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Biomedical subjects

J M Kim

Publications and source records attributed to J M Kim.

At least 127 records · Page 7Linked to original sources
PubMed2000

Microsurgical anatomic features and nomenclature of the paraclinoid region.

OBJECTIVE: We describe the detailed microsurgical anatomic features of the clinoid (C5) segment of the internal carotid artery (ICA) and surrounding structures, clarify the anatomic relationships of structures in this region, and emphasize the clinical relevance of these observations. Furthermore, because the nomenclature of the paraclinoid region is confusing and lacks standardization, this report provides a glossary of terms that are commonly used to descibe the anatomic features of the paraclinoid region. METHODS: The region surrounding the anterior clinoid process was observed in 70 specimens from 35 formalin-fixed cadaveric heads. Detailed microanatomic dissections were performed in 10 specimens. Histological sections of this region were obtained from the formalin-fixed cadaveric specimens. RESULTS: The clinoid segment of the ICA is the portion that abuts the clinoid process. This portion of the ICA can be directly observed only after removal of the clinoid process. The dura of the cavernous sinus roof separates to enclose the clinoid process. The clinoid segment of the ICA exists only where this separation of dural layers is present. Because the clinoid process does not completely enclose the ICA in most cases, the clinoid segment is shaped more like a wedge than a cylinder. The outer layer of the dura (dura propria) is a thick membrane that fuses with the adventitia of the ICA to form a competent ring that separates the intradural ICA from the extradural ICA. The thin inner membranous layer of the dura loosely surrounds the ICA throughout the entire length of its clinoid segment. The most proximal aspect of this membrane defines the proximal dural ring. The proximal ring is incompetent and admits a variable number of veins from the cavernous plexus that accompany the ICA throughout its clinoid segment. CONCLUSION: The narrow space between the inner dural layer and the clinoid ICA is continuous with the cavernous sinus via an incompetent proximal dural ring. This space between the clinoid ICA and the inner dural layer contains a variable number of veins that directly communicate with the cavernous plexus. Given the inconstancy of the venous plexus surrounding the clinoid ICA, we think that categorical labeling of the clinoid ICA as intracavernous or extracavernous cannot be justified.

Anatomy, Artistic↗
PubMed2000

Transactivation activity of the human cytomegalovirus IE2 protein occurs at steps subsequent to TATA box-binding protein recruitment.

The IE2 protein of human cytomegalovirus transactivates viral and cellular promoters through a wide variety of cis-elements, but the mechanism of its action has not been well characterized. Here, IE2-Sp1 synergy and IE2-TATA box-binding protein (TBP) interaction are examined by artificial recruitment of either Sp1 or TBP to the promoter. It was found that IE2 could cooperate with DNA-bound Sp1. A 117 amino acid glutamine-rich fragment of Sp1, which can interact with Drosophila TAF(II)110 and human TAF(II)130, was sufficient for the augmentation of IE2-driven transactivation. In binding assays in vitro, IE2 interacted directly with the C-terminal region of Sp1, which contains the zinc finger DNA-binding domain, but not with its transactivation domain, suggesting that synergy between IE2 and the transactivation domain of Sp1 might be mediated by other proteins such as TAF or TBP. It was also found that TBP recruitment to the promoter markedly increased IE2-mediated transactivation. Thus, IE2 acts synergistically with DNA-bound Sp1 and DNA-bound TBP. These results suggest that, in human cytomegalovirus IE2 transactivation, Sp1 functions at an early step such as recruitment of TBP and IE2 acts to accelerate rate-limiting steps after TBP recruitment.

Animals↗
PubMed2000

A novel factor isolated from Actinobacillus actinomycetemcomitans stimulates mouse B cells and human peripheral blood mononuclear cells.

A novel immunostimulating factor (ISTF) of Actinobacillus actinomycetemcomitans ATCC 29522 was isolated and characterized as inducing proliferation of mouse B cells and human peripheral blood mononuclear cells. This factor was isolated from the bacterial culture medium and purified by size exclusion chromatography, dye-ligand affinity chromatography, immunoaffinity chromatography using monoclonal antibodies, and preparative electrophoresis. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the purified ISTF migrated as a single band corresponding to a molecular mass of 13 kDa. ISTF was a proteinaceous material distinct from lipopolysaccharide; it directly induced the proliferation of B lymphocytes but had no effect on the proliferation of T lymphocytes, even in the presence of antigen-presenting cells. A B-lymphocyte-mitogenic activity of ISTF was also shown by flow cytometric analysis of responding cell subpopulations. Immunoblot analysis revealed that ISTF was a component of the outer membranes of bacteria, could exist as a soluble form, and was released by growing and/or lysed bacteria. These results suggest that ISTF produced by A. actinomycetemcomitans may play an important role in immunopathologic changes associated with A. actinomycetemcomitans infections.

