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Biomedical subjects

M Mizuno

Publications and source records attributed to M Mizuno.

702 records · Page 39Linked to original sources
PubMedDate not supplied

Ultrastructural immunocytochemical analysis of lymphocytes infiltrating bile duct epithelia in primary biliary cirrhosis.

Subpopulations of lymphocytes in portal areas, especially infiltrating bile duct epithelia were analyzed by light and electron microscopy using indirect peroxidase-labeled antibody method and monoclonal antibodies against pan-T (Leu 1), cytotoxic/suppressor T (Leu 2a), helper/inducer T (Leu 3a) and natural killer/K (Leu 7) and suppressor T (Leu 15) cells in liver biopsy specimens from four patients with primary biliary cirrhosis. Bile ducts with chronic nonsuppurative destructive cholangitis were observed in two patients. Leu 1+ and Leu 2+ cells were frequently seen in intimate contact with epithelial ductal cells. The majority of intraepithelial cells possessing Leu 2a antigen did not react with anti-Leu 15 antibody. Leu 3a+ or Leu 7+ cells seldom infiltrated ductal epithelia. These findings indicate that the majority of intraepithelial lymphocytes in bile ducts most likely represent Leu 2a+15- cytotoxic T cells. By immunoelectron microscopy, Leu 1+ or Leu 2a+ lymphocytes often breached the basement membrane of bile ducts and were present within dilated intercellular spaces between biliary epithelial cells. Furthermore, they often formed sharp or broad contacts with the epithelial cells, and occasionally pseudopods projecting from the surfaces of Leu 2a+ cells extended into the epithelial cells. Most of Leu 2a+ lymphocytes contained little cytoplasm with few granules and a small Golgi apparatus. Such findings suggest that cytotoxic T cells may contribute to the pathogenesis of chronic nonsuppurative destructive cholangitis in primary biliary cirrhosis.

Adult↗
PubMedDate not supplied

A study on the development of sleep-wakefulness cycle in the human fetus.

We observed fetal behavior by using three ultrasonic real-time scanners simultaneously in 30 normal pregnant women between 20 and 40 weeks of gestation and analyzed developmental changes in behavioral pattern focussing the attention on the characteristics of REM and non-REM sleep and wakeful state. The frequency of REM significantly increased with gestational age, and its occurrences formed a group in late pregnancy. REM and non-REM periods, which were defined as the phase with uninterrupted appearance of rapid eye movements and the phase without them over 3 min, respectively, became clearly distinguishable between 28 and 31 weeks of gestation. The correlation between the occurrence of rapid eye movements and breathing movements was high after 27 weeks. These results demonstrate the course of the development of sleep-wakefulness cycle in the human fetus.

Behavior↗
PubMedDate not supplied

Ultrastructural and immunohistochemical studies of Wharton's jelly umbilical cord cells.

In order to determine the significance of Wharton's jelly, the characteristics of these cells were examined by means of electron microscopy and immunohistochemistry. These cells possessed ultrastructural characteristics of both fibroblasts and smooth muscle cells, indicating that they are modified, rather than typical fibroblasts. Immunohistochemically those 'myofibroblasts' stained positive for actin, non-muscle myosin, vimentin and desmin. Staining for muscle myosin was negative, supporting the ultrastructural findings. As our results indicate that these cells can function in both fibrogenesis and cell contraction, we speculate that they may contribute to the elasticity of Wharton's jelly, by synthesizing collagen fibers, and participate in the regulation of umbilical blood flow by virtue of their contractile properties.

Connective Tissue↗
PubMedDate not supplied

Periodic alternating nystagmus and congenital nystagmus: similarities in possibly inherited cases.

In this paper, 2 patients, a daughter with periodic alternating nystagmus and a mother with congenital fixation nystagmus, are presented, and the similarities of the two disorders are discussed, not only in the eye movements, but also in their underlying abnormalities. The literature was reviewed, and the link between periodic alternating and congenital fixation nystagmus, which had been suggested based on circumstantial evidence, may be confirmed by our cases. The possible evidence of inheritance suggests that the two disorders share common abnormalities in visual processing.

Adult↗
PubMedDate not supplied

Post-caloric nystagmus by positional change. 2. Study in patients with spinocerebellar degeneration.

We investigated the postcaloric nystagmus that is related to positional change in 24 patients with spinocerebellar degeneration (SCD) and compared it with that in normal subjects. Six ears of 3 patients exhibited no evaluable caloric response. In 42 ears of 21 patients, the primary phase of caloric nystagmus was definitely observed. In 37 of 42 (88%) ears, postcaloric nystagmus was observed. The postcaloric nystagmus from a positional change in patients with SCD was significantly larger than that in control subjects. Furthermore, it was significantly exaggerated in patients with brainstem and cerebellar lesions in comparison with patients with pure cerebellar lesions. The degree of disturbance coming from visual suppression had only a limited correlation with the exaggerated postcaloric nystagmus. Also discussed are possible other factors affecting the exaggerated postcaloric nystagmus.

Adolescent↗
PubMedDate not supplied

Postcaloric nystagmus by positional change and other neurootological findings.

