Search PubMed⌕ Search

Biomedical subjects

Y Yoshimoto

Publications and source records attributed to Y Yoshimoto.

At least 127 records · Page 7Linked to original sources
PubMed1989

Implications of the Hiroshima-Nagasaki genetic studies for the estimation of the human "doubling dose" of radiation.

Since 1946 a continuous effort to evaluate the potential genetic effects of the atomic bombs has been sustained. Observations on children born in Hiroshima and Nagasaki include sex ratio, congenital malformations, stillbirths, survival of liveborn infants, chromosomal abnormalities (sex chromosomal abnormalities and balanced chromosomal rearrangements), mutations altering protein structure or activity, and physical growth and development. There are no statistically significant differences between the children of parents who received increased amounts of radiation at the time of the bombings and those whose parents did not. However, the difference between the two sets of children is consistent with the hypothesis of a genetic effect of the exposure, but its magnitude suggests humans are not as sensitive to the genetic effects of radiation as projected from the mouse paradigm.

Adolescent↗
PubMed1989

Ovulation following combined therapy with wen-jing-tang and clomiphene citrate therapy in anovulatory women.

The effect of combined therapy with Wen-Jing-Tang and clomiphene citrate on anovulation was studied in 16 infertile patients who did not respond to clomiphene citrate alone. Wen-Jing-Tang was given at a dose of 5 g a day every day from day 2 of the menstrual cycles and clomiphene citrate was given at 150 mg a day for 5 days from day 5 of the cycle. Ovulation occurred in 43.8% of the patients and 48.6% of the cycles. No case of ovarian hyperstimulation syndrome or pregnancy were observed. These results suggest that the combined therapy with Wen-Jing-Tang and clomiphene citrate should be used before therapy with human menopausal gonadotropin.

Adult↗
PubMed1989

[Basic studies on CaO-P2O5-MgO-SiO2-CaF system glass ceramics. 1. Morphology under the phase-contrast microscope and growth of cultured cells].

In order to determine the biocompatibility of glass ceramics which is one of the new biomaterials, in vitro studies were carried out by a cell culture method using four established cell lines. Materials used were glass ceramic disks with a diameter of 3 mm, and polystyrene coverslips of the same size as controls of the growth curve. Cells of each line were inoculated into 24-well multiplates at an appropriate density onto glass ceramic disks, and examined by phase contrast microscopy on the 1st, 3rd, 6th and 8th day. In addition, doubling time and saturation density were calculated from the growth curve. The results obtained were as follows. 1) Phase-contrast microscopy revealed that cells of each line attached to the disk within 24 hours and their numbers increased with time. After 8 days of cultivation, all of them reached confluence. 2) Contact with the glass ceramics did not cause cellular death or degeneration. Furthermore, the cultured cells showed the same morphological features as the control cells. 3) According to the growth curves, doubling time of all cells cultured with glass ceramics was shorter than that of the control cultures. On the other hand, saturation density was reduced to a minimum of 80% of the controls. These findings led to the conclusion that glass ceramic materials do not prevent the growth of cultured cells. According to the above results, glass ceramics possess the characteristics needed for bone grafts and implant materials.

Cell Line↗
PubMed1989

[Basic studies on CaO-P2O5-MgO-SiO2-CaF system glass ceramics. 2. Ultrastructural study on interface between culture cells and glass ceramics].

The aim of this study was to determine biocompatibility of glass ceramics and adhesion of cultured cells to glass ceramics. Four established cultured cell lines, human fibrosarcoma cells (HT-1080), human gingival carcinoma cells (Ca9-22), human osteosarcoma cells (NY) and mouse osteoblasts (MC3T3-E1), were used. For phase-contrast and electron microscopic observation they were cultured on substrates of glass ceramics or polystyrene coverslips as a control. The results obtained were as follows. Glass ceramics caused neither cellular degeneration nor death, as revealed by phase-contrast microscopy. By transmission electron microscopy an amorphous structure similar to the basal lamina was observed at the interface between the substrates and Ca9-22, and between glass ceramics and NY. A similar structure sometimes existed between the substrates and MC3T3-E1. On the other hand HT-1080 showed no such structure. The findings suggest that the biocompatibility of glass ceramics was satisfactory. Furthermore, from the clinical point of view it seems to be possible to close the material-tissue interface with epithelial, fibrocytic and osteocytic cells.

