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Biomedical subjects

K H Cho

Publications and source records attributed to K H Cho.

At least 55 records · Page 3Linked to original sources
PubMed2001

Effects of uwhangchungsimwon on cell viability, proliferation, and gene expression of human neuronal cell line IMR32.

Uwhangchungsimwon (pill, UC) is one of the traditional Korean medical prescriptions that has been most frequently used for stroke. To characterize the effects of UC on human neuronal cells, the human neuroblastoma cell line IMR32 was treated with UC, and cell viability, cell proliferation, apoptosis, and gene expression were analyzed. The effect of UC on recovery of cell viability was analyzed following stress induction by nutrient depletion or cold shock. Flow cytometric analysis of the cell cycle showed that UC inhibits cell cycle progression of IMR32 in a dose- and time-dependent manner. UC was also identified to increase cell viability and suppress apoptosis induction by a DNA-damaging agent, etoposide. Quantitative RT-PCR analysis revealed that expressions of the p53 tumor suppressor gene and its downstream effect, Waf1, are stimulated whereas expressions of positive cell cycle regulators, c-Myc, c-Fos, and Cyclin D1 were repressed by UC treatment. Moreover, while expression levels of apoptosis inhibitors, Bcl-2 and Bcl-XL were increased following UC treatment, that of an apoptosis promoter, Bax, was decreased. In addition, expression of BMP-7, which has been recently demonstrated to improve the motor neuron recovery from stroke, was induced by UC while it was not detected in untreated cells. Taken together, our data suggest that the pharmacoclinical effects of UC might be derived in part from its negative regulation of cell proliferation and apoptosis through the transcriptional control of related genes.

Apoptosis↗
PubMed2001

Normal and acutely torn posterior cruciate ligament of the knee at US evaluation: preliminary experience.

PURPOSE: To determine the ultrasonographic (US) findings of normal and acutely torn posterior cruciate ligament (PCL) of the knee and evaluate the usefulness of US in the injured PCL. MATERIALS AND METHODS: US images were obtained in 30 knees in 15 asymptomatic volunteers as a control group and in 35 patients clinically suspected of having an acute PCL injury. Only the distal half of the PCL was evaluated. Of the 35 patients, 28 had their PCL status confirmed: 13 had a normal PCL at magnetic resonance (MR) imaging plus clinical examination, and 15 had a torn PCL at either MR imaging and surgery or MR imaging and clinical follow-up. RESULTS: Normal PCLs were homogeneously hypoechoic, with a well-defined posterior border. Torn PCLs were heterogeneously hypoechoic (12 [80%] of 15 patients), with an indistinct posterior margin (11 [73%] of 15 patients). Torn PCLs were significantly thicker (range, 12.0-20.0 mm; mean, 15.6 mm +/- 2.5 [SD]; P <.01), as compared with normal PCLs in 13 patients (range, 3.8-5.8 mm; mean, 4.6 mm +/- 1.0; P <.01) and in the volunteers (range, 3.7-6.2 mm; mean, 4.5 mm +/- 1.2; P <.01). CONCLUSION: An acutely torn PCL thickens (>10 mm), loses its sharply defined posterior border, and has a heterogeneously hypoechoic appearance. US may be useful as a screening examination for patients suspected of having PCL injury and for deciding whether to perform more expensive MR imaging or surgical intervention.

Acute Disease↗
PubMed2001

5-fluorouracil-induced leukoencephalopathy in patients with breast cancer.

