCL17↗
PubMed2000

Active breathing control (ABC) for Hodgkin's disease: reduction in normal tissue irradiation with deep inspiration and implications for treatment.

PURPOSE: Active breathing control (ABC) temporarily immobilizes breathing. This may allow a reduction in treatment margins. This planning study assesses normal tissue irradiation and reproducibility using ABC for Hodgkin's disease. METHODS AND MATERIALS: Five patients underwent CT scans using ABC obtained at the end of normal inspiration (NI), normal expiration (NE), and deep inspiration (DI). DI scans were repeated within the same session and 1-2 weeks later. To simulate mantle radiotherapy, a CTV1 was contoured encompassing the supraclavicular region, mediastinum, hila, and part of the heart. CTV2 was the same as CTV1 but included the whole heart. CTV3 encompassed the spleen and para-aortic lymph nodes. The planning target volume (PTV) was defined as CTV + 9 mm. PTVs were determined at NI, NE, and DI. A composite PTV (comp-PTV) based on the range of NI and NE PTVs was determined to represent the margin necessary for free breathing. Lung dose-mass histograms (DMH) for PTV1 and PTV2 and cardiac dose-volume histograms (DVH) for PTV3 were compared at the three different respiratory phases. RESULTS: ABC was well-tolerated by all patients. DI breath-holds ranged from 34 to 45 s. DMHs determined for PTV1 revealed a median reduction in lung mass irradiated at DI of 12% (range, 9-24%; n = 5) compared with simulated free-breathing. PTV2 comparisons also showed a median reduction of 12% lung mass irradiated (range, 8-28%; n = 5). PTV3 analyses revealed the mean volume of heart irradiated decreased from 26% to 5% with deep inspiration (n = 5). Lung volume comparisons between intrasession and intersession DI studies revealed mean variations of 4%. CONCLUSION: ABC is well tolerated and reproducible. Radiotherapy delivered at deep inspiration with ABC may decrease normal tissue irradiation in Hodgkin's disease patients.

Heart↗
PubMed1999

Safe transplantation of blood type A2 livers to blood type O recipients.

BACKGROUND: Transplantation of blood type A subgroup 2 (A2) livers into non-A recipients has not been reported previously. A2 to O renal transplantation has been reported, with early results including some accelerated rejections and graft losses. This has led some to selectively offer A2 renal transplantation only for patients with low anti-A titers. Given the different clinical behavior of liver allografts to preformed antibody, we felt that such restriction was unnecessary. METHODS: We performed six cases of A2 to O liver transplantation with no augmented immunomodulation or restriction with regard to antibody titers. Clinical courses, anti-A titers, rejection rates, and graft and patient survival were evaluated. RESULTS: All six patients had high pretransplant anti-A titers (>1:8), and all six grafts functioned normally. There were nine rejections in the six patients, of which three were severe (steroid-resistant) and five were late (>90 days). No rejection was vascular, and no grafts were lost, with mean follow-up of 665 days. In one patient who had anti-A antibody measured at the time of rejection IGM titers increased from baseline. Currently all patients are home with normal function. CONCLUSIONS: We found that transplantation of blood group A2 livers into blood group O recipients is safe and can be performed without graft loss and without regard to anti-A titer level. The rate of acute cellular rejection is high in this small series, and a significant proportion of these events were late or required OKT-3. We did not rely on plasmapheresis or anti-A titer determinations. However, the potential for late rejection prompts us to consider the addition of a third immunosuppressive agent. The transplantation of A2 livers into O recipients can partially compensate for the more frequent use of O livers in recipients from other blood groups.

ABO Blood-Group System↗
PubMed1999

Bikunin, a serine protease inhibitor, is present on the cell boundary of epidermis.

Bikunin, which is an inhibitor of serine proteases, is widely distributed in human tissues, including liver, kidney, and mucous membranes of the stomach and colon. The aim of this study was to clarify whether bikunin is expressed in human epidermis and its appendages. Immunoblot analysis using a specific polyclonal antibody to bikunin revealed that a single 43 kDa protein is present in the cell lysate from the human keratinocyte cell line HaCaT. Immunohistochemically, dotted reaction products stained with anti-bikunin antibody were localized on the cell boundary in both basal and spinous cell layers, except on the cell boundary of the basal cells facing the basal membrane. There were no reaction products in the granular-horny cell layers. Reaction products stained with anti-bikunin antibody were also observed on the hair bulb cells and eccrine sweat gland cells, but not on apocrine sweat glands. Also, reaction products were observed on the luminal surface of the renal proximal tubules and in the cytoplasm of these cells. In immunoelectron microscopy, gold particles were observed on the cell membranes close to the desmosomal structures. Reverse transcription-polymerase chain reaction and northern blot analyses showed that mRNA specific for bikunin was expressed in HaCaT cells and human epidermal keratinocytes obtained from suction blisters, and was contained in a commercially available human keratinocyte cDNA preparation. These findings indicate that bikunin is expressed in keratinocytes and may play an important part in regulating keratinocytes in either mitosis or inflammation.

Antibodies↗
PubMed1999

The pattern of lymphoma in east Malaysian patients as experienced in the University Hospital, Kuala Lumpur.