Adjuvants, Immunologic↗
PubMed2000

The 17 nucleotides downstream from the env gene stop codon are important for murine leukemia virus packaging.

We have identified a previously unknown nucleotide sequence important for the packaging of murine leukemia virus. This nucleotide sequence is located downstream from the stop codon of the env gene but does not overlap the polypurine tract. Deletion of 17 bp from this region resulted in a more than 10-fold decrease in viral titer. Consistent with this result, the deletion mutant showed a 20- to 30-fold drop in the amount of virion RNA in the culture supernatant. The total amount of virion protein in the culture supernatant was comparable for the deletion mutant and the parental virus, suggesting that the mutant construct could release the empty viral particles. These results suggested that the packaging signal sequence might be present at the two extreme sites of the viral genome, one in the region around the splice donor sequence downstream from the 5' long terminal repeat (LTR) and the other immediately upstream from the 3' LTR. Implications for gene therapy, especially in regard to construction of retroviral vectors and packaging constructs, are discussed.

3T3 Cells↗
PubMed2000

Caspase-3 activation is required for Leydig cell apoptosis induced by ethane dimethanesulfonate.

Previous studies have shown that ethane dimethanesulfonate (EDS) causes the apoptotic death of Leydig cells. The molecular mechanism by which EDS elicits its effect remains uncertain. The present study tested the hypothesis that caspase-3 is involved in the EDS-induced death of rat Leydig cells. Leydig cells were isolated from adult Sprague Dawley at 3, 6, 12, or 24 h after the rats received an EDS injection. Low mol wt DNA fragments that are characteristic of apoptosis were evident by 12 h post-EDS, and the ladder pattern was more pronounced at 24 h. During this same time period, the number of terminal deoxynucleotidyltransferase-mediated deoxy-UTP-biotin nick end labeling (TUNEL)-positive cells increased. Western blot analysis revealed that procaspase-3 was present only at low levels in control Leydig cells, and increased through 6 h post-EDS. By 12 h, procaspase-3 was reduced, whereas the cleaved, active caspase-3 forms appeared at 12 h and increased through 24 h post-EDS. Caspase-3 activity was blocked by caspase-3 inhibitor. In vitro, EDS treatment induced Leydig cell apoptosis. In the presence of cell-permeable caspase-3 inhibitor, however, apoptosis was significantly suppressed, providing further evidence for the involvement of caspase-3 in EDS-induced Leydig cell apoptotic death. Immunohistochemical analysis revealed weak staining for caspase-3 in the cytoplasm of control Leydig cells. From 12-24 h post-EDS, the time interval during which the active forms of caspase-3 appeared, caspase-3 immunoreactivity increased and became localized to the nuclei. Apoptosis and caspase-3 were colocalized in Leydig cells by a histological method that combined TUNEL and caspase-3 immunohistochemistry. In these studies, TUNEL-positive cells all exhibited intense nuclear caspase-3 immunoreactivity, whereas TUNEL-negative cells exhibited weak caspase-3 immunoreactivity in the cytoplasm. Taken together, these results indicate that Leydig cell apoptosis induced by EDS is mediated by caspase-3 activation, and suggest that the translocation of the active caspase-3 forms to the nucleus may be involved.

Animals↗
PubMed2000

Incidence and significance of demonstrating the meniscofemoral ligament on MRI.

The aim was to evaluate how often MRI can detect the meniscofemoral ligament and if there is any relationship with the presence of lateral meniscal tears. Sagittal and coronal MR images of 138 patients with arthroscopically proven meniscal tears were included in this study. MR images were retrospectively reviewed for the presence of a meniscofemoral ligament and a lateral meniscal tear. The chi 2 test was used for statistical analysis. Either one or both meniscofemoral ligaments were shown in 114 (83%) of 138 patients on MR images. In 61 cases with a lateral meniscal tear, the meniscofemoral ligament was present in 82% (50/61) and absent in 18% (11/61). In 77 cases without lateral meniscal tear, the meniscofemoral ligament was present in 83% (64/77) and absent in 17% (13/77). A significant correlation was not established between the meniscofemoral ligament and lateral meniscal tear (p = 0.85).

Adolescent↗
PubMed2000

Immunoprophylactic effect of chicken egg yolk immunoglobulin (Ig Y) against porcine epidemic diarrhea virus (PEDV) in piglets.

