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Biomedical subjects

T Fujino

Publications and source records attributed to T Fujino.

At least 217 records · Page 12Linked to original sources

Allelotype of endometrial carcinoma.

An allelotype analysis of endometrial carcinoma was undertaken to identify chromosomal loci that are relevant to this tumor type. A total of 70 highly polymorphic microsatellite markers, distributed among all nonacrocentric chromosome arms, were examined for evidence of loss of heterozygosity or allelic imbalance in DNA samples from matched normal and tumor tissues. An average of 21 informative tumor cases were obtained for each marker. Allelic deletions or imbalance were observed on 31 of 41 chromosome arms with no marker showing an allelic loss ratio of greater than 33%. Those chromosome arms most frequently involved were 3p, 8p, 9p, 14q, 16q and 18q. There was a strong correlation between loss of heterozygosity on chromosome 14q and death from disease. These data indicate that the molecular genetic character of endometrial carcinoma is complex and that a relatively large number of different chromosomal loci are likely to play a role in the etiology and progression of this tumor type.

Chromosomes, Human, Pair 14↗

Variation in red blood cell deformability and possible consequences for oxygen transport to tissue.

Red blood cell (RBC)-plasma suspensions with a hematocrit of 10-12% were forced to flow through microchannels (equivalent diameter 6 microns, equivalent length 20 microns, 2600 in parallel) by applying a pressure difference of 20 cm H2O. Transit times for 100 microliters of fresh suspensions from 33 healthy male subjects aged between 24 and 63 ranged from 43.0 to 65.2 sec (mean +/- SD: 49.4 +/- 4.3 sec). Four measurements taken from two subjects at intervals over several weeks gave fluctuations of 45.1, 43.6, 47.6, and 45.9 sec and 52.3, 49.8, 60.1, and 50.0 sec, respectively. RBC deformability thus appeared to vary considerably between different subjects and also showed fluctuations between different days in any given subject. No correlation was obtained between the transit time and subject's age. However, higher whole blood hematocrit values were apparent in those suspensions that had longer transit times. A lower RBC deformability might be caused by dietary factors with resultant increased frequency of occasional stagnation of capillary blood flow, i.e., occasional tissue hypoxia. This would further result in an increased hematocrit.

Adult↗

The expulsion of Echinostoma trivolvis (Trematoda) from ICR mice: extension/retraction mechanisms and ultrastructure of the collar spines.

Ultrastructural observations of collar spines and surrounding tissues associated with extension/retraction mechanisms of the spines were made on Echinostoma trivolvis recovered from ICR mice or golden hamsters. The spine consisted mainly of a homogeneous, crystalline structure of moderate to heavy electron density. The spine was surrounded by an outer layer of tegument-like material. Interstitial material was located between this outer layer and the surrounding tegument. Muscle bundles associated with spine movements were anchored by hemidesmosomes to interstitial material. Contraction of these muscles caused an invagination of the tegument surrounding a spine, resulting in spinal protrusion. Relaxation of these muscles resulted in spinal retraction. An immunocytochemistry technique using colloidal gold confirmed the presence of actin in the collar spines. Most of the collar spines of excysted metacercariae and juveniles maintained in a defined medium supplemented with fresh hamster serum were extended, whereas worms maintained in mouse serum mainly showed retracted spines. Apparently, factors in mouse serum are involved in spinal retraction.

Actins↗

Fuzzy and conventional control of high-frequency ventilation.

A high-frequency ventilator was developed, consisting of a single-phase induction motor, an unbalanced mass and a mechanical vibration system. Intermittent positive pressure respiration was combined with high-frequency ventilation to measure end-tidal pCO2. Hysteresis was observed between the rotational frequency of the high-frequency ventilator and end-tidal pCO2. A fuzzy proportional plus integral control system, designed on the basis of the static characteristics of the controlled system and a knowledge of respiratory physiology, successfully regulated end-tidal pCO2. The characteristics of gas exchange under high-frequency ventilation was approximated by a first-order linear model. A conventional PI control system, designed on the basis of the approximated model, regulated end-tidal pCO2 with a performance similar to that of the fuzzy PI control system. The design of the fuzzy control system required less knowledge about the controlled system than that of the conventional control system.

