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Biomedical subjects

K Hayashi

Publications and source records attributed to K Hayashi.

At least 163 records · Page 9Linked to original sources
PubMed2001

Reduction of hematopoietic cell-specific tyrosine phosphatase SHP-1 gene expression in natural killer cell lymphoma and various types of lymphomas/leukemias : combination analysis with cDNA expression array and tissue microarray.

To investigate the lymphomagenesis of NK/T lymphoma, we comprehensively and systematically analyzed the expression pattern of the human NK/T cell line (NK-YS) genome by cDNA expression array and tissue microarray. We detected significant changes in the gene expression of NK-YS cell line: an increase in 18 and a decrease in 20 genes compared to normal NK cells or peripheral blood mononuclear cells. Among these genes, we found a strong decrease in hematopoietic cell specific protein-tyrosine-phosphatase SH-PTP1 (SHP1) mRNA by cDNA expression array and reverse transcriptase-polymerase chain reaction. Further analysis with standard immunohistochemistry and tissue microarray, which used 207 paraffin-embedded specimens of various kinds of malignant lymphomas, showed that 100% of NK/T lymphoma specimens and more than 95% of various types of malignant lymphoma were negative for SHP1 protein expression. On the other hand, SHP1 protein was strongly expressed in the mantle zone and interfollicular zone lymphocytes in reactive lymphoid hyperplasia specimens. In addition, various kinds of hematopoietic cell lines, particularly the highly aggressive lymphoma/leukemia lines, lacked SHP1 expression in vitro, suggesting that loss of SHP1 expression may be related to not only malignant transformation, but also tumor cell aggressiveness. SHP1 expression could not be induced in either of two NK/T cell lines by phorbol ester, suggesting that genetic impairment or modification with methylation of SHP1 DNA could be one of the critical events in the pathogenesis of NK/T lymphoma. This evidence strongly suggests that loss of SHP1 gene expression plays an important role in multistep tumorigenesis, possibly as an anti-oncogene in the wide range of lymphomas/leukemias as well as NK/T lymphomas.

DNA, Complementary↗
PubMed2001

An animal model for human EBV-associated hemophagocytic syndrome: herpesvirus papio frequently induces fatal lymphoproliferative disorders with hemophagocytic syndrome in rabbits.

Epstein-Barr virus-associated hemophagocytic syndrome (EBV-AHS) is often associated with fatal infectious mononucleosis. However, the animal model for EBV-AHS has not been developed. We reported the first animal model for EBV-AHS using rabbits infected with EBV-related herpesvirus of baboon (HVP). Eleven of 13 (85%) rabbits inoculated intravenously with HVP-producing cells developed fatal lymphoproliferative disorders (LPD) between 22 and 105 days after inoculation. LPD was also accompanied by hemophagocytic syndrome (HPS) in nine of these 11 rabbits. The peroral spray of cell-free HVP induced the virus infection with increased anti-EBV-viral capsid antigen-IgG titers in three of five rabbits, and two of these three infected rabbits died of LPD with HPS. Autopsy revealed hepatosplenomegaly and swollen lymph nodes. Atypical lymphoid T cells expressing EBV-encoded small RNA-1 infiltrated diffusely in many organs, frequently involving the lymph nodes, spleen, and liver. Hemophagocytic histiocytosis was observed in the lymph nodes, spleen, bone marrow, and thymus. HVP-DNA was detected in the tissues and peripheral blood from the infected rabbits by polymerase chain reaction or Southern blot analysis. Reverse transcriptase-polymerase chain reaction revealed both HVP-EBNA1 and HVP-EBNA2 transcripts, suggesting latency type III infection. These data indicate that the high rate of rabbit LPD with HPS induction is caused by HVP. This system is useful for studying the pathogenesis, prevention, and treatment of human EBV-AHS.

Animals↗
PubMed2001

Coronary atherosclerosis and oxidative stress as reflected by autoantibodies against oxidized low-density lipoprotein and oxysterols.

