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Biomedical subjects

Y Kuroki

Publications and source records attributed to Y Kuroki.

At least 55 records · Page 3Linked to original sources
PubMed2000

Surfactant proteins A and D bind CD14 by different mechanisms.

Surfactant proteins A (SP-A) and D (SP-D) are lung collectins that are constituents of the innate immune system of the lung. Recent evidence (Sano, H., Sohma, H., Muta, T., Nomura, S., Voelker, D. R., and Kuroki, Y. (1999) J. Immunol. 163, 387-395) demonstrates that SP-A modulates lipopolysaccharide (LPS)-induced cellular responses by direct interaction with CD14. In this report we examined the structural elements of the lung collectins involved in CD14 recognition and the consequences for CD14/LPS interaction. Rat SP-A and SP-D bound CD14 in a concentration-dependent manner. Mannose and EDTA inhibited SP-D binding to CD14 but did not decrease SP-A binding. The SP-A binding to CD14 was completely blocked by a monoclonal antibody that binds to the SP-A neck domain but only partially blocked by an antibody that binds to the SP-A lectin domain. SP-A but not SP-D bound to deglycosylated CD14. SP-D decreased CD14 binding to both smooth and rough LPS, whereas SP-A enhanced CD14 binding to rough LPS and inhibited binding to smooth LPS. SP-A also altered the migration profile of LPS on a sucrose density gradient in the presence of CD14. From these results, we conclude that 1) lung collectins bind CD14, 2) the SP-A neck domain and SP-D lectin domain participate in CD14 binding, 3) SP-A recognizes a peptide component and SP-D recognizes a carbohydrate moiety of CD14, and 4) lung collectins alter LPS/CD14 interactions.

Animals↗
PubMed2000

De novo trisomy 16p11.2-qter: report of an infant.

We report on a four-month-old girl with a de novo trisomy 16q [47,XX, +del(16)(p11.2).ish del(16)(p11.2)(wcp16+,D16Z2+,tel16q+, tel16p-)]. She had minor facial anomalies, limb anomalies, urogenital abnormalities, and severe cardiovascular defects. Autopsy confirmed left hypoplastic lung, total anomalous pulmonary venous drainage via coronary sinus, persistent left superior vena cava, patent ductus arteriosus, secundum atrial septal defect, bilateral hydronephrosis and hydroureters, uterus bicornis, and ovarian hypoplasia. Short tandem repeat polymorphism analysis indicated that the additional, structurally abnormal chromosome 16 was maternal in origin.

Chromosomes, Human, Pair 16↗
PubMed2000

Aberrant expression of photoreceptor-specific calcium-binding protein (recoverin) in cancer cell lines.

Cancer-associated retinopathy (CAR) is an ocular manifestation of a paraneoplastic syndrome whereby immunological reactions to retinal antigens aberrantly expressed in tumor cells lead to the degeneration of retinal photoreceptor cells. In our previous study (H. Ohguro et al., Invest. Ophthalmol. Vis. Sci., 40: 82-89, 1999), recoverin, a retina-specific calcium-binding protein, and heat shock cognate protein 70 (hsc 70) were identified as autoantigens recognized by sera from patients with CAR. Therefore, we suggested that autoimmune reactions against both recoverin and hsc 70 might be involved in the pathogenesis of CAR. To elucidate the initial step of the molecular pathology of CAR, we examined the expression of recoverin and hsc 70 by reverse transcription-PCR and Western blot using cell lines of several kinds of cancers, including lung small cell carcinoma, lung adenocarcinoma, gastric cancer, pancreatic cancer, breast cancer, uterine cervical cancer, endometrial cancer, and leukemia. Recoverin was expressed in 21 of the 31 cancer cell lines. The expression levels of hsc 70 were significantly higher in cancer cell lines than in noncancerous cell lines. However, no difference in the expression levels of hsc 70 was observed between recoverin-positive and -negative cell lines. Immunofluorescence labeling by the affinity-purified recoverin antibody revealed the immunoreactivity to recoverin as a granular pattern within the cancer cells. Lung adenocarcinoma A549 cells, which did not express recoverin, exhibited a significant reduction in cell proliferation upon transfection with human recoverin cDNA. Taken together, our present data suggest that the retina-specific calcium-binding protein recoverin is expressed in more than 50% of a variety of cancer cells and may play a significant role in the cell proliferation of these tumor cells.

