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Biomedical subjects

K Kitamura

Publications and source records attributed to K Kitamura.

At least 1,153 records · Page 64Linked to original sources
PubMed1985

[Traumatic mitral insufficiency: a case report].

A 25-year-old man was admitted to Juntendo University Hospital with chief complaints of nocturnal dyspnea and shortness of breath on Sept. 22, 1983. He had no history of rheumatic fever or bacterial endocarditis. He was violently kicked in the chest while practicing Shorinji-Kempo (Karate) in July 1977. His heart murmur was first noticed in April 1978, but he was asymptomatic for six years after the accident until transient nocturnal dyspnea developed January 1983. Physical examination on admission revealed a grade 4/6 apical holosystolic murmur, a markedly accentuated third sound, and hepatomegaly of two finger breadth in the right midclavicular line. An electrocardiogram revealed sinus tachycardia (100/min), left atrial overload and left ventricular hypertrophy. Chest radiography showed slight cardiac enlargement with a cardiothoracic ratio of 55%, and slightly increased pulmonary vascular markings. Two-dimensional echocardiography showed a markedly prolapsed posterior mitral leaflet and fluttering in diastole. Cardiac catheterization showed elevated pressure of pulmonary capillaries (a: 16, v: 30, mean: 19 mmHg), the pulmonary artery and the right ventricle. Left ventriculography revealed grade four (Sellers) mitral regurgitation. Mitral valve replacement was performed on October 13, 1983. A chorda tendinae supporting the posterior leaflet of the mitral valve was found to be ruptured just above its origin from the posterior papillary muscle. Histological examination of the resected valve showed increased spongiosa tissue which mimicked so-called myxomatous changes, but it seemed preferable to interpret this as a "secondary change due to increased hemodynamic stress" rather than the "primary change".

Adult↗
PubMed1985

[The effect of large dose dexamethasone on local cerebral blood flow (L-CBF) in ischemic rat brain].

Changes of local cerebral blood flow (l-CBF) were estimated by autoradiographic techniques in middle cerebral artery occlusion rats given a large dose of (3 mg/kg) dexamethasone. The sensory-motor, parietal, auditory and olfactory cortices showed a significant reduction (greater than 25%) of l-CBF. In MCA occlusion with large dose dexamethasone group, ischemic cortices showed significant reduction from the only MCA occlusion group (highest 36%). There was no significant reduction of l-CBF in the deep structures. The effects of dexamethasone on drains with various pathologies have been studied both clinically and experimentally with many kinds of techniques. These effects are now being reevaluated. Still controversial however, is the mechanism that determines whether dexamethasone has beneficial, non-beneficial, or harmful effect. This study may help us to unravel the mechanism of steroid effects, as well as the relationship between corticosteroid and central nervous system.

Animals↗
PubMed1985

[A case with postoperative calcified epidural hematoma].

In the literature, postoperative calcified epidural hematoma is not common. The authors report a case of calcified epidural hematoma after ventriculoperitoneal shunt, and radiotherapy for pinealoma. A 14-year-old boy was admitted to author's department on December 9, 1983, complaining of headache. He underwent a ventriculoperitoneal shunt on August 28, 1980 under the diagnosis of hydrocephalus caused by pinealoma. After the operation hydrocephalus improved. The patient had radiotherapy of 5090 rad. CT scan taken after the irradiation revealed reduction of the size of the tumor. On August 30, 1983, a ring calcification of epidural hematoma in the right parietal region was noticed on CT and plain skull X-rays. He was readmitted because of headache. There was no history of head injury. The calcified epidural hematoma was totally removed on December 12, 1983. The extirpated calcified epidural hematoma was 7.0 X 7.5 cm and 2.5 cm in thickness. Capsule formation was observed and ossification was also seen at dural side. No inflammatory finding was seen on histological examination. The postoperative course was uneventful. Etiology of calcified intracranial hematoma was discussed in relation to the present report, the relevant literature reviewed.

Adolescent↗
PubMed1985

[Myocardial damage (myocytolysis) caused by subarachnoid hemorrhage].