Clinical studies and animal experiments have demonstrated that oxidized low-density lipoprotein (oxLDL) and oxysterols play important roles in atherogenesis. OxLDL is immunogenic, and autoantibodies (Ab) against oxLDL are detectable in serum. We investigated the relevance of oxysterols and Ab against-oxLDL to coronary artery disease (CAD) in 183 patients undergoing coronary angiography. Patient groups included angiographically normal subjects (< 75% stenosis), others with spasm (> 75% narrowing in response to acetylcholine), and some others with fixed stenosis (> 75%). The group with stenosis was subdivided into patients with stable and unstable angina. Serum concentrations of autoantibodies and 25-, 27-, and 7-beta-hydroxycholesterols were significantly higher in the stenotic group than in the normal group (P < 0.01, P < 0.05, P < 0.05, and P < 0.05, respectively). Antibodies, but not oxysterol concentrations, were significantly greater in subjects with unstable than with stable angina (P < 0.01). We conclude that anti-oxLDL antibody and oxysterol concentrations are associated with coronary artery stenosis, and that oxidative stress may be greatly increased in unstable angina.

Adult↗
PubMed2001

Correlation between pupillary size and intraocular lens decentration and visual acuity of a zonal-progressive multifocal lens and a monofocal lens.

OBJECTIVE: To see whether there is a correlation between pupillary area or intraocular lens (IOL) decentration and tilt and the visual acuity (VA) at all distances for eyes with a zonal-progressive multifocal IOL or a monofocal IOL. DESIGN: Comparative, nonrandomized, interventional study. PARTICIPANTS: Fifty-five eyes of 55 patients undergoing five-zone refractive multifocal IOL implantation and 55 eyes of 55 age-matched patients undergoing monofocal IOL implantation. INTERVENTION: All eyes underwent phacoemulsification and IOL implantation. MAIN OUTCOME MEASURES: The VAs from far to near distances were examined using an all-distance vision tester at 1 month after surgery. The pupillary area was also measured using an infrared pupillometer, and the degrees of IOL decentration and tilt were measured using a Scheimpflug videophotography system. Univariate associations between VA and the pupillary area and IOL decentration or tilt were evaluated statistically. RESULTS: The mean intermediate VAs and contrast sensitivities at all spatial frequencies in the multifocal IOL group were worse than those in the monofocal IOL group, whereas near VA was better in the multifocal group. In the multifocal group, smaller pupillary area was associated significantly with worse near logarithm of the minimum angle of resolution (LogMAR) VA (r = 0.636), but not with far or intermediate VAs. When pupil diameter was 4.5 mm or greater, near mean VA reached 20/63. A greater degree of IOL decentration was associated significantly with worse far and intermediate LogMAR VAs (r = 0.460 at 5.0 m and 0.527 at 1.0 m) but not with near VA. When decentration was 0.9 mm or greater, distance mean VA did not reach 20/32. However, the correlation between tilt and VA was not statistically significant. In the monofocal group, no significant correlation was found between pupillary area, IOL decentration, or tilt and the VA. CONCLUSIONS: Smaller pupil size is correlated significantly with worse near VA, whereas greater decentration is correlated with worse distance and intermediate VA in eyes with refractive multifocal IOLs. Specifically, a pupil diameter of less than 4.5 mm cannot provide useful near VA, and decentration of 0.9 mm is the maximum allowable limit for adequate distance VA. However, pupil size and IOL decentration do not influence VA in eyes with monofocal IOLs.

Adult↗
PubMed2001

Enhancement of glomerular heme oxygenase-1 expression in diabetic rats.

An increase in oxidative stress in diabetic subjects is implicated to play a pivotal role in diabetic vascular complications. In response to oxidative stress, antioxidant enzymes are considered to be induced and protect cellular functions to keep in vivo homeostasis. However, it remains to be clarified whether antioxidant enzymes are induced against oxidative stress especially in renal glomeruli at an early stage of diabetes. To answer this question, we examined the gene expression of a variety of antioxidant enzymes in glomeruli isolated from streptozotocin-induced diabetic rats. The mRNA expression of antioxidant enzymes such as catalase, glutathione peroxidase, and CuZn-superoxide dismutase, was unaltered in glomeruli of diabetic rats and was comparable to control rats. In contrast, the mRNA expression of heme oxygenase-1 (HO-1) was enhanced in glomeruli of diabetic rats as compared with control rats. A treatment with insulin as well as with vitamin E (40 mg/kg body weight every other day, intra-peritoneal injection) normalized the mRNA expression of HO-1 in the glomeruli of diabetic rats. Immunohistochemical analysis revealed that the up-regulated expression of HO-1 protein was localized in glomerular cells of diabetic rats. In conclusion, these results provide the first evidence that among antioxidant enzymes HO-1 expression is preferentially increased in diabetic glomeruli.