Antigens, Neoplasm↗
PubMed2000

Purification and characterization of bovine cone arrestin (cArr).

To elucidate the quenching mechanism of phototransduction in vertebrate cone photoreceptors, a cDNA clone encoding cone specific arrestin (cArr) was isolated from a bovine retinal cDNA library using a human cArr cDNA probe. Affinity-purified anti-peptide antibody specific to cArr was prepared. Immunohistochemical staining displayed specific labeling of cArr in cone photoreceptors and immunoblotting identified a 46 kDa protein band. We purified cArr from bovine retinas by sequential column chromatography using DEAE-cellulose, gel filtration and mono Q columns. Binding studies revealed no binding of cArr to rhodopsin regardless of whether it was bleached and/or phosphorylated. cArr also failed to bind to heparin-Sepharose under conditions which rod arrestin (rArr) bound to the column. The present data suggest that cArr may play a role in the quenching of phototransduction in cone photoreceptors and that its activity therein is different to that of rArr.

Amino Acid Sequence↗
PubMed2000

Importance of the carboxy-terminal 25 amino acid residues of lung collectins in interactions with lipids and alveolar type II cells.

Surfactant proteins A and D (SP-A and SP-D) are structurally related members of the collectin family found in the alveolar compartment of the lung. SP-A binds dipalmitoylphosphatidylcholine (DPPC) and galactosylceramide (GalCer), induces liposome aggregation, and regulates the uptake and secretion of surfactant lipids by alveolar type II cells in vitro. SP-D binds phosphatidylinositol (PI) and glucosylceramide. The purpose of this study was to identify a critical stretch of primary sequence in the SP-A region Cys(204)-Phe(228) and the SP-D region Cys(331)-Phe(355) that is involved in protein-specific lipid and type II cell interactions. Chimeras ad1 and ad2 were constructed with rat SP-A/SP-D splice junctions at Cys(218)/Gly(346) and Lys(203)/Cys(331), respectively. Chimera ad1 but not ad2 retained DPPC liposome binding activity. Both chimeras retained significant binding to GalCer liposomes. Chimera ad1 did not bind to PI, whereas chimera ad2 acquired a significant PI binding. Both chimeras failed to induce liposome aggregation and to interact with alveolar type II cells. In addition, monoclonal antibody 1D6 that blocks specific SP-A functions did not recognize either chimera. From these results, we conclude that (1) the SP-A region Leu(219)-Phe(228) is required for liposome aggregation and interaction with alveolar type II cells, (2) the SP-A region Cys(204)-Cys(218) is required for DPPC binding, (3) the SP-D region Cys(331)-Phe(355) is essential for minimal PI binding, and (4) the epitope for mAb 1D6 is located at the region contiguous to the SP-A region Leu(219)-Phe(228).

1,2-Dipalmitoylphosphatidylcholine↗
PubMed2000

Histological evaluation of allograft bone after acetabular revision arthroplasty: report of two cases.

We recently had the opportunity to take histological sections from two patients who underwent acetabular reconstruction in which allograft and ME Müller acetabular roof reinforcement rings were used. In one patient (case 1), histological sections of the chipped allograft were taken on two separate occasions from the same area, at 7 months, and at 3 years and 11 months after the bone graft. The histology of the chipped allograft showed necrosis at 7 months, but almost normal morphology of trabecular bone formation at 3 years and 11 months after the bone graft. In the other patient (case 2) histological sections of the block allograft and chipped allograft were taken at 1 year and 8 months after the bone graft. The block allograft showed only a small amount of admixture of newly formed bone with the necrotic bone, while the chipped allograft showed a large amount of newly formed bone, with only a small amount of necrotic bone remaining. Therefore, we principally use chipped allograft for acetabular reconstruction, in order to achieve early and complete graft incorporation. If a block allograft is used in a weight-bearing area, it should be protected from excessive load by using an acetabular reinforcement device.