Animals↗
PubMed1989

Mechanism of the damaging effect of dermatomyositis mononuclear cells on cultured human skin fibroblasts.

We further studied the mechanism of action of peripheral mononuclear cells (MNC) from patients with dermatomyositis (DM) to strikingly suppress fibroblast proliferation in vitro. Attachment of MNC to fibroblasts was closely related to the mechanism. Most of attached MNC were activated T lymphocytes. Conditioned medium alone did not show any effects on fibroblasts. T8 positive cells and monocytes were essential to elicit the effect. Study of 51Cr release demonstrated that DM MNC augmented cytolysis of fibroblasts. It might be concluded that DM MNC possess T lymphocyte mediated cytotoxicity on fibroblasts and this causes the inhibition of fibroblast proliferation.

Adolescent↗
PubMed1989

Fluorescent antibodies in polymyositis using cultured human skin fibroblasts: granular perinuclear cytoplasmic staining pattern by sera from patients with polymyositis and pulmonary fibrosis.

Immunofluorescent antibodies were studied in sera from 48 patients with polymyositis (PM) and 149 control subjects using cultured human skin fibroblasts as substrate. Forty-six (95.8%) of PM sera showed a positive reaction. Among them, a characteristic granular perinuclear cytoplasmic staining was seen in 8 sera, including 4 with anti-Jo-1. Four of these 8 sera showed positive staining on HEp-2 cells with the same pattern. All patients showing this pattern of staining had pulmonary fibrosis which was not seen in control patients. Consequently, this staining pattern might be a specific marker for a subset of patients with PM with pulmonary fibrosis.

Adult↗
PubMed1989

Risk of cancer among children exposed to atomic bomb radiation in utero: a review.

We have examined the risk for cancer (incidence) over a period of 40 years, 1945-1984, among 1829 persons exposed in utero to the atomic bombing of Hiroshima and Nagasaki. This report adds eight years of follow-up to a previous report which was confined to mortality. Only two cases of childhood cancer were observed among these survivors in the first 14 years of life; both had been heavily exposed. Subsequent cancers have all been of the adult type. Not only did these latter cancers occur earlier in persons exposed to greater than 0.30 Gy than in unexposed (0 Gy) but the incidence continues to increase, and the crude cumulative incidence rate 40 years after the bombing is 3.9-fold greater in persons exposed to greater than 0.30 Gy. In the observation period 1950-1984, the relative risk for cancer at 1 Gy, based on the absorbed dose to the mother's uterus as estimated by the Dosimetry System 1986 (DS86), is 3.77 with a 95% confidence interval of 1.14-13.48. For all persons exposed to greater than 0.01 Gy, the average excess risk per 10(4) person-year-Gy is 6.57 (0.07-14.49), and the estimated attributable risk is 40.9% (2.9-90.2%). These results, when viewed in the perspective of fetal doses, suggest that susceptibility to radiation-induced cancers is higher in survivors exposed prenatally than in those exposed postnatally (at least, those exposed as adults). However, definitive conclusions must await further follow-up studies.

Female↗
PubMed1989

Anaphylactic symptoms due to chlorhexidine gluconate.

Six patients who developed urticaria, dyspnea, and anaphylactic shock due to topical application of chlorhexidine gluconate solution are described. Chlorhexidine gluconate was confirmed as the causative agent of type I hypersensitivity by intradermal, scratch, and epicutaneous tests. To prevent life-threatening adverse reactions, it seems important to use chlorhexidine gluconate on wound surfaces at a concentration of 0.05%, as recommended by the manufacturer; chlorhexidine gluconate may not be suitable for application to mucous membranes.

Adolescent↗
PubMed1988

Risk of cancer among children exposed in utero to A-bomb radiations, 1950-84.