Animals↗
PubMed2001

Prognostic significance of thrombomodulin expression and vascular invasion in stage I squamous cell carcinoma of the lung.

Thrombomodulin (TM) is an important modulator of intravascular coagulation. TM exists on endothelial cells and on several types of tumor cells, especially squamous cell carcinoma cells. Tumor cell TM is thought to be associated with progression and metastasis of the tumor. To evaluate the prognostic significance of TM in lung cancer, we examined TM expression and vascular invasion in surgical specimens obtained from 90 patients with completely resected stage I non-small cell lung cancer (NSCLC). In addition, we correlate these pathologic data to other clinicopathologic data, including the outcome of the patients. Squamous cell carcinomas had a significantly higher incidence (P<0.0001) of TM expression (22/36 cases, 61%) than adenocarcinomas (9/54 cases, 17%). In 36 squamous cell carcinoma patients, both vascular invasion (P=0.0153; risk ratio 6.507) and TM non-expression (P=0.0282; risk ratio 3.584) were significant for a poor prognosis. Univariate analysis of patient survival rates also revealed that vascular invasion and TM expression were significant prognostic factors (P=0.0036 and 0.012, respectively). Further, combination analysis of vascular invasion and TM expression in the squamous cell carcinoma patients showed that the 5-year survival rate was 90% in patients with TM expression and without vascular invasion, but 21% in patients with vascular invasion and without TM expression (P=0.0004). Since our results suggest that vascular invasion and TM expression are independent prognostic factors of stage I squamous cell carcinoma of the lung, and since the two factors play different roles in the metastatic process of cancers (promotion of metastasis by vascular invasion and inhibition of metastasis by TM expression), the combination evaluation of vascular invasion and TM expression may be very significant in evaluating the prognosis of patients with completely resected stage I squamous cell carcinoma.

Adult↗
PubMed2001

Disappearance of clonally expanded T cells after allogeneic leukocyte immunotherapy in peripheral blood of patients with habitual abortion.

Allogeneic leukocyte immunotherapy is often used to improve fertility of patients with habitual abortion (HA), which probably acts through immune-mediated mechanisms. However, the involvement of T cells is not clear. This study examined the effect of allogeneic immunotherapy on T cells of patients with HA. Peripheral blood mononuclear cells were obtained from 5 healthy women and 14 women with HA. RNA was isolated from mononuclear blood cells. Reverse transcription-polymerase chain reaction (RT-PCR), followed by single-strand conformational polymorphism (SSCP) were used to analyze the gene segments of T-cell receptor beta chain (TCRbetaV) variable regions. Oligoclonal accumulation of T cells was identified in peripheral blood of nonpregnant patients with a history of HA. It was also revealed, however, that immunostimulation reduced the number of accumulating T-cell clones (p = 0.0004). The results, together with the clinical effectiveness of immunotherapy, suggest that accumulation of T-cell clonotypes, which probably resulted from antigenic stimulation, is involved in the pathogenesis of HA.

Abortion, Habitual↗
PubMed2001

Acquired epileptiform opercular syndrome: a case report and results of single photon emission computed tomography and computer-assisted electroencephalographic analysis.

