Showing papers by "Kanazawa Medical University published in 1989"
TL;DR: DNA sequencing analysis revealed two types of cDNA clones from the sno (ski-related novel gene) gene, possibly due to alternative splicing, which is highly homologous with the v-ski protein.
Abstract: cDNA clones of ski and the ski-related gene, sno, were obtained by screening human cDNA libraries. The predicted open reading frame of h-ski could encode a protein of 728 amino acid residues. The h-ski protein is highly homologous with the v-ski protein. The overall homology between h-ski and v-ski is 91% at the amino acid level. DNA sequencing analysis revealed two types of cDNA clones from the sno (ski-related novel gene) gene, possibly due to alternative splicing. The first type, named snoN (non Alu-containing), encoded a protein of 684 amino acid residues. The second type, named snoA (Alu-containing), encoded a protein of 415 amino acid residues. The first 366 amino acid residues of snoN and snoA are the same, but subsequent amino acids show divergence. Several transcripts of h-ski (6.0, 4.7, 3.8, 3.0, 2.1 and 1.8 kb) were detected. The mRNAs of h-sno were 6.2, 4.4 and 3.2kb.
169 citations
TL;DR: It is suggested that bFGF is not essential as an autocrine or paracrine growth factor for angiogenesis in vivo because they block its biological activity.
Abstract: Two monoclonal antibodies (mAbs) against bovine heparin-binding growth factor II (HBGF-II)/basic fibroblast growth factor (bFGF) were obtained from mouse hybridoma cell lines. They were highly specific for bFGF from bovine, human, and mouse sources and did not cross-react with bovine heparin-binding growth factor I (HBGF-I)/acidic fibroblast growth factor (aFGF). The immunoglobulin class and subclass of these mAbs were IgG1, K. The apparent dissociation constant (Kd) for bFGF of these mAbs ranged from 10(-9) to 10(-10) M. One mAb (bFM-2) also cross-reacted with heat-inactivated bFGF, while the other mAb (bFM-1) did not, suggesting that bFM-1 recognized the conformation of the bFGF molecule necessary for its biological activity. These mAbs inhibited growth of cultured bovine capillary endothelial cells in both the presence and absence of exogenous bFGF, indicating the autocrine action of this growth factor in in vitro growth of these cells. On the other hand, injection of these hybridoma cell lines s.c. into the backs of athymic mice resulted in development of highly vascularized solid tumors and a sustained high level of anti-bFGF activity in the blood of the tumor-bearing mice. These findings suggest that bFGF is not essential as an autocrine or paracrine growth factor for angiogenesis in vivo. These mAbs should be useful in further studies on the physiological role and the conformation-function relationship of bFGF because they block its biological activity.
167 citations
TL;DR: This paper presents a systematic study of the response of the immune system to certain types of drugs and investigates its role in the development of Parkinson's disease.
111 citations
TL;DR: The results suggest that IL-6 produced by macrophages may play an important role in the growth of myeloma cells in vivo and that macrophage-derived factors or IL- 6 can be used for establishing humanMyeloma cell lines.
Abstract: Two IL-6-dependent human multiple myeloma cell lines, ILKM2 and ILKM3, were established from the bone marrow of patients with IgG-K multiple myeloma. Both cell lines had the typical morphology and immunocytochemical features of myeloma cells. The surface phenotype of both cell lines was PCA-1+, OKT10+, CD10(J-5)-, CD19(B4)-, CD20(B1)-, CD21(B2)-, and OKIa-1-. A monoclonal cytoplasmic Ig, IgG-K or K L chain, was positive in ILKM2 or ILKM3, respectively. EBV nuclear antigen was negative in both cell lines. They proliferated in the presence of macrophages or macrophage-derived factors (MDF). Among the recombinant cytokines examined, IL-6 most strongly augmented the growth of both cell lines. The anti-IL-6 antibody completely inhibited the IL-6-dependent growth and almost completely inhibited the MDF- or purified MDF-dependent growth of both cell lines, ILKM2 and ILKM3 are now being maintained in the culture medium containing 2 ng/ml rIL-6. These results suggest that IL-6 produced by macrophages may play an important role in the growth of myeloma cells in vivo and that macrophages or IL-6 can be used for establishing human myeloma cell lines.
106 citations
TL;DR: Cadmium exposure was found to affect health in a dose-related manner when the subjects were classified according to the average cadmium concentration in their village rice and their length of residence in the polluted area.
