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Biomedical subjects

K Nagashima

Publications and source records attributed to K Nagashima.

At least 361 records · Page 20Linked to original sources
PubMed1992

Expression of the angiotensinogen gene and localization of its protein in the human heart.

BACKGROUND: There have been no reports on the presence of the tissue renin-angiotensin system in the human heart, although the presence of angiotensinogen has been described in the animal heart. METHODS AND RESULTS: To determine whether angiotensinogen is synthesized in the human heart, we examined angiotensinogen messenger RNA (mRNA) synthesis in autopsy hearts by using ribonuclease protection assay. As a result, angiotensinogen mRNA was detected in the atrial muscle, muscles of the conduction system, and the left ventricular wall. In the left ventricular wall, mRNA expression was more prominent in the subendocardial muscles than in the midcardial or epicardial muscles. Using a monoclonal antibody to human angiotensinogen in immunoblotting experiments, we detected two closely spaced bands at approximately 70 kd in the heart, which was quite consistent with the human angiotensinogen molecule. Immunohistochemical studies with this monoclonal antibody demonstrated intense immunoreactivity in the atrial muscles, the muscles of the conduction system, and those of the subendocardial layers. CONCLUSIONS: We conclude that angiotensinogen was synthesized in the human heart. It was evident that the localization of angiotensinogen was not ubiquitous in the cardiac muscles, showing its predilection for the atrial muscles, muscles of the conduction system, and subendocardial layer of the left ventricle.

Angiotensin II↗
PubMed1992

Cerebellar form of progressive multifocal leukoencephalopathy in a patient with chronic renal failure.

Progressive multifocal leukoencephalopathy (PML) developed in a 64-year-old woman who had undergone hemodialysis treatment due to chronic renal failure (CRF) for 6 yr. Her initial symptom was ataxia, and computed tomographic (CT) scan and magnetic resonance imaging (MRI) suggested a demyelinating disease of the cerebellum. Her cell-mediated immunity was impaired. At autopsy, the cerebellar disease was confirmed as PML by ultrastructural and immunohistochemical studies. Moreover, the JC type of papova virus infection was verified by Southern blot analysis.

Cerebellar Diseases↗
PubMed1992

Detection of latent herpes simplex virus DNA and RNA in human geniculate ganglia by the polymerase chain reaction.

By using the polymerase chain reaction (PCR) we detected latent herpes simplex virus type 1 (HSV-1) in human geniculate and trigeminal ganglia obtained from autopsy cases. A pair of primers which were specific for a part of the HSV-1 thymidine kinase domain were used for detection of HSV DNA. We also examined the latency-associated transcript (LAT), known as latency-specific RNA, by means of reverse transcription-PCR with a pair of LAT-specific primers. HSV-1 DNA was detected in 16 of 17 (94%) trigeminal ganglia and in 15 to 17 (88%) geniculate ganglia of adults. We also demonstrated HSV-1 RNA derived from the LAT in both types of ganglia. These findings suggest that HSV-1 latently infects the majority of geniculate and trigeminal ganglia of adults, and that PCR and reverse transcription-PCR are useful tools for analysis of HSV latency.

Adult↗
PubMed1992

Cinatrins, a novel family of phospholipase A2 inhibitors. I. Taxonomy and fermentation of the producing culture; isolation and structures of cinatrins.

Cinatrins A, B, C1, C2 and C3, a family of phospholipase A2 inhibitors were isolated from the fermentation broth of Circinotrichum falcatisporum RF-641. They were found to be novel spiro-gamma-dilactones and gamma-lactones derived from 1,2,3,5-tetra or 1,2,3(or 1,2,4)-trihydroxypentadecane-1,2,3-tricarboxylic acids. Structures were elucidated by MS and NMR studies and chemical transformations. The structure of cinatrin C3 was confirmed by X-ray crystallographic analysis, and its absolute configuration was determined by comparison of the CD spectra with related compounds.

Chromatography↗
PubMed1992

[Multiple cerebral infarction by blood-borne tumor emboli in carcinoma of the mid-pharynx: an autopsy case].

In May, 1989, a-54-year old man was admitted complaining of sore throat and tumor of the neck which had persisted for 2 months. Mid-pharyngeal tumor was diagnosed as poorly differentiated squamous cell carcinoma (stage, T3N2M0) and the patient was treated with radiation (Co 65Gy) from May 30 to July 24 and chemotherapy (UFT), which therapies were effective. On Aug. 16, sudden onset of consciousness disturbance and hemiparesis was revealed, and MRI showed small cerebral infarction. He died on Oct. 23, of pneumonia. Pathological diagnosis revealed a case of carcinoma of the mid-pharynx with wide-spread tumor embolism. Multiple cerebral and myocardial infarctions, thrombus in pulmonary arteries and congestion of kidneys with tumor emboli, due to "disseminated intravascular carcinomatosis" were noticed. A direct cause of death was dyspnea due to multiple lung metastases, pneumonia and tumor embolism in the pulmonary and coronary arteries.