We report here a girl aged 5 years 3 months with cryptogenic localization-related epilepsy who showed a prolonged episode characterized by dysarthria, dysphagia, drooling and paresis of the right arm associated with almost continuous diffuse sharp-slow wave complexes during sleep. These symptoms were not directly related to seizures or to each sharp-slow wave complex revealed by examination during the video electroencephalographic (EEG) recording. The interictal single photon emission compute tomography showed a localized high perfusion area in the left posterior frontal region. The introduction of clonazepam completely controlled the clinical symptoms as well as the EEG abnormality within 2 weeks. After 4 months of remission, a similar episode recurred which was associated with aggravation of EEG. The clinical and EEG characteristics of this patient were identical to those of acquired epileptiform opercular syndrome (AEOS), a newly proposed epileptic syndrome, in which a transient operculum syndrome develops in association with continuous spike-and-wave activity during slow sleep (CSWS). Computer-assisted EEG analysis demonstrated that the epileptic EEG focus was located in the left sylvian fissure, and produced secondary bilateral synchronous sharp-slow complexes. The present study further supports the hypothesis that the electrical interference by CSWS creates bilateral opercular dysfunction through the mechanism of secondary bilateral synchrony, thus producing AEOS.

Child, Preschool↗
PubMed2001

Severe myoclonic epilepsy in infants--a review based on the Tokyo Women's Medical University series of 84 cases.

Severe myoclonic epilepsy in infants (SME) is one of the most malignant epileptic syndromes recognized in the latest classification of epileptic syndromes. The clinical details and electroencephalographic (EEG) characteristics have been elucidated by Dravet et al. The diagnosis of SME depends largely on the combination of clinical and EEG manifestations at different ages, of which the presence of myoclonic seizures appears to be the most important. However, because of the inclusion of different types of myoclonic attack and the lack of strict criteria for diagnosing SME, there has been some confusion as to whether patients without myoclonic seizures or myoclonus should be classified as SME, despite other identical clinical symptoms (SME borderlands (SMEB) group). Among the various clinical manifestations characterizing SME, special attention has been paid to seizures easily precipitated by fever and hot baths in Japan. We have demonstrated that the onset of myoclonic attack in these patients is very sensitive to the elevation of body temperature itself rather than its etiology. Using simultaneous EEG and rectal temperature monitoring during hot water immersion, we showed that epileptic discharges increased in frequency, and eventually developed into seizures at temperatures over 38 degrees C. We believe that the unique fever sensitivity observed in SME is similar to, but more intense than that of febrile convulsions. We have also identified a group of cases who have had innumerous myoclonic and atypical absence seizures daily which were sensitive to the constant bright light illumination. In these cases, spike discharges increased or decreased depending on the intensity of constant light illumination. Although these cases form the most resistant SME group, they lost the constant light sensitivity with increasing age, leaving only relatively common types of fever-sensitive grand mal seizures (FSGM) at the age of around 5 years. In the long run, only convulsive seizures continue, while myoclonic or absence seizures and photosensitivity disappear with advancing age, thus it is conceivable that SMEB constitutes a basic epileptic condition underlying SME. There is a clinical continuum that extends from the mildest end of SMEB to the severest end of SME with constant light sensitivity, with intermediates of frequent or infrequent myoclonic and absence seizures in-between. This spectrum concept appropriately explains the clinical variabilities between SME and SMEB during early childhood.

Electroencephalography↗
PubMed2001

Myoclonic-astatic epilepsy of early childhood--clinical and EEG analysis of myoclonic-astatic seizures, and discussions on the nosology of the syndrome.