99 citations
TL;DR: A three‐dimensional, in vivo method for determining the position of implanted intraocular lenses (IOLs) using an image‐processing technique has been developed and provides several kinds of biometry in pseudophakic eyes.
Abstract: A three-dimensional, in vivo method for determining the position of implanted intraocular lenses (IOLs) using an image-processing technique has been developed. Two images of the anterior segment of the eye with an implanted IOL were photographed with a Scheimpflug camera at slit-lamp angles of 90 degrees and 180 degrees. After geometrical correction, the contours of the original images were enhanced using binarization and curve-fitting techniques. These images afforded calculation of the angle of tilt of the IOL optic axis relative to a standard reference line which connected the center of anterior corneal surface curvature with the geometrical center of the pupil. The extent and direction of IOL decentration could also be shown. The IOL image in the posterior chamber was expressed as a wire-frame figure. This method provides several kinds of biometry in pseudophakic eyes.
61 citations
TL;DR: Estimating the biological threshold value of urinary Cd concentration in inhabitants exposed to environmental Cd in environmentally Cd-exposed populations and measuring the dose-response relationship between urinary cadmium (Cd) and beta 2-microglobulin (beta 2-mg) is carried out.
57 citations
TL;DR: The major components of SMP, which were purified about 100-fold from conditioned medium, stimulated DNA synthesis in human fibroblasts in culture and sulfation in chick embryonic cartilage in culture, showed almost the same cross-reactivity as multiplication-stimulating activity III-2 on RIA with the MAb.
Abstract: Somatomedin/insulin-like growth factor (IGF)-like polypeptides (designated SMP) were purified from the serum-free conditioned medium of cultured rat epithelial-like cells, 18,54-SF. A monoclonal antibody (MAb) was produced against partially purified SMP. The antibody was immunoglobulin Gi relatively specific for multiplication-stimulating activity III-2 (rat IGF-II), with a Kd value of 5.6 × 10-9 M. The antibody showed 100% cross-reactivity with human IGF-II and 10% crossreactivity with human IGF-I, but did not cross-react with insulin. For purification of SMP, therefore, immunoaffinity chromatography on Sepharose coupled with the MAb was used besides a procedure including ion exchange chromatography, gel filtration, and reverse phase HPLC. The purified SMP (at least five polypeptides) each gave a single peak on reverse phase HPLC and appeared as a single band with an apparent mol wt of 5000–8000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The major components of SMP (designated HPl-SMP ...
49 citations
TL;DR: It is indicated that exposure to cadmium could cause marked osteopenia, particularly in the women, as well as men and women living in the three different non-polluted areas.
Abstract: Bone density was measured in 28 women with itai-itai disease, 92 men and 114 women with cadmium-induced renal dysfunctions and 44 men and 66 women living in the three different non-polluted areas using a microdensitometer. The values of both indices corresponding to cortical width and bone mineral content were significantly lower in itai-itai disease patients than the cadmium-exposed women with renal dysfunctions and the non-exposed subjects. The cadmium-exposed women also showed a decrease in bone density compared with the non-exposed subjects. A significant decrease in bone density was also observed between cadmium-exposed men and the non-exposed subjects, although the difference was not as clear as in the women. The present study indicates that exposure to cadmium could cause marked osteopenia, particularly in the women.
47 citations
Journal Article•
TL;DR: The antitumor effect of ECS seen in the allogeneic mice was significantly reduced when the mice received whole body X-irradiation (5 Gy) before EAC implantation, and results suggest that the antitumors effect ofECS may be mediated through its immunomodulating action.
Abstract: A warm water-extract (ECS) prepared from dried Cordyceps sinensis (Berk.) Sacc., a Chinese traditional medicine, was tested for antitumor activity in vivo and in vitro. Ehrlich ascites carcinoma cells (EAC), allogeneic to ICR mice and Meth A fibrosarcoma (Meth A), syngeneic to BALB/c mice were used as the target tumor cell lines. Mice were inoculated i.p. with 1 x 10(6) EAC or 1 x 10(5) Meth A on Day 0, and ECS or saline (control) was injected i.p. to the mice from Day 1 to Day 4. ECS-treatment increased the median survival time of the allogeneic mice inoculated with EAC to 316% of the control. Eight of the 10 ECS-treated mice survived on the 60th day (Day 60) after EAC implantation. ECS-treatment also increased the median survival time of the syngeneic mice inoculated with Meth A to 312% of the control. Half of the ECS-treated mice survived on Day 60. On the other hand, no cytotoxic effect of ECS was found on either EAC or Meth A in vitro. The antitumor effect of ECS seen in the allogeneic mice was significantly reduced when the mice received whole body X-irradiation (5 Gy) before EAC implantation. These results suggest that the antitumor effect of ECS may be mediated through its immunomodulating action.