Animals↗

Surgical treatment for acute aortic dissection and coexistent degenerative aortic aneurysm. Report of three cases.

Acute aortic dissection occurring in an aorta previously afflicted with degenerative, atherosclerotic is unusual. We report three cases with acute aortic dissection (DeBakey type III-b) occurring in an aorta which had a preexistent degenerative aortic aneurysm. Two of the three patients had acute aortic dissection originating from the distal end of the degenerative aneurysm, and the remaining one had the acute aortic dissection and degenerative aneurysm at different segments of the aorta. Since the risk of rupture is likely to be much higher in the patients with coexistence of acute aortic dissection and degenerative aortic aneurysm, compared with patients with DeBakey type III acute aortic dissection alone, we believe that a prompt and aggressive surgical approach is essential to prevent rupture, and that digital subtraction angiography (DSA) is more helpful in making a correct diagnosis and in helping to decide surgical procedures and supportive methods than other noninvasive diagnostic procedures.

Acute Disease↗

Reconstruction of a floating thumb with an excess big toe.

In a three-year-11-month-old girl, an excess big toe was transferred microsurgically to replace a congenital floating thumb. The reconstructed thumb was evaluated nine years after the transfer. It showed almost normal growth, compared with the contralateral side, and the aesthetic result was excellent. However, the patient does not use the reconstructed thumb with much skill. The reasons for this are discussed, and the importance of performing surgery early in life is stressed.

Age Factors↗

Immunosuppression by a neutral thiol protease from parasitic helminth larvae in mice.

The composition and immunological suppression of a novel proteinaceous material, a neutral thiol protease (NTP), isolated from the metacercaria of the helminth Paragonimus westermani are reported. From cDNA cloning and sequencing, the protease was found to be composed of 215 amino acid residues and closely resembled the known cysteine proteases. Treatment of adult mice with the enzyme suppressed the delayed footpad reaction and haemagglutinin antibody production, and reduced expression of the major histocompatibility complex and interleukin 2 receptor on lymphocytes, and induced suppressor cells in the spleen. In addition, stable and long-term skin graft survival was achieved by concomitant administration of the enzyme at a low dose.

Amino Acid Sequence↗

Subcellular localization of Clostridium thermocellum ORF3p, a protein carrying a receptor for the docking sequence borne by the catalytic components of the cellulosome.

The ORF3 gene of Clostridium thermocellum encodes a polypeptide (ORF3p) which contains a receptor domain for the docking sequence borne by the catalytic subunits of the cellulosome and a triplicated domain related to some bacterial cell surface proteins. It was thus surmised that ORF3p is a surface protein. In this study, this hypothesis was confirmed. Subcellular fractionation, Western blotting (immunoblotting), and electron microscopy of immunocytochemically labeled cells indicated that ORF3p produced by C. thermocellum was located in the outer surface layer of the bacterium. This layer appeared to consist of a soft matrix shedding off particulate fragments. Nonsedimenting ORF3p derived from sonicated cells was associated with high-molecular-mass fractions (> 20 MDa), probably corresponding to fragments of the outer cell layer. The same high-molecular-mass fractions also contained the cellulosomal marker CipA. Contrary to CipA, however, ORF3p was not associated with 2- to 4-MDa fractions corresponding to individual cellulosomes, and a significant fraction of ORF3p failed to bind to cellulose. It is proposed that ORF3 and ORF3p be renamed olpA and OlpA, respectively (for outer layer protein).

Antibodies, Bacterial↗

Immortalization-susceptible elements and their binding factors mediate rejuvenation of regulation of the type I collagenase gene in simian virus 40 large T antigen-transformed immortal human fibroblasts.