This study examines the risk of cancer (incidence) over 40 years among the in-utero exposed survivors of the atomic bombing of Hiroshima and Nagasaki, and adds eight years of follow-up to a previous report confined to mortality. Only two cases of childhood cancer were observed among these survivors in the first 14 years of life; both had been heavily exposed. Subsequent cancers have all been of the adult type. Not only did the observed cancers occur earlier in the 0.30 + Gy dose group than in the 0 Gy dose group but also the incidence continues to increase, and the crude cumulative incidence rate, 40 years after the A-bombing, is 3.9-fold greater in the 0.30 + Gy group. In the observation period 1950-84, based on the absorbed dose to the mother's uterus as estimated by the 1986 dosimetry system (DS86), the relative risk of cancer at 1 Gy is 3.77 with a 95% confidence interval of 1.14-13.48. For the entire 0.01 + Gy dose group the average excess risk per 10(4) person-year-gray is 6.57 (0.07-14.49) and the estimated attributable risk is 40.9% (2.9-90.2%). These results, when viewed in the perspective of fetus doses, suggest that susceptibility to radiation-induced cancers is higher in prenatally than in postnatally exposed survivors (at least those exposed as adults). However, definitive conclusions must await further follow-up studies.

Adolescent↗
PubMed1988

Dynamic organization of Physarum plasmodium.

Birefringent fibrils (BRFs) with a positive sign composed of bundles of F-actin were found throughout the Physarum plasmodium with the mode of existence differing regionally. In the zone behind the leading edge of an advancing plasmodium, where cytoplasmic sol and gel were still not well differentiated, more BRFs came to the foreground when the endoplasm flowed backward (emptying phase), and a substantial portion disappeared when the endoplasm flowed forward (filling phase), except for nodes, from which BRFs were reorganized in the early emptying phase of each cycle. BRFs found in the wall of the streaming channel in the posterior network and the branched vein section ran in parallel to or helically around the channel. They were much more stable and maintained strong birefringence irrespective of the direction of the cytoplasmic flow. When the fan-like expanse ceased moving forward, the BRFs no longer appeared and disappeared cyclically but persisted in the area which had previously been the front. We concluded that the site of the active contraction-relaxation rhythm in an advancing plasmodium with antero-posterior polarity is restricted to its frontal zone and that the rest of the plasmodium is in a state of "tonus" which continuously imparts a certain level of hydrostatic pressure to the interior. The meaning of the tonus and the mechanics of tensile force production in the plasmodium are discussed in terms of a working hypothesis arrived at from the phase relationship between isometric and isotonic contraction waves.

Birefringence↗
PubMed1988

Mechanism of Ca2+ release in medaka eggs microinjected with inositol 1,4,5-trisphosphate and Ca2+.

The reaction time of Ca2+ release from cytoplasmic stores induced by microinjection of inositol 1,4,5-trisphosphate (IP3), calcium ionophore A23187, Ca2+, Sr2+, Ba2+, and cyclic guanosine 5'-monophosphate (cGMP) in Oryzias latipes eggs in Ca2+-free medium was measured by the luminescence of aequorin injected into the egg. Microinjection of IP3 or calcium ionophore induced rapid Ca2+ release without a time lag, while microinjection of either Ca2+ or cGMP required a time lag of 5-30 sec for Ca2+ release. Following microinjection of both IP3 and Ca2+, Ca2+ release commenced in a cytoplasmic region close to the egg surface. These results suggest that in the medaka egg, cytoplasmic Ca2+ induces Ca2+ release from cytoplasmic stores indirectly, probably via a membrane factor such as IP3.

Aequorin↗
PubMed1988

Cytoplasmic Ca2+ release induced by microinjection of Ca2+ and effects of microinjected divalent cations on Ca2+ sequestration and exocytosis of cortical alveoli in the medaka egg.

Intracellular release of Ca2+ by microinjection of Ca2+ was analyzed by measuring the luminescence of aequorin loaded in eggs of the medaka (Oryzias latipes). Microinjection of Ca2+ into the cortical cytoplasm induced propagative waves of cytoplasmic Ca2+ release and exocytosis of cortical alveoli initiated at the injection point. The Ca2+ wave was initiated with a time lag after some was sequestered at the region of the microinjection. Microinjection of Mg2+ or Mn2+ failed to trigger Ca2+ release and exocytosis. When the aequorin-loaded eggs were inseminated after microinjection of Mg2+, Mn2+, or Co2+ into a restricted region of the vegetal hemisphere, the wave of Ca release was propagated through the injected region toward the vegetal pole, but neither Ca sequestration (fall in Ca-aequorin luminescence) nor exocytosis occurred at the area of cortex where the eggs were injected with these divalent cations. These results suggest that a significant period is required to induce Ca2+ release from cytoplasmic stores by the increased Ca2+ concentration and that both the phenomena of Ca2+ release and Ca sequestration are involved in the process of exocytosis.