46 citations
TL;DR: It is suggested that both epinephrine and norepinephrine facilitated the viability of meiotic prophase spermatocytes and that a part of the meiotics pro phase sperMatocytes completed the meiotic divisions in the testicular cell culture.
Abstract: Dispersed testicular cells prepared from 14-d-old rats were cultured on type 1 collagen gels using a medium composed of a 1:1 mixture of Ham's F12 medium and Leibovitz's L15 medium (F12-L15 medium) containing 10% (vol/vol) fetal bovine serum. The viability of the spermatogenic cells was facilitated by supplementing a rat adrenal extract into the medium. The effective substance(s) (the survival factor) was purified from acid extracts of adrenals by molecular sieve high performance liquid chromatography and identified as epinephrine and norepinephrine. Both epinephrine and norepinephrine promoted the survival of the spermatogenic cells with a half saturating dose of 10 ng/ml. The spermatogenic cells, which could be cultured for 2 wk on a collagen gel by supplementing with the survival factor (epinephrine or norepinephrine), were subjected to Giemsa staining and to DNA flow cytometry. The following results were obtained: a) The spermatogenic cells from 14-d-old rats did not contain spermiogenic cells (1c-cells). b) During a culture period of 2 to 7 d the ratio of meiotic prophase spermatocytes (4c-cells) to premeiotic cells (2c-cells) increased. On Day 7, more than 90% of the surviving cells were meiotic prophase spermatocytes. c) On Day 10, spermatids (1c-cells) appeared for the first time. The time of the first appearance of spermatids in the culture was consistent with that in vivo. These results suggest that both epinephrine and norepinephrine facilitated the viability of meiotic prophase spermatocytes and that a part of the meiotic prophase spermatocytes completed the meiotic divisions in the testicular cell culture.
TL;DR: The data showed that nonstructural proteins NS3 and NS5 were membrane-associated proteins and suggest that NS5 and NS3 may play specific role(s) in flavivirus RNA replication.
TL;DR: Anti-HCMV antibodies markedly inhibited the binding of 125I-labelled human IgG Fc to the 130K and 50K species but inhibited to a lesser extent the binding to the 65K FcR.
Abstract: Immunoglobulin G Fc receptors (IgG FcRs) induced by human cytomegalovirus (HCMV) were isolated from solubilized HCMV-infected cell extracts by IgG affinity chromatography and analysed by Western blotting using 125I-labelled human IgG and Fc. FcR species of Mr 130K, 65K, 50K and 38K were found to mediate the binding of IgG. The 130K and 65K FcRs were also detected on HCMV virions. All four FcRs were reactive with a murine monoclonal antibody to herpes simplex virus glycoprotein E. Anti-HCMV antibodies markedly inhibited the binding of 125I-labelled human IgG Fc to the 130K and 50K species but inhibited to a lesser extent the binding to the 65K FcR.
TL;DR: In this article, a brain stem type neuro-Behcet's syndrome was studied with enhanced CT and MRI during the acute and chronic stage of the illness, and the lesion became low in signal intensity with T2-weighted image and reduced in its size without enhancement in brain CT.
Abstract: Brain stem type neuro-Behcet's syndrome was studied with enhanced CT and MRI during the acute and chronic stage of the illness. During the acute stage, brain CT revealed a low density lesion in the brain stem extending from the lower pons up to the midbrain ventrolaterally with marginal enhancement effect. T2-weighted image showed a high signal intensity lesion in the brain stem which mainly involved the basis ponti, tegmentum, tectum and cerebral peduncle. During the chronic stage, the lesion became low in signal intensity with T2-weighted image and reduced in its size without enhancement in brain CT. The prolonged relaxation time of the lesions was gradually normalized with steroid treatment. Sequential brain CT with enhancement and MRI study with T1- and T2-weighted images were useful to detect the lesions and to evaluate the activity in the neuro-Behcet's syndrome.
