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Biomedical subjects

N Aoki

Publications and source records attributed to N Aoki.

At least 289 records · Page 16Linked to original sources
PubMed1993

Vertebral artery aneurysm at the level of the cervicomedullary junction--case report.

A 39-year-old male presented with a ruptured vertebral artery aneurysm at the level of the cervicomedullary junction. Neuroradiological imaging demonstrated the aneurysm but not the anatomical relationships. Surgery in the chronic stage revealed that the aneurysm arose from the lowest part of the intradural vertebral artery. No vertebral artery proximal to the aneurysmal neck was identified in the intradural space. Clipping was difficult through the intradural approach. Acute treatment of such aneurysms requires control of the extradural vertebral artery with temporary clipping.

Adult↗
PubMed1993

Management of adult moyamoya disease.

The surgical management of adult moyamoya disease was evaluated retrospectively. Eight of 10 patients with hemorrhagic stroke had no bleeding episodes and eight of 11 patients with ischemic stroke were asymptomatic postoperatively. Angiography demonstrated neovascularization via the external carotid artery (ECA) in 22 sites (88%) and reduced basal moyamoya vessels in 11 sites (44%) postoperatively. These symptomatic improvements and angiographic findings suggest that reconstructive surgery for adult moyamoya disease patients with hemorrhagic or ischemic stroke is effective in decreasing hemodynamic stress in the basal moyamoya vessels and increasing the cortical blood supply via the ECA.

Adult↗
PubMed1993

[Clinical pharmacology and efficacy of S-1108].

We studied the pharmacokinetics of a new cephem antibiotic, S-1108, in patients with impaired kidney functions. Serum and urinary levels of S-1006 were determined after oral administration of S-1108 at 150 mg to 9 patients with renal dysfunction. In patients with severe renal impairment, high serum levels were maintained over long periods of time. Urinary excretion rates of S-1006 were lower as degrees of kidney failure were severer. S-1108 was administered to treat 27 patients with respiratory tract infections, and its clinical efficacy and safety were evaluated. The clinical efficacies were good in 26 patients, but poor in 1, yielding an efficacy rate of 96.3%. As to adverse reactions; diarrhea was observed in one case. Laboratory tests revealed elevated GOT and GPT in 1, and elevated gamma-GTP in another. These abnormalities, however, were slight and no severe side effects were caused by the drug.

Administration, Oral↗
PubMed1993

[Clinical evaluation and pharmacology of DQ-2556 in the patients with compromised renal function].

We studied the pharmacokinetics of a new cephem antibiotic, DQ-2556, in patients with impaired kidney function. The peak concentrations of the compound in the serum were observed irrespective of the degree of kidney failure 5 minutes after its bolus administration of 1.0 g intravenously, and no significant difference was observed in the concentrations among the patients. On the other hand, the decrease in its concentrations in the serum was impeded in proportion to degrees of kidney failure and, in particular, hemodialysis patients showed markedly delayed clearance of the drug from the serum; the half-lives in the serum (beta phase) were prolonged to ca. 6 hours in patients with severe kidney failure (Ccr ca. 20 ml/min) and did so markedly to ca. 17 to 21 hours in patients with hemodialysis as compared with ca. 2.5 hours in patients with slight kidney failure (Ccr ca. 50 ml/min). Urinary excretion rates (0-to-24 hours values) were ca. 70% in patients with slight kidney failure, ca. 60% in patients with moderate kidney failure and ca. 40% in patients with severe kidney failure, showing a tendency toward a decline in relation to increasing degrees of kidney failure. The compound showed a satisfactory dialytic property. The clinical efficacy and safety of DQ-2556 were evaluated upon administering if at daily doses of 0.5 g b.i.d. and 1.0 g b.i.d. for 7 and 14 consecutive days respectively, in patients with lower respiratory tract infections. The clinical efficacies were excellent in 2 patients, good in 11 and poor in 2, yielding a efficacy rate of 86.7%. No side effects were observed, though, a neutrophil sedimentation ratio decreased in a patient, and a down-shift of prothrombin activities was observed in another. These results suggest that DQ-2556 is useful for lower respiratory tract infections, but in patients with kidney failures it is required to seek the most suitable regimen since the excretion rates of the compound decrease as degrees of kidney failure become severer.

