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T Sugahara

Publications and source records attributed to T Sugahara.

At least 91 records · Page 5Linked to original sources
PubMed1997

Alcohol dehydrogenase-I from horse liver stimulates immunoglobulin production by human hybridoma and human peripheral blood lymphocytes.

Immunoglobulin production stimulating activity of alcohol dehydrogenase [EC 1.1.1.1] was assessed. Alcohol dehydrogenase-I (ADH-I) derived from horse liver stimulated IgM production by human-human hybridoma, HB4C5 cells producing human lung cancer specific monoclonal IgM. IgM production of HB4C5 cells was enhanced more than 6 fold by the addition of ADH-I at 400 microg/ml under serum-free condition. However, yeast derived ADHs, such as ADH-II and -III were ineffective to accelerate immunoglobulin production of the hybridoma line. These results imply that the immunoglobulin production stimulating effect of ADH-I is irrelevant to its enzymatic function, and defined as a novel feature of ADH-I. This enzyme also stimulated IgM and IgG production by human peripheral blood lymphocytes 2.9 fold and 1.4 fold, respectively. This fact suggests that ADH-I stimulates immunoglobulin production not only by specific hybridoma cell line, but also by non-specific immunoglobulin producers.

Alcohol Dehydrogenase↗
PubMed1997

MR changes in the calcarine area resulting from retinal degeneration.

PURPOSE: To study MR images for atrophic changes in the calcarine area resulting from retinal degeneration. METHODS: MR images from nine patients with retinal degeneration confirmed by ophthalmologic examination and from 30 healthy volunteers were reviewed. The causes of retinal degeneration were hereditary pigmentary degeneration of the retina (four patients), high myopia (two patients), and chorioretinal atrophy (three patients); all patients had visual disturbances and visual field abnormalities. To estimate the morphological changes of the calcarine area, the widths of the right and left calcarine fissures were measured on T1-weighted sagittal images and compared with images from age-matched control subjects. RESULTS: The calcarine fissures were significantly dilated in the patients with retinal degeneration. The anterior and middle points, which represent the peripheral visual field center, were more dilated than the posterior point. CONCLUSION: The MR findings suggested calcarine atrophy related to retinal degeneration. Transneuronal degenerative changes may occur in the calcarine area after retinal degeneration.

Aged↗
PubMed1997

MR of epidermoids with a variety of pulse sequences.

PURPOSE: To assess the usefulness of fluid-attenuated inversion recovery (FLAIR) and constructive interference in steady state (CISS) sequences in depicting epidermoid tumors. METHODS: Six patients with surgically confirmed epidermoid tumors in the subarachnoid space were examined with T1-weighted MR imaging with a spin-echo sequence, and with T2- and proton density-weighted imaging with a fast spin-echo sequence, a FLAIR sequence, and a CISS sequence. In the qualitative analysis, three observers compared the five sequences for visibility of tumors and presence of artifacts. A quantitative analysis was also performed by measuring the contrast-to-noise ratio. RESULTS: On visual assessment, the FLAIR sequence depicted all tumors as hyperintense relative to cerebrospinal fluid. The CISS sequence depicted all tumors as hypointense relative to cerebrospinal fluid and was considered to show tumor extension better than the FLAIR sequence. At quantitative analysis, the mean contrast-to-noise ratios of tumor to cerebrospinal fluid on T1-, T2-, and proton density-weighted images, and on FLAIR and CISS sequences were 2.85, 3.41, 4.42, 16.13, and 20.23, respectively. The contrast-to-noise ratios for the FLAIR and CISS sequences were significantly higher than those for the T1-, T2-, and proton density-weighted sequences. The contrast-to-noise ratio was not significantly different between FLAIR and CISS sequences, although the CISS sequence was slightly superior. CONCLUSION: CISS and FLAIR sequences depicted epidermoid tumors in the subarachnoid spaces better than conventional spin-echo images did. The CISS sequence produced a relatively constant contrast between the tumors and less artifactual interference.

Adolescent↗
PubMed1996

Expression of biologically active fusion genes encoding the common alpha subunit and either the CG beta or FSH beta subunits: role of a linker sequence.

The gonadotropin/thyrotropin hormone family is characterized by a heterodimeric structure composed of a common alpha subunit non-covalently linked to a hormone-specific beta subunit. The conformation of the heterodimer is essential for controlling secretion, hormone-specific post-translational modifications and signal transduction. Structure-function studies of FSH and the other glycoprotein hormones are often hampered by mutagenesis induced defects in subunit combination. Thus, the ability to overcome the limitation of subunit assembly would expand the range of structure activity relationships that can be performed on these hormones. Here we converted the FSH heterodimer to a single chain by genetically fusing the carboxyl end of the FSH beta subunit to the amino end of the alpha subunit in the presence or absence of a natural linker sequence. In the absence of the CTP linker, the secretion rate was decreased over three fold. (The CTP sequence is the last 28 amino acids of the CG beta sequence and contains four serine-linked oligosaccharides). Unexpectedly however receptor binding/signal transduction was unaffected by absence of the linker. Molecular modelling of the tethers lacking the linker sequence show that the alignment of the alpha/beta domains in the single chain differ substantially from that seen in the heterodimer. These data show that the single chain FSH was secreted efficiently and is biologically active and that the conformation determinants required for secretion and biologic activity are not the same.

