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Biomedical subjects

K Maeda

Publications and source records attributed to K Maeda.

At least 757 records · Page 42Linked to original sources
PubMed1994

Proliferating cell nuclear antigen labeling index of preoperative biopsy specimens in gastric carcinoma with special reference to prognosis.

BACKGROUND: Proliferating cell nuclear antigen (PCNA) is an auxiliary protein of DNA polymerase delta and is considered to correlate with the cell's proliferative state. Immunohistochemical methods with a anti-PCNA antibody (PC10) have particular advantages compared with other techniques because of the maintenance of the tissue architecture and simplicity of the methodology. The authors investigated the correlation between the tumor's proliferative activity and progression of gastric carcinoma using immunohistochemical staining with PC10. METHODS: One hundred eighty-nine endoscopic biopsy specimens from patients with gastric carcinoma before operation were investigated by immunohistochemical study, using anti-PCNA monoclonal antibody (PC10). The correlation of PCNA labeling index (percentage of positive cells in more than 500 tumor cells) with various clinicopathologic factors and prognosis was studied. RESULTS: The PCNA labeling index became higher as the histologic stage increased. In patients with lymph node metastasis, vascular invasion, liver metastasis, and peritoneal metastasis, the labeling index was significantly higher. In patients with high PCNA labeling index (50% or greater), prognosis was significantly poorer than in those with a low index (less than 50%). The rate of disease recurrence after curative resection was significantly higher in patients with high PCNA grade group. CONCLUSION: As a result of this study, PCNA labeling index is suggested to be correlated with the depth of invasion, organ metastasis, vascular invasion, and tumor stage and to be effective as a prognostic factor.

Adult↗
PubMed1994

High expression of CD56 (N-CAM) in a patient with cutaneous CD4-positive lymphoma.

Cutaneous lymphoma is a disease characterized with massive skin infiltration of lymphoid malignant cells. They commonly express some T-cell markers, such as CD2, CD3, CD4, and CD7, and thus termed as CTCL (cutaneous T cell lymphoma). Here, we present a case with CD56/N-CAM-positive cutaneous lymphoma, which appears lymphocytic morphology and expresses CD4, but does not express CD2, CD3, CD8, CD14, CD16, CD57, and CD20. The most malignant cells contained no distinctive azurophilic granules in the cytoplasm. Southern blot analysis revealed that T cell receptor-beta, gamma, and immunoglobulin heavy chain genes in the cells were in germ-line configurations. Electron microscopic examination showed characteristics of lymphoid cells with higher nucleocytoplasmic ratio and lacked structures typical of other cell types (i.e., epithelial cells, neuroendocrine cells, and mesenchymal cells). Thus, the cells are likely to be immature lymphoid cells. Histological analysis revealed the cells infiltrate mainly into the dermis with angiocentric growth pattern. The clinical course was aggressive, with rapid involvement of bone marrow and central nervous system. These striking features of the patient may represent a novel fraction (CD2-, CD4+, and CD56+) of cutaneous lymphoma.

Aged↗
PubMed1994

Co-stimulation with LFA-1 triggers apoptosis in gamma delta T cells on T cell receptor engagement.

Stimulation of T cells through the T cell receptor (TcR) initiate activation pathways, and paradoxically can also result in activation-induced cell death. Many factors influence a stimulated cell's decision to manifest one or the other. Here we show that co-stimulation with LFA-1 plays a key role in the choice between the two fates, differentiating between alpha beta and gamma delta T cells. Peripheral gamma delta. T cells but not alpha beta T cells undergo apoptosis upon co-cross-linking of TcR and LFA-1 in MRL lpr/lpr mice as well as +/+ mice. Our results suggest that apoptosis of gamma delta T cells is inducible by combined stimuli independent of the Fas-mediated pathway.

Animals↗
PubMed1994

Nucleotide sequence and characterization of the feline herpesvirus type 1 immediate early gene.

We report the nucleotide sequence of feline herpesvirus type 1 (FHV-1) immediate early (IE) gene encoding a homologue to the ICP4 protein of herpes simplex virus type 1 and its flanking sequences. When we examined the regulatory function of the FHV-1 IE gene product by using the transient transfection assay with an effector plasmid expressing the FHV-1 IE gene in combination with chimeric various promoter-chloramphenicol acetyltransferase reporter constructs, the product was able to transactivate a putative FHV-1 TK promoter, pseudorabies virus and equine herpesvirus type 1 ICP4 promoters, and human immunodeficiency virus (HIV) long terminal repeat (LTR) in Crandell feline kidney cells. Furthermore, the FHV-1 IE gene product could transactivate both feline immunodeficiency virus and HIV LTRs in SW480 cells but not in Felis catus whole fetus 4 cells.

