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Biomedical subjects

M Akima

Publications and source records attributed to M Akima.

At least 55 records · Page 3Linked to original sources
PubMed1987

A study on the microvasculature of the cerebellar cortex. The fundamental architecture and its senile change in the cerebellar hemisphere.

The arterial structure of the cerebellar cortex was studied by vascular stain and in diaphanized specimens after intra-arterial barium injections. A scanning electron microscope study on the corrosion cast of the arteries was also performed. Arteries distributed in the cerebellar hemisphere are classified into cortical, subcortical, and medullary arteries. The patterns of arterial distribution are similar to those in the cerebral cortex. The cortical arteries are subclassified into superficial, middle, and deep cortical branches. The superficial branches are very fine, forming capillary networks in the molecular layer. The middle cortical branches terminate in the Purkinje cell layer, by dividing into several branches extending parallel to the plane of this layer. These branches connect with capillaries in both the molecular and the granular layers. The deep cortical branches give off some collaterals along the Purkinje cell layer and terminate in the granular layer, by breaking up into capillary networks. The Purkinje cell layer is marked by arterial branches ramified from the middle and deep cortical branches and no particular dense capillary networks are formed in the Purkinje cell layer. The brains of older patients show intertwining of the middle and deep cortical branches, some forming "rope-like" appearance. These patterns are similar to those seen in the cerebral cortex, but they were found, in older people, in the cerebrum.

Aged↗
PubMed1987

Primary leiomyosarcoma of bone. A case report and review of the literature.

A 62-year-old female with primary leiomyosarcoma of the left femur is reported with a review of 21 cases reported in the literature. The resected specimen showed that the tumor extended from the femoral head to the diaphysis for 13 cm in length. The tumor showed mainly intramedullary proliferation, but extraosseous growth was also noted at the great trochanter. Microscopic examination revealed well differentiated leiomyosarcoma characterized by interlacing bundles of fusiform cells with eosinophilic cytoplasm and rod-shaped hyperchromatic nuclei. PAP stain of actin on the tumor cells was positive. On electron microscopy, microfilament of 6-8 nm in diameter, dense bodies, pinocytotic vesicles, marginal attachment plate, and basal lamina were noted. The patient died with pulmonary metastasis, 1 year and 7 months after the operation. An autopsy showed metastases in the right pelvic cavity and bilateral lungs, and confirmed the primary site to be the left femur.

Female↗
PubMed1986

A study on the microvasculature of the cerebral cortex. Fundamental architecture and its senile change in the frontal cortex.

The arterial architecture of the cerebral cortex and its changes along with aging were studied by microangiography, vascular staining, and scanning electron microscopy. The arteries distributed in the cerebral cortex and medulla were classified into cortical, subcortical, and medullary arteries. The cortical arteries were further classified into superficial, middle, and deep cortical branches according to the site of their termination. There were many fountain-like rami in the middle and deep cortical branches. These fountain-like rami were composed of several to many fine arteries, ramified from a small artery by repeated bifurcation within a short segment of its course. This structural pattern is probably responsible for the ease with which pronounced ischemic state may develop in their territories nourished by these branches, and they may play a significant role in the development of pseudolaminar necrosis of the cerebral cortex. Intertwining of small branches forming rope-like structures was observed with increasing frequency with age, suggesting that this phenomenon correlates with aging or is associated with brain atrophy. The intertwining was always clockwise when looking from the proximal side of the arteries towards their distal end. While the precise mechanism of the development of the intertwining remains unclear, torsion of the trunk of the blood vessels is thought to be the cause of the intertwining of the peripheral branches.

Adolescent↗
PubMed1985

Ossified metastatic transitional cell carcinoma of the bladder.

A case of ossified tumor in the anterior abdominal wall that proved to be a metastatic transitional cell carcinoma of the bladder is reported. Computerized tomography detected dense calcification within the tumor but it did not differentiate ossification from calcification. A soft x-ray roentgenogram of the resected tumor revealed a fine trabecular pattern of the ossified area.

Abdominal Muscles↗
PubMed1985

[Hematoma of the pineal region: a case report].

A 44-year-old man came to our clinic, complaining of slowly progressive disturbance of visual acuity and of ocular movement. This patient suffered from headache, narrowing of visual field and polyuria about 20 years ago, and received surgical and radiation therapy under the diagnosis of pituitary adenoma. Clinical symptoms and signs of this patient, except for bitemporal hemianopsia, almost completely disappeared after these treatment. The detailed information about the histology and radiation dose are not available at the present time. CT scan in our clinic revealed a round low-density area at the suprasellar region and a high density area at the left quadrigeminal cistern. Pineal calcification was compressed to the right about 2-3 mm from midline. This high density mass were not enhanced with contrast medium. Vertebral angiography showed a slight lateral displacement of the left medial posterior choroidal artery. Specimen of tissue removed 20 years ago was reexamined but definitive diagnosis could not be established. Presumptive diagnosis of an ectopic pinealoma in the suprasellar region treated successfully 20 years ago, and its recurrence in the pineal region was made. On May 24, the patient underwent a posterior fossa craniectomy and the pineal region was explored via the infratentorial supracerebellar approach. On sectioning the precentral cerebellar vein, yellowish mass was seen in the quadrigeminal cistern. Aspiration of this mass yielded dark red liquid hematoma. Incising into the capsule, a dark brownish mass of about 4g was removed en bloc.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Cardiovascular effects of a novel antihypertensive agent, SGB-1534, in miniature pigs.