Acetabulum↗
PubMed2000

Isolation of a thermophile degrading poly(butylene succinate-co-butylene adipate).

A thermophile, strain 73, which degrades poly(butylene succinate-co-butylene adipate) (PBSA) film was isolated from 95 soil samples obtained from different locations by cultivation using an enrichment culture technique at 60 degrees C. At this temperature, the strain grew on PBSA and the dissolved total organic carbon (TOC) concentration in the medium changed according to the growth stage, i.e., after the TOC concentration rapidly reached the minimum, it increased rapidly until it reached a peak and then decreased thereafter. During cultivation, PBSA was almost eliminated and the solution viscosity of the residual PBSA decreased markedly. Gel permeation chromatograms of the residual PBSA showed a significant decrease in the main peak and the appearance of a new peak at the low molecular weight region. The strain was identified as Bacillus stearothermophilus, which has an optimum growth temperature of approximately 63 degrees C.

Journal Article↗
PubMed2000

Differentiation and the polymorphic nature of the Y chromosomes revealed by repetitive sequences in the dioecious plant, Rumex acetosa.

The dioecious plant Rumex acetosa has a multiple sex chromosome system: females are 2n = XX + 12, males are 2n = XY1Y2 + 12, and the two Y chromosomes are heterochromatic. A DNA sequence abounded in the mare genome was isolated and analyzed. The sequence (RAE180) was a 180-bp-long tandemly arranged repetitive sequence, distributed in chromosomes Y1 and Y2, and two pairs of autosomes. Both Y chromosomes contained large amounts of RAE180 and the sequence formed many DAPI bands, while, on the two pairs of autosomes, RAE180 did not form DAPI bands. The internal structure and morphological changes of the Y chromosomes were analyzed by FISH, using RAE180 and the Y-chromosome-specific sequence RAYSI as probes. The pattern of the FISH signals caused by the accumulation of RAE180 and RAYSI suggested the structural change in the Y chromosomes during the process of sex chromosome evolution, and the morphological change in the Y chromosomes was explained by reciprocal translocation and inversion.

Chromosome Inversion↗
PubMed2000

Frontonasal dysplasia, macroblepharon, eyelid colobomas, ear anomalies, macrostomia, mental retardation, and CNS structural anomalies: another observation.

We report a Japanese girl with brachycephaly, a wide forehead, hypertelorism, macroblepharon with eyelid colobomas, ectropion, a broad nasal root, a depressed nasal tip, macrostomia, a small and grooved chin, ear anomalies, a structural anomaly of the corpus callosum, dilatation of the fourth ventricle, a urogenital sinus, and mental retardation. Cause and inheritance are unknown.

Abnormalities, Multiple↗
PubMed2000

Molecular cytogenetic analysis of supernumerary heterochromatic segments in Rumex acetosa.

The dioecious plant Rumex acetosa shows intraspecific karyotype variation, caused by supernumerary heterochromatic segments or DAPI (4',6-diamidino-2 phenylindole)-bands at the ends of the short arms of three pairs of autosomes. A DNA sequence (RAE730) specific to the supernumerary heterochromatic segments was cloned and sequenced. RAE730 was about 730 bp and AT-rich (71% AT-content). Using fluorescence in situ hybridization (FISH), RAE730 was localized in the supernumerary DAPI-positive heterochromatic segments on several mitotic chromosomes and chromocenters in interphase nuclei, but not in the DAPI-bands of Y or B chromosomes. RAE730 was tandemly arranged in the genome, and the copy number varied between plants from 40000 to 304000 copies per 2C, corresponding to the relative amount of supernumerary heterochromatic segments per genome. These results indicate that the karyotype variation caused by the supernumerary heterochromatic segment was generated by amplification or reduction of the tandem repeats of RAE730.

Base Sequence↗
PubMed2000

Serum levels of surfactant proteins A and D are useful biomarkers for interstitial lung disease in patients with progressive systemic sclerosis.