The purpose of this study is to determine the characteristic clinical features, radiologic findings, and precipitating and prognostic factors in the patients with breast cancer and with 5-Fluorouracil (5-FU)-induced leukoencephalopathy. We reviewed the medical records of six breast cancer patients who developed leukoencephalopathy after chemotherapy which included 5-FU and also evaluated thorough neurological examinations including mini-mental status examination, cerebrospinal fluid studies, brain images and brain biopsies. Six patients exhibited slowly progressing neurologic symptoms characterized by the impairment of cognitive function, abulia, ataxic gait, and/or akinetic mutism. None of the patients had any specific causes or etiologic factors for leukoencephalopathy. Brain MRI in all patients showed diffuse periventricular white matter changes in the T2-weighted MR image. Brain biopsy in Patient 1 showed fragmented axonal fiber and minimally deprived myelination with many scattered macrophages. Five patients who treated with steroids at the onset of neurological symptoms showed clinical improvement, regardless of their age, sex, the pathology and stage of breast cancer, or the total dosage of chemotherapeutic agents. We conclude that leukoencephalopathy in these cases could be attributable to 5-FU neurotoxicity and suggest that the administration of steroids might be the treatment of choice.

Adenocarcinoma, Mucinous↗
PubMed2001

Hyperfractionated re-irradiation using a 3-dimensional conformal technique for locally recurrent carcinoma of the nasopharynx; preliminary results.

To evaluate the efficacy of hyperfractionated re-irradiation using a three-dimensional conformal radiotherapy (3-D CRT) technique in patients with locally recurrent carcinoma of the nasopharynx. Four patients with locally recurrent nasopharyngeal cancer were retreated with a hyperfractionated schedule using a 3-D CRT technique. Re-irradiation was delivered in 1.1-1.2 Gy fractions twice per day (BID), with interfraction intervals of more than 6 hours. The total dose ranged from 59.4 to 69.2 Gy. A 3-D CRT technique with 5- or 6-field coplanar and/or non-coplanar beams were employed during the entire treatment procedure. All four patients achieved complete remission of locally recurrent lesions, with marked improvement of subjective symptoms, immediately after re-irradiation. All are alive and well without evidence of disease after limited follow-up periods, which range from 7 to 20 months. So far, there have been no radiation-induced neurologic complications. Four patients with locally recurrent carcinoma of the nasopharynx were successfully treated by hyperfractionated re-irradiation using a 3-D CRT technique. A relatively high re-irradiation dose of more than 60 Gy may be safely delivered with no serious acute or late radiation-induced complications in patients with local recurrences and who were initially treated with doses greater than 70 Gy.

Aged↗
PubMed2001

Role of individual amino acids of apolipoprotein A-I in the activation of lecithin:cholesterol acyltransferase and in HDL rearrangements.

The central region of apolipoprotein A-I (apoA-I), spanning residues 143--165, has been implicated in lecithin:cholesterol acyltransferase (LCAT) activation and also in high density lipoprotein (HDL) structural rearrangements. To examine the role of individual amino acids in these functions, we constructed, overexpressed, and purified two additional point mutants of apoA-I (P143R and R160L) and compared them with the previously studied V156E mutant. These mutants have been reported to occur naturally and to affect HDL cholesterol levels and cholesterol esterification in plasma. The P143R and R160L mutants were effectively expressed in Escherichia coli as fusion proteins and were isolated in at least 95% purity. In the lipid-free state, the mutants self-associated similarly to wild-type protein. All the mutants, including V156E, were able to lyse dimyristoylphosphatidylcholine liposomes. In the lipid-bound state, the major reconstituted HDL (rHDL) of the mutants had diameters similar to wild type (96--98 A). Circular dichroism and fluorescence methods revealed no major differences among the structures of the lipid-free or lipid-bound mutants and wild type. In contrast, the V156E mutant had exhibited significant structural, stability, and self-association differences compared with wild-type apoA-I in the lipid-free state, and formed rHDL particles with larger diameters. In this study, limited proteolytic digestion with chymotrypsin showed that the V156E mutant, in lipid-free form, has a distinct digestion pattern and surface exposure of the central region, compared with wild type and the other mutants. Reactivity of rHDL with LCAT was highest for wild type (100%), followed by P143R (39%) and R160L (0.6%). Tested for their ability to rearrange into 78-A particles, the rHDL of the two mutants (P143R and R160L) behaved normally, compared with the rHDL of V156E, which showed no rearrangement after the 24-h incubation with low density lipoprotein (LDL). Similarly, the rHDL of V156E was resistant to rearrangement in the presence of apoA-I or apoA-II. These results indicate that structural changes are absent or modest for the P143R and R160L mutants, especially in rHDL form; that these mutants have normal conformational adaptability; and that LCAT activation is obliterated for R160L.Thus, individual amino acid changes may have markedly different structural and functional consequences in the 143--165 region of apoA-I. The R160L mutation appears to have a direct effect in LCAT activation, while the P143R mutation results in only minor structural and functional effects. Also, the processes for LCAT activation and hinge mobility appear to be distinct even if the same region of apoA-I is involved. -- Cho, K-H., D. M. Durbin, and A. Jonas. Role of individual amino acids of apolipoprotein A-I in the activation of lecithin:cholesterol acyltransferase and in HDL rearrangements. J. Lipid Res. 2001. 42: 379--389.

