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Biomedical subjects

H Yagi

Publications and source records attributed to H Yagi.

At least 235 records · Page 13Linked to original sources
PubMed1990

Multiple carcinomata associated with anomalous arrangement of the biliary and pancreatic duct system. A report of two cases with a literature survey.

Two rare cases of multiple neoplasms occurring in association with anomalous arrangement of the pancreatobiliary duct system (PBD) are reported. Ultrasonography, computed tomography and endoscopic retrograde cholangiopancreatography revealed cholecystic tumor in the first case, and multiple choledochocholecystic tumors in the second case. In the first case, pancreatic tumor was discovered two years after cholecystectomy. In the second case, a pancreatic tumor was discovered incidentally in the removed pancreatic head after the operation. The histology of all of these biliary and pancreatic tumors revealed papillary adenocarcinoma in both patients, and additionally small pancreatic endocrine tumors were found in the first case. Postoperative prognosis was comfortably favorable in both patients. In a literature survey, two other cases of double carcinomata associated with anomalous PBD were found, in which the tumors showed the same histology of papillary adenocarcinoma and the postoperative prognoses were also good. These mutual clinicopathological features appear to suggest that this abnormal condition acts as a carcinogenetic risk factor in the pancreatic duct and the biliary duct system, and may finally cause multiple carcinomata in the PBD.

Adult↗
PubMed1990

N-terminal propeptide of type-III procollagen concentrations in the cord blood: an index of newborn maturity.

Cord serum concentrations of the N-terminal propeptide of type-III procollagen(PIIIP), insulin-like growth factor I (IGF-I), thyroid-stimulating hormone (TSH) and free thyroxine were measured in 149 neonates, consisting of 22 small for gestational age, 95 appropriate for gestational age, 21 large for gestational age and 11 neonates of less than 24 weeks of gestation. Their gestational ages (GAs) ranged from 20 to 41 weeks. A significant negative correlation was found between PIIIP levels and GA (r = -0.83, p less than 0.001). No significant difference was found in PIIIP levels between SGA and LGA neonates, when there were no difference in their GAs, in spite of a significant difference in their birth body weights (p less than 0.01). The high concentrations of the cord serum PIIIP did not appear to be influenced by either IGF-I or thyroid hormones, nor was there any relationship between PIIIP and the birth body weight, but only with GA, suggesting that determining cord levels of PIIIP seems to provide a useful parameter for the assessment of newborn maturity.

Biomarkers↗
PubMed1990

Doppler assessment of pulmonary hypertension induced by hypoxic breathing in subjects susceptible to high altitude pulmonary edema.

To verify the abnormal pulmonary vascular response implicated in the pathogenesis of high altitude pulmonary edema (HAPE), we examined the hemodynamic responses to hypoxia in HAPE-susceptible subjects (HAPE-S) by means of both right heart catheterization and pulsed Doppler echocardiography. The HAPE-S were seven men and one woman with a history of HAPE. Six healthy volunteers who had repeated experiences of mountain climbing without any history of altitude-related problems served as control subjects. The HAPE-S showed much greater increase in pulmonary vascular resistance (PVR) than did the control subjects, resulting in a much higher level of pulmonary arterial pressure (Ppa) under acute hypoxia both of 15% O2 and 10% O2. We then evaluated the usefulness of pulsed Doppler echocardiography in the prediction of pulmonary hypertension. Acceleration time (AcT) and right ventricular ejection time (RVET) were measured from the flow velocity pattern in the right ventricular outflow tract. The ratio of AcT to RVET was correlated to invasively determined mean Ppa (Ppa) and PVR. The results were as follows: (1) AcT/RVET = 0.52 to 0.0047 (Ppa), r = -0.93, SEE = 0.017, p less than 0.001 (HAPE-S); (2) AcT/RVET = 0.55 to 0.0055 (Ppa), r = -0.70, SEE = 0.030, p less than 0.001 (HAPE-S); (4) AcT/RVET = 0.52 to 0.00077 (PVR), r = -0.91, SEE = 0.016, p less than 0.001 (control subjects). We conclude that HAPE-S have a constitutional abnormality in the pulmonary vascular response to hypoxia, which is a possible causative factor of HAPE, and that pulsed Doppler echocardiography may be supportive to assess the pulmonary vascular pressor response in the HAPE-S.

Adult↗
PubMed1990

Immune deficiency of the CTS mouse. I. Deficiency of in vitro T cell-mediated immune response.

