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Biomedical subjects

M Takimoto

Publications and source records attributed to M Takimoto.

At least 19 recordsLinked to original sources
PubMed1992

[Athyreotic congenital hypothyroidism in two sisters].

Two sisters with athyreotic congenital hypothyroidism are described. This is the fifth report on athyreotic congenital hypothyroidism in siblings. The elder sister is 14 years old and the younger one is 12. The parents have no consanguinity or family history of thyroid disease. Both of the patients were born before the start of neonatal screening tests for congenital hypothyroidism. After birth, they had jaundice, abdominal distention and constipation, which are typical symptoms of congenital hypothyroidism. Serum T4 levels were decreased, and the serum TSH levels were markedly increased. Therefore we diagnosed them as having congenital hypothyroidism. They have received replacement therapy with thyroxine since diagnosis and have shown normal development physically and psychologically. They were tested for thyroid scintigram when the elder sister was 9 years old and the younger one was 7. 123I thyroid uptakes were 0.69% and 0.64%, respectively. The thyroid scans demonstrated no focus of accumulation of 123I. They do not have trapping defect of iodine, because 123I ratio of saliva and serum were 41.3 and 46.3, respectively. From these results, we diagnosed them as having athyreotic congenital hypothyroidism. They and their mother do not have any antithyroid antibodies. We suppose that some genetic factor is responsible for the athyreotic congenital hypothyroidism.

Child↗
PubMed1992

Autocrine receptors for endothelins in the primary culture of endothelial cells of human umbilical vein.

Human umbilical vein endothelial cells (HUVECs) in primary culture produced and secreted endothelin 1 (ET-1) actively. Specific binding of [125I]ET-1 to these cells was not detectable because of the saturation of ET receptors with endogenously produced ET-1. However, addition of phosphoramidon, an inhibitor of ET-converting enzyme, to the medium reduced the production of ET-1 and thus the receptors on HUVECs were made available for exogenously added [125I]ET-1. Binding studies using phosphoramidon-treated HUVECs indicated the existence of a non-isopeptide-selective type (ETB) of ET receptor with a Kd of 17 pM. This receptor is thought to be involved in ET-induced vasodilation in an autocrine manner in vivo.

Binding Sites↗
PubMed1992

Antigenic analysis of human haemopoietic progenitor cells expressing the growth factor receptor c-kit.

The cell surface molecule encoded by the protooncogene c-kit has recently been identified as the receptor for a growth factor variously termed stem cell factor (SCF), mast cell growth factor or steel factor. Using the c-kit antibody 17F11 we analysed, in triple staining experiments, the surface molecule profile and scatter characteristics of c-kit+CD34+ human haemopoietic progenitor cells. In 10 normal bone marrow samples we found 19-51% of CD34+ bone marrow progenitor cells to coexpress c-kit. These c-kit+CD34+ bone marrow cells turned out to represent a phenotypically heterogeneous population. A considerable proportion coexpressed CD33 (52 +/- 23%), and/or CD71 (62 +/- 26) antigens, marker molecules previously shown to be expressed by committed in vitro colony forming cells but not by their precursors. In line with a relatively differentiated phenotype c-kit+CD34+ cells also gave rise to on average higher forward and right-angle light scattering signals. The proportions of CD38 and/or HLA-D expressing cells were similar in the c-kit+ and in the c-kit- subsets of CD34+ progenitor cells. Coexpression of CD19 was found to be less frequent in the c-kit+ (4 +/- 5%) as compared to the c-kit- (17 +/- 14%) fraction of CD34+ cells. CD7+ CD34+ bone marrow cells were hardly detectable and their numbers too low to allow further subdivision in c-kit+ and c-kit- subsets.

Antigens, CD↗
PubMed1992

[Characteristics of group A streptococci isolated from children with non-suppurative complication or severe infection].

