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Biomedical subjects

S Kondo

Publications and source records attributed to S Kondo.

At least 865 records · Page 48Linked to original sources
PubMed1990

Organ culture of human scalp hair follicles: effect of testosterone and oestrogen on hair growth.

Whole human scalp hair follicles were cultured. The follicles were dissected from skin pieces of normal scalp and put into 1.5 ml of incubation medium in a closed 5 ml glass tube under an atmosphere of 95% O2 and 5% CO2. The tube was rolled at 15 rpm at 36 degrees C. Remarkable hair growth was noticed for 7 to 8 days. Hair root sheaths also grew with the hair shafts. The structure of the hair bulbs was well maintained for at least 6 days, and then the hair matrix cells started to degenerate. Fetal calf serum was not essential for hair growth in vitro, but increased the growth rate slowly. Testosterone and oestrogen inhibited hair growth in vitro to a similar extent. The minimum effective doses of both hormones to suppress hair growth were around 5 ng/ml, which corresponds well to the normal plasma level of testosterone in adult males in vivo, suggesting that scalp hair growth may be critically controlled by testosterone in adult males.

Autoradiography↗
PubMed1990

Clinical manifestations in anticardiolipin antibody-positive patients with progressive systemic sclerosis.

Anticardiolipin antibody-positive patients with progressive systemic sclerosis were analyzed. Elevated anticardiolipin antibody titers were observed in 13 of 40 cases (33%). Anticardiolipin antibody titer was significantly higher in patients with progressive systemic sclerosis type 1 than in those with type 2 or type 3. Occurrence of anticardiolipin antibody was significantly more frequent in patients positive for anti-nRNP antibodies, rheumatoid factor, or thrombocytopenia. In contrast, patients with proximal scleroderma, scarring, or esophageal hypomotility were positive for anticardiolipin antibody less frequently. These results suggest that anticardiolipin antibody might be closely associated with lupuslike clinical manifestations in a subset of progressive systemic sclerosis or definite progressive systemic sclerosis with thrombocytopenia, rheumatoid factor, or anti-nRNP antibodies.

Autoantibodies↗
PubMed1990

Characterization of a splicing mutation in group A xeroderma pigmentosum.

The molecular basis of group A xeroderma pigmentosum (XP) was investigated by comparison of the nucleotide sequences of multiple clones of the XP group A complementing gene (XPAC) from a patient with group A XP with that of a normal gene. The clones showed a G----C substitution at the 3' splice acceptor site of intron 3, which altered the obligatory AG acceptor dinucleotide to AC. Nucleotide sequencing of cDNAs amplified by the polymerase chain reaction revealed that this single base substitution abolishes the canonical 3' splice site, thus creating two abnormally spliced mRNA forms. The larger form is identical with normal mRNA except for a dinucleotide deletion at the 5' end of exon 4. This deletion results in a frameshift with premature translation termination in exon 4. The smaller form has a deletion of the entire exon 3 and the dinucleotide at the 5' end of exon 4. The result of a transfection study provided additional evidence that this single base substitution is the disease-causing mutation. This single base substitution creates a new cleavage site for the restriction nuclease AlwNI. Analysis of AlwNI restriction fragment length polymorphism showed a high frequency of this mutation in Japanese patients with group A XP: 16 of 21 unrelated Japanese patients were homozygous and 4 were heterozygous for this mutation. However, 11 Caucasians and 2 Blacks with group A XP did not have this mutant allele. The polymorphic AlwNI restriction fragments are concluded to be useful for diagnosis of group A XP in Japanese subjects, including prenatal cases and carriers.

Amino Acid Sequence↗
PubMed1990

Apparently beneficial effect of low to intermediate doses of A-bomb radiation on human lifespan.

Among about 100,000 A-bomb survivors registered at Nagasaki University School of Medicine, 290 male subjects exposed to 50-149 cGy showed significantly lower mortality from non-cancerous diseases than age-matched unexposed males. This was deduced from the fitting of a U-shaped dose-response relationship. Reasons for this effect in males, but not in females, are discussed with reference to selection of individuals and to hormesis.

Dose-Response Relationship, Radiation↗
PubMed1990

Induced rates of mitotic crossing over and possible mitotic gene conversion per wing anlage cell in Drosophila melanogaster by X rays and fission neutrons.