Adult↗
PubMed1993

[A case of surgically resected primary pulmonary lymphoma with IgG-paraproteinemia: gene analysis was effective for establishing its diagnosis].

A 69-year-old woman was hospitalized because of abnormal lung shadow and IgG-lambda paraproteinemia. She was otherwise healthy and asymptomatic. Chest roentgenogram showed a consolidation in the right lower lobe. Chest CT showed a tumour in S8 and subpleural interstitial shadow in S10. No intrathoracic lymphadenopathy was found. Serum IgG was 6,109 mg/dl. The cell count obtained by bronchoalveolar lavage (BAL) was 44.5% plasma cells and 17.5% lymphocytes. CD19-positive lymphocytes were prominent. The IgG/albumin ratio was 13 times higher, and IL-6/albumin ratio was 29 times higher in lavage fluid than in serum. Transbronchial lung biopsy (TBLB) specimen showed interstitial infiltration of plasma cells and lymphocytes. Right lower lobectomy was performed, and serum IgG subsequently decreased to about 4,000 mg/dl. DNA was extracted from the surgical specimen, and analyzed by Polymerase Chain Reaction (PCR) method. A rearrangement band was amplified with Fr3a & VLJH primers (immunoglobulin heavy chain gene). The infiltrated cells were proved to be monoclonal B-cells. This case was diagnosed as small lymphocytic lymphoma, plasmacytoid. Most primary pulmonary lymphomas are well differentiated B-cell type, and the histopathological findings resemble those of LIP or pseudolymphoma. Gene analysis may thus be an effective procedure for the distinction between inflammatory and neoplastic cell proliferation, such as LIP and lymphoma.

Aged↗
PubMed1993

Detection of thrombomodulin in human lung cancer cells.

Thrombomodulin (TM), which usually exists in vascular endothelial cells and exerts an anticoagulant activity, was detected by Western blot analyses and immunocytochemical staining using three anti-TM monoclonal antibodies in cultured cell lines derived from a squamous cell carcinoma and an adenocarcinoma of the lung, but was not detected in a cell line derived from a small cell carcinoma. Functional assays indicated that TM detected in these cells was functionally active. The presence of TM in 22 specimens of surgically removed lung cancer tissue was also examined by an immunohistochemical method. TM was present along the cell membranes in 4 (36%) of 11 squamous cell carcinomas examined, but was not detected in 10 adenocarcinomas and 1 large cell carcinoma examined. Because TM is identical to fetomodulin, which modulates embryogenesis, the authors have concluded that TM is an oncodevelopmental antigen. The authors have also suggested that functionally active TM on lung cancer cells may modulate cancer cell behaviors in such ways as exhibiting anticoagulant activity.

Adenocarcinoma↗
PubMed1993

[Falx metastasis of thymic carcinoma: a case report and review of literature].

A patient, a 72-year-old male, with a thymic carcinoma spreading to the extrathoracic region, is reported. he had undergone a thoracotomy and received radiation-and chemotherapy. Four months later, the patient was noticed to have a mild left sided hemiparesis. Further evaluations revealed metastasis of thymic carcinoma to the bone and intracranial region. Surgical treatment for intracranial lesion was performed, and the patient's left sided hemiparesis was cleared. Thymic carcinoma is uncommon, and its intracranial metastasis is rare. We found 27 previous reports of intracranial metastasis of thymic carcinoma and malignant thymoma. This time, we report a case of thymic carcinoma with intracranial (falx) metastasis, and discuss the concept of thymic carcinoma and thymomas in a review of the literature.

Aged↗
PubMed1993

[Progress in diagnosis of disseminated intravascular coagulation (DIC)--diagnostic criteria of DIC].