The cardiovascular effects of SGB-1534 (3-[2-[4-(o-methoxyphenyl)-1-piperazinyl]-2,4(1H,3H)-quinazolinedione monohydrochloride) were investigated in pentobarbital-anesthetized miniature pigs. SGB-1534 infused i.v. at a rate of 3 micrograms/kg . hr-1 caused a gradual decrease of systemic blood pressure reaching a plateau level, with a peak fall of about 20% of the preinfusion value, 30-60 min after the start of the infusion. Significant reductions of coronary vascular resistance and left ventricular (LV) end-diastolic pressure were also observed. Changes in LV systolic pressure, coronary blood flow and pressure-rate product were not significant, while heart rate and LVdp/dt max were significantly increased. The pressor response to a bolus i.v. injection of epinephrine (1 microgram/kg) was significantly inhibited during i.v. infusion of SGB-1534. The results indicate that SGB-1534 is an antihypertensive agent, probably related to its alpha-adrenergic blocking action in peripheral vasculatures.

Anesthesia↗
PubMed1985

[An autopsy case of Prader-Labhart-Willi syndrome].

An autopsy case of 23-years-old man with Prader-Labhart-Willi syndrome (P-L-W syndrome), who had died by acute renal failure due to burn injury, was reported. P-L-W syndrome was constituted by hypotonia, hypogonadism, hypomentia, obesity and other minor anomalies, however, CNS anomaly had not been reported. The patient sat at 3 years of age, walked at 4 years old, began to utter single words at 3-4 years, and he began to obese at 4 years of age. He fulfilled the condition of P-L-W syndrome mentioned above. On his age 15, laboratory findings on admission revealed remarkable diabetic pattern by oral glucose tolerance test and intelligence quotient was 28, and the other laboratory findings were within normal limit. During his clinical history, complications of diabetes mellitus, such as diabetic retinopathy and neuropathy, were aggrevated, and upstanding and gait were impossible at 20 years of age. On his age 23, he suffered from burn injury at left lower extremity and he fell in acute renal insufficiency. Five autopsy cases of P-L-W syndrome have been reported so far, however, CNS anomaly has not been observed. Following anomalies in our case was recognized, such as shortness of the frontal lobe, partial micropolygyria of the dentate nucleus, heterotopia of the inferior olivary nucleus, ectopia of Purkinje cell in the molecular layer, heterotopia of middle sized neuron in the deep white matter of the cerebellum and large number of residual nerve cells in the cerebral subcortical white matter.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Neuropathology of familial erythrophagocytic lymphohistiocytosis: six cases and review of the literature.

The authors report the brain findings in six cases of familial erythrophagocytic lymphohistiocytosis (FEL) and review the literature, focusing primarily on the neurologic and neuropathologic aspects. Clinically, the most common neurologic abnormalities in the six patients were stupor or coma and seizures, with hemiplegia and cranial nerve palsies. Neuropathologic changes were characterized by infiltration of the meninges by lymphocytes and histiocytes and perivascular lymphocytic cuffing and diffuse proliferation of histiocytes in the brain parenchyma. The severity of the brain involvement was variable. In the mildest case there was only meningeal involvement. More severely involved cases showed meningeal and perivascular infiltration of lymphoid cells in the brain. In the most severely involved cases, there was, in addition, diffuse cerebral infiltration by histiocytes accompanied by multifocal necrosis. Some cases showed disproportionately greater involvement of the brain than of the visceral organs. The authors conclude that "meningoencephalitis," histiocytic invasion, and necrotizing brain lesions are characteristic of FEL, although the mechanism of their production is not known. Frequent seizures and disseminated intravascular coagulopathy may be contributory.

Brain↗
PubMed1984

Hypotensive effects and biotransformation of nicorandil, a new antianginal agent, administered to rats by different routes: comparison with nitroglycerin and isosorbide dinitrate.

The effects of nicorandil, N-(2-hydroxyethyl)nicotinamide nitrate (ester), in reducing systemic blood pressure (SBP) in rats were studied in comparison with isosorbide dinitrate and nitroglycerin. The drugs were administered to pentobarbitone-anaesthetized rats by jugular vein (i.v.), portal vein (p.v.), intrajejunal (i.j.), intraperitoneal (i.p.) and subcutaneous (s.c.) routes. Nicorandil was absorbed rapidly through all routes, and caused marked hypotension dose-dependently. With isosorbide dinitrate and nitroglycerin, unlike nicorandil, the p.v. dose required to induce a vasodepressor response was significantly greater than that required to cause a comparable response after i.v. administration. In non-recirculating rat liver perfusion experiments, nicorandil was reduced only 5-10% during a single passage through the liver, while nitroglycerin was reduced over 95%. In recirculating liver perfusion experiments, the progressive decrease of nicorandil in the blood recirculated was accompanied by a corresponding increase of SG-86, a dinitrate compound of nicorandil (its main metabolite). Sixty min after dosing, nicorandil was decreased by approximately 73% of the initial nicorandil blood concentration and SG-86 was increased by approximately 70%. The extent of degradation of nicorandil in liver homogenates, examined by thin-layer chromatography, was in the following order: rat = guinea-pig greater than dog = monkey greater than pig. In these species a close inverse relationship is apparent between the rate of liver nicorandil degradation and hypotensive effects of nicorandil.