We determined the characteristics of group A streptococci isolated from 29 sporadic cases with non-suppurative complication or severe infection during a 15-year period from 1977 to 1991. The clinical diagnoses of children included 4 patients with rheumatic fever, 2 with reactive arthritis, 2 with central nervous system complication, 5 with glomerulonephritis, 11 with Honoch-Schölein purpura, 4 with sepsis and 1 with empyema. Twenty-four strains were isolated from throat swabs, 4 from blood specimens and one from pleural fluid. M/T-serotypes and the number of isolates were as follows; 1/1:10, 3/3:1, 3.3R/3:3, 4/4:7, 5/NT:1, 12/12:3, 18/18:2, 62/12:1, NT/13:1. All 29 isolates had productivity for at least one of streptococcal pyrogenic exotoxins (SPEs) A, B and C. Two strains were positive for A, 2 for A and B, 3 for A, B and C, 9 for B and 13 for B and C. Of 11 isolates from patients with Henoch-Schönlein purpura, 7 and 2 strains were serotyped in M1 and M4, respectively, but none was in M12. Ten of 11 isolates were positive for SPE B or SPEs B and C.

Adolescent↗
PubMed1991

Spectroscopic studies on lambda cro protein-DNA interactions.

Spectroscopic (circular dichroism and fluorescence) and thermodynamic studies were conducted on lambda Cro-DNA interactions. Some base substitutions were introduced to the operator and the effects on the conformation of the complex and thermodynamic parameters for dissociation of the complex were examined. It was found that, (1) in the specific binding of Cro with DNA which has a (pseudo) consensus sequence, DNA is overwound, while in non-specific binding it is unchanged, or rather unwound; (2) substitution of central base-pairs or the introduction of a mismatched base-pair at the center of the operator reduces the extent of DNA conformational change on Cro binding and lessens the stability of the Cro-DNA complex, even though there is apparently no direct interaction between Cro and DNA at these positions; (3) stability of the complex increases with the degree of DNA conformational change of the same type during binding; (4) in some cases of specific binding, there are three states in the dissociation of the complex as observed by salt titration: two conformational states for the complex depending on salt concentration and, in non-specific binding, dissociation is a two-state transition; (5) the number of ions involved in interactions between Cro and 17 base-pair DNA is about 7.7 for NaCl titrations; (6) dissociation free energy prediction of the Cro-DNA complex by simple addition of the dissociation free energy change of a single base-pair substitution agrees with our experimental results when DNA overwinding occurs during binding, i.e. in specific binding.

Base Sequence↗
PubMed1990

[Growth rate of experimental colonic cancer in rats].

Colonic cancers were induced in rats by subcutaneous injection of 1,2-Dimethylhydrazine. Tumor growth patterns were estimated by means of a double contrast barium enema technique. Tumor growth was almost exponential and the average doubling time was 20 +/- 5 (m +/- S.D.) days, at which time three different types of tumor growth patterns: Constant type, decreasing type and reaccelerating type, were noted. Serial double contrast barium enema technique appeared to be an useful method of studying in vivo primary colonic cancer growth patterns in rats.

1,2-Dimethylhydrazine↗
PubMed1989

Thrombus formation on the aorta injured by angioplasty and its prevention with dilazep in atherosclerotic rabbits.

To estimate the effect of dilazep in preventing restenosis after a transluminal angioplasty, we have attempted an animal experiment in which the efficacy of drug was tested on an angioplastic injury superimposed on to atherosclerotic lesions. Using a modification of Block's method, atherosclerotic lesions first were made in the rabbit aorta by an initial ablation of the endothelium, followed by successive cholesterol feedings. Then, for our second step, an angioplastic injury was inflicted on the atherosclerotic lesions. The thirty two rabbits used were divided into 3 groups: those given dilazep (100 micrograms/kg i.v.), those given dipyridamole (100 micrograms/kg i.v.) and a control group that was given the same volume of 0.9% saline. The angioplastic area in which thrombi developed was semiquantitatively measured and compared among all three groups. The mean value of the thrombus area in the dilazep group was 60% smaller and the distribution pattern of the thrombus by size was found to be composed of smaller thrombi than those of the control group. Dipyridamole showed the same trend as did dilazep, but less effectively. Our animal model and semiquantitative evaluation method that we employed were found useful from the view point of an easy applicable and inexpensive methodology. Our results point towards the possible clinical use of dilazep in the future, so as to prevent thrombus formation, which seems to cause the restenosis phenomenon that often occurs in patients who have undergone a coronary angioplasty.

