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Biomedical subjects

M Sakata

Publications and source records attributed to M Sakata.

At least 109 records · Page 6Linked to original sources
PubMed1996

Increase in corneal epithelial cell size with extended wear soft contact lenses depends on continuous wearing time.

AIM: Although 1 week of continuous wearing time (CWT) is recommended for extended wear soft contact lenses (EWSCL), there have been few studies concerning the appropriateness of this or other CWTs. The current study was undertaken to examine the effect of various CWTs on the cornea by observing the corneal epithelium. METHODS: Specular microscopy was used to evaluate corneal epithelial changes induced by EWSCL in 19 myopic patients (24.0 (SD 6.7) years), divided into four groups: CWT of 0, 1, 3, and 6 days. RESULTS: The initial mean cell area was 628.2 (13.4) micron2. After 6 months this was 629.3 (28.6) micron2 for daily wear (ns), and 660.0 (40.9) micron2, 727.7 (49.6) micron2 (p < 0.01), and 815.5 (67.2) micron2 (p < 0.01) for CWT of 1, 3, and 6 days, respectively (p < 0.01). CONCLUSION: These findings indicate that the corneal epithelium changes proportionally with the CWT; the shorter the CWT, the better the epithelial morphology. This suggests that the CWT for EWSCL be minimised, so as to reduce the potential risk of contact lens related problems.

Adult↗
PubMed1996

Effects of zinc and copper on uptake of cadmium by LLC-PK1 cells.

Effects of zinc (Zn) and copper (Cu) on cadmium (Cd) accumulation were investigated in LLC-PK1 cells. Coincubation with Zn or Cu decreased Cd uptake by the cells in a concentration-dependent manner. Cd accumulation data suggested that Cd is taken up by the cells via simple diffusion and carrier-mediated transport. Zn and Cu significantly increased the Km of Cd uptake with no or little effect on the Vmax. Pretreatment of the cells with ouabain and a metabolic inhibitor (FCCP) significantly decreased Cd accumulation, and coincubation with Zn or Cu led to an additional decrease in Cd accumulation by these cells. Overall, it seems that, in addition to simple diffusion, Cd is also taken up by LLC-PK1 cells via carrier-mediated mechanisms that are competitively inhibited by Zn and Cu.

Animals↗
PubMed1996

Partially-hydrophobized polymer particles derived from N,N-dimethylaminopropylacrylamide for endotoxin removal from acidic protein solution.

Novel copolymeric adsorbents for the selective removal of endotoxin from an acidic protein solution were prepared. The adsorbents comprise spherical copolymers derived from N,N-dimethylaminopropylacrylamide (DMAPAA) and divinylbenzene (DVB). When the molar ratio of DMAPAA to DVB was 80/20 (amino-group content: 5.1 meq/g) and the pore size (molecular mass exclusion of polysaccharide, Mlim) was 4000 to 10000, DMAPAA/DVB showed high endotoxin-adsorbing activity at pH 5.0 to 9.0 and ionic strengths of mu = 0.05 to 0.4. The capacity of the adsorbent (Mlim: 4000) was 390 micrograms of endotoxin (lipopolysaccharide purified from E. coli O111:B4) per ml of the adsorbent using the batchwise method. The apparent dissociation constant between endotoxin and the adsorbent was 2.2 x 10(-12) M. On the other hand, the adsorption of bovine serum albumin, an acidic protein, by the adsorbent increased with an increase in Mlim from 4000 to 10000, but decreased with an increase in ionic strength (mu) from 0.05 to 0.2. As a result, DMAPAA/DVB (80/20) (Mlim: 4000) selectively removed endotoxin from various acidic protein solutions at pH 7.0 and mu = 0.05. The residual concentration of endotoxin in the protein solution always decreased to a concentration lower than 0.1 ng/ml, and recovery of the protein was more than 97%.

Acrylamides↗
PubMed1996

[The transport of enoxacin in cultured kidney epithelial cells LLC-PK1].