Amino Acids↗
PubMed2001

Cutaneous photodamage in Koreans: influence of sex, sun exposure, smoking, and skin color.

BACKGROUND: Severe wrinkles and pigmentary changes of the exposed skin indicate substantial damage due to UV radiation. Many investigators believe that the principal manifestation of photodamage in Asians is pigmentary change rather than wrinkles. However, to our knowledge, no well-designed study has investigated the characteristics of cutaneous photodamage in Asian skin. OBJECTIVE: To access the severity of wrinkles and dyspigmentation in Koreans exposed to sun and who smoked. METHODS: We developed new photographic scales for grading wrinkles and dyspigmentation in 407 Koreans to assess the severity of the wrinkles and dyspigmentation. We interviewed subjects to determine cumulative sun exposure and smoking history, and measured the skin color of individual subjects. RESULTS: Our photographic scales provided a reliable evaluation of photodamage severity in Koreans. The pattern of wrinkling in both sexes is similar, but women tended to have more severe wrinkles (prevalence odds ratio, 3.7). However, the pattern of dyspigmentation differed between the sexes. Seborrheic keratosis is the major pigmentary lesion in men, whereas hyperpigmented macules are the prominent features in women. Cigarette smoking is an independent risk factor for wrinkles, but not for dyspigmentation, in Koreans, and causes additive detrimental effects to wrinkles induced by aging and sun exposure. The constitutive skin color did not show any correlation with wrinkles or dyspigmentation. However, facultative pigmentation (sun exposure index) may reflect lifetime sun exposure, and it shows a good correlation with wrinkles in Koreans. CONCLUSION: Wrinkling is a major feature of photoaging in Koreans, as are pigmentary changes; smoking, sun exposure, and female sex are independent risk factors for wrinkles.

Adult↗
PubMed2000

In vitro efficacy of recombinant diphtheria toxin-murine interleukin-4 immunoconjugate on mouse glioblastoma and neuroblastoma cell lines and the additive effect of radiation.

OBJECT: The prognosis for patients with primary malignant brain tumors is poor despite aggressive treatment, and tumor recurrence is common regardless of the chosen therapy. Although multimodal treatment does not provide a cure, it is necessary to determine which treatment modalities have the greatest cytotoxic effect and can potentially prolong survival. Immunotoxin therapy is a novel approach for the treatment of tumors, and it has been successfully used in the central nervous system. Because the interleukin (IL)-4 receptor is commonly expressed on brain tumor cells, the purpose of this study was to evaluate the cytotoxic effect of using a modified diphtheria toxin-murine IL-4 (DT390- mIL4) immunoconjugate for the treatment of murine brain tumor cell lines and to determine whether the addition of radiation therapy could potentiate the effect of this agent. METHODS: Spontaneous murine glioblastoma (SMA-560) and two neuroblastoma (Neuro-2a and NB41A3) cell lines were treated using DT390-mIL4 at different concentrations, and the anti-mouse IL-4 monoclonal antibody (11B11) was used for blocking its cytotoxicity. Other SMA-560 and Neuro-2a cell lines were treated using 500 cGy of radiation 3 hours before DT390-mIL4 treatment. Cytotoxity was evaluated using a trypan blue viability assay. The immunoconjugate exhibited a dose-dependent cytotoxic effect with 50% inhibitory concentration values of 0.56 x 10(-9) M in SMA-560, 1.28 x 10(-9) M in Neuro-2a, and 0.95 x (-10) M in NB41A3 cell lines. The cytotoxicity of DT390-mIL4 was specifically blocked by an excess of 11B11. Cytotoxicity was additive when the DT390-mIL4 at 10(-9) M immunoconjugate administration was followed by radiation therapy. CONCLUSIONS: These results indicate that the IL-4 receptor can be a target for diphtheria toxin fusion proteins and that radiation can potentiate the effects of DT390-mIL4. The development of multimodal approaches to treat malignant brain tumors with agents that have different mechanisms of action may be beneficial.

