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Biomedical subjects

I Nakano

Publications and source records attributed to I Nakano.

At least 181 records · Page 10Linked to original sources
PubMed1995

Protective effect of nitric oxide on development of acute pancreatitis in rats.

Nitric oxide (NO) has been implicated to regulate pancreatic circulation, promote capillary integrity, and inhibit leukocyte adhesion. We investigated the role of NO in the development of pancreatitis. Nitro-L-arginine, an inhibitor of NO synthase, in total dose of 35 mg/kg body wt was infused in the rats with edematous pancreatitis induced by two intraperitoneal injections of cerulein (20 micrograms/kg). L-Arginine (125 or 250 mg/kg), a NO donor was intravenously administered twice in the rats with hemorrhagic pancreatitis induced by water-immersion stress plus two intraperitoneal injections of cerulein (40 micrograms/kg). The degree of pancreas edema, serum amylase levels, and histologic alterations were investigated. Nitro-L-arginine exacerbated cerulein-induced pancreatitis and caused a decrease in pancreatic blood flow. L-Arginine ameliorated the severity of hemorrhagic pancreatitis dose dependently and improved the pancreatic blood flow. These findings suggest that NO could confer protection against the development of hemorrhagic pancreatitis, probably through improvement of the pancreatic microcirculation.

Acute Disease↗
PubMed1995

Hepatitis C virus infection and genotypes in Japanese hemophiliacs.

Liver function and antibodies to hepatitis C virus and to human immunodeficiency virus-1 were examined in 195 Japanese patients with hemophilia. One hundred and seventy-three were positive for antibody to HCV and 61 for antibody to human immunodeficiency virus-1. In 63 patients, we examined HCV genotypes according to the double polymerase chain reaction method. Forty cases (63%) were infected with hepatitis C virus with a single genotype, including type 1a in five, type 1b in 21, type 2a in seven and type 2b in seven; 16 (25%) were infected with double genotypes, including types 1a + 1b in 14, types 1b + 2a in one and types 1b+2b in one; and four (6%) were infected with triple genotypes, including types 1a + 1b + 2b in two. Genotype could not be determined in three patients by this method. In the 191 nonhemophiliac patients with chronic hepatitis C, HCV genotyping was as follows: type 1a in 0, type 1b in 121, type 2a in 40 and type 2b in 10 of 171 cases (89.5%) with single infection and types 1b + 2a in five and types 2a + 2b in one of six (5.5%) with double infection. In the remaining 14 patients, genotype could not be determined. Frequent transfusion of domestic and/or imported coagulation factor concentrates probably caused the high incidence of HCV infection with rare or mixed genotypes in Japanese hemophiliacs.

Adolescent↗
PubMed1995

Effect of endothelin-1 on the development of hemorrhagic pancreatitis in rats.

BACKGROUND: It has been hypothesized that microcirculatory disturbance plays an important role in the development of severe pancreatitis. In this study we investigated the effects of exogenous endothelin-1 on the development of severe pancreatitis in rats. METHODS: Acute pancreatitis was induced by two intraperitoneal injections of cerulein (10 micrograms/kg body weight). Endothelin-1 was administered via an abdominal aortic catheter as a bolus of 250-750 pmol/kg BW every hour for 4 h. RESULTS: Remarkable morphologic changes in the pancreas, including hemorrhage, and increases in serum amylase level and active elastase content in pancreatic tissue were observed in rats treated with cerulein plus endothelin-1 in a dose-dependent manner 5 h after the first cerulein injection. Local pancreatic blood flow decreased significantly, and microcirculatory disturbances in the pancreas were demonstrated. CONCLUSIONS: These results suggest that endothelin-1 causes pancreatic microcirculatory disturbance and might be a contributing factor in the aggravation of acute pancreatitis.

Acute Disease↗
PubMed1995

Acute encephalopathy with bilateral thalamotegmental involvement in infants and children: imaging and pathology findings.

PURPOSE: To investigate the imaging and pathologic characteristics of acute encephalopathy with bilateral thalamotegmental involvement in infants and children. METHODS: Five Japanese children ranging in age from 11 to 29 months were studied. We performed CT imaging in all patients, 10 MR examinations in four patients, and an autopsy in one patient. RESULTS: The encephalopathy affected the thalami, brain stem tegmenta, and cerebral and cerebellar white matter. The brain of the autopsied case showed fresh necrosis and brain edema without inflammatory cell infiltration. Petechiae and congestion were demonstrated mainly in the thalamus. CT and MR images showed symmetric focal lesions in the same areas in the early phase. These lesions became more demarcated and smaller in the intermediate phase. The ventricles and cortical sulci enlarged. MR images demonstrated T1 shortening in the thalami. The prognosis was generally poor; one patient died, three patients were left with severe sequelae, and only one patient improved. CONCLUSIONS: The encephalopathy might be a postviral or postinfectious brain disorder. T1 shortening in the thalami indicated the presence of petechiae.