TL;DR: Results indicate that the reduction of hepatic low‐Km aldehyde dehydrogenase activity is a change that occurs subsequent to liver damage, which may be important in the pathogenesis of alcoholic liver injury.
TL;DR: Each of the three patients reported here presented with an epidural mass as the initial clinical manifestation of malignant lymphoma, taking a skeptical view of the existence of “primary” spinal epidural lymphoma.
Abstract: Three patients with non-Hodgkin's lymphoma involving the spinal epidural space are reported. All three patients, a 3-year-old boy (Case 1), a 63-year-old female (Case 2), and a 64-year-old male (Case 3), manifested signs and symptoms of neurological involvement before the diagnosis of malignant lymphoma was established by tissue examination. The tumors were located in the thoracic (Case 3) and thoracolumbar regions (Cases 1 and 2). The initial signs and symptoms of all cases were low back pain and progressing myelopathies. Bony abnormalities of the vertebrae, seen on both plain X-rays and computed tomographic scans, were unremarkable except for bilateral L 1 pedicle erosion observed in Case 2. Total or subtotal tumor removal was followed by radiation therapy with or without chemotherapy in all cases. The primary lesion in Case 1 was a paravertebral lymphoma that had invaded the adjacent thoracolumbar epidural space through the intervertebral foramina. In Case 2, the primary lesion, documented by post-mortem examination, was a submucosal lymphoma of the stomach. In Case 3, the site of primary lesion could not be determined, although splenic and retroperitoneal nodal involvement was found at autopsy. The authors take a skeptical view of the existence of “primary” spinal epidural lymphoma, which has been reported a few times. Each of the three patients reported here presented with an epidural mass as the initial clinical manifestation of malignant lymphoma.
TL;DR: The facial position and balance of eyes, nose, and mouth in typical Japanese individuals were investigated and it was found that Japanese tend to have a longer upper lip and shorter chin length compared with Caucasians.
Abstract: The facial position and balance of eyes, nose, and mouth in typical Japanese individuals were investigated, based on the golden proportion for each of these relationships. We found that Japanese tend to have a longer upper lip and shorter chin length compared with Caucasians. We believe that this tendency represents a general facial characteristic of the Oriental population. Each ratio obtained from determinations by our method was used for preoperative and postoperative aesthetic analysis in maxillofacial surgery. This method is considered useful because it permitted us to understand quantitatively the positional relationship and the balance of eyes, nose, and mouth in the face and to make comparisons with typical subjects.
TL;DR: Results imply that the catalysis of steady-state ATP hydrolysis can proceed even if one of the three beta subunits in F1-ATPase is not functional.
Abstract: Homogeneous populations of hybrid alpha 3 beta 3 gamma complexes of the thermostable F1-ATPase containing one, two, or three copies of the mutationally impaired beta subunits were produced using the solid phase reconstitution method. Two kinds of mutated beta subunits were used for the reconstitution, one of which lacked the ability to bind any adenine nucleotides. The complexes containing one impaired beta and two wild-type beta subunits retained a significant amount of ATPase activity with cooperative kinetics, whereas those containing two or three impaired beta subunits showed very little ATPase activity. These results imply that the catalysis of steady-state ATP hydrolysis can proceed even if one of the three beta subunits in F1-ATPase is not functional.
Journal Article•
TL;DR: The results suggest that melanin influences the intraocular dynamic mode of a new quinolone agent, NY-198, and that useful information about the influence of melanin in the drug dynamics of ocular tissues can be obtained from in vitro experiments.
Abstract: The influence of melanin on the intraocular dynamics of a new quinolone anti-bacterial agent, NY-198, was investigated in albino and pigmented rabbit eyes. Drug uptake into the cornea of the removed eye was almost the same in both albino and pigmented eyes. However, drug uptake into the iris-ciliary body and release volume and time from the tissues were significantly higher and longer in pigmented eyes than in albino rabbit eyes. Penetration of NY-198 into the cornea, the iris-ciliary body and the serum, administered either systemically or locally into the living eyes of pigmented rabbit was significantly higher than that observed in albino rabbit eyes. Drug affinity for melanin was examined utilizing synthetic melanin. Regarding OFLX, NY-198, CEZ, LMOX, CMX, SISO and TOB, drug-melanin combined ratios ranged from 9.1% to 95.5%. SISO and TOB showed antibacterial activity reduction against E, Coli and B. Subtilis. The results suggest that melanin influences the intraocular dynamic mode of a new quinolone agent, NY-198, and that useful information about the influence of melanin in the drug dynamics of ocular tissues can be obtained from in vitro experiments.