A case of subarachnoid hemorrhage complicated by neurogenic pulmonary edema and neurogenic myocardial damage is reported. A 50-year-old woman was admitted following the sudden onset of headache and disturbance of consciousness due to a ruptured internal carotid posterior communicating artery aneurysm on the right side. She showed respiratory failure due to pulmonary edema, which subsequently improved with the mechanical ventilation. After that, she manifested chest distress and hypotensive episode then occurred. An ECG showed QS wave and ST elevation which suggested the presence of inferolateral myocardial damage. Subsequent rises in serum GOT, GPT, LDH and CPK were noticed. CPK-MB and LDH I and V isozyme levels rose. An echo cardiogram showed hypokinesis of the apical half of the left ventricular septum. The patient died on 5th hospital day due to rerupture of the cerebral aneurysm. Autopsy revealed diffuse myocytolysis with coagulation necrosis of the heart muscle without occlusion of coronary arteries. A small hemorrhagic lesion was found in the hypothalamus. We suggested that a hypothalamic lesion due to subarachnoid hemorrhage stimulated the sympathetic nervous system which in turn discharged endogenic catecholamine. This was probably accompanied by vasospasm of the coronary arteries and systemic peripheral arterioles. Furthermore, myocardial oxygen consumption could have been increased by the increase in catecholamine. Finally, it gave rise to neurogenic pulmonary edema and extensive diffuse myocytolysis of the heart occurred.

Cardiomyopathies↗
PubMed1984

Lipid binding activities of the P2 protein in peripheral nerve myelin.

Lipid binding activities of the P2 protein in peripheral nerve myelin were examined using retinoic acid, retinol and oleic acid as ligands. The P2 protein showed the specific binding affinity to both of retinoic acid and retinol. The binding site of these ligands was suggested to be similar. In addition, the high binding activity of the P2 protein with oleic acid was also observed. The ligands specificities of the P2 protein are clearly different from those of cellular retinoic acid binding protein (CRABP), cellular retinol binding protein (CRBP), and Z protein. In amino terminal sequence, however, the P2 protein contained considerable homologous structure to these lipid binding proteins. Therefore, the P2 protein and these lipid binding proteins may belong to a family of structurally related proteins evolved from a common ancestral gene.

Amino Acid Sequence↗
PubMed1984

CT findings in patients with gliomas, surviving more than 10 years.

After reviewing the latest CT scans of 23 mostly low grade glioma patients who survived more than 10 years after treatment, it was suggested that loss of the original tumour bulk and frequently the presence of porencephalic cavity replacing the original tumour, with a smooth lining which is not contrast-enhanced is essential to assume a clinical "cure" in the case of intrinsic cerebral gliomas. In the case of gliomas growing within the ventricle or subarachnoid space, tissue with calcium deposit but without contrast-enhancement was noted, although the number of cases was limited.

Adolescent↗
PubMed1984

Left ventricular function and muscle mechanics in hypertrophied rabbit heart.

Ventricular contractile performance was studied in relation to wall muscle mechanics in isolated rabbit left ventricles during pressure-overloaded hypertrophy. The isovolumic pressure-volume relation of the hypertrophied ventricle (LVH) shifted to the left and upward from the normal control (NC) (P less than 0.001), but calculated wall stress at each normalized circumferential length decreased in LVH. The pressure-ejection rate relation, determined accurately by velocity control technique, could be adequately approximated by a hyperbola. In LVH, the maximum pressure (Po) was larger (154.3 +/- 17.0 mmHg), whereas the maximum ejection rate (Vej max) was smaller (13.7 +/- 4.2 ml/s, P less than 0.001) than those for NC (127.7 +/- 23.3 mmHg and 22.3 +/- 5.7 ml/s, respectively). The pressure-stiffness relation was linear in both groups, but the vertical axis intercept increased, indicating increased resting stiffness in LVH. Ventricular volume stiffness vs. the mean wall stress relationship of LVH shifted upward, whereas the normalized wall muscle stiffness vs. the mean wall stress relationship of LVH showed a smaller slope. Thus the hypertrophied ventricle can maintain its pumping ability at normal or augmented levels with depressed contractile function of the wall muscle.

Animals↗
PubMed1984

An altered distribution and elimination of digoxin in anemic patients and experimentally induced anemic rats.

Digoxin was administered orally to eight anemic patients in their anemic and convalescent stages, and serum digoxin concentration was determined by radioimmunoassay. In the anemic patients a significantly lower level of serum digoxin concentration was observed in anemic state compared with convalescent stage at 72 hours after the drug administration (p less than 0.01). In usual clinical use, a full digoxin effect is expected to be attained as 72 hours. Tritiated digoxin was administered intravenously to anemic and control rats and the tritium in samples of the blood, myocardium and urine were counted in a liquid scintillation counter. The anemic rats showed significantly lower level of serum 3H-digoxin at 6 hours (p less than 0.01) and lower myocardial concentration at 24 hours (p less than 0.01). Larger amount of urinary excretion of 3H-digoxin was observed in the anemic rats 6 hours after the drug administration. No significant difference in fecal excretion of 3H-digoxin was found between the anemic and control rats.

Anemia, Hypochromic↗
PubMed1984

A morphometrical study of myocardial disarray associated with right ventricular outflow tract obstruction.