Dramatic changes occur in expression of the type I collagenase gene during the process of immortalization in simian virus 40 large T antigen-transformed human fibroblasts (S. Imai and T. Takano, Biochem. Biophys. Res. Commun. 189:148-153, 1992). From transient transfection assays, it was determined that these changes involved the functions of two immortalization-susceptible cis-acting elements, ISE1 and ISE2, located in a 100-bp region about 1.7 kb upstream. The profiles of binding of an activator, Proserpine, to the enhancer ISE1 were similar in the extracts of young, senescent preimmortalized and immortalized cells. ISE2 contained both negative and positive regulatory elements located adjacent to each other. The positive regulatory element consisted of a tandem array of putative Ets family- and AP-1-binding sites. An activator, Pluto, interacted with this positive regulatory element and had an AP-1-related component as a complex. The binding activity of Pluto was predominantly detected only in the extract from senescent preimmortalized cells. In contrast, a repressor, Orpheus, which bound to the ATG-rich negative regulatory element of ISE2, was prominently detected in extracts from both young preimmortalized and immortalized cells and appeared to suppress transcription in an orientation-dependent manner. Thus, the interplay of Pluto and Orpheus was suggested to be crucial for regulation of the collagenase gene accompanying in vitro aging and immortalization. Proserpine seemed to interact with Pluto to mediate strong expression of the collagenase gene in cellular senescence. On the basis of these results, we propose a model for regulation of the collagenase gene during in vitro aging and immortalization.

Antigens, Viral, Tumor↗

Effects of hydrocortisone on transmembrane currents in guinea pig ventricular myocytes--possible evidence for positive inotropism.

Steroid hormones are thought to have a positive inotropic action, but the precise electrophysiological effects which underlie this positive inotropism remain unknown. The effects of hydrocortisone on the L-type calcium current (ICa) of the isolated guinea pig ventricular cells were investigated under the whole-cell voltage-clamp recording. Hydrocortisone (10(-6) to 10(-5) M) increased the amplitude of ICa without any changes in the voltage-dependency in ICa. This agent retarded the fast inactivation component of ICa, but not the slow component. On the other hand, hydrocortisone slightly reduced the slope conductance of inward rectifying potassium current (IK1) at potentials less than -50mV. This effect on IK1 is favorable for the activation of ICa. Thus, these results indicate that the positive inotropism of hydrocortisone is mediated, at least in part, by a direct potentiating effect on ICa.

Animals↗

Thrombotic obstruction of the right coronary artery in a postoperative patient with Bland-White-Garland syndrome.

A 53-year-old female presented with symptoms of severe chest and back pain associated with oliguria. The patient had a history of exertional dyspnea since the age of 20, and easy fatigability since the age of 27. At the age of 41, she noted marked exacerbation of these symptoms after suffering from a cold and was ultimately diagnosed as having Bland-White-Garland (BWG) syndrome with mitral valve regurgitation. The patient then underwent re-implantation of an anomalous left coronary artery from the pulmonary artery to the posterolateral wall of the aorta. Eleven years later, she re-presented with symptoms of angina and congestive heart failure. Coronary angiography was subsequently performed and a total occlusion of the right coronary artery with probable thrombus was revealed. The right coronary artery was filled via collaterals from the implanted left coronary artery. Mitral regurgitation was noted during angiography. The patient underwent aorto-coronary artery bypass grafting of the right coronary artery and concomitant mitral valve replacement. Her postoperative condition remained excellent.

Coronary Angiography↗

[The nature of the external ionic modulation of the myocardial electrical propagation: importance of the safety factor].

The mechanisms of conduction change depending on the extracellular K+ and Ca2+ concentrations ([K+]o and [Ca2+]o, respectively) were investigated. Simultaneous measurements of active and passive membrane properties and net membrane excitability were fulfilled by arranging the intra- and extracellular microelectrodes in a superfused and paced guinea pig papillary muscle. Internal longitudinal resistance (ri), as a parameter of passive property, was evaluated by the intra- and extracellular voltage ratio. The maximum upstroke rate (Vmax) was used as an active property. Apparent threshold potential (Vth) was defined by the breakpoint in the action potential upstroke fitted semilogarithmically. Graded rise in [K+]o (from 2.7 to 15.0 mM) evoked a progressive fall in Vmax, and was associated with less negative resting membrane potential and constant ri. Conduction velocity (theta) was the maximum in 9.0 mM [K+]o ("supernormal" conduction) but not in 2.7 mM [K+]o which gave the greatest Vmax ("subnormal" conduction). Safety factor of conduction (S), as an index of net excitability, could most readily account for the [K+]o-dependent change in theta. This was true also in the case of [Ca2+]o elevation (from 0.9 to 5.4 mM). These results indicate that the cation-modulated propagation is governed by the cable theory including S as a matrix of combined active and passive properties.

