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Biomedical subjects

S Kanazawa

Publications and source records attributed to S Kanazawa.

At least 55 records · Page 3Linked to original sources
PubMed2000

Assessment of secondary necrosis of Jurkat cells using a new microscopic system and double staining method with annexin V and propidium iodide.

Using a new system developed by us for acquiring microscopic images automatically, we compared the morphological changes that apoptotic cells undergo with changes in the staining pattern of annexin V-enhanced green fluorescent protein (AV-EGFP) and propidium iodide (PI) in individual cells. Jurkat cells were treated with 5 mM CaCl2 alone, anti-Fas antibody and heating at 42 degrees C for 30 min or 46 degrees C for 60 min, and then were incubated in medium with 5 mM CaCl2. Time-lapse DNA fragmentation analysis and morphological observation revealed that the anti-Fas antibody and heating at 42 degrees C for 30 min induced typical apoptosis in the cells, and heating at 46 degrees C for 60 min induced typical necrosis. Time-lapse observation of individual cells stained with AV-EGFP and PI confirmed that apoptotic cells were stained at first with AV-EGFP alone, and thereafter also with PI when the cellular membrane ruptured and the cell underwent secondary necrosis. Most of the cells which underwent necrosis were stained simultaneously with AV-EGFP and PI. There was a significant time interval between the staining of individual cells with AV-EGFP, indicating apoptosis, and staining of these cells with PI, which indicated the occurrence of secondary necrosis. These results suggest that time-lapse examinations are necessary to distinguish apoptosis, secondary necrosis and necrosis in cells from one another. This study presents direct evidence that apoptotic cells undergo secondary necrosis, which could be recognized with PI.

Annexin A5↗
PubMed2000

Glomosporin, a novel antifungal cyclic depsipeptide from Glomospora sp. I. Production, isolation, physico-chemical properties and biological activities.

A novel antifungal cyclic depsipeptide termed glomosporin, which has a fatty acyl side chain, was isolated from a barley solid culture of Glomospora sp. The strain was isolated from fallen pine leaves collected in Fukusima Prefecture, Japan and identified as Glomospora sp. BAUA 2825. Glomosporin was purified by butanol extraction followed by preparative HPLC. Glomosporin showed antimicrobial activity against fungi including clinically important Aspergillus fumigatus.

Animals↗
PubMed2000

Novel human topoisomerase I inhibitors, topopyrones A, B, C and D. I. Producing strain, fermentation, isolation, physico-chemical properties and biological activity.

In the course of a screening program for specific inhibitors of human topoisomerase I using a recombinant yeast, we have discovered four new active compounds. All four compounds were isolated from the culture broth of a fungus, Phoma sp. BAUA2861, and two of them were isolated from the culture broth of a fungus, Penicillium sp. BAUA4206. We designated these compounds as topopyrones A, B, C and D. Topopyrones A, B, C and D selectively inhibited recombinant yeast growth dependent on expression of human topoisomerase I with IC50 values of 1.22, 0.15, 4.88 and 19.63 ng/ml, respectively. The activity and selectivity of topopyrone B were comparable to those of camptothecin. The relaxation of supercoiled pBR322 DNA by human DNA topoisomerase I was inhibited by these compounds, however they did not inhibit human DNA topoisomerase II. Topopyrones A, B, C and D were cytotoxic to all tumor cell lines when tested in vitro. Topopyrone B has potent inhibitory activity against herpesvirus, especially varicella zoster virus (VZV). It inhibited VZV growth with EC50 value of 0.038 microg/ml, which is 24-fold stronger than that of acyclovir (0.9 microg/ml). Topopyrones A, B, and C were inhibitory to Gram-positive bacteria.

Anthraquinones↗
PubMed2000

Novel human topoisomerase I inhibitors, topopyrones A, B, C and D. II. Structure elucidation.