Porcine epidemic diarrhea virus (PEDV) is the causative agent of neonatal diarrhea in piglets, which causes high mortality rates. In this study, the immunoprophylactic effects of chicken egg yolk immunoglobulin (Ig Y) against PEDV were investigated in neonatal pigs. Ig Y was found to reduce the mortality in piglets after challenge exposures. The field application of Ig Y also revealed significant differences in survival rates of piglets given Ig Y, as compared with placebo or control. The results in this study indicated that Ig Y against PEDV could be an alternative way of supplementing prophylactic measures like colostral antibodies from sows.

Animals↗
PubMed2000

Apoplexy of pituitary macroadenoma after combined test of anterior pituitary function.

Pituitary apoplexy has been reported as a very rare complication of combined tests of anterior pituitary function and of TRH or gonadotropin-releasing hormone (GnRH) administration in pituitary tumor. A 34-year-old man with a GH-secreting pituitary macroadenoma and diabetes mellitus received an injection of 400 microg TRH, 100 microg GnRH, and 0.15 U/Kg regular insulin. Twenty minutes later, he complained of a severe headache and vomited. Visual acuity and visual field did not change and his headache was persistent during the next 24 hours of conservative management. Magnetic resonance imaging (MRI) of the sella turcica done the day after the event showed definitive elevation of the optic chiasm and slight enlargement of tumor and focal areas of mixed high signal and low signal intensities in the macroadenoma on noncontrast T1-weighted images. Headache subsided markedly within a day of octreotide therapy. Transsphenoidal removal of the pituitary tumor was performed 9 days after the hormone study. Ischemic necrosis and hemorrhage were confirmed in the acidophilic adenoma with positive immunostaining for GH. Postoperative course was uneventful and his serum insulin-like growth factor-1 (IGF-1) level and blood glucose levels were normalized. Three months after the surgery the dynamic test was repeated without adverse effects. To our knowledge, this is a very rare case of apoplexy of GH-secreting pituitary adenoma after a combined stimulation test of anterior pituitary function.

Acromegaly↗
PubMed2000

Metastatic tumors in the sellar and parasellar regions: clinical review of four cases.

Metastatic tumors in the sellar and parasellar regions are uncommon and rarely detected in clinical practice. We present four cases of sellar and parasellar metastatic tumors, which metastasized from distant organ in one case and extended directly from adjacent structures in three. Common presenting symptoms were cranial neuropathies, headache and facial pain. Invasion into the cavernous sinus was noted in all cases. We report rare cases of sellar and parasellar metastases. Also, we should consider the possibility of metastasis in these regions for patients who showed the above clinical presentations in systemic cancer patients. In extensive diseases, transient symptomatic relief could be obtained by direct surgical management, even in restricted degree.

Adenocarcinoma↗
PubMed2000

Spontaneous programmed cell death of peripheral blood mononuclear cells from HIV-infected persons is decreased with interleukin-15.

Interleukin 15 (IL-15) is an important regulatory cytokine in cellular immunity. In vitro replacement of IL-15 has been shown to enhance immunity in Human immunodeficiency virus type 1 (HIV-1) infected lymphocytes. We evaluated the effect of IL-15 on the survival of peripheral blood mononuclear cells of HIV patients by examining in vitro lymphocyte apoptosis, and correlated the process with Bcl-2 and Fas gene regulation. Peripheral blood mononuclear cells (PBMC) from 21 HIV-infected adults and 24 HIV-seronegative healthy individuals were isolated and cultured to determine the effect of escalating doses of IL-15 (0, 1, 10, 100, 1000 ng/mL) on apoptosis. Lymphocyte proliferation assay with (3H) TdR was measured and Bcl-2 and Fas gene regulation was observed. The results were as follows: 1) IL-15 reduced culture induced lymphocyte apoptosis in HIV patients in a dose dependent manner, and reached a plateau level at a concentration of 100 ng/ml; 2) IL-15 significantly reduced the level of apoptosis after 3 days (14%) and 5 days (15%) of culture in HIV patients, while no difference was observed in HIV (-) donors; 3) The percentage of viable cells among the total number of lymphocytes was significantly enhanced by 25% in HIV patients with IL-15; 4) Bcl-2 expression was decreased in HIV patients (53.9 +/- 12.3%) compared to HIV (-) donors (93.0 +/- 3.7%), and IL-15 increased Bcl-2 expression by 21.2 +/- 5.2% in HIV patients; 5) Fas expression was increased in HIV patients (70.2 +/- 4.6%) compared to HIV (-) donors (32.4 +/- 4.3%), and IL-15 increased Fas expression by 8.4 +/- 1.2% in HIV (-) donors. Our findings indicate that IL-15 may influence immunologic abnormalities in HIV infection, particularly its ability to prevent apoptosis of lymphocytes by suppressing the down-modulation of Bcl-2. This may provide an experimental basis for IL-15 immunotherapy.