Alphaherpesvirinae↗
PubMed1994

Distribution of apoptosis-mediating Fas antigen in human skin and effects of anti-Fas monoclonal antibody on human epidermal keratinocyte and squamous cell carcinoma cell lines.

Fast antigen is a cell surface protein that mediates apoptosis. Using immunohistological, flow cytometry and electron microscopic analyses, we investigated the expression of Fas antigen on various skin tissues, and on cultured SV40-transformed human epidermal keratinocyte cell line KJD and human skin squamous cell carcinoma cell line HSC. The Fas antigen was widely distributed in skin components such as the keratinocytes in the lower portion of the epidermis, epidermal dendritic cells, endothelial cells, fibroblasts, apocrine glands, eccrine sweat glands, sebaceous glands, some normal melanocytes and infiltrating lymphoid cells. It was also strongly expressed on the keratinocytes of lichenoid eruptions seen in lupus erythematosus and lichen planus, and on the spongiotic or acanthotic epidermis seen in chronic eczema, adult T-cell leukaemia/lymphoma (ATLL) and atopic dermatitis. Its expression was closely correlated with lymphoid infiltrating cells and it was strongly expressed in lymphoid neoplastic cells, particularly ATLL cells, and fibroblasts seen in dermatofibroma. However, the antigen was not detected on basal cell epithelioma cells, some malignant melanomas or any junctional naevi. The cell lines KJD and HSC strongly expressed the Fas antigen, and crosslinking of the Fas antigen by an anti-Fas monoclonal antibody induced apoptosis of these cell lines. These results indicate that the apoptosis-mediating Fas antigen may play an important role in normal skin turnover and cell differentiation, in immune regulation of skin tumours, and in the pathogenesis of various skin diseases.

Antibodies, Monoclonal↗
PubMed1994

Effects of insertion of multiple AP-1 binding sites into the U3 region of the long terminal repeat of feline immunodeficiency virus.

An oligonucleotide containing multiple AP-1 binding sites was introduced into the regulatory sequence in the long terminal repeat (LTR) of feline immunodeficiency virus (FIV). Chloramphenicol acetyltransferase assay revealed that basal promoter activity of the mutated LTR was higher than that of the wild-type LTR in Crandell feline kidney (CRFK) cells. The mutated LTR was introduced into an infectious molecular clone of FIV and the clone was transfected into CRFK cells. The virus production of the mutant in the cells was as high as that of the wild-type when determined by the reverse transcriptase activity assay. The growth of the mutant virus obtained from the transfected CRFK cells was examined in feline T lymphoblastoid cell lines (MYA-1 and FeL-039 cells) and primary feline peripheral blood mononuclear cells (fPBMCs). The growth was delayed when compared with that of the wild-type virus in all the cells used. Upon examination by polymerase chain reaction, the length of the LTR of the mutant virus was shortened in both MYA-1 cells and fPBMCs. Sequence analysis revealed that the insertion was completely deleted 39 days after infection in the MYA-1 cells.

Animals↗
PubMed1994

Clinical course and long-term prognosis of Crohn's disease in Japan.

The long-term outcome of Crohn's disease was reviewed in 74 patients who had a history of more than 10 years (range 10.8-27.3) since disease onset. The observation period was between 4.3 and 18.5 years, the mean and SD being 10.6 +/- 3.1 years. The means and SD of age at onset and final observation were 21 +/- 7 and 37 +/- 8 years, respectively. Fifty-eight of the 74 patients had not undergone bowel resection at the time of diagnosis; of these 58, 31 (53.4%) had an operation for the disease during the follow-up period. Thus, of the 74 patients, 47 (63.5%) (these 31, plus the 16 who had undergone bowel resection at the time of diagnosis) had an operation at least once during a follow-up period of 10 years or more. The cumulative operation rates 5, 10, and 15 years after onset in the 74 and 58 patients above were 18.9%, 6.9%, and 40.8%, and 34.8%, 49.1%, and 46.0%, respectively. The corresponding figures 5 and 10 years after diagnosis in all 74 patients and the 58 patients were 32.3% and 28.6% and 47.3% and 46.3%, respectively. There were no significant differences in the incidence of operation rate in relation to anatomical involvement. Cumulative reoperation rates 1, 3, 5, and 10 years after the first operation in the 31 patients who were operated on during the follow-up period were 3.4%, 6.9%, 25.5%, and 51.7%, respectively. Three patients died, the causes of death in one being directly related to Crohn's disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Intestinal and extraintestinal complications of Crohn's disease: predictors and cumulative probability of complications.