Animals↗
PubMed1996

Characterization of the O-glycosylation sites in the chorionic gonadotropin beta subunit in vivo using site-directed mutagenesis and gene transfer.

Human chorionic gonadotropin (CG) is a member of a family of glycoprotein hormones which are heterodimers containing two nonidentical subunits: a common alpha and a hormone-specific beta subunit. One of the distinguishing features of the CGbeta subunit is the presence of four serine acceptors clustered within the last 25 amino acids. We previously demonstrated that this carboxyl-terminal region is important for maintaining its biologic half-life, and when the sequence was genetically fused to either the common alpha or follitropin beta subunits, O-glycosylation was observed. Because this carboxyl-terminal sequence is located at the end of the subunit, we considered this region a convenient in vivo model for studying O-linked glycosylation in domains containing multiple serine recognition sites. A CGbeta gene was engineered in which the N-linked sites were inactivated to eliminate background from those carbohydrate groups. Using this construct, we made a series of truncation and amino acid substitutions of acceptor serines, and these mutants were transfected into Chinese hamster ovary cells. O-Glycosylation was determined by [3H]glucosamine incorporation and glycanase sensitivity of the products on SDS-polyacrylamide gels. We show that the O-linked sites comprise independent repetitive regions in which each acceptor serine has a recognition signal bounded by the next carboxy acceptor serine within four to five amino acids. It is also apparent that recognition of one site is not dependent on the glycosylation of another acceptor. Amino acid mutations in the acceptor regions demonstrated the importance of proline as a necessary feature for O-linked recognition in the CGbeta sequence.

Amino Acid Sequence↗
PubMed1996

Expression of biologically active fusion genes encoding the common alpha subunit and the follicle-stimulating hormone beta subunit. Role of a linker sequence.

The gonadotropin/thyrotropin hormone family is characterized by a heterodimeric structure composed of a common alpha subunit noncovalently linked to a hormone-specific beta subunit. The conformation of the heterodimer is essential for controlling secretion, hormone-specific post-translational modifications, and signal transduction. Structure-function studies of follicle-stimulating hormone (FSH) and the other glycoprotein hormones are often hampered by mutagenesis-induced defects in subunit combination. Thus, the ability to overcome the limitation of subunit assembly would expand the range of structure-activity relationships that can be performed on these hormones. Here we converted the FSH heterodimer to a single chain by genetically fusing the carboxyl end of the FSH beta subunit to the amino end of the alpha subunit in the presence or absence of a linker sequence. In the absence of the CTP linker, the secretion rate was decreased over 3-fold. Unexpectedly, however, receptor binding/signal transduction was unaffected by the absence of the linker. These data show that the single-chain FSH was secreted efficiently and is biologically active and that the conformation determinants required for secretion and biologic activity are not the same.

Amino Acid Sequence↗
PubMed1996

Three cases of oblique facial cleft.

Three patients with an oblique facial cleft are described. One patient displayed ring constriction, lymphoedema, distal pseudosyndactyly and an occipital encephalocele to which an amniotic band was attached at birth. Therefore, it was obvious that the oblique facial cleft was accompanied by an amnion rupture sequence. These signs were not apparent in the other patients. However, one of the patients demonstrated various anomalies, amongst which syndactyly on the right foot, scoliosis, microcephaly, microphthalmia and corneal opacity suggested that the patient may have been affected by the amnion rupture sequence, except for polydactyly on the left foot, cleft hand and vertebra plana.

Abnormalities, Multiple↗
PubMed1996

Case report: hypoglossia-hypodactylia syndrome.

A case of hypoglossia-hypodactylia syndrome is described. The infant was characterized by micrognathia, accompanied by a defect of the gingiva, and hypoplasia of the tongue. There was defect in the right arm below the elbow. The right foot manifested syndactyly of the great, second and third toes and osseous fusion of the first and second metatarsi and proximal phalanges. In the left foot brachydactyly of the great and fifth toes, syndactyly of the second, third and fourth toes, hypoplasia of the first and second metatarsi and defect in the first phalanx were evident.

Abnormalities, Multiple↗
PubMed1996

Withaferin A: a new radiosensitizer from the Indian medicinal plant Withania somnifera.