Journal Article•
TL;DR: The relationship between gamma-GTP and BP was shown, by multiple regression analysis, to be independent of age, obesity and the dose of alcohol consumed, and to be a useful indicator of the susceptibility to the pressor effect of alcohol.
Abstract: The associations among alcohol consumption, gamma-glutamyl transpeptidase (gamma-GTP) activity in serum and blood pressure (BP) were analysed in a cross-sectional study of 1,156 healthy male workers 35 to 59 years of age, consisting of 349 non-drinkers, 682 light-daily drinkers (consuming less than 58 ml of alcohol per day) and 125 heavy-daily drinkers consuming more. No marked elevation of BP with high alcohol consumption was seen in the present subjects. On the other hand, a linear elevation of BP together with an increase in serum gamma-GTP activity was found in subjects above 40 years of age. The BP levels corresponding to the three different drinking habits, non-drinkers, light drinkers and heavy drinkers, were similar to each other regarding gamma-GTP levels. The relationship between gamma-GTP and BP was shown, by multiple regression analysis, to be independent of age, obesity and the dose of alcohol consumed. The contribution to the rise in BP of the dose of alcohol consumed, in comparison with that of gamma-GTP, was negligible. Serum gamma-GTP activity is a useful indicator of the susceptibility to the pressor effect of alcohol.
TL;DR: The common finding in renal infarction and ischemia in cases was the area of low signal intensity on MRI, which indicated a long T1 relaxation time.
Abstract: Two cases of renal segmental infarction and 1 case of renal patchy ischemia demonstrated by magnetic resonance imaging (MRI) are reported. MRI of renal infarction in two renal grafts following surgical ligation revealed an area of noncorticomedullary differentiation and an area with a low signal intensity. Renal ischemia in 1 patient with acute renal dysfunction with severe loin pain and patchy renal vasoconstriction was visualized as an ill-defined focus of low signal intensity in the renal cortex, indicating a long T1 relaxation time. Delayed wedge-shaped contrast enhancement was demonstrated on CT scan in the same area. The common finding in renal infarction and ischemia in our cases was the area of low signal intensity on MRI.
TL;DR: The results strongly indicate that human IGF-II is primarily produced in paraganglionic tissues and tumors.
TL;DR: The results suggest that the duration of uremia is the most important factor in the development of acquired renal cysts.
TL;DR: Almost all cysts accompanying acquired cystic disease of the kidney, including those with single-layered and multilayered epithelia, as well as solid adenomas and renal cell carcinomas, are derived from proximal tubules.
Abstract: The origins of acquired cysts, hyperplastic epithelia of cyst walls, and renal cell carcinomas were investigated by evaluating their lectin conjugate reactivity. Paraffin-embedded blocks from 9 patients with acquired cystic disease were examined by the high-sensitivity lectin-antilectin immune peroxidase method. 11–176 lesions in each patient, 690 lesions in total, were stained both with Tetragonolobus lotus lectin (T) and peanut lectin (P); the former is specific for proximal tubules and the latter for distal tubules and collecting ducts. Out of 606 acquired cysts with single-layered epithelia, 559 (92.2%) were positive for T and negative for P, and 66 out of 75 (88.0%) cysts with hyperplastic multilayered epithelia were positive for T and negative for P. Three out of 4 solid adenomas and, to varying degrees, 5 renal carcinomas revealed the same reaction. These results suggest that almost all cysts accompanying acquired cystic disease of the kidney, including those with single-layered and multilayered epithelia, as well as solid adenomas and renal cell carcinomas, are derived from proximal tubules.
TL;DR: Results indicated that mitochondria are varied in the intensity of cytochrome oxidase activity among 3 types of pulmonary alveolar epithelial cells, and that the image-analyzing measurement of the accumulation rate of reaction product may be useful for quantitative analysis of enzyme activity, in particular, in the cells which are difficult to isolate from complex tissues.