DIC is an acquired disorder in which intravascular coagulation may lead to microvascular fibrin formation and a hemorrhagic diathesis. If DIC is acute and severe, fibrin formation may lead to microvascular thrombosis, and consumption of coagulation factors and platelets may result in a hemorrhagic diathesis. Secondary to or simultaneously with coagulation, the fibrinolytic system may be activated, accentuating the bleeding tendency. All the systems involved in DIC, such as coagulation, fibrinolysis, kallikrein-kinin, complement, and possibly other systems are regulated. Coagulation is the central event of DIC. The different coagulation factor derivatives may be generated that can be determined and used as markers for the degree of DIC and for effective control of therapy. Some of the procoagulant and anticoagulant factors are converted in the course of coagulation to their active forms and activation peptides. The active factor is subsequently neutralized by forming a complex with an inhibitor. Hemostatic molecular markers, D-dimer of cross-linked fibrin degradation products (D-dimer), thrombin-antithrombin III complex (TAT), and plasmin-alpha 2-plasmin inhibitor complex (PIC) have all been used for the diagnosis of DIC.

Antifibrinolytic Agents↗
PubMed1992

Detection of JC virus in the brains of aged patients without progressive multifocal leukoencephalopathy by the polymerase chain reaction and Southern hybridization analysis.

Ninety-one brain tissue sections taken at autopsy from 33 elderly patients (63-100 years old) without progressive multifocal leukoencephalopathy were examined for the presence of JC virus DNA by the polymerase chain reaction and Southern hybridization analysis after DNA extraction. JC virus DNA was detected in 15 sections from 10 patients. These results suggest that JC virus is frequently present in the brains of aged patients.

Aged↗
PubMed1992

Cardiac metastasis of lung cancer. A study of metastatic pathways and clinical manifestations.

BACKGROUND: Although lung cancer frequently spreads to the heart, details of cardiac metastases of lung cancer have not been fully discussed. The authors attempted to elucidate the relationship between the mechanisms of cardiac metastasis and a variety of clinical manifestations caused by cardiac metastasis. METHODS: Clinical and autopsy records were reviewed in 74 autopsied cases of lung cancer. In cases with cardiac metastasis, the metastatic pathways to the heart were determined by the macroscopic examinations, and the relationship between the metastatic pathways and the clinical manifestations were studied. RESULTS: Metastases to the pericardium or heart were seen in 23 cases (31%). A lymphatic metastatic pathway was detected in 18 cases (hilar lymphatic routing in 12 cases, and mediastinal lymphatic routing in 6 cases), and a hematogenous metastatic pathway was detected in 5 cases. Malignant pericardial effusion was documented in 15 of 23 cases. The metastatic pathway in 14 of 15 cases was lymphatic (hilar lymphatic routing in 10 cases, and mediastinal lymphatic routing in 4 cases). Patients showing lymphatic metastasis had higher incidence of malignant pericardial effusion than those with hematogenous metastasis (P less than 0.05). Of 23 cases of cardiac metastasis, myocardial infarction was found in 1 case, resulting from the compression of the coronary arteries by the tumor. Concurrent supraventricular arrhythmias were recorded in eight cases with cardiac metastasis. Patients with cardiac metastasis had higher incidence of arrhythmia than those without cardiac metastasis (P less than 0.05). In cases of cardiac metastasis, patients with arrhythmia were older (P less than 0.01) than those without arrhythmia. CONCLUSIONS: The authors concluded that the hilar lymphatic pathway is essential for early development of malignant pericardial effusion in lung cancer and that aging and cardiac metastasis may be responsible for arrhythmia in patients with lung cancer.

Age Factors↗
PubMed1992

Protein C deficiency Hong Kong 1 and 2: hereditary protein C deficiency caused by two mutant alleles, a 5-nucleotide deletion and a missense mutation.