The structures of novel topoisomerase I inhibitors, topopyrones A, B, C and D were elucidated by spectral analysis of the chemical derivatives. These compounds are an anthraquinone type containing a fused 1,4-pyrone moiety. Topopyrones A and B contain a chlorine atom, however C and D do not. It was suggested that topopyrones B and D are converted from topopyrones A and C, respectively by Wessely-Moser type rearrangement.

Anthraquinones↗
PubMed2000

[CT-guided needle biopsy in malignant lymphoma: current techniques and its usefulness].

Histological examination of adequate biopsy specimens is fundamental to the management of patients with malignant lymphoma. Core-needle biopsy with computed tomography potentially provides a better basis for this assessment. Image-guided needle biopsy should be the first procedure performed in the diagnosis of lymphoma, except in easily accessible superficial neck, inguinal, and axillary nodal sites. Recent studies have shown a diagnostic accuracy of 83% to 87%. We describe the biopsy technique that have been successful in our personal experience. From our experience, CT-guided core-needle biopsies prove sufficient information for the diagnosis of and subsequent therapeutic decision to treat most cases of lymphoma.

Biopsy, Needle↗
PubMed2000

[Biopsy].

We reviewed the current devices, techniques, guiding images, indications and complications of needle biopsy with CT guidance. The development of new devices such as automated cutting needle has enabled radiologists to obtain tissue specimens of good quality at biopsy. Techniques such as the tandem or coaxial method ensure more a more accurate biopsy route. And helical CT and CT fluoroscopy have markedly shortened the time required for needle biopsy. However, we sometimes encounter minor complications, and rarely major ones, during and after needle biopsy. Some of these complications may be caused by malpractice. Therefore it is important always to pay attention to the possibility of complications of needle biopsy and to minimize radiation exposures from CT fluoroscopy.

Biopsy, Needle↗
PubMed1999

Basic study on gene therapy of human malignant glioma by use of the cationic multilamellar liposome-entrapped human interferon beta gene.

For gene therapy of human malignant glioma, we adopted positively charged multilamellar liposomes entrapping the human interferon beta (hIFN-beta) gene. One week after the transplantation of human malignant glioma U251-SP cells to produce glioma in nude mouse brain, the liposomes entrapping the gene (500 ng of DNA per 25 nmol of lipids per 2 microl) were injected into the same site of the cell transplantation once every second day for a total of five injections; and by this means the tumor completely disappeared. To confirm the antiproliferative effect of hIFN-beta, we performed an in vitro study using a plasmid containing a secretion signal sequence-deleted hIFN-beta gene and one containing the hIFN-beta gene inserted in reverse. In both cases, there was no hIFN-beta release into the medium and no growth inhibition effect. On addition of anti-hIFN-beta antibody to the medium, the growth inhibition effect was abolished. As this cell line expresses IFN-alpha/beta receptor, the hIFN-beta produced in the transfected cells could be released and acted in a paracrine manner. For 120 days the body weight change of normal mice treated by the same procedure as used in the curing experiment was not significant among the groups injected with empty liposomes, plasmid only, and liposomes entrapping the gene. In all of these three groups, death, abnormal behavior, and significant histological changes were not observed.

Animals↗
PubMed1999

Synthesis of 5-hydroxy-2-(beta-D-ribofuranosyl)pyran-4-one from a pyranulose glycoside.

The synthesis of 5-hydroxy-2-(beta-D-ribofuranosyl)pyran-4-one (9) is described. Treatment of pyranulose glycoside with bromine in carbon tetrachloride afforded brompyranulose glycoside in 90% yield. The reaction of (6S)- and (6R)-4-bromo-6-hydroxy-6-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)-6H- pyran-3-one (2) in acidic media was examined with the following results: the reaction of 2 with trifluoroacetic acid (TFA) in dioxane afforded a mixture of 5-hydroxy-2-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)pyran-4-one (3) and its furan derivative 5-hydroxy-2-{5-(benzoyloxy)methyl]furan-2-yl}pyran-4-one (4), but the use of hydrochloric acid formed the bromofurfural, 3-bromo-5-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)-2-furancarboxyal dehyde only. Acetylation of a mixture (3 and 4) with acetic anhydride facilitated product separation to give the corresponding acetates 5-acetoxy-2-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)pyran-4-one (5) and 5-acetoxy-2-{5-[(benzoyloxy)methyl]furan-2-yl}pyran-4-one (6). Treatment of 5 with hydrazine afforded 3-hydroxymethyl-6-(beta-D-ribofuranosyl)-1H-pyridazin-4-one in 43% yield. Debenzoylation of 5 with aq ammonia gave 9 in 50% yield.