To find a less-invasive and lung-specific clinical biomarker, we measured serum levels of surfactant proteins A and D (SP-A and SP-D) by sandwich enzyme-linked immunosorbent assays in 42 patients with progressive systemic sclerosis (PSS) to evaluate their significance in relation to the presence of interstitial lung disease (ILD) and to assess their diagnostic merits. The patients were divided into two groups based on findings by chest computed tomography (CT): 30 patients with ILD (CT-positive ILD group), and 12 patients without any lung abnormalities (CT-negative ILD group). The CT-positive ILD group was further divided into two groups: 24 patients with ILD detectable by chest plain radiography (X-ray-positive ILD group) and six patients with ILD showing no abnormality (X-ray-negative ILD group). The levels of SP-A and SP-D in sera were significantly higher in the CT-positive ILD group than in the CT-negative ILD group. They were also significantly higher in the X-ray-positive ILD group than in the CT-negative ILD group. In the X-ray-negative ILD group, their levels were higher than those of the CT-negative ILD group. We next estimated sensitivity and specificity of SP-A, SP-D, and X-ray for detecting ILD on CT. Sensitivity of SP-D was high (77%) as well as that of X-ray (80%), whereas SP-A showed a low sensitivity (33%). Remarkably, five of six patients in the X-ray-negative ILD group showed SP-D concentrations over its cut-off level, thereby demonstrating that an SP-D assay contributes to the detection of ILD overlooked by X-ray. Moreover, a combination of X-ray and SP-D dramatically increases sensitivity to 97%. Specificity of SP-A, SP-D, and X-ray to the CT-negative ILD group was 100%, 83%, and 100%, respectively. In conclusion, this study indicates that elevated levels of serum SP-A and SP-D reflect well the presence of ILD and that the combination of SP-D and X-ray contributes to reduce the risk of clinicians overlooking ILD complicated by PSS, although a repetition in another set of subjects is needed to confirm these indications.

Adult↗
PubMed2000

Serum surfactant proteins A and D as prognostic factors in idiopathic pulmonary fibrosis and their relationship to disease extent.

Idiopathic pulmonary fibrosis (IPF) is a progressive, life-threatening, interstitial lung disease of unknown etiology. For optimal therapeutic management of IPF an accurate tool is required for discrimination between reversible and irreversible types of the disease. However, such noninvasive tools are few, and even with high-resolution computed tomography (HRCT), which is the most trusted method for doing so, the nature of the disease activity in IPF cannot always be accurately predicted. The aims of the present study were to assess the values of surfactant protein (SP)-A and SP-D in semiquantifying the extent of disease in IPF and in predicting deterioration in restrictive pulmonary function and survival over a follow-up period of 3-yr. SP-A and SP-D in sera were measured with enzyme-linked immunosorbent assays as previously described. Fifty-two IPF patients were studied to evaluate the association between serum SP-A and SP-D and disease extent on HRCT, deterioration in pulmonary function, and survival during 3 yr of follow-up. Both SP-A and SP-D concentrations were significantly correlated with the extent of alveolitis (a reversible change), whereas they did not correlate with the progression of fibrosis (an irreversible change). The SP-D concentration, unlike that of SP-A, was also related to the extent of parenchymal collapse and the rate of deterioration per year in pulmonary function. The concentrations of SP-A and SP-D in patients who died within 3 yr were significantly higher than in patients who were still alive after 3 yr. We propose that assays of SP-A and SP-D in sera from IPF patients are useful tools for understanding some pathologic characteristics of the disease, that SP-D may be a good predictive indicator of the rate of decline in pulmonary function, and that a combination of the assays for SP-A and SP-D may be helpful in predicting the outcome of patients with IPF.

Aged↗
PubMed2000

Effects of aging on surfactant forms in rats.

Surfactant present in the alveolar space exists in two major forms: functional large aggregate forms (LA) and nonfunctional small aggregate forms (SA), but there is no information about the changes of surfactant forms and the rate of conversion of LA to SA in the aged lungs. The purpose of the present study was to investigate the developmental aspects of surfactant forms in newborn, young, middle-aged and aged rats, LA and SA were recovered from alveolar lavages of rats. The rate of conversion from LA to SA was then analysed using a surface-area cycling technique. Age-related changes of saturated phosphatidylcholine (Sat-PC) and surfactant protein A (SP-A) pool sizes were also evaluated in alveolar lavages. The alveolar lavages recovered from aged rats contained a significantly higher proportion of LA than did those obtained from young or newborn rats. There was also an age-related decrease in the rate of conversion from LA to SA in vitro. The Sat-PC pool sizes in the alveolar lavages decreased with age, but the SP-A contents were similar between young and aged rats. These results suggested that decreased form conversion may contribute to maintaining functional surfactant pool sizes in the lungs of aged rats.