Animals↗
PubMed1984

[Primary seminal vesicle carcinoma in a 19-year-old male].

A 19-year-old male with papillary adenocarcinoma of the seminal vesicle with cyst is reported. Cytological and histopathological studies were carried out and the relevant literature was perused. There are only 6 cases of carcinoma and 40 cases of cyst of the seminal vesicle in the Japanese literature. Moreover, ours is the first reported case of the co-existence of carcinoma and cyst in the seminal vesicle. There may be a pathogenetic relationship between the carcinoma and cyst in our case.

Adenocarcinoma, Papillary↗
PubMed1983

Is the cardiovascular effect of nitroglycerin related to the prostaglandin system in the dog?

Open-chest dogs were used for studies of the effects of intra-coronary (0.3-10 micrograms) or i.v. nitroglycerin (0.3-100 micrograms/kg) on systemic blood pressure (SBP), heart rate, left ventricular (LV) pressure, coronary blood flow and vascular resistance in the absence of presence of indomethacin (3 mg/kg i.v.). The nitroglycerin-induced changes in the cardiovascular parameters were not significantly modified by indomethacin (3 mg/kg i.v.). The dose of indomethacin used was large enough to inhibit significantly, for more than 2 h, the coronary vasodilation induced by arachidonic acid (100 micrograms) administered intra-arterially. The present study suggests that the cardiovascular action of nitroglycerin may not be mediated through the prostaglandin system.

Animals↗
PubMed1983

Evaluation of the isolated perfused heart of mice, with special reference to vasoconstriction caused by intracoronary acetylcholine.

A perfusion model of isolated hearts (left in situ) was developed in mice. The heart was perfused retrogradely, according to the Langendorff technique, under a fixed flow rate of about 4 ml/min with physiological saline solution. Left ventricular (LV) cavity pressure, LV dP/dt max, heart rate, and arterial perfusion pressure were measured. Stable levels of mechanical parameters were reached within 30 min following the start of perfusion and were maintained for more than three hours. Single doses of acetylcholine (ACh, 0.003-1 microgram) administered into the coronary perfusion system elicited a dose-dependent increase (vasoconstriction) followed by a decrease (vasodilation) in perfusion pressure. Coronary vasoconstriction in response to ACh was especially prominent. LV systolic pressure, LVdP/dt max, and heart rate resulted in a decrease followed by an increase. A single injection of atropine (10 micrograms) antagonized both cardiac and vascular (vasoconstrictor and dilator) effects of ACh. The present studies substantiate the validity of this experimental model for the assessment of the action of drugs on the heart and coronary vasculature.

Acetylcholine↗
PubMed1983

Effects of a new antianginal agent, nicorandil, on the cardiovascular system of the miniature pig: with special reference to coronary vasospasm.

The cardiovascular and vasospasmolytic effects of a newly developed nicotinamide derivative, N-(2-hydroxyethyl)nicotinamide nitrate(ester) (nicorandil), were examined in anesthetized, open-chest "miniature" pigs, and compared with those of nitroglycerin. Nicorandil, administered i.v. in doses of 10 micrograms/kg to 1 mg/kg, decreased systemic blood pressure, left ventricular (LV) systolic pressure, pressure rate product and coronary and femoral vascular resistance. It pronouncedly increased coronary blood flow and slightly increased heart rate. An increase, often preceded by a decrease, occurred in the LVdP/dt max. In doses of 10 to 100 micrograms/kg, nicorandil induced a slight increase followed by a decrease in femoral blood flow, but larger doses always decreased it. Similar results were obtained with nitroglycerin for all the cardiovascular parameters tested except LVdP/dt max and coronary blood flow. Unlike nicorandil, nitroglycerin induced a decrease often preceded by an increase in the LVdP/dt max. In doses of 1 to 30 micrograms/kg, nitroglycerin caused a decrease preceded by a slight and transient increase in the coronary blood flow. Nicorandil, administered i.v. in doses of 30 micrograms/kg to 1 mg/kg, inhibited coronary vasoconstriction caused by methacholine (3 or 10 micrograms) and norepinephrine (2-4 micrograms in the presence of propranolol) injected directly into the coronary artery. The magnitude and duration of this antagonism depended on the dose of nicorandil used. Although nitroglycerin in a dose of 10 or 30 micrograms/kg also effectively inhibited coronary vasoconstrictor responses to the two vasoactive agents, dipyridamole (60 micrograms/kg) failed to do so. Thus, nicorandil has prominent vasospasmolytic effects and is an efficacious coronary vasodilator which reduces afterload.

Animals↗