Animals↗
PubMed2000

A key point mutation (V156E) affects the structure and functions of human apolipoprotein A-I.

A naturally occurring point mutant of human apolipoprotein A-I (apoA-I), V156E, which is associated with extremely low plasma apoA-I and high density lipoprotein (HDL) levels, and coronary artery disease (Huang, W., Sasaki, J., Matsunaga, A., Nanimatsu, H., Moriyama, K., Han, H. Kugi, M., Koga, T., Yamaguchi, K., and Arakawa, K. (1998) Arterioscler. Throm. Vasc. Biol. 18, 389-396), was produced in an Escherichia coli expression system. The purified recombinant proapoA-I V156E mutant was examined in its structural and functional properties, both, in the lipid-free and lipid-bound states. In the lipid-free form the mutant protein exhibited small changes in conformation, but was more stable, and quite resistant to self-association, compared with control apoA-I. The V156E mutant was able to interact with phospholipid (PL) at high PL:protein ratios (95:1, mol/mol), but was inefficient in forming reconstituted HDL (rHDL) complexes at lower PL:protein ratios (40:1). In the lipid-bound, rHDL state, the mutant protein was somewhat more alpha-helical and formed a larger complex (110 A) than control apoA-I (97 A). Furthermore, the rHDL particles containing the V156E mutant did not rearrange to smaller particles in the presence of low density lipoproteins, and had minimal reactivity with lecithin-cholesterol acyltransferase (LCAT), compared with rHDL particles made with control apoA-I. These results suggest a key role for Val-156, or the adjacent central region of apoA-I in the modulation of apoA-I conformation, stability, and self-association in solution, and in the formation of small HDL, the conformational adaptability of apoA-I leading to structural rearrangements of HDL, and the activation of LCAT.

Apolipoprotein A-I↗
PubMed2000

Enzymatic and energetic properties of the aerobic respiratory chain-linked NADH oxidase system in the marine bacterium Pseudomonas nautica.

Membranes of Pseudomonas nautica, grown aerobically on a complex medium, oxidized both NADH and deamino-NADH as substrates. The activity of membrane-bound NADH oxidase was activated by monovalent cations including Na+, Li+, and K+. The activation by Na+ was higher than that by Li+ and K+. The maximum activity of NADH oxidase was obtained at about pH 9.0 in the presence of 0.08 M NaCl. The NADH oxidase activity was completely inhibited by 60 microM 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO), while the NADH:quinone oxidoreductase activity was about 37% inhibited by 60 microM HQNO. The activities of NADH oxidase and NADH:quinone oxidoreductase were about 40% inhibited by 60 microM rotenone. The fluorescence quenching technique revealed that electron transfer from NADH to ubiquinone-1 (Q-1) or oxygen generated a membrane potential (deltapsi) which was larger and more stable in the presence of Na+ than in the absence of Na+. However, the All was highly sensitive to a protonophore, carbonyl-cyanide m-chlorophenylhydrazone (CCCP) even at alkaline pH.