Aging↗
PubMed2000

Increased levels of surfactant protein A and D in bronchoalveolar lavage fluids in patients with bronchial asthma.

Surfactant proteins (SP)-A and SP-D are collagen-like glycoproteins belonging to the "collectin" class of C-type lectins, which are primarily synthesized in type II cells. Recent studies reported the possibility of local production of SP-A and SP-D in the airways, but the amounts of surfactant proteins in patients with bronchial asthma have not been studied. The composition of surfactant proteins in mild, stable asthmatics in the first lavage as bronchial lavage (BL) and the second and third lavages consecutively as alveolar lavages (AL) were therefore, analysed separately. The co-relationships in the BL between the amounts of surfactant proteins and those of fucose, which is one of the markers of submucosal secretion were also analysed. Increased amounts of SP-A in BL and AL of in asthmatics were found as compared with those in controls. A high concentration of SP-D in the AL asthma patients was also found. The levels of SP-A correlated with those of fucose in patients with bronchial asthma (r=0.849, p<0.01). The observations in the present study suggested that surfactant protein A may be secreted from the airways with allergic inflammation in a different manner from the alveoli. The increased levels of surfactant proteins A and D may play a protective role in an allergic inflammation in the pathogenesis of bronchial asthma.

Adult↗
PubMed1999

Apple-peel intestinal atresia associated with balanced reciprocal translocation t(2;3)(q31.3;p24.2) mat.

Apple peel intestinal atresia is an apple-peel-appearing bowel obstruction of unknown cause. We describe a Japanese girl with the apple-peel jejunal atresia associated with apparently balanced reciprocal translocation between chromosomes 2 and 3, t(2;3)(q31. 3;p24.2)mat. The translocation breakpoints in the patient may become candidate regions for the putative gene causing apple-peel atresia. Alternatively, the association of the two abnormalities in the patient is coincidental because her phenotypically normal mother had the same chromosome translocation.

Chromosome Banding↗
PubMed1999

Phosphorylation of extracellular signal-regulated kinases 1 and 2 in 3T3-L1 adipocytes by stimulation of beta(3)-adrenoceptor.

Recent studies have revealed that activated extracellular signal-regulated kinases (ERKs) 1 and 2 by the stimulation of beta(3)-adrenoceptors played a critical role in cell survival in brown adipocytes. On the other hand, phosphorylation of ERK1/2 via beta(3)-adrenoceptors and its physiological and pathological significance in white adipocyte has remained uncertain despite the increasing significance of functioning white adipocytes. Accordingly, we here studied phosphorylation of ERK1/2 caused by the stimulation of beta(3)-adrenoceptors in 3T3-L1 adipocytes, and the roles of phosphorylated ERK1/2 in lipolysis. Phosphorylation of ERK1/2 was induced by a selective beta(3)-adrenoceptor agonist, DL-4-[2'-¿2-hydroxy-2-(3-chlorophenyl)ethylamino¿propyl] phenoxyacetic acid sodium salt sesquihydrate (BRL37344), in 3T3-L1 adipocytes in a time- and dose-dependent manner. The phosphorylation of ERK1/2 by BRL37344 was sensitive to the cyclic AMP (cAMP)-dependent protein kinase inhibitor, N-[2-((p-bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide (H89). To elucidate the roles of phosphorylated ERK1/2 in lipolysis, the effect of a selective inhibitor of ERK1/2 phosphorylation, 2'-amino-3'-methoxyflavone (PD98059), was examined. This inhibitor did not alter the lipolytic action caused by BRL37344, even at concentrations sufficient to block phosphorylation of ERK1/2, suggesting that ERK1/2 play no role in the lipolysis caused by BRL37344 in 3T3-L1 adipocytes.

3T3 Cells↗