As a model for chromosome aberrations, radiation-induced mitotic recombination of mwh and flr genes in Drosophila melanogaster strain (mwh +/+ flr) was quantitatively studied. Fission neutrons were five to six times more effective than X rays per unit dose in producing either crossover-mwh/flr twins and mwh singles-or flr singles, indicating that common processes are involved in the production of crossover and flr singles. The X-ray-induced rate/wing anlage cell/Gy for flr singles was 1 X 10(-5), whereas that of crossover was 2 x 10(-4); the former and the latter rate are of the same order of magnitude as those of gene conversion and crossover in yeast, respectively. Thus, we conclude that proximal-marker "flr" singles induced in the transheterozygote are gene convertants. Using the model based on yeast that recombination events result from repair of double-strand breaks or gaps, we propose that mitotic recombination in the fly is a secondary result of recombinational DNA repair. Evidence for recombinational misrepair in the fly is given. The relative ratio of radiation-induced mitotic crossover to spontaneous meiotic crossover is one order of magnitude higher in the fly than in yeast and humans.

Animals↗
PubMed1990

Long-term organ culture of rabbit skin: effect of EGF on epidermal structure in vitro.

A method is described for maintaining the epidermal structure of normal rabbit ear skin explants in organ culture for up to 12 weeks. Split-thickness skin specimens were put in diffusion chambers made of either millipore filters or bovine collagen membranes, and then submitted to a roller tube culture at 15 rpm and 36 degrees C. The culture medium was Dulbecco's modified Eagle's medium (DMEM) supplemented with 20% fetal calf serum (FCS) + 0.4 micrograms/ml hydrocortisone. The gas used in the culture tube was air + 5% CO2. Autoradiography revealed the incorporation of [3H]-glycine into the 68-kD keratin band of explants for up to 12 weeks, indicating that normal keratinization was maintained throughout the entire culture period. The turnover time of the epidermis from basal layer to granular layer was around 7 d in both the early and late stages of culture. The addition of epidermal growth factor (EGF) to the culture caused the epidermis to become acanthotic with orthokeratosis, but with high concentrations of EGF (greater than or equal to 10 ng/ml) parakeratosis and increased proliferation of the epidermis occurred. Dexamethasone (DMS) strongly inhibited the EGF effect.

Animals↗
PubMed1990

Human squamous cell carcinoma from skin: establishment and characterization of a new cell line (HSC-5).

A new cell line, designated as HSC-5 and derived from human skin squamous cell carcinoma (SCC), has been established in vitro and maintained proliferative in continuous tissue culture for over two years. The cells grow in a monolayer in vitro and have anaplastic epithelioid features. The doubling time was about 35 hr at the 30th passage. Chromosome analysis showed hypotetraploidy with a modal number of 76. A trial of transplantation of the cultured cells into nude mice was not successful. Analysis of cytokeratins from HSC-5 by two-dimensional gel electrophoresis revealed polypeptides No. 5, 8, 13, 18 and 19. The cell line is available to other investigators.

Carcinoma, Squamous Cell↗
PubMed1990

Defective DNA repair in cultured melanocytes from xeroderma pigmentosum patients.

The DNA repair of ultraviolet (UV)-induced damages in primary cultured melanocytes from xeroderma pigmentosum (XP) patients and normal subjects were studied by measuring unscheduled DNA synthesis (UDS) on autoradiographs. Melanocytes were cultured in alpha-minimum essential medium (alpha-MEM) supplemented with 10% fetal calf serum (FCS), 12-O-tetradecanoyl-phorbol-13 acetate (TPA), and geneticin. The levels of UDS in XP melanocytes were compared with those in normal melanocytes. In both normal and XP melanocytes, post-UV-UDS increased dose-dependently at doses of 5-10 J/m2. XP melanocytes exhibited various levels of defect in DNA repair, depending on the type of XP. Melanocytes from XP-A patients displayed very low levels of UDS, only 6.2-8.4% that of the normal melanocytes. However, UDS values in melanocytes from intermediate groups, XP-D, XP-E, and XP-F, were relatively high, 37.2-53.5% of the control in XP-D, 50.0-66.5% in XP-E, and 38.2-46.7% in XP-F, respectively. Melanocytes from XP-variant patients exhibited almost normal levels of UDS, 87.7-91.6% of those from normal subjects. The levels of UDS in XP melanocytes were very similar to those in fibroblasts isolated from the same specimens.

Adolescent↗
PubMed1990

The occurrence of alpha (1----2) linked N-acetylperosamine--homopolymer in lipopolysaccharides of non-O1 Vibrio cholerae possessing an antigenic factor in common with O1 V. cholerae.