Bacterial Proteins↗
PubMed2000

The role of radiosurgery for multiple brain metastases.

OBJECT: The authors evaluated the role of stereotactic radiosurgery (SRS) in patients with multiple brain metastases by analyzing prognostic factors that predict survival. METHODS: Between March 1991 and January 1999, 83 patients with multiple brain metastases underwent SRS in which they used a 6 mV linear accelerator. The median radiation dose of 15 Gy (range 6-50 Gy) was delivered to the 40 to 90% (median 87%) isodose line encompassing the target. Actuarial overall survival was calculated from the date of SRS by using the Kaplan-Meier method. Univariate comparisons of survival between different groups were performed using a log-rank test. All 83 patients were included in the calculation of overall survival. Actuarial overall survival was 22% at 1 year and 13% at 2 years, and a median survival of 5.4 months (range, 0.3-28.8 months) was demonstrated. Variables that predicted survival were Karnofsky Performance Scale (KPS) score, extracranial disease status, and the number of intracranial metastases. Median survival in patients with a KPS score greater than as compared with less than 70 was 9.1 and 2.7 months, respectively (p = 0.002). Median survival when comparing absence and presence of extracranial disease was 9.9 and 4.1 months, respectively (p = 0.02). Median survival in patients harboring two, three, or four or more lesions was 6.6 months, 5.4 months, and 2.7 months, respectively (p = 0.02). In patients with a KPS score greater than or equal to 70 and with three or fewer lesions, median survival was 7 months or longer. In patients with four or more lesions median survival was 7.4 months for those with no extracranial disease and 2.4 months for those with extracranial disease. Other variables tested (sex, histological tumor type, previous resection, location of metastases, treatment modality, and tumor status) did not influence outcome. CONCLUSIONS: The absence of extracranial disease, a KPS score greater than or equal to 70, and fewer number of metastases were shown to be significant predictors of longer survival. Stereotactic radiosurgery appears to be a reasonable therapeutic option in patients with up to three lesions when their KPS score is greater than or equal to 70, regardless of extracranial disease status. In those with four or more metastases, however, SRS should be limited to those with no extracranial disease.

Adult↗
PubMed2000

Taurine intake and excretion in patients undergoing long term enteral nutrition.

The purpose of this study was to investigate whether serum concentration and urinary excretion of taurine are influenced by marginal taurine intake. Twenty one male patients (75 to 95 years old), suffering from coronary heart disease, multiple cerebral infarction, cancer, subdural hematoma or respiratory failure were grouped according to duration of tube feeding (group one, 5.9 +/- 2.9; group two, 14.8 +/- 2.3; group three 48.0 +/- 22.7, mean +/- SD, months). The mean intake of taurine was 347.0 +/- 25.6, 339.8 +/- 25.6 and 337.1 +/- 259 micromol/day (mean +/- SEM) in group one, two and three, respectively. The fasting serum taurine levels were 106.5 +/- 9.6, 95.0 +/- 9.9 and 56.8 +/- 11.0 micromol/L (mean +/- SEM) in group one, two and three, respectively. Taurine level in group three patients was significantly lower than that of group one and two (p<0.05). The twenty-four hour urinary taurine excretion was 776.1 +/- 176.7, 782.4 +/- 245.3 and 388.3 +/- 169.3 micromol/day (mean +/- SEM) in group one, two and three, respectively. These results suggest that marginal taurine intake in patients receiving long term tube feeding could result in taurine deficiency.

Aged↗
PubMed2000

Long-term survival with metastatic cancer to the brain.