The postcaloric nystagmus (PCN) by positional change from the supine position to the upright position and other neurootological findings were studied. Twenety-one patients with a clinical diagnosis of spinocerebellar degeneration or Arnold-Chiari malformation were studied. There was a significant negative correlation between maximum slow phase eye velocity in postcaloric nystagmus by positional change (V2) and maximum slow phase eye velocity in optokinetic nystagmus pattern test (r = -0.47; n = 21). Moreover, patients with vertical gaze nystagmus (VN) had significantly larger V2 than patients without VN. However, there was no significant difference for V2 between patients with and without rebound nystagmus. Through these studies, the authors discussed probable mechanisms and responsible lesions for the exaggerated PCN by positional change.

Adolescent↗
PubMedDate not supplied

Bilateral pseudo-internuclear ophthalmoplegia in myasthenia gravis.

A 38-year-old male with bilateral pseudo-internuclear ophthalmoplegia (-INO) in myasthenia that could have been misdiagnosed as INO in multiple sclerosis is reported. He experienced fluctuating symptoms including double vision, imbalance, and tinnitus. His eye movements simulated bilateral INO, with a downshoot in abduction. After thymectomy, his eye movements became normal. From our case and a review of the literature, we propose that ptosis, downshoot, and fatigability are likely to be signs of pseudo-INO in myasthenia, whereas an impaired vertical smooth pursuit is unlikely. Dissociated nystagmus and monocular overshoot might be the results of central compensation.

Adult↗
PubMedDate not supplied

Suppression by 1-(2-tetrahydrofuryl)-5-fluorouracil in combination with uracil of preneoplastic mammary hyperplastic alveolar nodule formation in SHN virgin mice.

It is known that hyperplastic alveolar nodule (HAN) is a representative preneoplastic state in mammary glands of mice. We examined the effect of 1-(2-tetrahydrofuryl)-5-fluorouracil and uracil (UFT) on HAN formation in a high mammary tumour strain of SHN virgin mice. Oral administration of UFT for 5 months beginning at one month of age significantly reduced the number of HAN and DNA-synthesizing enzyme activities in the mammary glands. These results indicate that long-term administration of low dose UFT reduces the de novo and salvage synthesis of DNA and suppresses preneoplastic HAN.

Animals↗
PubMedDate not supplied

Endometriosis impairs glycogen synthesis in human endometrium.

Glycogen content in endometrium with endometriosis was about half of that without endometriosis at the secretory phase, whereas no difference was found in the proliferative phase. The activity of glycogen synthetase in endometrium with endometriosis was reduced to 25% and 23% of that without endometriosis in the late proliferative and midsecretory phase, respectively. The activity of glycogen phosphorylase was also significantly lower in endometrium with endometriosis in the late proliferative phase. However, the activity increased conspicuously in the midsecretory phase, and thus there was no difference in activity in endometrium with or without endometriosis. The observed lowered capacity of glycogen synthesis may lead to understanding the mechanism of infertility associated with endometriosis.

Adult↗
PubMedDate not supplied

Adaptation of skeletal muscles to training.

Based on the myosin ATPase reaction, human skeletal muscles are composed of two main fibre types, named slow (ST) and fast (FT) twitch fibres, respectively. With few exceptions, ST and FT fibres are evenly represented in the muscles, however with a large interindividual variation. Endurance athletes tend to have a predominance of ST fibres while sprinters have a predominance of FT fibres. The ST fibres are surrounded by 3-4 capillaries, and they have the largest potential for terminal oxidation and the smallest for glycolysis. Of the FT fibres, two subtypes may be distinguished (a and b), of which no FTb fibres are seen in the endurance trained muscles of athletes. Training also results in an increase in the number of capillaries for all fibre types. FTa fibres have a metabolic potential which is intermediate to that of the ST and FTb fibres. With endurance training, the potential for terminal oxidation increases, resulting in a larger ability to use fat as a fuel during submaximal exercise and in a reduced production of lactate. Thus, training has a glycogen sparing effect and endurance increases. Human intercostal muscles appear to have approximately 60% ST fibres. In the external intercostal muscles, the number of capillaries and the occurrence of FTb fibres is similar to the findings in untrained muscles. In contrast, the internal intercostal muscles placed in the mid-axillary line have no FTb fibres and relatively many capillaries. Thus, these (expiratory) muscles appear to be extensively used.

Adenosine Triphosphatases↗
PubMedDate not supplied

Normal and neoplastic mammary gland growth in MMTV/TGF alpha transgenic mice.

Biochemical and Dynamic change of mammary glands in different reproductive states were studied in comparison with histological structures in female and male transgenic mice bearing human transforming growth factor alpha (TGF alpha) cDNA under the control of the mouse mammary tumour virus enhancer/promoter. Female and male F1 mice between SHN female and transgenic male mice were divided into TGF alpha (+) and TGF alpha (-) groups according to the presence of TGF alpha gene at approximately 50 days of age. While there was little difference in mammary gland contents of DNA and RNA in females at 2 months of age, both nucleic acid contents were elevated markedly in TGF alpha (+) female mice with large variations at 4 months. These extremely high DNA and RNA contents in the TGF alpha (+) group declined to the level of the TGF alpha (-) group in the middle of pregnancy and at the end of pregnancy, respectively. Thymidine kinase (TK) activity in the mammary glands as an index of DNA synthesis was significantly higher in TGF alpha (+) mice than in TGF alpha (-) mice at both 2 and 4 months of age and the high TK in TGF alpha (+) mice also declined to the level of TGF alpha (-) mice with pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