In this study, the transport of enoxacin (ENX) was investigated in a LLC-PK1 kidney epithelial cell line. The uptake of ENX by LLC-PK1 monolayers cultured in plastic dishes was shown to be temperature-dependent and concentration-dependent. Cimetidine and guanidine inhibited the uptake of ENX, whereas TEA and NMN did not. The basolateral to apical flux of ENX across LLC-PK1 monolayers cultured on permeable supports was about two times larger than the apical to basolateral flux. The basolateral to apical flux of ENX was remarkably inhibited by guanidine, whereas it was not inhibited by TEA, NMN and cimetidine. The apical to basolateral flux of ENX was inhibited by cimetidine and guanidine, whereas it was not inhibited by TEA and NMN.

Animals↗
PubMed1996

8-Bromo-cAMP inhibits glucose transport activity in mouse placental cells in culture.

Glucose plays an important role in fetal development and energy metabolism. Facilitative glucose transporter-1 (GLUT1) has been found in placenta. However, little is known about GLUT1 modulation in placental cells. To examine changes in mouse placental GLUT1 levels caused by 8-bromo-cAMP, we performed 2-deoxyglucose uptake experiments, Northern blot analysis and immunoblot analysis using a primary mouse placental cell culture. Immunohistochemical analysis showed that GLUT1 was localized to the ectoplacental cone and the labyrinth zone of mouse placentas on days 7 and 11 of pregnancy respectively. Treatment of mouse placental cells with 250 mumol/l 8-bromo-cAMP resulted in a significant (P < 0.01) decrease in glucose uptake on days 2-5 of culture. The inhibitory effect of 8-bromo-cAMP on glucose uptake was concentration-dependent. Glucose uptake was also inhibited by 100 micrograms/l cholera toxin and by 0.1 mmol/l forskolin. Northern blot and immunoblot analysis revealed that both GLUT1 mRNA and protein levels were also decreased by 8-bromo-cAMP. These findings suggest that 8-bromo-cAMP inhibits glucose transport activity in mouse placental cells in culture.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1996

Monoclonal antibodies (NU-T1 and NU-T2) recognizing antigens expressed on human T cells.

Two murine monoclonal antibodies (mAb) designated as NU-T1 and NU-T2 were generated to identify the novel antigens expressed on human T cells. NU-T1 reacted with peripheral blood T cells, but not with granulocytes or monocytes, whereas NU-T2 were not reactive with peripheral blood lymphocytes, granulocytes or monocytes. Both NU-T1 and NU-T2 reacted with thymocytes. The incidence of NU-T1 or NU-T2 reactivity with the leukemic cells from patients with various types of leukemia was as follows: 12/12 or 4/12 in acute lymphocytic leukemia (ALL) of T cell type, 6/6 or 0/7 in adult T cell leukemia, 0/6 or 0/19 in ALL of non-T non-B cell type, and 0/8 or 0/8 in acute myelocytic leukemia, respectively. The incidence of NU-T1 and NU-T2 reactivity with human leukemic T cell lines were 4/10 and 5/10, respectively. In contrast, neither NU-T1 nor NU-T2 reacted with B cell lines, non-T non-B cell lines, or myeloid cell lines tested. These results indicate that NU-T1 and NU-T2 recognize two distinct differentiation antigens expressed on the cells in the T cell lineage. These mAb would be useful reagents to study the function of human T cells and the immunophenotyping of human T cell malignancies.

Antibodies, Monoclonal↗
PubMed1996

Expression of MAGE gene family in lung cancers.

MAGE gene family encodes tumor-specific antigens recognized on HLA-A1 by cytotoxic T lymphocytes. We have investigated the mRNA expression of MAGE gene family in lung cancers using MAGE gene specific primers, reverse transcription-polymerase chain reaction (RT-PCR) and restriction enzyme analysis. MAGE-1, -3, -4, -41 or -6 gene was respectively expressed in 6, 5, 6, 7, and 4 of 53 lung cancer tissues (8 to 13%) or in 0, 6, 6, 7 or 8 of 14 lung cancer cell lines (0 to 53%). These results suggest that a substantial proportion of lung cancers express MAGE genes.

Antigens, Neoplasm↗
PubMed1996

An autopsy case of abandoned infant body with severe destruction.

