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Biomedical subjects

Y Ichikawa

Publications and source records attributed to Y Ichikawa.

At least 577 records · Page 32Linked to original sources
PubMed1989

Anti-herpesvirus activity of carbocyclic oxetanocin G in vitro.

A series of new compounds, carbocyclic oxetanocins, have been synthesized and their anti-herpesvirus activity determined. Carbocyclic oxetanocin G (OXT-G) was most active against herpes simplex virus (HSV) and human cytomegalovirus (HCMV) among carbocyclic oxetanocins tested; the median effective concentrations (EC50) for HSV-1, -2, and HCMV were 0.23, 0.04 and 0.40 micrograms/ml, respectively. The EC50 value of carbocyclic OXT-G against HSV-2 was significantly lower than those of acyclovir, ganciclovir (DHPG) and OXT-G, while the value for HCMV was comparable to those of DHPG and OXT-G. Carbocyclic OXT-G showed much higher activity against TK+ HSV-2 than against a TK- mutant, suggesting that this compound is a good substrate for HSV-2-induced TK. The antiviral activity of the compound was only partially reversed even by the addition of 100-fold excess deoxyguanosine. The results suggest that the mode of action of carbocyclic OXT-G is different from that of OXT-G.

Animals↗
PubMed1989

[A case of anti-phospholipid antibody syndrome presenting chorea as an initial manifestation].

A 20 year old female patient with anti-phospholipid antibody syndrome who presented chorea as an initial symptom is described. At the age of 14, she noticed involuntary movements of upper and lower extremities bilaterally. The CT scan revealed the presence of low density areas in the right caudate nucleus and left putamen. The result of the laboratory tests included antibodies to nuclear antigens (positive FANA and anti-DNA), prolonged PT and APTT, biological false positive for syphilis. Her serum contained antibodies to cardiolipin and phosphatidylserine as demonstrated by specific ELISA assay method. The clinical diagnosis of chorea was made and haloperidol was administered with partial symptomatic improvements. The patient reported here is the first well documented case of anti-phospholipid antibody syndrome presenting chorea as an initial manifestation in the Japanese literature.

Adult↗
PubMed1989

[Effects of high temperatures on chromosomes of normal and transformed human cells].

The effects of the high temperature on the chromosome of normal and transformed human cells were examined using a temperature gradient incubator (T.G.I., Model TN-212) in culture. The cell nucleus were damaged, specifically fragmentation occurred under the hyperthermic treatments. The diploid cells were passaged at three different temperature conditions ranging from 39.0-41.5 degrees C. It was found that the polyploid cells (predominantly tetraploid) were increased in these conditions compared with the cells cultured at 37 degrees C. We observed the chromosomal aberrations (break, stickiness, fragmentation, etc.) in the cells treated with high temperature for the various periods of time. The results indicated that the transformed cells were more high-temperature sensitive than the normal cells with respect to the chromosomal aberrations. The trend was seen in this experiment, in which the chromatid breaks of HAIN-55 and MKN-1 cell strains occurred more on the large chromosomes such as the ones in group A, B and C under the hyperthermic treatments.

Cell Line, Transformed↗
PubMed1989

[Effects of the cholestatic factor and the prostaglandin E1 derivative on the level of cAMP in isolated hepatocytes of rats].

It has been reported that cAMP in hepatocytes plays an important role in bile discharge. Therefore, in order to examine the action mechanism of the cholestatic factor, we studied the effect of the cholestatic factor and prostaglandin E1 derivative which inhibits the activity of the cholestatic factor on the cAMP level in hepatocytes. As a result, the cAMP level in hepatocytes was decreased by treatment with the cholestatic factor, but was increased by the prostaglandin E1 derivative. Furthermore, the cAMP level which was decreased by the cholestatic factor returned to the original level by treatment with the prostaglandin E1 derivative. Because the increase in the cAMP level in hepatocytes promotes the bile acid independent bile discharge, it is suggested that the cholestatic factor reduces the bile flow by the decrease in the cAMP level in hepatocytes, and that the prostaglandin E1 derivative competes with the action of the cholestatic factor through the increase in the cAMP level in hepatocytes.

Alprostadil↗
PubMed1989

[Disseminated intravascular coagulation related to atherosclerosis and aneurysm of aorta: successful management with subcutaneous self injection of heparin sodium].

We described here a seventy-one year-old male, who had repeated disseminated intravascular coagulation related to atherosclerosis and aneurysm of the aorta, and was successfully treated with self-subcutaneous injection of heparin sodium. He developed gingival bleeding and purpura in 1977. He was first treated with prednisolone (30 mg/day) and ACTH-Z under the diagnosis of idiopathic thrombocytopenic purpura associated with chronic thyroiditis, since platelet count (0.2 x 10(4)/microliters) was markedly decreased and megakaryocytes in the bone marrow were increased. By the treatment, platelet count recovered to 16.7 x 10(4)/microliters, while fibrin-degradation product levels were increased and hypofibrinogenemia developed, suggesting disseminated intravascular coagulopathy. Additional treatment with heparin was effective, and the coagulation studies became normal. In 1980, he again developed the episode with thrombocytopenia. At this time, prednisolone did not improve the episode, but heparin was effective. Since 1983, an enlargement of abdominal aorta had been recognized and gradually progressed. In 1983, he developed lumbago and abdominal pain, and received an emergency operation using artificial Y-graft vessel under the diagnosis of rupture of the aneurysm. There was no evidence of consumption coagulopathy at that time. He had been well until 1987, when he developed the third episode of thrombocytopenia with gingival bleeding. Thrombocytopenia was controlled with the treatment of heparin, but needed a continuous treatment with heparin. Thereafter, he has been well managed with self-injection of the anticoagulant, heparin sodium.