Withaferin A, a steroidal lactone isolated from the roots of the Indian medicinal plant Withania somnifera, reduced survival of V79 cells in a dose-dependent manner. LD50 for survival was 16 microM. One-hour treatment with a non-toxic dose of 2.1 microM before irradiation significantly enhanced cell killing, giving a sensitizer enhancement ratio (SER) of 1.5 for 37% survival and 1.4 for 10% survival. SER increased with drug dose, but at higher doses the increased lethality appears to be due to two effects-- drug toxicity and radiosensitization. The drug induced a G2/M block, with a maximum accumulation of cells in G2-M phase at 4 h after treatment with 10.5 microM withaferin A in 1 h. The applicability of this drug as a radiosensitizer in cancer therapy needs to be explored.

Animals↗
PubMed1996

Application of a new method for anthropometric analysis of the nose.

An accurate, quantitative method of measuring external nasal forms was developed in which facial plaster models were measured with a highly accurate contact-type three-dimensional coordinate measurement apparatus. Subsequently, we have developed techniques to identify the landmarks of a face automatically from the three-dimensional data and to superimpose two sets of data automatically for the purpose of sectional and longitudinal analyses, respectively. These techniques were applied to patients with unilateral cleft lip nasal deformities. Consequently, we were able to observe shifts in the facial landmarks and subtle three-dimensional changes.

Adolescent↗
PubMed1996

The carboxy-terminal region of the beta-subunits of luteinizing hormone and chorionic gonadotropin differentially influence secretion and assembly of the heterodimers.

One of the major structural differences between the LH beta and CG beta subunits is the carboxy-terminal region: beyond amino acid 114, LH beta has a hydrophobic heptapeptide stretch, while CG beta contains a 31-amino acid hydrophilic carboxy-terminal peptide (CTP) that is O-glycosylated. The CG beta subunit is secreted quantitatively as a monomer and assembles efficiently whereas secretion and assembly of LH beta is inefficient. We previously implicated the carboxy-terminal heptapeptide as a determinant for the different intracellular behavior manifested by the LH beta subunit compared with the CG beta subunit. Here we tested the function of the heptapeptide and CTP domains by fusing them to their counterparts at amino acid 114 of CG beta or LH beta subunits. The secretion and assembly of these chimeras were examined in transfected Chinese hamster ovary cells. Removal of the heptapeptide enhanced the amount of LH beta subunit secreted 4-fold compared with intact LH beta. Fusion of this heptapeptide to CG beta 114, i.e. CG beta lacking the CTP, decreased the amount of secreted subunit 2-fold compared with wild type human CG beta. Similar experiments reveal that although deleting the CTP from the CG beta subunit did not significantly alter secretion, the combination efficiency of the truncated subunit was reduced to 60%. Perturbing the native carboxy-terminal sequence of either subunit increased the heterogeneity of the secreted forms. This result suggests that these regions are also involved in the posttranslational processing of the asparagine-linked oligosaccharides of the beta-subunits. Fusion of the LH beta heptapeptide to the truncated CG beta subunit decreased combination with the alpha-subunit. These data further support the hypothesis that the carboxy-terminal regions of LH beta and CG beta subunits play a role in the intracellular behavior of the corresponding heterodimers.

Animals↗
PubMed1996

Three-dimensional comparison between the palatal forms in infants with complete unilateral cleft lip, alveolus, and palate (UCLP) with and without Hotz's plate.

A three-dimensional measuring system was developed to analyze changes in palatal forms of UCLP infants. This system quantified the change of the curved surface on a palate by automatically superimposing two wireframe models obtained from casts at different stages of growth. It also analyzed the curvature of the palatal surface. This system was used to study the palates of 20 infants with unilateral cleft lip and palate (UCLP), from the first to fourth months after birth (12 with Hotz's plate and 8 without, selected at random). Both major and lesser maxillary segments without Hotz's plate remained anterior and lateral although those with Hotz's plate moved mesially during the fourth month after birth. In addition, the degrees of curvature on the palatal surfaces with Hotz's plate were less than those without Hotz's plate.

Alveolar Process↗
PubMed1996

Three-dimensional comparison between the palatal forms in infants with complete unilateral cleft lip, alveolus, and palate (UCLP) with and without Hotz's plate.

A three-dimensional measuring system was developed to analyze changes in palatal forms of UCLP infants. This system quantified the change of the curved surface on a palate by automatically superimposing two wireframe models obtained from casts at different stages of growth. It also analyzed the curvature of the palatal surface. This system was used to study the palates of 20 infants with unilateral cleft lip and palate (UCLP), from the first to fourth months after birth (12 with Hotz's plate and 8 without, selected at random). Both major and lesser maxillary segments without Hotz's plate remained anterior and lateral although those with Hotz's plate moved mesially during the fourth month after birth. In addition, the degrees of curvature on the palatal surfaces with Hotz's plate were less than those without Hotz's plate.