One case of infanticide and abandonment by the natural mother is presented. The body was extensively damaged, evidently by a fox. Fortunately, since the body showed less advanced putrefaction due to cold weather, it was possible to narrow down the cause of death and to detect the drug which had been forced down the victim's throat before the crime. However, our estimates of age and postmortem interval were erroneous. We comment as to why we were misled. Pathological problems associated with "aspiration of vomitus" are also discussed.

Age Determination by Teeth↗
PubMed1996

Bucillamine induced pulmonary injury occurs with immunoglobulin decrease.

We describe pulmonary involvement in 3 patients with rheumatoid arthritis treated with bucillamine. In all 3, synovitis was in remission. The common radiological characteristic was mottled dense infiltrates, in which were air bronchograms, in the bilateral central lung, sparing the periphery. Lung biopsies in 2 cases revealed organizing exudates in the alveolar ducts and alveoli, and cellular infiltration into alveoli and septa. Serum immunoglobulin (Ig) levels decreased markedly at the time of involvement. After discontinuation of bucillamine, lung injury resolved without exacerbation of synovitis and Ig levels increased. A mechanism involving decreased Ig concentration is suggested.

Aged↗
PubMed1996

Localization of human placental glucose transporter 1 during pregnancy. An immunohistochemical study.

To elucidate the potential roles of glucose transporter 1 (GLUT1) in human placenta during pregnancy, we examined the localization of GLUT1 in human placenta at various stages by immunohistochemistry with an anti-GLUT1 antibody by use of both light and electron microscopy. Specific staining for GLUT1 was localized on the apical brush border and along the basal plasma membrane of the syncytiotrophoblasts. The staining at the apical side was more intense than that at the basal side during the early stages of gestation. In later gestational stages, however, the staining pattern at the apical side became blurred and the staining intensity at the basal side increased. The cytotrophoblasts, seen embedded in the basal part of the syncytiotrophoblasts, seemed to show immunoreactivity for GLUT1 along the plasma membranes at the light-microscopic level. However, immuno-electron microscopic analysis with either pre- or post-embedding methods revealed that specific staining for GLUT1 was hardly observed on the cytotrophoblasts, but the cytotrophoblasts were often surrounded by immunoreactive processes of syncytiotrophoblasts. The blood capillaries and erythrocytes in the stroma of placental villi were always immunoreactive for GLUT1 throughout pregnancy. These findings suggest that GLUT1 may play a vital role in human pregnancy.

Capillaries↗
PubMed1996

[Rupture of the aneurysm of the sinus valsalva: thirteen years after the initial diagnosis].

We report a case of an unruptured aneurysm of the sinus Valsalva (URASV) which was followed thirteen years without surgery. A 47-year-old female had a heart murmur detected at age 34 during pregnancy. Though an URASV was diagnosed, because the aneurysm was less than 1 cm in size, no surgery was advised at that time. Thirteen years later, she gradually noticed of increased heart beats and also dyspnea on exertion. Echocardiogram showed an aneurysm of the sinus Valsalva ruptured to the RV cavity. In June 1994, resection of the aneurysm was performed. One year later, the patient was asymptomatic. This may be the second longest long-term follow-up report of the patient with an unruptured aneurysm of the sinus Valsalva.

Aneurysm, Ruptured↗
PubMed1995

Expression and localization of glucose transporter 1 (GLUT1) in the rat oviduct: a possible supplier of glucose to embryo during early embryonic development.

The oviduct fluid mainly derived from the oviduct epithelium is reported to provide the environment necessary for embryonic development. To elucidate the origin of glucose in the oviduct fluid, we examined the expression and localization of glucose transporter 1 (GLUT1) in the rat oviduct by Northern blot analysis, immunoblot analysis and immunohistochemistry using both light and electron microscopy. Northern blot and immunoblot analyses both showed the presence of the GLUT1 mRNA and protein. Specific staining for GLUT1 was observed in the ampulla and the isthmus, but only slightly in the fimbria and the utero-tubal junction. Staining was confined to the luminal surface of the epithelial mucosa. Immunoelectron microscopic analysis revealed that GLUT1 was observed only on the surface of the microvilli in non ciliated secretory cells, but not in ciliated cells. These findings suggest that GLUT1 plays an important role in the glucose transfer from the oviduct epithelium into the lumen and in maintaining the adequate glucose concentration of the oviduct fluid for embryonic development in rat oviduct.