Apoptosis↗
PubMed2000

Serologic and histopathologic study of Chlamydia pneumoniae infection in atherosclerosis: a possible pathogenetic mechanism of atherosclerosis induced by Chlamydia pneumoniae.

Chronic infection and inflammation have recently been implicated as important etiologic agents for atherosclerosis in general and, in particular, ischemic heart disease. Several agents have been suggested as possible candidates for the chronic inflammation including cytomegalovirus, Helicobacter pylori and Chlamydia pneumoniae. We hypothesized that a vascular infection with C. pneumoniae may induce a chronic inflammatory reaction in the host vascular tissue and activated inflammatory cells may express inflammatory mediators such as cyclooxygenase-2 (COX-2) and matrix metalloproteinases (MMPs). At first, we evaluated the relationship between C. pneumoniae infection and atherosclerosis indirectly by serologic study, and then, to confirm our hypothesis, we performed an immunohistochemical study of atherosclerotic plaques. The seropositive rate of anti-Chlamydia pneumoniae IgG was higher in the disease group (Group I, 59.8%, n = 254) than in the negative control group (Group III, 47.4%, n = 97) (p = 0.041), but the anti-Chlamydia pneumoniae IgA was not different in seropositivity between the two groups (Group I, 64.6%; Group III, 57.7%). The simultaneous seropositive rates of both IgG and IgA were 56.7% in Group I and 43.3% in Group III (p = 0.033). In subgroups without the conventional risk factors of atherosclerosis, these findings were more prominent. Furthermore, we performed immunohistochemical staining on the atherosclerotic aortic tissues obtained from patients that were seropositive to C. pneumoniae (n = 5), by using antibodies to C. pneumoniae, COX-2, and MMP-9. The immunoreactivity for COX-2 and MMP-9 increased in the atherosclerotic plaques itself, predominantly in the surrounding area of immunoreactive C. pneumoniae. These findings support our hypothesis and C. pneumoniae may participate in a pathogenetic mechanism for atherogenesis or progression of atherosclerosis. The present study may open a promising perspective concerning future therapeutic trials of chronic inflammation related atherogenesis under pathophysiological conditions.

Aged↗
PubMed2000

Endoscopic mucosal resection with a ligation device for early gastric cancer and precancerous lesions: comparison of its therapeutic efficacy with surgical resection.

Endoscopic mucosal resection with a ligation device (EMR-L) has become important in the curative treatment of precancerous lesions and early gastric cancers (EGCs), but little is known of the long-term efficacy and survival rates of EMR-L compared with surgical resection. We analyzed the therapeutic efficacy and safety of EMR-L in cases of EGC and precancerous lesions and compared the results of EMR-L with those of gastrectomy in patients with EGC over the same periods. EMR-L was performed on 20 EGCs and 54 precancerous lesions including tubular adenomas with or without severe dysplasias in 74 patients. Macroscopic type, size and location of the lesion were determined by endoscope, and the depth of invasion in EGCs was determined by endoscopic ultrasonography and confirmed by pathologic examination of the resected specimens. All the EGC cases were endoscopically followed up for at least 18 months (range, 18-66 months). Patients were selected that underwent subtotal gastrectomy and the survival rates were compared with those that underwent EMR-L. Complete resection was made in a single EMR-L treatment session in 61 cases (82.4%; 91.5%, were precancerous lesions and 65% were EGCs). After a repeat trial of EMR-L, the total rate of complete resection of precancerous lesions and EGCs was 92.6% and 85.0%, respectively. The survival rate of EGCs showed that complete resection by EMR-L resulted in 2 and 5 year survival rates of 100% and 95%, which are comparable to those of surgery (100% and 100%). This study suggests that EMR-L is a technically simple, minimally invasive and highly safe and effective treatment modality for selective EGCs, and offers an alternative to surgical treatment.

Adult↗
PubMed2000

Restoration of P-glycoprotein function is involved in the increase of natural killer activity with exogenous interleukin-15 in human immunodeficiency virus-infected individuals.