PURPOSE: The aim of this study is to elucidate the clinical and neurophysiological characteristics of the myoclonic, myoclonic-astatic, or astatic seizures in patients with myoclonic-astatic epilepsy (MAE) of early childhood, and to discuss on the nosology of this unique epileptic syndrome. SUBJECTS: The subjects included 30 patients, who fulfilled the following modified International League Against Epilepsy (ILAE) criteria for MAE, and whose main seizures were captured by video-electroencephalographs (EEG) or polygraphs. The modified ILAE criteria includes: (1) normal development before onset of epilepsy and absence of organic cerebral abnormalities; (2) onset of myoclonic, myoclonic-astatic or astatic seizures between 7 months and 6 years of age; (3) presence of generalized spike- or polyspike-wave EEG discharges at 2-3 Hz, without focal spike discharges; and (4) exclusion of severe and benign myoclonic epilepsy (SME, BME) in infants and cryptogenic Lennox-Gastaut syndrome based on the ILAE definitions. RESULTS: The seizures were investigated precisely by video-EEG (n=5), polygraph (n=2), and video-polygraph (n=23), which identified myoclonic seizures in 16 cases (myoclonic group), atonic seizures, with or without preceding minor myoclonus, in 11 cases (atonic group), and myoclonic-atonic seizures in three cases. All patients had a history of drop attacks, apart from ten patients with myoclonic seizures. Myoclonic seizures, involving mainly the axial muscles were classified into those with mild intensity not sufficient to cause the patients to fall (n=10) and those that are stronger and sufficient to cause astatic falling due to flexion of the waist or extension of the trunk (n=6). Patients in the atonic group fell straight downward, landed on their buttocks, and recovered immediately. Analysis of the ictal EEGs showed that all attacks corresponded to the generalized spike or polyspikes-and-wave complexes. In the atonic form, the spike-and-wave morphology was characterized by a positive-negative-deep-positive wave followed by a large negative slow wave. In two patients, the intensity of the atonia appeared to correspond to the depth of the positive component of the spike-and-wave complexes. We did not detect any significant differences in the clinical and EEG features and prognosis, between the atonic and myoclonic groups. CONCLUSIONS: Although the determination of exact seizure type is a prerequisite for diagnosing an epileptic syndrome, the strict differentiation of seizure type into either a myoclonic or atonic form, does not appear to have a significant impact on the outcome or in delineating this unique epileptic syndrome. At present, we consider it better to follow the current International Classification of Epileptic Syndromes and Epilepsies until a more appropriate system than the clinico-electrical approach for classifying patients with MAE is available.

Child, Preschool↗
PubMed2001

Debittering of protein hydrolyzates.

Enzymatic hydrolysis of proteins frequently results in bitter taste, which is due to the formation of low molecular weight peptides composed of mainly hydrophobic amino acids. Methods for debittering of protein hydrolyzates include selective separation such as treatment with activated carbon, extraction with alcohol, isoelectric precipitation, chromatography on silica gel, hydrophobic interaction chromatography, and masking of bitter taste. Bio-based methods include further hydrolysis of bitter peptides with enzymes such as aminopeptidase, alkaline/neutral protease and carboxypeptidase, condensation reactions of bitter peptides using protease, and use of Lactobacillus as a debittering starter adjunct. The causes for the production of bitter peptides in various food protein hydrolyzates and the development of methods for the prevention, reduction, and elimination of bitterness as well as masking of bitter taste in enzymatic protein hydrolyzates are presented.

Journal Article↗
PubMed2001

Histomorphometric description of allograft bone remodeling and union in a canine segmental femoral defect model: a comparison of rhBMP-2, cancellous bone graft, and absorbable collagen sponge.

The purpose of this study was to determine the effect of recombinant human bone morphogenetic protein type 2 (rhBMP-2) on the histomorphometry of femoral allograft-host bone union and allograft remodeling. A 6 cm mid-diaphyseal femoral defect was created and filled with an allograft stabilized with an interlocking nail in 21 dogs. Dogs were randomly divided into three equal groups and the allograft-host bone junctions and the mid-diaphyses of the allografts were treated with either an absorbable collagen sponge (ACS) loaded with rhBMP-2 (BMP group), an autogenous cancellous bone graft (CBG group), or ACS loaded with buffer solution (ACS group). All dogs received daily tetracycline until sacrifice at 24 weeks to label new bone formation. Histomorphometric analyses on sections of proximal and distal allograft-host bone junctions and the mid-diaphyseal portion of allografts were performed using fluorescent and regular light microscopy. Analyses of the host bone and junctions between allograft and host bone revealed significantly greater new bone formation and larger osteon radii in the BMP group compared to CBG and ACS groups and contralateral intact bone. Porosity in CBG and ACS groups was significantly higher than in the BMP group, which had similar values to intact bone. In transverse sections of allografts, the largest pore diameters were present in the CBG group. Based on all parameters measured, significantly higher bone turnover occurred in the outer cortical area of the allograft in all groups as compared to the inner cortical and mid-cortical areas. New bone formation and osteon radius/osteon width in allografts were similar for all three groups. Higher porosity and larger pore diameters in the CBG and ACS groups suggested higher bone resorption versus formation in these groups compared to the BMP group. The results of this study reveal more balanced allograft bone resorption and bone formation in the BMP group, with greater resorptive activity in the CBG and ACS groups. However, neither rhBMP-2 nor autogenous bone graft increased allograft incorporation when compared to the negative control (ACS group).