Animals↗
PubMed1995

Detection of MAGE-4 protein in lung cancers.

Expression of genes of the MAGE family, which encode tumor-rejection antigens recognized on HLA-AI and -Cw1601 by cytotoxic T lymphocytes (CTL), was investigated in lung cancers at the mRNA [MAGE-1, -2, -3/-6, and -4 (4a and/or 4b)] and protein (MAGE-4) levels. MAGE-1, -2, -3/-6 and -4 genes were expressed, respectively, at the mRNA level in 6, 7, 20 and 7 of 53 lung cancers (50 non-small-cell lung cancers and 3 small-cell lung cancers) by the reverse transcription-polymerase chain reaction (RT-PCR) method. Polyclonal antibody (Ab) and monoclonal antibody (MAb) against recombinant MAGE-4b protein were developed to detect MAGE-4 protein. Both the polyclonal Ab and the R5 MAb recognized a 45-kDa protein in extracts of MAGE-4 mRNA-positive lung cancers, and showed no apparent cross-reactivity with the other MAGE gene products except with MAGE-4a by immunoblot analyses and transfection experiments. MAGE-4 protein was detected on 13 of 44 (30%) lung cancers (18 to 55,989 pg/mg) by ELISA with the polyclonal Ab and R5 MAb. These 13 lung cancers consisted of 6 of 6 MAGE-4 mRNA-detectable and 7 of 38 MAGE-4 mRNA-undetectable lung cancers. Histologically, these comprised 7 of 10 squamous-cell carcinomas, 4 of 30 adenocarcinomas and 2 of 3 small-cell lung cancers. The proportions of MAGE gene-positive samples, at both the mRNA and protein levels, correlated with the size of the primary tumors and with regional node involvement. These results should provide important information on specific immunotherapy of lung cancers using MAGE gene products.

Animals↗
PubMed1995

Ocular surface changes and discomfort in patients with meibomian gland dysfunction.

OBJECTIVE: To determine the importance of meibomian gland dysfunction (MGD) on the ocular surface. DESIGN: Prospective study. SETTING: A university-based referral practice. PATIENTS: Patients with ocular discomfort (147 eyes) and without ocular discomfort (54 eyes) were examined. In the total 201 eyes, MGD was defined as the presence of an obstruction of the meibomian orifices (obstruction group [n = 54]) or the absence of a gland structure (gland dropout group [n = 36]), or both of these findings (combined group [n = 38]). There were not any findings of MGD in 73 eyes (non-MGD group). MAIN OUTCOME MEASURES: Scores that were obtained from fluorescein and rose bengal staining, the breakup time of the tear film, the rates of tear evaporation and tear production, and meibography. RESULTS: Of the 147 eyes with ocular discomfort, 95 (64.6%) had either an obstruction of an orifice or gland dropout, or both. The combined group had higher scores for staining with fluorescein (P = .002) and rose bengal (P = .021) compared with that in the non-MGD group. The rate of tear production was increased more in the gland dropout group than in the non-MGD group (P = .002). The rate of tear evaporation was significantly increased in the gland dropout group (P = .017). CONCLUSION: Meibomian gland dysfunction is a major cause of ocular surface abnormalities and ocular discomfort.

Adult↗
PubMed1995

Mercury uptake by primary cultures of rat renal cortical epithelial cells. I. Effects of cell density, temperature, and metabolic inhibitors.