The cataract Shionogi (CTS) mouse characterized by cataracts and microphthalmia is a sister strain of the NOD mouse. We have made the immunological characterization of the CTS mouse by means of in vitro assays. Splenocytes of the CTS mouse were very low in the responsiveness to T cell mitogens such as Con A and PHA but not to a B cell mitogen, LPS. The production of IL 2 and expression of IL 2-receptor of spleen cells after in vitro stimulation with Con A decreased in the CTS mouse, when compared with those in the NOD and the other reference strains. In mixed lymphocyte culture, CTS splenocytes did not proliferate and did not generate cytotoxic T lymphocytes when cocultured with splenocytes of the C3H/He mouse. The NK activity against YAC-1 target cells was lower in the CTS mouse than in the C3H/He mouse, an NK high responder, but higher than in the NOD mouse, a low responder. These results suggest that the CTS mouse is deficient in T cells. Subset analysis of splenic lymphocytes of the CTS mouse using flow cytometry revealed that the percentage of T cells in the CTS mouse was significantly lower than those in the reference strains, which was consistent with the reduced responsiveness to T cell mitogens in the CTS mouse. The deficiency in the Ly-2+ T cell subset was particularly striking. However, the response to PHA of the splenocytes of the CTS mouse was normalized when T cells were enriched by nylon wool-passing and cell-sorting. Therefore, it seems that decreased T cell activity is due to a decrease in T cell number and not to dysfunction of individual T cells.

Animals↗
PubMed1990

Vital root resection with advanced periodontitis--case reports.

Furca of multi-rooted teeth are sometimes affected by advanced periodontitis and supporting tissue is almost lost around one of two or two of three roots, while the remaining root or roots are supported by a relatively intact periodontium. In these situations, the procedure of root resection has usually been carried out. Though the necessity of prior or simultaneous endodontic treatment will be considered concomitantly, it is not clear the good periodontal results can be obtained in such cases by these endodontic treatments. If the technique of vital root resection should be indicated to these cases, the vitality of the tooth would be retained and the damage would be minimal. The technique of vital root resection and two periodontally successful clinical cases are presented. This technique appears appropriate in cases in which a multi-rooted tooth is afflicted with a hopeless periodontitis involving one or two roots.

Adult↗
PubMed1990

[Cervical cancer].

Although the surgical treatment for the uterine cervical carcinoma has been accepted as until recently one of the most effective therapies in terms of radicality, various complications following the operation have tormented patients for a long time, resulting in the deterioration of the quality of their lives. The complications include a loss or an impairment of fecundability, morbidities due to the castration, problems of sexual life, urinary disturbances such as dysuria, incontinence and a loss of feeling of urgency, renal dysfunction, persistent constipation and lymphedema on legs. The serious psychological handicaps are included also. During many years, however, the accumulation of the knowledge which is related to a development of the cancer, recognition of the localisation and an extent of the lesion and prognostic factors, has encouraged the developments of improved methods to keep the essential physiological functions and avoiding a loss of radicality. Those are a laser therapy, retaining of ovaries and preservation of pelvic autonomic nerves including bladder branches. Here, indications, methods and the clinical results of those improved surgical methods are presented and the problems remaining to be resolved are discussed.

Female↗
PubMed1990

[A case of Behçet's disease with hemoptysis and chest X-ray abnormality].

A 41-year-old man was admitted to our hospital because of hemoptysis and dyspnea. Physical examination disclosed oral ulcer, acne and scrotal ulcer. Although ocular lesions were absent, the needle reaction was positive. Then we diagnosed this case as incomplete type of Behçet's disease. Chest X-ray showed diffuse retinolinear shadows in the entire lung field and an infiltrative shadow in the left middle lung field. CT-scan revealed interstitial shadows in the entire lung field, a wedge-shaped shadow in left S6 and aneurysmic dilatation of the left lower lobe pulmonary artery. Pulmonary angiography showed obstruction and aneurysmic dilatation of the left lower lobe pulmonary artery. Pathological examination of the TBLB specimen revealed thickening of the vessel wall, perivascular infiltrations of mononuclear cells, hemorrhage and slight thickening of alveolar septae. These findings were compatible with pulmonary lesions of Behçet's disease. After administration of corticosteroid, the symptoms and the chest roentgenographic findings improved. Pulmonary lesions of Behçet's disease were discussed.

Adult↗
PubMed1989

Screening of aromatase-containing neurons in rat forebrain: an immunohistochemical study with antibody against human placental antigen X-P2 (hPAX-P2).