Acute Disease↗
PubMed1995

[Treatment of intractable postherpetic neuralgia and blepharospasm: intraneural injection of adriamycin].

Adriamycin, an anthracycline antineoplastic agent, can swiftly be transported to the sensory or somatic motor neurons by way of axoplasmic transport when injected into the subepineurium of the trigeminal nerve or sciatic nerve in experimental animals, and is consequently able to induce degeneration of the neurons without any systemic side effects. Intraneural injection of this agent was carried out for the treatment of a total of 22 patients presenting with intractable neural dysfunction (12 with neuralgia, including 7 with post-herpetic neuralgia and 10 with facial dystonia). The nerve which innervated the affected site was exposed under local anesthesia and approximately 10-60 microliters of 1-20% adriamycin was injected into the subepineurium. Results of the treatment after average follow-up periods of 21.5 months were as follows: Out of 12 patients with neuralgia, good results were obtained in 2 cases (16.7%), fair results in 6 cases (50.0%) (overall effective rate 67.7%). There were no changes in symptoms in 4 cases (33.3%). Out of 10 patients with facial dystonia, good results were obtained in 2 cases (20.0%), fair in 2 cases (20.0%) (overall effective rate 40.0%), and no changes in symptoms in 6 cases (60.0%). No major complications were encountered during these procedures and, once symptoms had disappeared after the treatment, no recurrence of symptoms was experienced. This method clearly differs from other various kinds of simple peripheral neurotomy, since transection of the peripheral nerve does not cause any, destructive changes in the sensory ganglion or motor nucleus and, hence, symptoms may recur.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

[Enteroglucagon].

Explore the source record for details and available documents.

Glucagon-Like Peptides↗
PubMed1994

Astrocytic straight tubules in the brain of a patient with Pick's disease.

This report concerns an immunohistochemical and ultrastructural study of cerebral astrocytes in a patient with Pick's disease of 20 years' duration. The autopsied brain was prominently small (710 g) with marked fronto-temporal lobar atrophy. Histological examination demonstrated profound neuronal loss and spongy changes with tau-positive Pick bodies in the frontal and temporal cortex. In addition, many glial cells in the temporal lobe white matter contained round to oval, argentophilic and slightly hematoxinophilic cytoplasmic inclusions that were also immunolabeled with the anti-tau antibody. On electron microscopy, the glial inclusions were observed in the perikarya of astrocytes that were recognized as such from intracytoplasmic glial filaments and the presence of gap junctions. The inclusions were free in the cytoplasm, without a limiting membrane, and mainly comprised irregular aggregations of bundles of about 15-nm straight tubules, which were indistinguishable from those of intraneuronal Pick bodies. Furthermore, various patterns of accumulation of the same straight tubules were frequently noted in perivascular astrocytic processes carrying a basal lamina. These findings indicate that in Pick's disease astrocytes are also affected by a similar insult to that which affects neurons.

Aged↗
PubMed1994

Protective effects of gabexate mesilate on acute pancreatitis induced by tacrolimus (FK-506) in rats in which the pancreas was stimulated by caerulein.

We investigated the acute effects of the immunosuppressive agent, tacrolimus (FK-506), on the exocrine pancreas, in rats with or without stimulation of the pancreas, and evaluated the protective effects exerted by gabexate mesilate (FOY). While an intravenous injection of FK-506 did not change serum amylase levels during the 5-h observation period, this agent increased pancreatic amylase and protein content, and decreased the content of pancreatic DNA. Histologically, we observed intra-acinar vacuolization and individual cell necrosis. When the pancreas was stimulated by two intraperitoneal injections of caerulein (5 micrograms/kg) at 1-h intervals, however, which treatment did not induce any evident pancreatic change, FK-506 significantly increased serum amylase, pancreatic wet weight, and pancreatic amylase and protein, and decreased pancreatic DNA. Histologically, there were significant dose-related differences in the severity of intra-acinar vacuolization, interstitial edema, neutrophil infiltration, individual cell necrosis, and hemorrhage. Levels of intrapancreatic elastase were elevated and local pancreatic blood flow was reduced. Treatment with FOY improved the FK-506-induced acute pancreatitis, but did not increase the pancreatic blood flow. These findings indicate that FK-506 enhances abnormal pancreatic enzyme secretion and suggest that therapeutic doses of this agent can induce acute pancreatitis when the pancreas is stimulated. A protease inhibitor may protect the exocrine pancreas in patients who receive FK-506 after organ transplantation.

Amylases↗
PubMed1994

A neuropathological study of a case of lupus erythematosus with chorea.