A depressed level of natural killer (NK) activity is one of the various immunologic abnormalities in human immunodeficiency virus (HIV) infection. Interleukin-15 (IL-15), an immunotherapeutic candidate in HIV infection, increases NK activity and induces the excretion of CC-chemokines from divergent immune cells, but the mechanisms of NK activity enhancement by IL-15 stimulation is not clearly established in HIV infection. This study examined whether CC-chemokines, which are known to increase NK activity, are secreted adequately in HIV-infected individuals, and also investigated whether P-glycoprotein is involved in NK activity enhancement after IL-15 administration. NK activity increased with IL-15 stimulation in NK cells of HIV-infected individuals, as it does in normal NK cells. IL-15 stimulates NK cells to secrete CC-chemokines, such as, macrophage inflammatory protein-1alpha (MIP-1alpha), macrophage chemotactic protein-1alpha (MCP-1alpha) and regulated upon activation, normal T cells expressed and secreted (RANTES) in both HIV-infected individuals and controls with no significant difference. P-glycoprotein expression and function is decreased in HIV-infected individuals and restored only in NK cells of HIV-infected individuals after IL-15 stimulation. P-glycoprotein may play a role in the mechanism of increased NK cell activity in HIV-infected individuals after IL-15 stimulation.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

Helicobacter pylori in dental plaque and saliva.

BACKGROUND: About half of the world population is infected with H. pylori, but the transmission and the source of this infection are still unclear. Recently, dental plaque (DP) and saliva have been implicated as possible sources of H. pylori infection. This study was done to investigate the detection rates of H. pylori in the DP and saliva by use of PCR depending on H. pylori infection state of gastric mucosa. METHODS: In 46 subjects, gastric H. pylori colonization was evaluated with CLO test, microscopy of Gram stained mucosal smear, culture and histology after modified Giemsa staining in the antrum and body, respectively. A patient was regarded as H. pylori positive if one or more of the four aforementioned test methods demonstrated H. pylori colonization of the gastric mucosa. For detection of H. pylori in the DP and saliva, PCR assay was done with ET4-U and ET4-L primers. To estimate the sensitivity and specificity of this PCR, H. pylori positivity was evaluated in the antrum and body, separately. RESULTS: The sensitivity of mucosal PCR was 50.0% (27/54) and the specificity 86.8% (33/38). When a subject was regarded as H. pyloi positive, if either antrum or body mucosal H. pylori was is positive, the positive rate of mucosal PCR was 62.1% (18 subjects) in the 29 H. pylori-positive and 17.6% (3 subjects) in the 17 H. pylori-negative subjects. DP PCR was positive in 2 of 29 H. pylori-positive subjects (6.9%) and none in the 17 H. pylori-negative (0%). Saliva PCR was positive in 4 of 14 H. pylori-positive subjects (28.6%) and none of 6 H. pylori-negative (0%). CONCLUSION: The detection rates of H. pylori in DP and saliva by PCR were rather low, 6.9% and 28.6%, respectively, and these rates might have been underestimated by low sensitivity of the PCR method used in this study. However, the results that H. pylori was found in the DP and saliva suggest that the oral cavity can perform a role as a reservoir of H. pylori in Korea.

Dental Plaque↗
PubMed1999

Determination of betaine in Lycium chinense fruits by liquid chromatography-electrospray ionization mass spectrometry.

A rapid and sensitive high-performance liquid chromatography-electrospray mass spectrometric method has been developed for the determination of betaine in Lycium chinense fruits. Betaine was analyzed on a system consisting of a NH2 stationary phase and a mobile phase of water-acetonitrile (25:75) by isocratic elution for 40 min. Betaine was identified and quantitated by electrospray ionization mass spectrometry with selected ion monitoring of the protonated ion [Betaine+H]+ and clustered ions [nBetaines+H]+. The limit of detection for betaine by this method was ca. 0.2 ng/ml and the relative standard deviations of the assay (intra- and inter-day) were less than 8.1%.

Betaine↗
PubMed1999

Effects of capsaicin on induction of c-jun proto-oncogene expression in Fisher-344 rats by N-methyl-N'-nitro-N-nitrosoguanidine.

N-Methyl-N'-nitro-N-nitrosoguanidine (MNNG) is a potent inducer of cellular stress leading to chromosomal aberrations, point mutations, and cell death. To study the effect of capsaicin on c-jun expression when given with MNNG to rats, Fisher-344 rats that had been administered MNNG were treated with capsaicin in their diet and organs were removed for measuring c-jun transcripts. We show that pre- or post-treatment of capsaicin relative to MNNG administration up- or down-regulates (depending on the organ) c-jun expression in a consistent pattern in most organs. In fact, we found in this study that capsaicin inhibits c-jun induction, stimulated by MNNG, in the spleen, heart, stomach and lung. Since MNNG, a methylating agent, is a powerful carcinogen that is very effective in the induction of c-jun mRNA, the results suggest that capsaicin uptake in the diet could play a role in inhibition of tumorigenesis induced by MNNG.

Animals↗