Brain Neoplasms↗
PubMed1992

HTLV-I associated gastric lymphoma.

A large gastric lymphoma was detected in a 42-year-old woman who was seropositive for HTLV-I. The tumor was histologically shown to be of diffuse large cell type, and phenotypic analysis revealed high expression of CD3 and CD4, indicative of a helper/inducer type of T-cell lymphoma. In Southern blot analyses, the tumor cells showed T-cell receptor re-arrangement and contained proviral DNA of HTLV-1.

Adult↗
PubMed1992

[Arterial redistribution to prevent hepatic arterial occlusion and gastric ulcer using hepatic arterial infusion chemotherapy with percutaneous catheterization].

Clinical usefulness of arterial redistribution using steel coils to prevent hepatic arterial occlusion and gastric ulcer was compared with the conventional method. Fifty-two patients with liver malignancies were inserted with steel coils into the common hepatic artery after percutaneous hepatic catheterization (CHA-coil) to prevent hepatic arterial occlusion. The tip of the indwelling catheter was fixed to the vascular wall, and the contact area between the catheter and blood into the liver became smaller. Fifty-nine other patients were inserted with steel coils into the right gastric artery (RGA-coil) to prevent gastric ulcer. The CHA-coil succeeded in 84% of the patients, and hepatic arterial occlusion occurred in only 4% of these patients. The RGA-coil succeeded in 88%, and gastric ulcer occurred in 2%. The rates of hepatic arterial occlusion (4%) and gastric ulcer (2%) were much decreased in comparison with 25% and 16%, respectively, in the previous cases undergoing percutaneous hepatic catheterization without such arterial redistribution. In conclusion, these procedures are highly effective to prevent complications of hepatic arterial infusion employing percutaneous hepatic catheterization and to allow continuation of arterial infusion chemotherapy for longer periods.

Catheterization↗
PubMed1992

[A case of hypothalamic astrocytoma with precocious puberty].

A case of hypothalamic astrocytoma with precocious puberty is presented. In July 1989, a 2-year-old girl was admitted to our hospital because of vaginal bleeding and enlargement of breasts. Breast development was Tanner's stage 3 and no pubic hair was present. Endocrinological evaluation revealed a slightly high level of LH, but the responses of LH and FSH to LH-RH test resulted in exceedingly high values similar to those in adults. Plain CT scan showed an isodense mass in the suprasellar cistern which was not enhanced following administration of contrast medium. MR imaging revealed the precise location of the mass attached to the posterior hypothalamus between the pituitary stalk and the mamillary bodies in sagittal view. The signal intensity of the mass was homogenous and isointense relative to the gray matter on T1 weighted image. But on T2 weighted image, it showed high signal intensity compared with the normal brain parenchyma. A right fronto-temporal craniotomy was performed and the tumor was partially removed. Histological examination disclosed moderate hypercellularity of glial cells but no neurons were visible. This appeared to be astrocytoma grade II. In the literature, CT and MRI behaviour of hypothalamic hamartomas are almost similar to our case. Therefore we think it is not possible at the present time to differentiate a low grade astrocytoma from hamartoma when using CT and MRI alone. In this case, the mechanism of development of precocious puberty seemed to be due to hypothalamic compression by the tumor.

Astrocytoma↗
PubMed1991

Inhibition of nerve growth factor-induced neurite outgrowth of PC12 cells by a protein kinase inhibitor which does not permeate the cell membrane.

K-252a, a protein kinase inhibitor of microbial origin, has proven to be a specific inhibitor of nerve growth factor. In this study, the effects of K-252b, the 9-carboxylic acid derivative of K-252a, on nerve growth factor-induced neurite outgrowth in PC12 cells was examined. K-252b is hydrophilic and does not permeate the cell membrane of PC12 cells, whereas K-252a clearly does. K-252b is, however, as potent as K-252a itself in inhibiting the nerve growth factor-induced neurite outgrowth. These results can be interpreted to suggest that effects of K-252b may be through surface-bound/anchored K-252b-sensitive molecules on PC12 cells.

Adrenal Gland Neoplasms↗
PubMed1991

Structure of a new cyclotetrapeptide trapoxin A.

C34H42N4O6, Mr = 602.73, triclinic, P1, a = 14.707 (2), b = 15.559 (2), c = 13.026 (1) A, alpha = 112.23 (1), beta = 97.25 (1), gamma = 60.67 (1) degree, V = 2399.1 (6) A3, Z = 3, Dx = 1.251 Mg m-3, lambda(Cu K alpha) = 1.54178 A, mu = 0.71 mm-1, F(000) = 966, T = 295 K, R = 0.042 for 7802 observed reflections [Fo greater than 3 sigma (Fo)]. The structure of trapoxin A was determined as cyclo[-(S)-phenylalanyl-(S)-phenylalanyl-(R)-pipecolinyl- (2S,9S)-2-amino-8-oxo-9,10-epoxydecanoyl-]. There are three crystallographically independent molecules in the cell. These molecules are linked to each other by NH...O hydrogen bonds to form an infinite chain extending along the a axis.