Aromatase-containing neurons were immunohistochemically examined in rat brains by using a polyclonal antibody against human placental antigen. The antibody recognizes cytochrome P-450 portion of aromatase, an enzyme converting androgen to estrogen. A large group of strongly immunoreactive cells was identified in the ventral pallidum, which extends caudally from the area surrounding the islands of Calleja. Other strongly or moderately stained cell groups were observed in the cerebral cortex, the amygdaloid area, the nucleus of the diagonal band, and the area anterior to the posterior commissure. Only a few stained cells were present in the medial preoptic region. These findings cast doubt upon the previous assumption, based on biochemical analysis of tissue samples, that the center of the aromatizing system is in the medial preoptic region. They indicate instead that most aromatase-containing neurons of rats lie within the ventral pallidum ventromedially adjacent to the preoptic area.

Animals↗
PubMed1989

Behavioral characteristics of the SAM-P/8 strain in Sidman active avoidance task.

The behavior of the senescence-accelerated mouse (SAM-P/8) at the age of 1, 2, 4 and 10-11 months in Sidman active avoidance learning was analyzed, and compared to findings in the controls (SAM-R/1). At the age of 1 and 2 months, learning was comparable in these two strains. At the age of 4 and 10-11 months, SAM-P/8 but not SAM-R/1 learned active avoidance. We propose that SAM-P/8 can serve as a valid model of deficits in learning and memory.

Aging↗
PubMed1989

Insulin-like growth factor I (IGF-I) production and the presence of IGF-I receptors in rat medullary thyroid carcinoma cell line 6-23 (clone 6).

To clarify whether insulin-like growth factor I (IGF-I) is an autocrine growth factor of rat medullary thyroid carcinoma (MTC) cell line, 6-23 (clone 6), IGF-I binding to MTC cell membranes, IGF-I levels in the conditioned culture medium of MTC cells and the effects of IGF-I on methyl-[3H]thymidine incorporation to MTC cells were examined. Scatchard analysis of saturation binding studies revealed the association constant and the maximal binding capacity were 1.0 x 10(9) M-1 and 199 fmol/mg of membrane protein, respectively. The binding of [125I]IGF-I to MTC cell membranes was inhibited by unlabeled IGF-I, IGF-II and insulin; the relative potencies were IGF-I greater than IGF-II much greater than insulin, suggesting the presence of type I IGF receptors in MTC cells. IGF-I levels in the conditioned culture medium of MTC cells were 120 +/- 3 pM (mean + SE). IGF-I (10(-10) to 10(-8) M) dose-dependently stimulated methyl-[3H]thymidine incorporation to MTC cells. These findings suggest a possible role of IGF-I as an autocrine growth factor for MTC cells.

Animals↗
PubMed1989

Brain function in patients with cerebral fat embolism evaluated using somatosensory and brain-stem auditory evoked potentials.

In two victims of traffic accidents with broken bones and fat embolism, serial recordings of somatosensory evoked potentials (SEPs) and brain-stem auditory evoked potentials (BAEPs) were examined to assess brain function. Initial SEPs and BAEPs revealed normal subcortical components, while the late cortical components of SEPs were abolished, findings indicative of diffuse dysfunction of grey rather than of white matter. As the neurological functions became normal, the late components appeared. It is concluded that while absent late components of SEPs do reflect cortical dysfunction, they are not necessarily associated with a poor prognosis. Repetitive recordings of SEPs appear to be a useful tool for assessing the neurological condition and the prognosis of patients with cerebral fat embolism.

Adult↗
PubMed1989

Mutagenic specificity of a potent carcinogen, benzo[c]phenanthrene (4R,3S)-dihydrodiol (2S,1R)-epoxide, which reacts with adenine and guanine in DNA.

Mutations were induced in the supF gene of the pS189 shuttle vector by treatment with optically active benzo[c]phenanthrene (4R,3S)-dihydrodiol (2S,1R)-epoxide in vitro and replication in human cells. The induced mutation frequency was 60-fold greater than the spontaneous rate, and most of the mutations analyzed were transversions (86%), which principally consisted of similar numbers of A.T----T.A and G.C----T.A changes. The unusual susceptibility of A.T pairs to mutation by this chemical agent is consistent with its chemical reactivity toward adenine and argues that the mutations are targeted to the adducts formed. The central base in the sequences 5'-AGA-3', 5'-AAC-3', and 5'-GAG-3' was particularly susceptible to mutation. Twelve "hotspots" in the supF gene accounted for most mutations seen. Some of these hotspots differed from those found by others for racemic benzo[a]pyrene dihydrodiol epoxide and, even when a hotspot was common, the mutagenic changes were not always the same. Although adenine insertion opposite a noninstructional lesion could account for most of the data, no single mutagenic mechanism could encompass all of it. The cellular machinery that converts chemical damage to mutations must determine the mutational result to a large extent, but the findings herein show that the chemical agent itself plays a large role in determining both the location and the nature of the mutations that arise.

Adenine↗
PubMed1989

Spontaneous spongy degeneration of the brain stem in SAM-P/8 mice, a newly developed memory-deficient strain.