Of 238 patients with Crohn's disease seen at our clinics from April 1973 to August 1988, 203 patients were selected for this study, since they fulfilled the following criteria: they had been followed up for more than 6 months as outpatients or had been treated as inpatients for more than 1 month. They were studied to elucidate: (a) the different types and incidence of various complications, (b) the factors related to complications present at the time of diagnosis, (c) predictors of new complications arising after diagnosis, and (d) the cumulative incidence of complications occurring during the course of the disease from the times of onset and diagnosis. Of the intestinal complications, perianal fistula was most common (33%), followed by strictures with dilatations of the proximal bowel (21%), and internal fistula (14%). Of the extraintestinal complications, menstrual disturbance was the most common (18% of the female patients), followed by arthritis (10%), and aphthous stomatitis (10%). As for the factors influencing complications present at the time of diagnosis, the pattern of bowel involvement was significantly correlated with the presence of intestinal stricture, while the erythrocyte sedimentation rate was significantly correlated with the presence of perianal fistula. A significant predictor of new complications arising after diagnosis was the general well-being of patients at the time of diagnosis. Patients who, at diagnosis, already have complications such as stricture, abdominal abscess, internal or external fistula, massive hemorrhage, and free perforation or anal lesions are more likely to develop new complications in addition to those present at diagnosis, compared with patients without any complications at diagnosis (P = 0.055).

Adult↗
PubMed1994

Spontaneously perforated pyometra presenting as diffuse peritonitis: report of a case.

We report herein a rare case of spontaneously perforated pyometra found in a 72-year-old woman who was admitted to our hospital with abdominal pain and vomiting. A distended abdomen with muscular rigidity, a positive Blumberg sign, and a WBC count of 11,900/mm3 indicated diffuse peritonitis, although a plain abdominal X-ray film revealed no free air in the peritoneal cavity. An emergency laparotomy was performed, which revealed a lot of pus, and perforation in the fundus of a distended uterus. The patient was therefore diagnosed as having suffered uterine perforation associating with a pyometra, and a total hysterectomy with bilateral salpingo-oophorectomy was carried out. Histological examination revealed a pyometra with inflammation and destruction of the endometrium and myometrium, and cervical occlusion with no evidence of malignancy. Postoperatively, the patient developed a subcutaneous abscess and pneumonia, but recovered and was discharged on the 74th day after her operation. Thus, although rare, spontaneously perforated pyometra should be considered when elderly women present with acute abdominal symptoms.

Aged↗
PubMed1994

Metabolic effect of PGE1 analogue 01206.alpha CD on nerve Na(+)-K(+)-ATPase activity of rats with streptozocin-induced diabetes is mediated via cAMP: possible role of cAMP in diabetic neuropathy.

We investigated the dose-dependent effects of prostaglandin E1 (PGE1) analogue, OP1206.alpha CD (OP), on motor nerve conduction velocity (MNCV), nerve blood flow (NBF) and Na(+)-K(+)-ATPase (ATPase) activity in streptozocin-induced diabetic rats. At 10 micrograms/kg/day, OP ameliorated MNCV and NBF, but no ATPase activity, whereas at 30 micrograms/kg/day it increased MNCV and ATPase activity, but not NBF. These results suggested a possible direct metabolic effect of OP, at least at a certain dose, on ATPase activity independent of NBF. Since PGE1 exerts an effect on nerve cAMP content, we conducted an in vitro study to clarify the relationship of cAMP to the modulation of ATPase activity in diabetic nerves. We studied sciatic nerves isolated from 53 rats with streptozocin-induced diabetes that had exhibited hyperglycemia for 6 wk. OP increased the activity of ATPase and the accumulation of cAMP in a dose-dependent manner. Dibutyryl cAMP, a cAMP analogue, and aminophyline, which increases nerve cAMP content, enhanced ATPase activity in a dose-dependent manner. In addition, the increased activity of ATPase in diabetic nerves produced by OP was suppressed by a protein kinase inhibitor, H8. These results suggest that ATPase activity in diabetic nerves might be regulated or modified by cAMP and, possibly, by protein kinase A, a finding that is important for clarifying the pathogenesis of diabetic neuropathy and for developing new approaches to treatment.

Alprostadil↗
PubMed1994

Cerebrospinal fluid (CSF) neuropeptide Y- and somatostatin-like immunoreactivities in man.