Amino Acid Sequence↗
PubMed1991

Chemotactic peptide from ropalidian wasp as well as the authentic chemotactic tripeptide stimulates two distinct pathways in neutrophils, but the [LYS7] analog does only one of them.

In our previous study on chemotactic peptide isolated from Ropalidian wasp, it was found to induce not only chemotaxis but also other cellular responses, such as superoxide generation and lysosomal enzyme release, but [Lys7] analog was found to induce only chemotaxis but not others. Here, studies on intracellular Ca2+ changes and receptor-binding revealed that the wasp chemotactic peptide and the authentic tripeptide stimulated two distinct receptors, but that the [Lys7] peptide could have access to only one of them.

Animals↗
PubMed1991

Distribution of atrial natriuretic peptide in the conduction system and ventricular muscles of the human heart.

Atrial natriuretic peptide (ANP), a cardiac hormone, is known to be located in the atrial specific granules, but its presence and localization in the ventricular muscle of the human heart has not been examined fully. Using a specific antibody to human ANP, we studied the conduction system and ventricular muscle with immunohistochemical and ultrastructural methods in 30 hearts obtained at autopsy. These included 12 normal and 18 diseased hearts. In the normal hearts, ANP-positive granules, which were regularly observed in the atrial myocytes, were found in small quantities in the cells of the penetrating and branching bundles in 4 of 12, and in the cells of the ventricular free walls in 2 of the 12 hearts. In the diseased hearts, the positivity increased significantly (P less than 0.05), being found in 13 of 18 (72.2%) conduction systems and 10 of 18 (55.6%) ventricular muscles. The granules were confirmed to be immunoreactive with ANP by ultrastructural examination. Furthermore, the presence of ANP mRNA in the conduction system as well as in the ventricular myocytes was demonstrated by Northern blot hybridization for which we used the complementary DNA of human ANP. Thus, a small quantity of ANP appears to be synthesized and stored in the conduction system and ventricles of some normal hearts. However, ANP was shown to be present in a larger percentage of the diseased hearts.

Aged↗
PubMed1991

Cystic endocrine tumor of the pancreas.

A large cystic tumor in the pancreatic body was found incidentally in an 85-yr-old male. A distal pancreatectomy was performed after a diagnosis of cystadenocarcinoma. Microscopic examination of the resected specimen revealed a pancreatic cystic endocrine tumor; however, this tumor produced no symptoms. Immunohistochemical studies of the tumor cells showed positivity for gastrin, neuron-specific enolase, chromogranin A, and synaptophysin, and two cell types of neurosecretory granules were recognized in electron-microscopic studies. Although endocrine tumors of the pancreas are usually solid and cystic change occurs only rarely, such tumors should be considered in the differential diagnosis of patients who have a cystic lesion in the pancreas.

Aged↗
PubMed1991

Tumourous deposition of calcium pyrophosphate dihydrate crystals in the wrist. A case report.

A 63-year-old man had a tumourous deposition of calcium pyrophosphate dihydrate crystals in the palmar aspect of the wrist. Traumatic micro-fracture or osteoarthritis was thought to have triggered the deposition of these crystals. It should be possible to differentiate the lesion clinically and radiologically from tumoural calcinosis, in which the deposits consist of calcium carbonate and/or calcium phosphate.

Calcium Pyrophosphate↗
PubMed1991

Primary seminoma of the seminal vesicle: report of a case.

We report on the clinical and histological findings of a primary extragonadal germ cell tumor that was proved to be a seminoma of the seminal vesicle. The patient had left ureteral obstruction at diagnosis. The testes were normal on physical and ultrasound examination, and the retroperitoneum was free of tumor. There was no recurrence 8 months postoperatively.

Dysgerminoma↗
PubMed1991

Pathological features of virus infections of the central nervous system (CNS) in the acquired immunodeficiency syndrome (AIDS).

Neurological disorders are a common cause of morbidity and mortality in the acquired immunodeficiency syndrome (AIDS). In this report we describe the neuropathological changes associated with both human immunodeficiency virus (HIV) infection and with the major opportunistic virus infections, cytomegalovirus (CMV), JC papovavirus (JCV) and herpes simplex virus (HSV) seen in AIDS. In addition "in situ" hybridization studies have been employed for the detection of virus genomic material in each case and the usefulness of this method in supporting the pathological diagnosis is demonstrated. Mechanisms whereby HIV infection results in leukoencephalopathy and the possible contributing roles of the three opportunistic virus infections are discussed.

Acquired Immunodeficiency Syndrome↗