Analog-Digital Conversion↗
PubMed1996

Three-dimensional comparison between the palatal forms in complete unilateral cleft lip and palate with and without Hotz plate from cheiloplasty to palatoplasty.

The palatal forms in 20 infants with a complete unilateral cleft lip, and palate (12 with a Hotz palate and 8 without, selected at random) were studied from birth until 18 months of age. Using techniques developed previously, the degree of curvature in the palate and the magnitude of migration of the maxillary segments were measured three-dimensionally. Furthermore, using a newly developed method to approximate a set of the points on the alveolar ridge to a circle in a plane, the form of the alveolar arch was evaluated. Results from the group with a Hotz plate revealed that the plate possesses four effects not seen in the group without a Hotz plate. The size of the palate was larger, and the sagittal gap between the two segments of the maxilla was smaller. These results suggest that the appliance could stimulate the growth of the segments and could prevent collapse of the maxillary arch from the force of lip closure. Third, the steepness of the segments toward the nasal cavity was smaller, possibly occurring because the appliance prevents tongue intrusion into the cleft. Fourth, the magnitude of migration of the lesser segment toward the cleft edge of the major segment was larger. This result suggests that the appliance could guide the growth of the maxillary segments to narrow the cleft width until 18 months of age.

Alveolar Process↗
PubMed1996

[Establishment of reference intervals and physiological parameters for 13 serum proteins in healthy Japanese adults].

Using a nephelometry with a new calibrator in which values were assigned from EU/CRM470, a new international reference preparation, we have established for the first time the reference intervals of 13 different serum proteins in Japanese adults. Based on the NCCLS guideline C28-P, a new statistical and concrete procedure was revised and used for this study. It is clearly shown here that standardisation of serum proteins can be possible under the qualified assay system, making it possible to share the reference intervals among laboratories under well-controlled quality assurance. New aspects of serum protein variations were discovered in relation to physiologic changes and life styles.

Adult↗
PubMed1996

[Standardization of quantitative measurement of rheumatoid factor].

Recently many automated methods have been developed for a quantitative measurement of rheumatoid factor (RF). As they are widely used, it has been claimed that estimated values of RF are quite different among institutions. Standardization of quantitative measurement of RF is, therefore, required. The subcommittee for standardization of RF of the Ministry of Health and Welfare of Japan, worked from 1988 to 1994 in order to obtain an appropriate national standard of RF and has reached the conclusion that murine monoclonal rheumatoid factor (mRF) would be recommended as a new national standard of RF, which allows new expression of RF value (microgram/ml equivalent to the mRF instead of unit/ml referred to the WHO standard). There are two types of methods widely used for the quantification of RF. The first type is a method of light scattering analysis which is based on interaction of RF with particle-coated or aggregated human IgG (Fc) in nepherometry or turbidimetry, RF being expressed as unit/ml referred to the WHO standard. The second is a radioimmunoassay or an enzyme immunoassay in which RF is expressed as index compared to arbitrary standard. The former expression of RF is recognized to indicate agglutination titer of RF and the latter expresses the concentration of RF. The subcommittee decided to target on the former type of methods because of rapid prevalence with large inter-laboratory variations. The mRF is able to agglutinate proportionally IgG-complex with various features in wide range (x x microgram/ml to more than 1 mg/ml). It can be measured by nepherometry and turbidimetry with sufficient stability. The mRF has no misgivings in present and future supply and in immutability after a century. One of the largest advantages of the use of mRF national standard is expected to be able to eliminate the inter-laboratory variations of RF values which are considered to be mainly derived from different methods of laboratory instruments as well as from biological properties of polyclonal RF. The use of microgram/ml equivalent to mRF instead of unit/ml referred to the WHO standard makes it possible to determine the exact RF value of test serum since the mRF preparation could be adjusted to the best concentration to be requested by any available method of instrument to measure agglutination titer of RF.

Animals↗
PubMed1995

The mode of actions of glyceraldehyde-3-phosphate dehydrogenase identified as an immunoglobulin production stimulating factor.

Immunoglobulin production stimulating factor-II alpha, which enhances immunoglobulin production of human and mouse hybridomas was purified from cell lysate of human Burkitt's lymphoma, Namalwa cells, and identified as glyceraldehyde-3-phosphate dehydrogenase. The enhancement of immunoglobulin production with this enzyme was not linked with its enzymatic activity. The enzyme enhanced immunoglobulin productivity of transcription-suppressed hybridomas, but did not enhance that of translation-suppressed hybridomas. From these results, it is suggested that this enzyme takes part in the post-translational control or the enhancement of translation activity to stimulate immunoglobulin production of hybridomas.

Glyceraldehyde-3-Phosphate Dehydrogenases↗