Animals↗
PubMed1988

Enterotoxigenicity of Staphylococcus intermedius of canine origin.

Seventy-three staphylococcal strains isolated from pyrodermatitis in dogs were classified as Staphylococcus intermedius (52 strains) or Staphylococcus aureus (21 strains) on the basis of acetoin formation, anaerobic mannitol fermentation, aerobic maltose fermentation, pigmentation, coagulation of human plasma, and reaction on crystal violet agar. Enterotoxin was produced by 13 of the 52 S. intermedius strains and 6 of the S. aureus strains. The highest percentage of enterotoxigenic strains produced enterotoxins C (6 strains), D (7 strains), and E (6 strains). Four strains produced the toxic shock syndrome toxin-1. There was little difference in the antibiotic susceptibility between the enterotoxigenic and non-enterotoxigenic strains.

Animals↗
PubMed1988

A case of membranous lipodystrophy complicated by Fanconi's syndrome.

A case of membranous lipodystrophy complicated by Fanconi's syndrome is described. A 40-year old man complaining of pain in his legs was admitted to our hospital. Roentgenograms showed cystic changes in the long bones. Biopsy of the affected lesion of the femur revealed a peculiar membranocystic structure in the marrow that is typical of membranous lipodystrophy. He had a neuropsychiatric disorder which is often associated with this disease. Laboratory studies were remarkable for renal proximal tubular dysfunction, i.e., Fanconi's syndrome. Membranous lipodystrophy is a rare, hereditary disease that has been reported mainly from Japan and Finland. This is the first case of this disease complicated by Fanconi's syndrome. The possible relationship between these disorders is discussed.

Adult↗
PubMed1988

Clinico-statistical study on acoustic tumors with sudden hearing loss.

Acoustic tumors associated with sudden hearing loss were studied clinico-statistically to clarify the differential diagnosis between so-called sudden deafness and acoustic tumor of this type. A significant difference was found in the frequency of such abnormalities as gaze nystagmus, canal paresis in the caloric (nystagmus) test, inhibition of optokinetic nystagmus, dilatation of the internal auditory canal, and cranial nerve signs. However, there was no significant difference in such symptoms as preceding upper respiratory tract infection and rotatory vertigo at the onset of sudden deafness. In this study, most of the patients with sudden deafness had tumors of 2 cm or larger in diameter. Apart from the atypical feature of sudden onset, the acoustic tumors of this type have several characteristics. Therefore, the differential diagnosis of two diseases is not difficult if the possibility of acoustic tumor is taken into consideration and the above tests are performed for equivocal cases. The CT scan provides the most useful information for making a definite diagnosis of acoustic tumors in cases of this type.

Audiometry, Pure-Tone↗
PubMed1988

Lunch induces an increase in the plasma prolactin concentration, but not vasoactive intestinal peptides or cholecystokinin.

Ingestion of lunch is known to be associated with acute release of prolactin (PRL). The neuroendocrine mechanism of this release was examined by measuring changes in serum vasoactive intestinal peptides (VIP) and cholecystokinin (CCK) after the noon meal in six normal men. The serum PRL concentration was significantly increased (40% above the level before lunch) from 30 min to 1 h 45 min after beginning to eat. However, the ingestion of lunch had no remarkable effects on the plasma immunoreactive concentration of VIP and CCK. Thus the changes in the plasma concentration of these two gut-brain peptides did not coincided with acute PRL release after ingestion of lunch, suggesting either that these two gut-brain peptides are probably not involved in PRL release after lunch, or that the level of these two gut-brain peptides in the general circulation may not represent that in the hypophyseal portal plasma.

Adult↗