Factors affecting the renal uptake of inorganic mercury were investigated using primary cultures of rat renal cortical epithelial (RCE) cells under protein- and amino acid-free conditions. The cells were isolated from kidneys of adult rats and cultured. Confluence of culture (cell density), monitored morphologically and by total protein content, was achieved on Day 5. The RCE cells were incubated with 1 microM Hg at 37 degrees C for 30 min, followed by washing with phosphate-buffered saline containing various chelating agents (i.e., EGTA, PEN, DMSA, and BAL) to remove the surface-bound, noninternalized Hg. A substantial portion of Hg was bound to the cell surface. The removal of Hg from these binding sites was dependent on the stability constants of the chelating agents for Hg and lipophilic BAL removed the most Hg. Hg accumulation by the cells was dependent on cell density and decreased as the cell culture became confluent, possibly due to the formation of tight junctions resulting in a majority of the Hg transport occurring through the apical membrane. As measured after BAL washing, metabolic inhibitors, NaF, DNP, and ouabain decreased Hg accumulation by 28% and low temperature (4 degrees C) decreased it by 62%. Dependence of Hg uptake on metabolic energy and temperature suggests that a part of Hg is transported via active transport system. The pronounced decrease of Hg uptake at 4 degrees C indicates that, in addition to active transport, Hg transport also involves simple diffusion, some of which is dependent on membrane fluidity. It is concluded that Hg transport in RCE cells through the apical membrane occurs mainly by diffusion, and to a smaller extent by active transport.

Animals↗
PubMed1995

Mercury uptake by primary cultures of rat renal cortical epithelial cells. II. Effects of pH, halide ions, and alkali metal ions.

The effects of pH, halide ions, and alkali metal ions on the uptake of inorganic mercury (Hg) were investigated in confluent primary cultures of rat renal cortical epithelial cells. The cells were incubated with 1 microM Hg in phosphate buffer at pH 5.5, 6.4, or 7.4 for 30 min at 37 degrees C. Incubation of cells at pH 5.5 resulted in a 22% increase in total Hg accumulation over those cells that were incubated at pH 7.4. Almost all of this increase was accounted for in the membrane fraction. In contrast, there was a 33% reduction in internalized Hg in cells incubated at pH 5.5. This may be explained by the conversion of hydroxide forms of Hg (Hg(OH)Cl and Hg(OH)2) to the chloride forms (HgCl2, HgCl3-, and HgCl4(2-) at a lower pH (decreased OH-) condition. In the presence of halide ions, the cells internalized Hg in the relative order of affinity of the halide ions for Hg2+ (i.e., F- < Cl- < Br- < I-). Br- and I- resulted in a 67 and 142% increase in internalized Hg over that by Cl-. The relatively high membrane binding and internalization of Hg in the presence of Br- and I- was possibly due to the formation of highly lipophilic complexes of Hg (i.e., HgBr2 and HgI2). The replacement of NaCl in the incubation medium by KCl caused a 36% decrease in internalized Hg. LiCl had a similar effect on the internalization of Hg. The above results suggest that in rat renal proximal tubules Hg uptake involves Na(+)- and H(+)-dependent mechanisms.

Animals↗
PubMed1995

Changes in epidermal growth factor receptor and the levels of its ligands during menstrual cycle in human endometrium.

We examined menstrual cycle-dependent changes in the expression of human endometrial epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha), and epidermal growth factor receptor (EGFR) and their mRNA using immunoblot analysis, 125I-EGF binding, and competitive reverse transcription and polymerase chain reaction (RT-PCR). We also studied their localization in the endometrial tissue by immunohistochemistry. Endometrial samples were obtained at three stages of menstruation: the early follicular stage, which exhibits low serum estradiol (E2) and progesterone (P) levels; the late follicular stage, which exhibits high E2 and low P levels; and the luteal stage, which exhibits high E2 and P levels. Immunohistochemical examination showed that EGF, TGF alpha, and EGFR were localized to the endometrial epithelium. Immunoblot analysis revealed that endometrial EGF, TGF alpha, and EGFR levels were significantly (p < 0.01) increased at the late follicular and luteal stages compared to the early follicular stage. 125I-EGF-specific binding levels at the late follicular and luteal stages were significantly (p < 0.01) higher than at the early follicular stage, consistent with the results of immunoblot analysis. Competitive RT-PCR revealed that EGF, TGF alpha, and EGFR mRNA levels were significantly (p < 0.01) higher at the late follicular and luteal stages than at the early follicular stage. Changes in EGF, TGF alpha, and EGFR mRNA levels were consistent with changes in protein levels. These findings suggest that synthesis and expression of human endometrial EGF, TGF alpha, and EGFR vary with the stage of the menstrual cycle and that their expression in the human endometrium is associated with the increase in the serum E2 but not with the increase in P levels.

Binding, Competitive↗