Neuropathological examination in a 48-year-women of SLE with chorea was performed. Histological examination of the putamen showed a widespread neuronal loss associated with reactive astrocyte proliferation and neuropil rarefaction at both sides. Disappearance of large neurons was more prominent than that of small ones. Although a few old and fresh microinfarcts were scattered in the same area, there was no significant pathological abnormality in small vessels. The caudate nuclei also showed a few irregular microinfarcts and spotty loss of neurons associated with reactive astrocytosis. These neuropathological changes might be related to the appearance of choreatic movement in patients with SLE.

Astrocytes↗
PubMed1994

Location of the corticospinal tract in the internal capsule at MR imaging.

PURPOSE: To examine whether hyperintense foci in the posterior internal capsule (IC) on T2-weighted magnetic resonance (MR) images represent fibers of the corticospinal tract (CST). MATERIALS AND METHODS: The authors reviewed MR images of 100 control subjects and 35 patients with amyotrophic lateral sclerosis (ALS) and brain specimens from seven control subjects and five ALS patients. RESULTS: In the posterior IC, the brain specimens from control subjects demonstrated a pale area with large axons and thick myelin sheaths. In five ALS patients, the brain specimens showed degeneration of the CST in the same region. MR images demonstrated abnormal hyperintensity that represented degeneration of the CST in five of 35 ALS patients. In the same region, hyperintense foci were found in the control subjects. CONCLUSION: Normal hyperintense foci in the IC represent the fibers of the CST. The presence of large fibers with thick myelin sheaths may play an important role in these signal intensity variations.

Aged↗
PubMed1994

Localization of synaptophysin immunoreactivity in the human liver.

The distribution of synaptophysin, specifically located in nerve terminals, was investigated immunohistochemically in normal and diseased human livers in 4 patients with normal liver, 6 with chronic active hepatitis, 12 with cirrhosis, and 8 with hepatocellular carcinoma. In normal liver and chronic hepatitis synaptophysin immunoreactivity was detected in the lobules and portal areas. In cirrhosis it was found in the fibrous septum but in no pseudolobules. Parenchymal innervation would thus appear to cease with the development of cirrhosis, and denervation from the parenchyma may lead to various functional abnormalities in liver cirrhosis. In hepatocellular carcinoma no synaptophysin immunoreactivity was found along carcinomatous sinusoids. Immunoreactive spots were present in the capsules of hepatocellular carcinoma to a much lesser extent than in the fibrous septum of cirrhosis. Neural functions may thus have little effect on the microcirculation of hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed1994

[Early detection of primary liver cancer--diagnosis of small liver cancer by needle aspiration biopsy].

Small liver cancer is defined as a solitary hepatocellular carcinoma (HCC) with a diameter less than 2cm. To detect liver cancer as early as possible, patients with liver cirrhosis are screened by ultrasound scanning. Pathological diagnosis in needle aspiration biopsy materials is needed because of low positivity of imaging other than ultrasound scanning. Pathological features are different from those of classical hepatocellular carcinoma. Most of the small HCCs are characterized by the following features: (1) increased cellularity, (2) increased nucleus/cytoplasm ratio, (3) irregular thin trabecular pattern, (4) pseudoglandular or acinar structures, (5) increased staining affinity (eosinophilic/basophilic), (6) frequent fatty change, and (7) residue of the portal tract. Capsules of HCCs, 1-1.5 cm in diameter, are formed. Before the formation of capsules, cancerous cells show a replacing growth pattern. Two cases of small HCC are presented, and these characteristic features are explained.

Biopsy, Needle↗
PubMed1993

On the possibility of autolysosomal processing of skein-like inclusions. Electron microscopic observation in a case of amyotrophic lateral sclerosis.

Hyaline-like inclusions (HLIs) and skein-like inclusions (SLIs) were recently observed in the lower motor neurons in amyotrophic lateral sclerosis (ALS). HLIs mainly consist of randomly arranged neurofilaments and abnormally large (about 15 nm) fibrils, while SLIs comprise bundles of the abnormally large fibrils alone. Although the abnormal fibrils have been reported to be ubiquitinated in both types of inclusions, their final catabolic destination in the neurons is unknown. Electron microscopic observation of the lower motor neurons in an ALS case revealed several neurons containing SLIs in addition to ones containing HLIs. Bundles of SLIs, which were located close to HLIs or were observed by themselves without an HLI, were frequently associated with flattened cisterns; some were wrapped, some were completely sequestrated, and some were demarcated together with a portion of moderately electron dense cytoplasm by cisterns or double-membraned units. These features resemble reported early stages in the formation of autolysosomes, and thus indicate that at least some of the bundles of SLIs or parts of them in the lower motor neurons in ALS undergo degradation through the autolysosomal pathway.

Amyotrophic Lateral Sclerosis↗