In order to define quantitatively the histological characteristics of the hypertrophied myocardium of the right ventricular outflow tract in patients with congenital heart disease, a light-microscopic study of biopsy specimens obtained from 20 cases with tetralogy of Fallot (TOF) and 14 cases with muscular obstruction of the right ventricular outflow tract ( RVOTO ) was performed using a semi-automatic sampling counter. As the controls, the crista supraventricularis of 11 autopsied cases without cardiac disease were used. The TOF patients were divided into two groups: those with (9 cases) or without (11) a history of hypoxic spells. The myocyte diameter was calculated according to Chalkley 's and Arai 's method. The areas of myocardial fibrosis and myocyte disarray were determined quantitatively by the point count method. Myocardial fibrosis was classified into five types: focal, mild perimysial, severe perimysial, perivascular and plexiform. In the control group, the myocyte diameter and area of fibrosis and disarray tended to increase with age. In the obstructive groups, the myocyte diameter and area of disarray were greater than those of the control in any age group. Myocyte diameter tended to increase with age in all groups, except for the TOF cases with a history of hypoxic spells. The latter also had the largest area of myocardial disarray (25.3%) (p less than 0.01), and a largest area of fibrosis (20.5%) than the TOF cases without spell (14.4%), but severe perimysial fibrosis was observed in only five out of the nine patients with spells. The lack of a relation between the pressure and the presence of an increased area of the myocardial disarray in TOF with spells implies that this myocardial change is brought about by myocardial abnormality accompanied by cardiac malformation.

Adolescent↗
PubMed1984

Actions of nipradilol (K-351), a new alpha- and beta-adrenoceptor blocker, on the rabbit portal vein.

Nipradilol but not desnitro nipradilol [N-) nipradilol) inhibited the norepinephrine (NE)-induced depolarization and contraction of the rabbit portal vein. The NE-induced contraction and depolarization were also blocked by prazosin, but not blocked by yohimbine. Therefore, nipradilol possesses an alpha 1-blocking action. The order of potency was prazosin greater than nipradilol greater than yohimbine greater than (N-)-nipradilol = 0. With applications of field stimulations to muscle tissues, the smooth muscle membrane was depolarized with a latency of several seconds, and the action potential was generated. These phenomena were blocked by tetrodotoxin (TTX), prazosin or nipradilol, but not by yohimbine. Isoproterenol (Isop) inhibited the 30 mM K-induced contraction, and this inhibitory action was blocked by (N-), nipradilol, nipradilol or propranolol, dose-dependently. The potency of beta-blocking actions of nipradilol was much the same as that observed by propranolol and (N-) nipradilol. When nipradilol (10(-5) M) was applied to the tissue, the amplitude of the 30 mM K contraction was slightly reduced. Such inhibitory action was not observed by application of (N-) nipradilol. The Ki values of nipradilol for blocking actions on the NE-induced contraction and Isop-induced relaxation were of the same order of 10(-7) M. Therefore, the potencies of alpha 1-blocking and beta-blocking actions of nipradilol may be the same in the rabbit portal vein. These findings suggest that the vasodilating action of nipradilol on the rabbit portal vein is mainly due to the alpha 1-blocking action and that the nitrate action of this agent may be weak.

Adrenergic alpha-Antagonists↗
PubMed1984

Restoration of fertility with gonadotropin and bromocriptine in a hypogonadal man after removal of macroprolactinoma.

A case of male hypogonadism after removal of macroprolactinoma was successfully treated with gonadotropin. A 35-year-old man treated surgically for pituitary adenoma had elevated plasma prolactin and impaired pituitary function after the operation. He was on replacement of hydrocortisone, levothyroxine and testosterone depot along with bromocriptine. Normal plasma testosterone levels were achieved with HCG, 3,000 IU three times a week. The addition of 75 IU of FSH daily restored spermatogenesis and the sperm count reached the fertile range at the 11th month. Doses of HCG and FSH were cut in half at the 10th month without affecting the plasma testosterone levels. His wife was impregnated at the 12th month and gave birth to a normal baby girl.

Adult↗
PubMed1984

Puberty due to ectopic HCG production in a girl with suprasellar ectopic pinealoma associated with panhypopituitarism.

A 13.5-year-old girl who developed puberty due to HCG production by suprasellar ectopic pinealoma was reported. This girl appeared to be in a state of precocious puberty at the age of 5 when ectopic pinealoma was first diagnosed. Her breasts started to develop at 13 years of age in spite of hypopituitarism. Plasma LH was found to increase for several months and gave rise to suspicion of the recurrence of the tumor, which was confirmed by the detection of HCG in plasma and CSF. Precocious puberty or puberty can be a characteristic endocrinological manifestation of an HCG producing tumor not only in boys but also in girls. The measurement of plasma HCG (or LH) can be a useful tumor marker in following the clinical course of an HCG producing tumor.

Adolescent↗