Angioplasty, Balloon↗
PubMed1989

fos/jun and octamer-binding protein interact with a common site in a negative element of the human c-myc gene.

A negative element has previously been localized to a 57-base pair segment approximately 300 base pairs upstream of the human c-myc promoter P1. Within this element, a 26-base pair region was protected in vitro from DNase I digestion with a HeLa cell nuclear factor(s). Two specific DNA-protein complexes were identified in gel retardation assays using HeLa cell nuclear extracts and an oligonucleotide probe spanning the footprinted region. Exonuclease and chemical footprint analyses suggested that the binding sites for both complexes are almost entirely overlapping. One of the complexes was eliminated by oligonucleotide competitors possessing known AP-1 binding sites. This same complex reacted strongly with anti-fos immunoglobulin suggesting a role for c-fos in governing c-myc expression. Precipitation of fos protein bound to c-myc DNA that was immobilized on beads confirmed the involvement of c-fos in a specific complex with the c-myc upstream sequence. In contrast, the other complex seen by the c-myc probe could not be competitively inhibited by AP-1 binding sites and was not affected by anti-fos antibody. Instead, this complex was efficiently eliminated by unlabeled oligonucleotides containing the octamer DNA motif found in immunoglobulin gene promoters. Purified octamer-binding proteins formed stable complexes with the 26-base pair c-myc sequences. These results demonstrate that degeneracy in the consensus recognition sequences of these distinct factors allows each of them to bind the c-myc negative element. The interaction of known transcriptional activators with a negative element suggests that the same factors can mediate both transcriptional activation and repression.

Base Sequence↗
PubMed1989

A FOS protein is present in a complex that binds a negative regulator of MYC.

Regulation of the human proto-oncogene MYC apparently plays an important role in cellular proliferation and the genesis of diverse tumors. Transcription from MYC is governed principally by two promoters known as P1 and P2. Previously we have detected a negative regulator of these promoters upstream of MYC. We now report that this regulator comprises no more than 26 bp of DNA, with sequence that resembles the regulators of at least two other genes, and we describe nuclear factors that interact with the regulator. Nuclear extracts from human cells form three distinctive complexes with the negative regulator. One of these complexes includes the product of the proto-oncogene FOS or an antigenically related protein, and the FOS protein may, in turn, be associated with the product of the proto-oncogene JUN. Similarly, FOS and JUN proteins produced by translation in vitro bind cooperatively to the negative regulator. These results raise the possibility that FOS and JUN participate in the regulation of MYC.

Animals↗
PubMed1989

Distinct factors bind the AP-1 consensus sites in gibbon ape leukemia virus and simian virus 40 enhancers.

We have demonstrated that the gibbon ape leukemia virus (GALV) enhancer AP-1 element and the simian virus 40 AP-1 enhancer element bind different factors in HeLa nuclear extracts. A 39-kilodalton HeLa nuclear protein and the c-fos protein bind to the GALV element. Antibodies to c-fos abolish binding to the GALV AP-1 site. In contrast, anti-c-fos immunoglobulin fails to inhibit formation of the simian virus 40-specific complex from extracts of HeLa cells. Thus, AP-1-binding complexes are subject to compositional variation at different binding sites.

Animals↗
PubMed1989

[Comparing development with physical fitness, motor ability, and health of children among various living environment].