We have measured cerebrospinal fluid (CSF) neuropeptide Y-like immunoreactivity (NPY-LI) and somatostatin-like immunoreactivity (SLI) in control subjects and in patients with various neurologic disorders. We observed a significant reduction in CSF SLI in control subjects over 60 years of age, compared with the younger controls. CSF SLI was significantly decreased in multiple sclerosis (MS), or Guillain-Barre syndrome, compared with that of age-matched control subjects. A reduced concentration of NPY-LI was found in CSF of patients with MS. We have also examined the molecular heterogeneity of peptide-LI in CSF. Gel chromatography, not high performance liquid chromatography (HPLC), suggested two NPY immunoreactive materials in CSF. Gel chromatography and HPLC revealed three SLI components in CSF: somatostatin 14, somatostatin 28 and a higher molecular weight precursor. Our results suggest that 1) there may be more than one form of NPY in human CSF, and 2) somatostatin neurons might be more susceptible to alteration than NPY neurons in various pathological conditions and aging.

Adult↗
PubMed1994

Current status of research on biophysical effects of ultrasound.

This overview of bioeffects of ultrasound presents some key aspects of selected papers dealing with biophysical end-points. Its purpose is to establish a basis for exposure and dosimetric standards for medical ultrasonic equipment. It is intended to provide essential background resource material for the medical/scientific community, and more specifically for scientific working groups. This document was prepared by members of the Safety Committee of the World Federation for Ultrasound in Medicine and Biology. It was produced as a resource document in response to a request for information by Working Group 12 (Ultrasound exposure parameters) of the International Electrotechnical Commission Technical Committee 87, Ultrasonics. IEC TC 87, WG12 is the working group responsible for generating international standards for the classification of equipment by its acoustic fields based on safety thresholds. Our paper is intended to update and supplement information on the thermal mechanism provided in the publication, "WFUMB Symposium on Safety and Standardisation in Medical Ultrasound: Issues and Recommendations Regarding Thermal Mechanisms for Biological Effects of Ultrasound" (WFUMB 1992). It also provides an overview of trends in research into nonthermal mechanisms as a preliminary to the next WFUMB Symposium on Safety of Medical Ultrasound when this subject will be examined in detail by a select group of international experts. The WFUMB-sponsored workshop will take place in Utsunomiya, Japan during 11-15th July, 1994. The purpose of the meeting is to evaluate the scientific literature and to formulate internationally accepted recommendations on the safe use of diagnostic ultrasound that may be endorsed as official policy of the WFUMB. It should be noted that the current publication is not intended for review or endorsement as an official WFUMB document. It is produced as a scientific paper by individuals who are members of the WFUMB Safety Committee, and it therefore represents the opinions of the authors. Nevertheless, during the preparation of this document, contributions were received from members of the International Electrotechnical Commission Technical Committee 87 as well as many other individual experts, and the authors sincerely acknowledge their support.

Air↗
PubMed1994

Carrier-state infection of feline T-lymphoblastoid cells with feline calicivirus.

The susceptibility of feline T lymphocytes to feline calicivirus (FCV) in vitro was investigated using feline T-lymphoblastoid cell lines, namely MYA-1 and FL74 cells. The virus titers of supernatants in FCV-infected MYA-1 and FL74 cell cultures increased rapidly, and FCV antigens were also detected in the FCV-infected cells. There were slight differences in the molecular weights of capsid proteins expressed in FCV-infected MYA-1, FL74 and Crandell feline kidney cells. MYA-1 and FL74 cells were productively and persistently infected with FCV, and FCV antigens were observed in the FCV-infected cells for more than one month. At 3 months post infection, FCV-infected FL74 cells that stopped producing infectious FCV could be reinfected with FCV. However, no cytopathic effects were observed.

Animals↗
PubMed1994

A histochemical study of the behavior of macrophages during experimental apical periodontitis in rats.

The behavior of macrophages from experimentally induced periapical lesions of rats was studied in paraffin sections using nonspecific esterase and a monoclonal antibody, ED1. Macrophages were seen near the regularly arranged osteoblasts in controls and the detached osteoblasts at the initiation phase of bone resorption. In addition, numerous macrophages were widely distributed throughout the periodontium at the activation phase of bone resorption. On the other hand, macrophages were rarely seen near the bone formation surfaces, but large numbers of macrophages were localized in microabscess at the activation phase of bone formation. It is suggested that macrophages may play an important role in activation of osteoclastic bone resorption and inhibition of complete bone repair in bone remodeling during experimental apical periodontitis.

Alveolar Bone Loss↗