Action Potentials↗

Successfully treated optic nerve infiltration with adult T-cell lymphoma.

A 45-year-old woman with adult T-cell leukemia had a sudden onset of decreased vision with central scotoma in the right eye. Right optic disc edema and thickening of the optic nerve were observed by magnetic resonance imaging. A diagnosis of leukemic infiltration to the optic nerve was made. A course of oral corticosteroid therapy was prescribed and 40 Gy of radiation was administered to the whole brain and right orbit. Her visual acuity recovered from finger counting to 20/20 within 3 weeks. We believe that this patient represents the first report of successfully treated optic nerve infiltration with adult T-cell leukemia caused by human T-lymphotropic virus type-I infection.

Female↗

Expulsion of Echinostoma trivolvis (Cort, 1914) Kanev, 1985 and retention of E. caproni Richard, 1964 (Trematoda: Echinostomatidae) in C3H mice: pathological, ultrastructural, and cytochemical effects on the host intestine.

C3H mice were infected with 30 metacercarial cysts of either echinostome to study the pathological, ultrastructural, and cytochemical effects of the infection on the mouse small intestine. In mice infected with Echinostoma caproni, the intestine showed villous atrophy with fused or eroded villi. The microvilli of the enterocytes were sparse and distorted and showed reduced alkaline phosphatase activity. The crypts of Lieberkuhn were hyperplastic and showed a marked reduction in goblet and Paneth cells. As compared with uninfected controls, there was a marked reduction in glucose-6-phosphatase activity in the enterocytes of the infected gut. Collagen fibers and the number of fibroblasts were increased under the epithelium. In mice infected with E. trivolvis, the tips of the intestinal villi were bent and blunted. The microvilli of the enterocytes were less tightly packed than those of uninfected controls. The mitochondria in the enterocytes were irregularly shaped, contained intracristal bodies, and showed increased cytochrome oxidase activity as compared with those of uninfected controls. The crypts were hyperplastic but showed an increase in the numbers of goblet and Paneth cells. The fibroblasts and collagen fibers showed abnormal development. The ultrastructural and cytochemical differences seen in this study reflect the uniqueness of the host-parasite relationship of each of these echinostome species in the gut of the C3H mouse.

Animals↗

Infectivity and sporogony of Caryospora-type oocysts of Isospora rivolta obtained by heating.

The infectivity and sporogony of Caryospora-type oocysts of Isospora rivolta obtained by heat treatment were examined. Fresh unsporulated oocysts of I. rivolta were heated at 50 degrees C for 5 min, then poured into a cold 2% potassium dichromate solution and incubated at 25 degrees C. To observe the stage of sporulation, 100 oocysts were examined at 2-h intervals after incubation. The earliest sporulated oocysts were observed at 14 h and the sporulation time was 22 h, similar to that of nontreated oocysts. To determine the infectivity, only Caryospora-type oocysts were collected after sporulation and inoculated orally into cats and mice. The mice were killed at 7 days after inoculation, and their mesenteric lymph nodes and spleens were fed to other cats. All of these cats shed oocysts. The newly discharged oocysts developed into the Isospora type after sporulation. These results suggest that the Caryospora-type oocysts transformed only morphologically after heat treatment and were as infective as the nontreated oocysts to host animals.

Animals↗

Studies on host specificity in Paragonimus westermani: ultrastructural study of inflammatory reactions to the parasite in rat muscles.

Inflammatory reactions to the lung fluke, Paragonimus westermani, in an abnormal host, the rat, were studied by electron microscopy. Inflammatory cells accumulated around the worms in rat muscles, but the reaction varied significantly in intensity as well as distribution of inflammatory cells from worm to worm in the same and different hosts. In an accumulation of inflammatory infiltrates around the worm, eosinophils were more commonly seen, and neutrophils and macrophages were fewer in number. Mast cells appeared rarely. Where inflammatory cells touched to the worms, the tegument of the worms was covered with moderately electron-dense flocculent material which included dense granules. This material, which probably consisted of immune complexes of host antibody and antigen secreted from tegumental granules, seemed to block the inflammatory cells from adhering to the worm surfaces. Inflammatory cells made direct contact with worm surfaces where flocculent material was absent. Dense secretory material was discharged from some eosinophils as a result of degranulation.

Animals↗