This study had the purpose to compare with development of fitness, motor ability and health among various living environments of the sea-side, the urban, and the mountain districts, where were situated at Nadachi town on the suburbs of Niigata Prefecture. Five hundred thirty-five children (aged 4-15 yrs) were measured at the kindergarten, the fundamental school, and the junior high school. Measuring items of the physique were the height, the weight, the chest circumference, the sitting height, and the foot area. Physical fitness tests were the muscular grip-strength, the lung vital capacity, the closed-eye single-leg balance, the dipping time of the upper extremity, the vertical jump, the standing trunk flexibility, the endurance run, and pull-up. And, motor ability tests were the finger tapping, 5m shuttle run, 50m dash, and the ball throwing. As items of health inspection, the blood pressure (systolic and diasystolic) and the visual ability were adopted. As results of this study, following data were obtained; 1) At the sea-side environment, development of the muscle power, the respiratory function, and the physique were showed much faster rate of growth at the childhood than that of the other ones, significantly (P less than 0.01). 2) At the mountain environment, the arch-bend of the foot print only were appeared larger areas than that of the other ones, significantly (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[A case report of compression of right pulmonary artery and bronchus by aneurysmal dilated ascending aorta in tetralogy of Fallot--suspension of ascending aorta].

The patient was a 63-days-old boy who was admitted to our hospital because of moderate cyanosis and tachypnea. After admission, severe respiratory distress and emphysematous change of the right lung on the chest X-ray developed progressively. Echocardiogram and angiocardiogram demonstrated that a tetralogy of Fallot associated with right aortic arch and absence of pulmonary valve, and revealed remarkably dilated ascending aorta which compressed the right pulmonary artery and bronchus. Therefore, the emergency operation in that the ascending aorta was suspended to the 2nd rib was performed through a right thoracotomy. After surgery, his respiratory distress and emphysema of the right lung completely disappeared. To our knowledge, this is the 2nd reported case in which suspension of ascending aorta was successfully performed for pulmonary complication in congenital cardiovascular anomalies as this patient.

Airway Obstruction↗
PubMed1989

[Surgical experiences of Cor triatriatum in infancy].

Three operative cases with Cor triatriatum, age ranged from 30 days to 16 months, were presented. All types were IB1 of Lucas-Schmidt's classification and one patient was associated with right upper PAPVC. One patient died of low output syndrome due to preoperative shock. Communication of abnormal diaphragm in left atrium varied from small and multiple to 5 mm in diameter. Their preoperative diagnoses were established by two-dimensional echocardiogram prior to angiocardiogram and the intracardiac communications were well evaluated by color doppler echocardiogram which was superior to angiocardiogram in this evaluation. Postoperatively, no abnormal diaphragm were detected in two survivors. The diagnosis and operative procedure for this anomaly were discussed on.

Angiocardiography↗
PubMed1988

Depression of T cell-mediated immunity and enhancement of autoantibody production by natural infection with microorganisms in spontaneously hypertensive rats (SHR).

We studied the effects of breeding conditions on the development of immunological abnormalities in spontaneously hypertensive rats (SHR) with congenital T cell depression. The depression of T cell functions, the production of natural thymocytotoxic autoantibody (NTA), and the development of polyarteritis nodosa were more evident in SHR reared under a conventional (CV) environment than in specific-pathogen-free (SPF) SHR bred in a semi-barrier system. Enhancement of these immunologic abnormalities was also observed by the conventionalization of SPF-SHR. A high frequency of antibodies to mouse hepatitis virus (MHV), Sendai virus, and Mycoplasma pulmonis was detected in CV rat sera, whereas no antibodies were detected in SPF-SHR. The experimental infection of Sendai virus induced the enhancement of T cell depression and of NTA production in SPF-SHR. We interpret these results to mean that the natural infection of microorganisms causes an acceleration of immunologic abnormalities in SHR reared in a CV environment.

Animals↗