Anti-Bacterial Agents↗
PubMed1999

Eosinophilic granuloma (Kimura's disease) of the orbit: a case report.

BACKGROUND: Eosinophilic granuloma of the soft tissue, Kimura's disease, is a benign slow-growing tumor that is manifested clinically by one or more inflammatory nodules involving mainly the face and scalp, but rarely the eye. CASE REPORT: The patient was a 32-year-old male with swelling of the left lower eyelid, marked peripheral blood eosinophilia and increased serum immunogloblin E. MRI revealed swelling of all rectus muscles of the left eye, but no tumor mass. Corticosteroid treatment reduced the swelling of the eyelid, but it recurred after corticosteroid was discontinued. Eight years later the patient returned with a complaint of increased swelling of the left lower eyelid. An elastic, nontender, soft tumor mass was palpable subcutaneously in the left lower eyelid extending into the orbit. MRI revealed a tumor mass in the left orbital space. The parotid gland was also swollen and palpable. Both tumors were resected surgically, and histopathological study revealed prominent proliferation of lymphoid follicles with germinal centers showing interfollicular infiltration by eosinophils. The pathological findings in the parotid gland were similar. The diagnosis was Kimura's disease. CONCLUSION: This patient is unique in that he had no tumor at the first examination, only swelling of the rectus muscles, and a tumor mass appeared many years later. Unilateral swelling of the rectus muscles may be one of the first signs of Kimura's disease. Not only tumor but also swelling of the rectus muscles limited ocular movement.

Adult↗
PubMed1999

Malignant mesothelioma of the tunica vaginalis testis: report of a case.

We describe herein the case of a 68-year-old man with malignant mesothelioma of the tunica vaginalis testis. The pathological diagnosis was based upon the clinical findings, gross and microscopic morphology, and special stains. Malignant mesothelioma is a rare tumor associated with asbestos exposure that can be effectively treated with orchidectomy via an inguinal approach.

Aged↗
PubMed1999

Preoperative assessment of adenylylcyclase activity as a functional marker of islet cell quality after transplantation in rats.

To determine the potential value of measuring adenylylcyclase activity as a pre-transplant functional marker of pancreatic islet cell quality, a production rate of adenosine 3':5'-monophosphate was measured with a fluorometric assay in rat islet cells before transplantation. Islets were stored for different periods of time (0 to 96 hours) and in different preservation solutions. The adenylylcyclase activities of islets stored in University of Wisconsin (UW) solution for 3 hours after isolation were significantly higher than those stored in Hanks' balanced salt solution. Similarly, the adenylylcyclase activities of islets stored for more than 24 hours in UW solution decreased significantly with prolonged storage time. Preoperative adenylylcyclase activity was compared with post-transplant islet function in a rat model of diabetes. Transplant success was evaluated by measuring blood glucose level and body weight. Although all transplants were ultimately successful in this study, the rate at which they achieved euglycemia varied, and this is the property that correlated with pre-transplant basal or forskolin-stimulated adenylylcyclase activity. Additional studies showed that it was feasible to measure adenylylcyclase activity in human islet cells. We conclude that preoperative measurement of basal and stimulated adenylylcyclase activity may provide a useful clinical marker for assessing islet cell quality and differences in preservation media and may predict transplant success. Based on these data, additional studies evaluating the feasibility of using adenylylcyclase activity as a research and clinical marker of islet cell viability are warranted.

Adenylyl Cyclases↗