Absorbable Implants↗
PubMed2001

Changes in posterior capsule opacification after poly(methyl methacrylate), silicone, and acrylic intraocular lens implantation.

PURPOSE: To prospectively evaluate the progression of posterior capsule opacification (PCO) after poly(methyl methacrylate) (PMMA), silicone, and acrylic intraocular lens (IOL) implantation. SETTING: Hayashi Eye Hospital, Fukuoka, Japan. METHODS: Three hundred eyes of 300 patients scheduled to have IOL implantation were initially randomized into 3 groups based on IOL type: PMMA, silicone, or acrylic. Of the 300 eyes, 269 completed the follow-up. The PCO density in these eyes was measured 1 week and 3, 6, 12, 18, and 24 months postoperatively using special computer software developed for the Scheimpflug videophotography system. Visual acuity and the incidence of neodymium:YAG (Nd:YAG) laser capsulotomy were also examined. RESULTS: Three months postoperatively and later, the mean PCO value in the PMMA group increased significantly (P <.0001); the increase in the silicone and acrylic groups was not significant. The PCO value in the PMMA group was significantly greater than in the silicone or acrylic group (P <.0001). The PCO value in the acrylic group was slightly less than in the silicone group at 18 and 24 months, but the difference was marginal. The survival rate not requiring Nd:YAG capsulotomy was least in the PMMA group, followed by the silicone and acrylic groups in that order (P <.0001). The mean logMAR visual acuity in the PMMA group increased postoperatively and was worse than in the silicone or acrylic group. CONCLUSIONS: The degree of PCO after PMMA IOL implantation progressed significantly with time, while the progression after silicone and acrylic IOL implantation was slight. Therefore, PCO in eyes with a PMMA IOL was significantly more extensive than in those with a silicone or acrylic IOL and resulted in marked impairment of visual acuity.

Acrylic Resins↗
PubMed2001

Effect of cataract surgery on intraocular pressure control in glaucoma patients.

PURPOSE: To examine the effect of cataract surgery on intraocular pressure (IOP) control in eyes with angle-closure glaucoma (ACG) and open-angle glaucoma (OAG). SETTING: Hayashi Eye Hospital, Fukuoka, Japan. METHODS: This study included 74 eyes with ACG and 68 eyes with OAG having cataract surgery. The IOP was measured and the number of glaucoma medications recorded preoperatively, 1 month postoperatively, and then every 3 months. The IOP control in the 2 groups was compared using survival analysis, with failure criteria being an IOP greater than 21 mm Hg, addition of medications, or the need for additional glaucoma surgery. RESULTS: The mean IOP and number of medications decreased significantly after surgery in both groups (P <.0001). However, the mean decrease in IOP and percentage of IOP reduction in the ACG group were greater than in the OAG group, and fewer medications were required in the ACG group. The cumulative survival probability of IOP control at 24 months was 91.9% in the ACG group and 72.1% in the OAG group. The survival curve in the ACG group was significantly better than in the OAG group (P =.0012). The IOP was controlled without medication in 30 eyes (40.5%) in the ACG group and 13 (19.1%) in the OAG group; the difference between groups was significant (P =.0055). CONCLUSIONS: Cataract surgery substantially reduced IOP and the number of medications required for IOP control in glaucomatous eyes. Specifically, cataract extraction normalized the IOP in most eyes with ACG.

Aged↗
PubMed2001

Study on early-onset benign occipital seizure susceptibility syndrome.