Lymphoma is a highly heterogeneous group of malignant disease. This study aimed to elucidate the pattern of lymphoma in the East Malaysian patient population. 107 cases of confirmed lymphomas from East Malaysian biopsy material were retrieved from the files of the Department of Pathology, University of Malaya, in the 3-year period between 1981 to 1983. With the use of a panel of lymphoid antibodies, the disease was sub-classified using the Rye classification for Hodgkin's lymphoma (HL) and the REAL classification for non-Hodgkin's lymphoma (NHL). All of the cases were tested for the presence of the Epstein-Barr virus by EBER-ISH. There were 11 (10.3%) HL, 80 (74.7%) B-NHL and 16 (15%) T-NHL. The HL:NHL ratio was 1:9. The most common tumour in children was Burkitt's lymphoma 7/13 (53.8%). In the adult group, there were 72/94 (76.6%) B-NHL ¿diffuse large cell type 51 (of which 2 were CD30+), Burkitt's lymphoma 8, follicular lymphoma 5, low grade MALT 2, mantle cell type 1 and not otherwise specified due to poor morphology 5¿, 13/94 (13.8%) T-NHL and 9/94 (9.6%) HL. Of the 9 adult HL, the most common subtype was nodular sclerosis (6, 66.7%). The EBER positive rate in classical HL, T-NHL, BL and B-NHL were 33.3%, 56.3%, 60.0% and 3.1% respectively. In conclusion, the spectrum of lymphoma seen in East Malaysia was rather similar to West Malaysia except for the very low prevalence of peripheral T-cell lymphoma (PTCL) in Sarawak (3.3%).

Adolescent↗
PubMed1999

Pattern of lymph node pathology in a private pathology laboratory.

Lymph node excision biopsy is commonly carried out for the investigation of lymphadenopathy. The objective of this study is to elucidate the pattern of nodal pathology seen in a private pathology practice. A total of 137 nodal biopsies for primary investigation of nodal enlargement were retrieved from the files in a private diagnostic pathology laboratory in the year 1997. Lymph nodes excised for cancer staging were excluded from this study. The histology was reviewed based on H&E stained sections, and with additional histochemical and immunoperoxidase stains when deemed necessary. Cases of malignant lymphomas were sub-classified with the aid of further immunophenotyping using a panel of monoclonal and polyclonal lymphoid antibodies. One case was excluded from this study due to inadequate tissue for further assessment. There were 58 males and 78 females, giving a ratio of 1:1.3 in the remaining 136 cases. They consisted of 13 Malays (M), 108 Chinese (C), 14 Indians (I) and 1 other ethnic group (O). The ratio of M:C:I:O was 1:8.3:1.1:0.1. The majority of the cases were in the age range of 20 to 50 years. The pathology consisted of 17 (12.5%) malignant lymphomas [6 Hodgkin's lymphoma, 11 non-Hodgkin's lymphoma], 35 (25.7%) metastatic carcinomas, 45 (33.1%) reactive hyperplasia, 19 (13.9%) tuberculosis, 11 (8.2%) Kikuchi's disease and 9 (6.6%) others (Castleman's disease 2, cat scratch disease 2, Kimura's disease 1, sarcoidosis 1, non-specific lymphadenitis 3). All categories of nodal disease showed approximately similar ratio of ethnic and gender distribution as above, except for Kikuchi's disease, for which 100% of the patients were female. The most common site of biopsy was from the head and neck region, particularly the cervical group of nodes. The most common nodal pathology seen in the private laboratory was reactive hyperplasia, followed by metastatic carcinoma. Malignant lymphoma constituted only 12.5% of the cases.

Adolescent↗
PubMed1997

Differentiation to an NGF-dependent state and apoptosis following NGF removal both occur asynchronously in cultures of PC12 cells.

Long-term timelapse videomicroscopy was used to investigate the relationships and transitions between mitosis, differentiation, and apoptosis in cultures of NGF-differentiated PC12 cells. After 4 days in NGF, cultures were at an early stage of neuronal differentiation. Removal of NGF led to an appreciable increase in apoptosis with no effect on the relatively high mitotic rate. After 7 days in NGF, cells were more neuronal; NGF withdrawal again resulted in no change in the low mitotic rate but an even greater increase in apoptosis, eventually leading to considerable net loss of cells. After 10 days, cells were terminally differentiated; removal of NGF did not affect the negligible mitotic rate but induced a dramatic increase in apoptosis resulting in death of most of the cells. Apoptosis in the fraction of cells that had become NGF-dependent followed a similar timecourse and was characterized by the same morphology at all three differentiation states. Thus, acquisition of NGF-dependence in PC12 cultures seemed to be the result of a steadily increasing percentage of cells that had each undergone a relatively rapid transition to a postmitotic, NGF-sensitive state. These studies were also helpful for elucidating the timing of apoptosis. Onset of apoptosis was markedly asynchronous within a culture, but the active, blebbing phase, once initiated, always lasted about 45 min, regardless of differentiation state or time spent without NGF. Thus, the active phase might represent a conserved sequence of events that every cell must ultimately undergo before apoptotic death.

Animals↗
PubMed1992

Laparoscopic-assisted abdominoperineal resection with pull-through (sphincter saving).

The sphincter-saving pull-through operation for midrectal cancer has never been popularized because it has been considered to be against the principles of sound cancer surgery, because of its technical difficulty, and because of the assumption that sphincter mass is involved even in the early stages of cancer. We have observed, however, that even in far advanced midrectal cancer sphincter mass is rarely involved, primarily because of the basic difference in drainage systems (lymphatic and vascular) of the lower rectum and the midrectum. We believe therefore, that the pull-through operation for an early midrectal cancer (6-12 cm) is an acceptable procedure, especially for patients who adamantly refuse colostomy and have no gross findings of involvement of the sphincter mass. This paper presents our technique of laparoscopic assisted abdominoperineal resection with pull-through. The advantages of this technique are as follows: (a) it avoids colostomy and maintains continence of stool; (b) blind dissection is unnecessary and minimal bleeding occurs; (c) postoperative wound pain is lessened and time to recovery shortened; (d) exposure is excellent throughout the procedure.

Adenocarcinoma↗