A spontaneous spongy degeneration of the brain stem and spinal cord was discovered in a murine model of accelerated senescence (SAM), cared for under both conventional (SAM-P/8) and specific pathogen-free (SAM-P/8/Ta) conditions. SAM-P/8 and SAM-P/8/Ta showed no clinical neurological abnormalities, yet there was a deterioration in learning and memory abilities. Light microscopic examination revealed a spongy degeneration in the brain stem and spinal cord, in the reticular formation, and proliferation of hypertrophic astrocytes in the spongy area. The spongiform degeneration progressed with advancing age from four to eight months, after which the entire brain was involved. Astrocytosis increased with advancing degeneration. Ultrastructurally, mild dendritic swelling occurred at one month of age. At two months of age, moderate postsynaptic swelling and a widening of intracellular membrane structure were observed, and at age five months there were large vacuoles circumscribed by membranous lamellae, identifiable as myelin. Vacuoles in SAM-P/8 proved to be swollen neuronal processes and oligodendroglial processes. These SAM-P/8 and SAM-P/8/Ta strains of mice are new memory-deficient strains with spontaneous spongy degeneration associated with aging.

Animals↗
PubMed1989

Developmental changes in agonist-mediated gastric smooth muscle contraction in the rabbit.

We studied smooth muscle strips from rabbit proximal stomach to explore the age-related changes in agonist-mediated contraction. Strips from neonatal (1 d) and weanling (11 wk) rabbits were oriented to measure isometric tension in circular muscle. Bethanechol stimulated maximal tension in both age groups. Although the potencies for bethanechol were similar (ED50 approximately 5 microM), the maximal response was nearly 4-fold greater in weanling (1140 +/- 73 mN/cm2) versus neonate (305 +/- 54 mN/cm2), p less than 0.001. Maximum stress increased with age for bethanechol, high extracellular K+, and substance P, but not for serotonin, cholecystokinin octapeptide, neurotensin, or bombesin. Only bombesin stimulated larger contraction in neonates (152 +/- 37 mN/cm2) versus weanlings (86 +/- 20 mN/cm2), p less than 0.05. Potencies did not change with age, except for substance P and serotonin. Substance P and serotonin induced early phasic and prolonged tonic contractions, which were unaffected by tetrodotoxin or atropine. ED50 for the phasic and tonic components of substance P-stimulated contraction in neonates were 1.8 and 7.7 nM. Substance P was 60-70 times more potent in neonates versus weanlings (p less than 0.001). ED50 for serotonin-stimulated contraction in neonates (33 and 22 nM, respectively) were 20-30 times more potent than in weanlings (p less than 0.05). Motilin, morphine, epidermal growth factor, and gastrin did not stimulate contraction at either age. We conclude that age-dependent changes in agonist potency and efficacy may be one factor to explain in part the changes that occur in gastric motility during postnatal development.

Animals↗
PubMed1989

Complete atrioventricular block associated with regional myocardial scarring in a patient with Coxsackie B2 myocarditis.

Transient atrioventricular (A-V) conduction abnormalities are often experienced in patients with evolving acute viral myocarditis, but persistent complete A-V block requiring permanent cardiac pacing is rare. We describe a case who developed irreversible complete A-V block during the long-term course of Coxsackie B2 myocarditis. The endomyocardial biopsy revealed inflammatory cellular infiltrates and myocyte necrosis. A left ventriculogram and echocardiogram consistently demonstrated an aneurysm in the basal portion of the interventricular septum. It was speculated that the extensive myocardial scar caused by acute myocarditis resulted in the ventricular aneurysm of this particular myocardial region involving the A-V conduction system.

Adult↗
PubMed1989

[Classification and surgical repair of congenital ear lobe anomalies].

We encountered 21 cases of congenital ear lobe anomalies at our clinic during the past seven years. This report presents our system for classification of these cases and describes some typical cases. We divided ear lobe anomalies into four groups according to the type of lobe as follows; large, adhesive, defective and cleft ear lobe type. In the large lobe type, the ear lobe is characteristically large. For the adhesive lobe type, no angle is formed between the ear lobe and the face, i.e. the helix is elongated in a straight line towards the face. The cleft ear lobe type is classified into two surgical categories, viz. the cleft and appendage types. The former is recognized by a cleft on the lobe which continues from the helix, whereas the latter type has an appendage on the lobe. Combinations of these two types are included in the cleft type because a cleft in the lobe is more significant in terms of the shape of the repaired ear lobe. As regards the surgical repair of these anomalies, careful consideration is required in order to accomplish tridimensional reconstruction and create the natural curve of the lobe using z-plasty and other local flaps.

Adolescent↗