Metastatic cancer to the brain has a poor prognosis. The focus of this work was to determine the incidence of long-term (> or = 2y) survival for patients with brain metastases from different primary cancers and to identify prognostic variables associated with prolonged survival. A retrospective review of 740 patients with brain metastases treated over a 20 y period identified 51 that survived 2 or more years from the time of diagnosis of the brain metastasis. Prognostic variables that were examined included age, sex, histology, tumor number and location, and treatment. In the 51 patients, 35 (69%) had single lesions and 16 (31%) had multiple tumors. For all tumor types (740 patients), the actuarial survival rate was 8.1% at 2 y, 4.8% at 3 y, and 2.4% at 5 y. At 2 y, patients with ovarian carcinoma had the highest survival rate (23.9%) and patients with small cell lung cancer (SCLC) had the lowest survival rate (1.7%). At 5y, survival rates were 7.8% for ovarian carcinoma, 2.9% for non-SCLC, 2.3% for melanoma and renal cell carcinoma, 1.3% for breast carcinoma and there were no survivors with SCLC, gastrointestinal, bladder, unknown primary, or prostate cancer. Age, sex, histology, location for single tumors, systemic chemotherapy, and stereotactic radiosurgery did not significantly influence survival. The presence of a single lesion (P = 0.001, chi-square test), surgical resection (P= 0.001), and WBRT (P = 0.009) were favorable prognostic variables for extended survival. Multiple bilateral metastases was a poor prognostic indicator (P= 0.001). Multivariate analysis showed younger age (P< 0.05), single metastasis (P < 0.0001), surgical resection (P < 0.0001), whole brain radiation therapy (P < 0.0001), and chemotherapy (P = 0.0288) were associated with prolonged survival. 29 patients (57%) died of systemic disease progression, 9 (18%) died of central nervous system progression, and the cause of death was unknown in 3 (6%). Patients with a single non-SCLC, breast, melanoma, renal cell, and ovarian carcinoma brain metastasis have the best chance for long-term survival if treated with surgical resection and WBRT.

Adult↗
PubMed2000

Zucchini green mottle mosaic virus is a new tobamovirus; comparison of its coat protein gene with that of kyuri green mottle mosaic virus.

A novel virus we call zucchini green mottle mosaic virus (ZGMMV) was isolated from zucchini squash and its properties were determined. The size and shape of its virions, and other properties suggest that the virus is a tobamovirus. The coat protein (CP) genes of ZGMMV and kyuri green mottle mosaic virus (KGMMV), which also infects zucchini squash plants, were cloned and their nucleotides sequences were determined. The CP genes of ZGMMV and KGMMV are composed of 161 amino acid residues, and they share 77.6% amino acid identity. Western blot analysis showed that the two viruses are serologically related but not identical. Comparison of the sequences with those of sixteen other tobamoviruses revealed that the two viruses had much higher identity to cucumber green mottle mosaic virus (CGMMV), another tobamovirus infectious to cucurbit plants, than other tobamoviruses. The nucleotide and amino acid sequences of ZGMMV were from 29.5 to 78.4% and from 29.3 to 77.6% identical, respectively, to those of other tobamoviruses. The predicted virion assembly origins of the two tobamoviruses were located in the CP region of the genomic RNAs, and the predicted secondary structures were more similar to that of CGMMV than those of other tobamoviruses. The seventeen tobamo-viruses could be classified into three main subgroups based on the phylogenetic tree analysis on the CP gene, and ZGMMV and KGMMV formed a third subgroup together with CGMMV and sunn-hemp mosaic virus (SHMV). These results show that ZGMMV is a previously unknown member of the Tobamovirus genus.

Base Sequence↗
PubMed2000

Nitric oxide production by high molecular weight water-soluble chitosan via nuclear factor-kappaB activation.