Chemical analysis was carried out on lipopolysaccharides from Vibrio cholerae bio-serogroup Hakata 487-85. The O-specific chain of the phenol-soluble lipopolysaccharides was demonstrated by 13C-NMR spectroscopy and methylation analysis to contain a linear homopolymer of alpha(1----2) linked N-acetylperosamine (4-acetamido-4,6-dideoxy-D-mannopyranose), which was closely similar to but not identical to a linear alpha(1----2) linked N-3-deoxy-L-glycerotetronyl (S-2,4-dihydroxybutyryl) perosamine-homopolymer constituting that of O1 Vibrio cholerae lipopolysaccharides.

Amino Sugars↗
PubMed1990

Xeroderma pigmentosum group D patient bearing lentigo maligna without neurological symptoms.

A 35-year-old Japanese female patient with xeroderma pigmentosum (XP), registered as XP114TO, was assigned to complementation group D by the cell fusion complementation test. The patient had manifested moderate solar sensitivity and freckles by the age of 6 years. The skin phototest using 290- and 300-nm monochromatic ultraviolet (UV) light revealed slightly lowered minimal erythema doses at 24 h after irradiation. The XP114TO skin fibroblasts exhibited about the 6-fold higher sensitivity to the lethal effect of 254-nm UV as did normal cells. Unscheduled DNA synthesis (UDS) induced in XP114TO cells by 254-nm UV (10 J/m2) was 33% of normal, falling into the group D range of 25-50% UDS. The patient developed lentigo maligna on the right side of the nose. Unlike the typical XP group D cases in the West, she showed no neurological abnormalities.

Adult↗
PubMed1990

Cyclic adenosine monophosphate production and contractile response induced by beta-adrenoceptor subtypes in rabbit urinary bladder smooth muscle.

The spontaneous contractile force of muscle strips isolated from male rabbit urinary bladder dome [detrusor) and base (trigonal muscle) was dose dependently inhibited by isoproterenol, a non-specific beta-adrenoceptor agonist. The relaxant response to 10(-6) M isoproterenol in the detrusor muscle was completely blocked by butoxamine (10(-4) M), a selective beta-2-antagonist, and by propranolol (10(-6) M), a non-specific beta-antagonist, but not by metoprolol (10(-6) to 10(-4) M), a selective beta-1-antagonist. Relaxation of trigonal muscle induced by 10(-6) M isoproterenol was inhibited 30% by metoprolol (10(-5) M), 70% by butoxamine (10(-4)M), and 100% by propranolol (10(-6) M). Terbutaline, a selective beta-2-adrenoceptor agonist, also caused dose dependently a relaxant response in detrusor and trigonal muscle. The maximum relaxant responses to isoproterenol and terbutaline were significantly greater in detrusor than in trigonal muscle. Dobutamine, a relatively specific beta-1-adrenoceptor agonist, caused a small but significant relaxant response in trigonal, but no change in detrusor muscle. In trigonal muscle the relaxant response to dobutamine was less than that to terbutaline. Cyclic adenosine monophosphate accumulation in detrusor did not significantly increase after administration of dobutamine, but significantly increased after administration of terbutaline. On the other hand, not only terbutaline, but also dobutamine, markedly increased cyclic adenosine monophosphate accumulation in trigonal muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗
PubMed1990

Localization of tissue plasminogen activator on experimental thrombi in rats.

The localization of tissue plasminogen activator (t-PA) or urokinase plasminogen activator (u-PA) on thrombi was investigated in disseminated intravascular coagulation rats (DIC rats) induced by thrombin. One hour after the intravenous infusion of thrombin to rats, the plasma fibrinogen level decreased, while the plasminogen activator activity in the plasma euglobulin fraction increased. The whole body autoradiography was studied after an injection of [125I]fibrinogen in DIC rats. The high radioactivity which indicated the presence of microthrombi was observed in the renal cortex, liver, spleen and lung. Furthermore, a large venous thrombus with higher radioactivity was observed in the abdominal vena cava. These results show that the thrombin-treated animal is one of the best DIC models. After the intravenous administration of [125I]t-PA, the autoradiograms of DIC rats showed a radioactivity in the blood and much higher radioactivities in the renal cortex, spleen and lung in comparison with the normal rat. However, there was no difference in the distribution of [125I]u-PA between normal and DIC rats at all. The strong radioactivity of [125I]t-PA but not [125I]u-PA was observed on the surface of large thrombus in the vena cava. These results suggest that t-PA localizes more preferentially on microthrombi than u-PA. The ratio of the radioactivity in the tissue to that in the blood was calculated to compare quantitatively the localization of [125I]t-PA and [125I]u-PA on microthrombi formed in organs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Rational risk estimation in relation to atomic bomb radiation.