Abstract: Cytochemically demonstrated cytochrome oxidase activities in mitochondria of rat pulmonary alveolar epithelial cells were quantitatively compared. As the standardized procedures, lungs were fixed for 10 min at 4 degrees C with 2% pure glutaraldehyde, and incubated for different times at 37 degrees C in a medium containing 1.0 mg/ml 3,3'-diaminobenzidine-4HCl, 1 mg/ml cytochrome c, 0.1 mg/ml catalase, 7% sucrose, and 0.1 M phosphate buffer, pH 7.4. Electron micrographs were then obtained, and the densities of the reaction deposits in the mitochondrial intermembrane-intracristal space were measured in an image analyzer, and were plotted in terms of time in minutes. The initial velocity (maximal rate) of the activity expressed as deposit accumulation rate (% area/60 min) filling the mitochondrial intermembrane-intracristal space of Type I, Type II and Type III cells was 40, 130 and 9.3, respectively. These results indicated that mitochondria are varied in the intensity of cytochrome oxidase activity among 3 types of pulmonary alveolar epithelial cells, and that the image-analyzing measurement of the accumulation rate of reaction product may be useful for quantitative analysis of enzyme activity, in particular, in the cells which are difficult to isolate from complex tissues.
TL;DR: Data indicate that monoclonal proliferation of B-cell lineage in patients with SS, benign or malignant, takes place more often among RF-producing clones than other B- cell disorders.
TL;DR: Mechanisms for suppression in offspring whose mothers were stimulated during pregnancy are suggested and precursor B-cells of experimental offspring responded as hapten specific antibody forming cells by employing homologous haptens and heterologous carrier antigens.
Abstract: Pregnant B10.A(3R) and B10.A(5R) mice were immunized with heterologous erythrocyte and protein antigens and the active immune responsiveness of their offspring was investigated by the plaque-forming cell (PFC) assay. In offspring derived from mothers which were stimulated with optimal amounts of antigens and which had fully developed antibody-forming cells, there was a clear-cut suppression in development of specific PFC over a significant period after delivery. In order to characterize the suppressor cell population, spleen cells were prepared from offspring whose mothers were immunized and thereafter treated by anti I-Jk or anti I-Jb monoclonal antibody and complement (C′) followed by adoptive transfer to normal corresponding mouse strain. Only the group that received 3R spleen cells treated with anti I-Jb monoclonal antibody and C′ had no suppressed PFC. To clarify the suppressor site in offspring, precursor B-cells of experimental offspring responded as hapten specific antibody forming cells by employing homologous hapten and heterologous carrier antigens. These results suggest mechanisms for suppression in offspring whose mothers were stimulated during pregnancy.
Journal Article•
TL;DR: Wound closure of planarian regenerates was studied by light and electron microscopy and cell stratification at the wound margin was the result of active cell migration at the time of amputation.
Abstract: Wound closure of planarian regenerates was studied by light and electron microscopy. Quick response of epidermal cells after amputation depended on muscular contraction near the open wound. Early epithelization involved both active and passive cell migration phenomena. First, the old cells from the dorsal and ventral epidermis facing the wound simultaneously spread to close the wound surface, joining first near the wound center. This was facilitated by the contraction. Cell stratification at the wound margin was the result of active cell migration at the time of amputation. Secondly, these cells were passively stretched from the wound margin so that the stratification disappeared. Partial relaxation of the wound was a causative factor for extreme elongation of the wound epidermal cells. Disappearance of hemidesmosomal attachments was initiated by the collapse of the basal lamina. This was obviously linked to cell locomotion. Further development of the wound epidermis was accomplished by the successive supplementation of precursor cells from the newly formed regeneration blastema (mainly rhabdite-forming cells).
TL;DR: Sleep spindle characteristics and spindle power periodicity were studied in 4 identical and 3 fraternal twin pairs and suggest that the sleep cycle which is expressed by periodic appearance of spindle powers is genetically determined.
Abstract: Sleep spindle characteristics and spindle power periodicity were studied in 4 identical and 3 fraternal twin pairs (mean age, 16 years). There were no significant genetic effects such as concordance between the identical twins and discordance between the fraternal twins for mean duration, mean amplitude and mean frequency of spindles. Spindle periodicity, which is correspondent to the sleep cycle, was visually more similar between the identical twins than between the fraternal twins. These observations suggest that the sleep cycle which is expressed by periodic appearance of spindle powers is genetically determined. On the other hand, some spindle characteristics and some physical measures had significant relationships. These relationships may suggest that some spindle characteristics are influenced by the individual development rather than by a genetic trait.