High molecular weight water-soluble chitosan (WSC), having an average molecular weight of 300000 Da and a degree of deacethylation over 90%, can be produced using a simple multi-step membrane separation process. In this study, the effect of WSC on the production of nitric oxide (NO) in RAW 264.7 macrophages was evaluated. Water-insoluble chitosan alone has been previously shown to exhibit in vitro stimulatory effect on macrophages NO production. However, WSC had no effect on NO production by itself. When WSC was used in combination with recombinant interferon-gamma (rIFN-gamma), there was a marked cooperative induction of NO synthesis in a dose-dependent manner. The optimal effect of WSC on NO synthesis was shown 24 h after treatment with rIFN-gamma. The increased production of NO from rIFN-gamma plus WSC-stimulated RAW 264.7 macrophages was decreased by the treatment with N(G)-monomethyl-L-arginine (N(G)MMA). The increase in NO synthesis was reflected, as an increased amounts of inducible NO synthase protein. In addition, synergy between rIFN-gamma and WSC was mainly dependent on WSC-induced tumor necrosis factor-alpha (TNF-alpha) and nuclear factor-kappaB (NF-kappaB) activation. The present results indicate that the capacity of WSC to increase NO production from rIFN-gamma-primed RAW 264.7 macrophages is the result of WSC-induced TNF-alpha secretion via the signal transduction pathway of NF-kappaB activation.

Animals↗
PubMed2000

Ultrasound of the adult hip.

The adult hip is a new and challenging site for evaluation with ultrasound (US). Clinically, diseases involving the hip region may be difficult to diagnose without the help of imaging. The hip region is a crossroad for numerous vascular, nervous, and muscular structures that pass between the trunk and the lower extremity. Thus, inflammatory processes and neoplasms may spread to and from the hip, buttock, thigh, pelvis, and retroperitoneum, and trauma may also effect the adjacent areas of the trunk and thigh. Because it is a crossroad, many conditions that are not specific to the hip occur in this area, including inguinal lymphadenopathy, pathology from the abdomen or the genitalia (intestinal hernia, inflammation, and infection), and even referred pain from spinal disorders. The goals of US imaging are the detection and localization of these pathological processes, the differentiation of intra-articular andextra-articular pathology, and the performance of diagnostic and therapeutic interventional procedures. This article reviews the hip anatomy, followed up by a discussion of the US evaluation and differential diagnosis of common pathology occurring in the hip area. This includes joint effusion, arthritis, loose bodies, bursitis, pseudoaneurysm, muscle and tendon diseases, as well as tumor and tumor-like lesions such as hematoma, abscess, and lymphadenopathy.

Abscess↗
PubMed2000

A new skin equivalent model: dermal substrate that combines de-epidermized dermis with fibroblast-populated collagen matrix.

Epidermis reconstructed on de-epidermized dermis (RE-DED) and on fibroblast-populated collagen matrix (Living Skin Equivalent) showed a histologic resemblance to native epidermis. However, some abnormalities have been found including different expression pattern of differentiation markers from native epidermis. In this study, to reconstruct an epidermis model resembling native epidermis more closely than previous skin equivalents, de-epidermized dermis (DED) was raised on fibroblast-populated collagen matrix and keratinocytes were cultured on top of the DED at the air-liquid interface. The new skin equivalent like RE-DED showed a similar morphology to that of native epidermis. Immunohistochemical studies revealed that differentiation markers such as involucrin, loricrin and filaggrin but not keratin 1 expressed similar pattern characteristics to native epidermis compared with those of RE-DED. In addition, the new model showed some fibroblasts in the DED as a result of migration from the fibroblast-populated collagen matrix, mimicking a living dermis in vivo. These results indicate that the new model seems to be a better skin equivalent model than previous models. Also, they provide additional evidence that the presence of fibroblasts improves epidermal differentiation.

Cells, Cultured↗
PubMed2000

Reconstruction of human hard-palate mucosal epithelium on de-epidermized dermis.

Artificial hard-palate mucosa equivalents were reconstructed using keratinocytes derived from normal human hard-palate and de-epidermized dermis. Reconstructed hard-palate mucosal epithelium formed in three-dimensional culture was compared to native hard-palate mucosal epithelium and reconstructed oral buccal mucosal epithelium with regard to keratin expression. Artificial hard-palate mucosal epithelium reconstructed in medium with delipidized serum showed a differentiation pattern similar to that of hard-palate epithelium in vivo. The present study also confirmed that keratinocytes derived from hard-palate mucosa are intrinsically different from those of nonkeratinizing oral surfaces.

Cell Communication↗