We characterized a mutant protein C gene from an individual with no detectable protein C antigen in blood plasma. Southern blot hybridization analysis with human protein C cDNA demonstrated neither gross deletion nor rearrangement of the gene. Sequencing all the exons and exon-intron boundaries of the gene except the 3' noncoding region showed two mutant alleles. The one, derived from the mother, represents a deletion of 5 nucleotides (nt) (CCCGC) in the end of exon VI (mutation I), predicted to result in the generation of a new stop codon due to a reading frameshift and the premature termination of translation. The other, derived from the father, represents a point mutation (G to A) in exon IX (mutation II), resulting in an amino acid substitution, Gly-376(GGC) to Asp(GAC), in the catalytic domain of the protein. Allele-specific oligonucleotide probe hybridization confirmed the presence of the two mutations. Mutation I would result in a truncated polypeptide of 169 amino acid residues that lacks the heavy chain. Mutation II gives rise to an alteration of a highly conserved amino acid, Gly-376. These data indicate that this patient is a compound heterozygote of the two mutant alleles, each one inherited from each parent. Transient expression assays using COS-7 cells transfected with mutated protein C expression vectors suggested that each of the two mutations leads to the protein C deficiency by causing an impairment of secretion of the respective mutant proteins.

Amino Acid Sequence↗
PubMed1992

Molecular basis for Glanzmann's thrombasthenia (GT) in a compound heterozygote with glycoprotein IIb gene: a proposal for the classification of GT based on the biosynthetic pathway of glycoprotein IIb-IIIa complex.

The genetic basis for Glanzmann's thrombasthenia (GT) was elucidated on a compound heterozygote with glycoprotein (GP)IIb gene: an opal mutation at the end of exon 17 (CGA----TGA) results in only a trace amount of GPIIb mRNA, and a splicing mutation at the acceptor site of exon 26 (CAG----GAG) causes an in-frame, exon skipping process from exon 25 to 27. This aberrant transcript encodes a single-chain polypeptide characterized by a 42-amino acid deletion, which includes the proteolytic cleavage site(s) and a unique, proline-rich region at the location corresponding to the carboxyl-terminal of the normal GPIIb alpha-chain. These characteristics are shared by a previously reported defective GPIIb molecule, which is neither assembled with GPIIIa nor transported to the cellular surface. Despite its normal transcription level, expression of the present defective GPIIb molecule was significantly decreased (approximately 6% of the control level). Because the precursor GPIIb molecule is assembled with GPIIIa in the endoplasmic reticulum (ER) and its processing, as well as stability, is dependent on the GPIIIa subunit, the defective GPIIb molecule may be rapidly degraded by the intrinsic quality control system of the ER due to its inability to form a stable heterodimer complex as a consequence of its misfolded structure. Although we did not confirm that the GPIIIa genes of this individual were normal, GPIIIa may be secondarily decreased (approximately 11% of control), because a large part of it could not be complexed, making it vulnerable to proteolysis. To elucidate the molecular basis for GT, we propose here a classification of GT based on the biosynthetic pathway of the GPIIb-IIIa complex.

Base Sequence↗
PubMed1992

Chlorination of cellulose with N-chlorosuccinimide-triphenylphosphine under homogeneous conditions in lithium chloride-N,N-dimethylacetamide.

Microcrystalline cellulose was chlorinated with N-chlorosuccinimide-triphenylphosphine under homogeneous conditions in LiCl-N,N-dimethylacetamide. At the early stage of the reaction only replacement of the 6-hydroxyl groups with chlorine was observed, and 3-hydroxyl groups were replaced at a lower rate with Walden inversion. The effects of reaction conditions on the extent of chlorination were studied in detail. More than two equivalents of chlorination reagents per glucose residue were necessary to attain a high degree of substitution (ds) by chlorine, and the maximum ds attained was 1.86. Chlorinated disaccharides were found in the hydrolyzates of chlorodeoxycelluloses hydrolyzed under mild conditions, and their structures were studied by mass spectrometry.

Acetamides↗