This paper summarizes genetic and somatic data on persons exposed to low doses of atomic bomb radiation in Hiroshima and Nagasaki. Compared with experimental estimates, the new dosimetry system proposed in 1986 underestimates neutron doses, supporting qualitatively the conclusion by the 1965 dosimetry system that Nagasaki A-bomb emitted predominantly gamma rays whereas Hiroshima A-bomb emitted both gamma rays and fast neutrons. A theory based on two recessive mutations in hemopoietic stem cells is proposed to explain radiation leukemogenesis. The theory can explain, at least partly, the actual dose-response curve for incidences of acute leukemia in Hiroshima but cannot explain chronic leukemia in Nagasaki. Existence of a large threshold dose in the latter's dose relationship supports the hypothesis that A-bomb radiation at high doses above a threshold value was a promoter and/or progressor of leukemia. Various lines of evidence that support this hypothesis are presented. Hence, it is not warranted to assume that risk of death from cancer at a high dose, say, 1 Gy can be divided by 100 to obtain the risk at 1 cGy. Risk at low doses should be assessed by direct scrutiny of actual data at low doses in spite of their large statistical uncertainty. Actual data show that A-bomb survivors at 1-9 cGy had apparently lower incidences of tumors than unexposed persons.

Adult↗
PubMed1990

Effects of a low, oral dose of nisoldipine on the systemic and coronary hemodynamics and the prostaglandin metabolism of ischemic heart disease patients.

This study investigated the effects of a low dose of nisoldipine (5 mg, p.o.) in 10 patients with ischemic heart disease. The patients were subjected to a 90-min exercise regimen before and after a 5 mg dose of nisoldipine, using a supine bicycle ergometer adjusted to each patient's limitations. The mean blood plasma level of nisoldipine was 3.8 +/- 3.1 (SD) ng/ml. The drug significantly decreased the systolic arterial pressure in patients throughout the experimental session, whereas a change in the diastolic arterial pressure appeared only at the submaximal stage of the exercise. Additionally, at maximal exercise, nisoldipine caused a decrease in the mean coronary sinus pressure from 11.4 +/- 7 mmHg to 6.5 +/- 5 mmHg (p less than 0.01). By contrast, while at rest, nisoldipine decreased the coronary vascular resistance from 1.5 +/- 0.7 mmHg/ml/min to 1.0 +/- 0.7 mmHg/ml/min (p less than 0.05). After exercise, the drug decreased thromboxane B2 levels from 1133 +/- 907 pg/ml to 720 +/- 379 pg/ml (p less than 0.05) in the coronary sinus blood, and increased the 6 keto-prostaglandin F1 alpha levels from 465 +/- 135 pg/ml to 559 +/- 167 pg/ml (p less than 0.05) in brachial artery blood. This suggests that a low, oral dose of nisoldipine can moderately improve the systemic and coronary hemodynamics and afterloads, and may assist in improving the prostaglandin metabolism in ischemic heart disease patients.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

[Investigation on thermal-neutron sensitivity of commercial BeO(Na) thermoluminescence dosimeter and development of thermal-neutron insensitive BeO(Na) phosphors encapsulated in quartz-capillary].

BeO(Na) TLD on the market, UD-170 L, gives thermoluminescence response equivalent to irradiation with 3.2 +/- 0.5 cGy of 60Co gamma-rays after irradiation with 10(10) thermal neutrons per cm2. Because of this neutron sensitivity, UD-170 L is not suitable for measurement of gamma-rays in gamma-neutron mixed radiation from a nuclear reactor of Kinki University when we use it for radiobiological research. To reduce this troublesome sensitivity, we replaced the glass capillary used for UD-170 L with a quartz capillary. Quartz tube encapsulated BeO(Na) showed a markedly reduced response to thermal neutrons.

Equipment Design↗
PubMed1990

[Movements of facial surface in edentulous patients].

The purpose of this study was to investigate the influence of complete denture on the movement of the soft tissues surrounding the oral cavity during oral function. Total of 71 clinically healthy edentulous patients were selected for this study. Forty-seven points on the skin surface of the face of each subject were selected as measuring points and were marked. The movement of these measuring points under the condition of thrusting of the lips, pulling the mouth corners backward, intentional occlusion and smile were measured three-dimensionally when the denture was worn and not worn. The findings were as follows: 1. The changes in the facial structure with and without the denture were marked in the lips. 2. The changes in the movement of the measuring points on the lip surface with and without the denture were found to be large during the thrusting of the lips and pulling the mouth corners backward. 3. The changes in the movement of the measuring points in the lower parts of the facial surface with and without the denture could be measured over a wide range during intentional occlusion. 4. Activities of the mouth corner points were marked, but the changes in the movement with and without the denture were insignificant.

Adult↗