We prospectively studied the early-onset benign occipital seizure susceptibility syndrome to confirm the benign prognosis. The patients were 37 children followed for more than 2 years after meeting the following criteria on the first examination: (1) normal development before the onset of epilepsy, (2) onset between 1 and 8 years of age, (3) normal brain MRI and cranial CT findings, (4) partial seizures manifested both initial ictal vomiting and tonic eye-deviations, and (5) normal background activity with or without epileptic EEG foci regardless of location. The incidence and clinical characteristics of seizures, response to treatment, and EEG findings were analyzed. The total number of seizures ranged from one (n = 6) to 27 times, with a median of five times. Recurrent prolonged attacks resistant to antiepileptic drugs were recognized in 15 children, who had earlier onset of epilepsy and more frequent complications than the remaining 22 children. Interictal EEG revealed occipital foci in 26 children, 17 of whom later revealed a shift in predominant foci. At the final examinations, 28 patients had been seizure-free for at least 2 years. The clinical picture of this syndrome ranges from those with a few seizures to those with recurrent prolonged seizures initially resistant to antiepileptic drugs despite ultimate remission by 12 years of age.

Age Factors↗
PubMed2001

Evaluation of mite allergen-induced Th1 and Th2 cytokine secretion of peripheral blood mononuclear cells from atopic dermatitis patients: association between IL-13 and mite-specific IgE levels.

There have been several reports about Th1/Th2 imbalances in atopic dermatitis (AD), but there have been few precise investigations about the differences between Th1 and Th2 cytokine secretion patterns of peripheral blood mononuclear cells (PBMCs) in such patients. We cultured PBMCs, taken from AD patients and healthy subjects, with dust mite extract (DME) and measured subsequent immunoreactive interferon (IFN)-gamma (Th1 cytokine), interleukin (IL)-4, IL-5, and IL-13 (Th2 cytokines) levels in the supernatants by ELISA assays. There is a difference between IL-4 and IL-13 secretion patterns by DME-stimulated PBMCs in AD subjects; immunoreactive IL-4 levels were detectable maximally within 24-h cultures, while IL-13 levels increased time-dependently within 7-day cultures. IL-13 levels were significantly elevated in AD subjects compared to healthy subjects, while IFN-gamma levels did not significantly differ between the two groups. IL-13 levels were significantly higher in AD patients who had high levels (>100 U/ml) of Dermatophagoides pteronyssinus-specific IgE (Dp-IgE) than in those AD patients who had low levels (<10 U/ml) of Dp-IgE. Tacrolimus (FK-506), at a concentration of 10(-8) M, significantly inhibited DME-induced IL-13 production from PBMCs. These findings suggest that IL-13 produced by Th2 cells are involved in IgE overproduction in AD subjects.

Adult↗
PubMed2001

Bacterial expression and characterization of starfish phospholipase A(2).

Phospholipase A(2) (PLA(2)) from the pyloric ceca of the starfish Asterina pectinifera showed high specific activity and characteristic substrate specificity, compared with commercially available PLA(2) from porcine pancreas. To investigate enzymatic properties of the starfish PLA(2) in further detail, we constructed a bacterial expression system for the enzyme. The starfish PLA(2) cDNA isolated previously (Kishimura et al., 2000b. cDNA cloning and sequencing of phospholipase A(2) from the pyloric ceca of the starfish Asterina pectinifera. Comp. Biochem. Physiol. 126B, 579-586) was inserted into the expression plasmid pET-16b and the PLA(2) protein was expressed in Escherichia coli BL21 (DE3) by induction with isopropyl-beta-D(-)-thiogalactopyranoside. The recombinant PLA(2) produced as inclusion bodies was dissociated with 8 M urea and 10 mM 2-mercaptoethanol and renatured by dialyzing against 10 mM Tris--HCl buffer (pH 8.0). Renatured PLA(2) was purified by subsequent column chromatographies on DEAE--cellulose (DE-52) and Sephadex G-50. Although an N-terminal Ser in the native starfish PLA(2) was replaced by an Ala in the recombinant PLA(2), the recombinant enzyme showed essentially the same properties as did the native PLA(2) with respect to specific activity, substrate specificity, optimum pH and temperature, and Ca(2+) requirement.

Animals↗