Aged↗
PubMed1989

[A case of lupus nephritis resistant to steroid pulse therapy markedly improved by bolus intravenous cyclophosphamide therapy].

Bolus intravenous cyclophosphamide therapy (IVCY) has recently been the subject of considerable attention because it is occasionally very effective in the treatment of severe lupus nephritis. However only a few reports on this form of therapy have been noted in Japan. Described here is a patient with lupus nephritis accompanied by multi-organ disorders resistant to various therapies including methylprednisolone pulse therapy which responded dramatically to IVCY. The patient, a 37-year-old woman with a history of systemic lupus erythematosus (SLE) starting in 1984, was admitted to our hospital with increasing generalized edema and malaise in January 1987. Evaluation revealed hypoalbuminemia, hypoxemia, ascites, hypocomplementemia and leukopenia. The patient was treated with high-dose oral prednisolone, however the lupus nephritis deteriorated and a high urinary protein level, massive ascites, and pericardial and pleural effusions were noted. Involvement of the central nervous system (CNS) was also observed. Subsequently, she was treated with intravenous methylprednisolone pulse therapy and low-dose oral cyclophosphamide. As her disease was refractory to these treatments IVCY was initiated in May 1987, at a dose 0.5-0.8 g/m2. A total of 3 doses were given, and treatment was discontinued in October 1987 because of marked clinical improvement. After the final IVCY treatment she was discharged, and her subsequent clinical course over a year with a maintenance dose of prednisolone has been uneventful. Thus, IVCY seemed to be useful in the treatment of severe lupus nephritis. More rigorous comparisons of IVCY with other therapies are necessary.

Adult↗
PubMed1989

[Ileovesical fistula due to Crohn's disease: a case report].

A 24-year-old male first experienced pollakisuria, dysuria, pneumaturia and diarrhea in May 1988. Intravenous pyelography showed a normal upper urinary tract but bladder wall irregularity at the dome was observed. Cystoscopic examination revealed bullous edema, erythema and presence of a mucous-like substance. Barium enema X-ray examination revealed inflammatory changes at the terminal ileum but no fistulous connection was noted. Mild ulceration was observed on colon fiberscopic examination. At operation, a severely inflamed lower ileum firmly adherent to the dome of bladder as well as to the sigmoid colon was observed. Fistulous communication between bladder and ileum was also noted. Resection of diseased ileum, sigmoid colon and partial cystectomy were carried out. The patient remains well, without enteric or bladder symptoms.

Adult↗
PubMed1989

[A case of ankylosing spondylitis complicating Crohn's disease].

A 20-year-old man, who had suffered from ankylosing spondylitis for about 1 year, was admitted to our hospital due to melena and syncope. Physical examination revealed tenderness of abdomen and sacroiliac joint, and decreased spinal mobility. X-ray examination showed sacroiliitis and squaring of vertebral bodies. RA test and RAHA, negative; CRP, strongly positive; HLA-B 27 positive. Intestinal barium enema revealed skipping longitudinal fissure at terminal ileum, and a biopsy specimen of the colon revealed non-caseating granuloma. The association of ankylosing spondylitis and Crohn's disease has widely been known in Europe and United States; but this is the first case reported in detail in Japan, where incidences of both diseases were much lower than those found in Caucasians.

Adult↗
PubMed1989

Anticardiolipin antibodies by an enzyme-linked immunosorbent assay: fundamental studies on the conditions for antigen-application and specificity of the assay.

We have established an enzyme-linked immunosorbent assay (ELISA) for anticardiolipin antibodies (aCL) using standard sera obtained from the Rayne Institute, St. Thomas' Hospital (London, U.K.). In this study, we compared several fundamental requirements for the assay with the standard assay as a reference, such as conditions for antigen application and test samples using our patients' samples. In addition, the specificity of our assay and cross-reactivities of aCL were also evaluated. In the standard assay, the concentration of antigen was optimal in the range of 30-100 micrograms/ml. The antigen-coating temperature was optimal at 4 degrees C for 16 hours. The method based on rapid evaporation of CL-ethanol solution can be used instead of the standard method. On the other hand, there was no significant difference in the results between physical conditions of the antigen (CL-ethanol solution vs. CL-micelles), between washing solutions (saline vs. PBS containing 0.05% Tween-20) and between test samples (sera vs. plasma). The aCL activity in our patients' samples was almost completely inhibited by pre-incubation of sera with either CL or phospholipid reagent for activated partial thromboplastin time (APTT). Interestingly, the aCL activity of the lupus anticoagulant was negative, but aCL-positive samples were also absorbed by the reagent for APTT. No inhibition of the aCL activity, however, was observed when patients' sera were preincubated with ss-DNA.

Autoantibodies↗
PubMed1989

[Adrenal tumors discovered incidentally on ultrasonography: three case reports].

A series of three adrenal tumors is reported. They were discovered incidentally on ultrasonography for screening. One case was a benign pheochromocytoma and the others were non-functioning adrenocortical adenomas. They were hypoechoic on ultrasonography and were 4.5 x 3.5 x 4.0, 3.0 x 2.5 x 2.5 and 3.5 x 2.5 x 2.0 cm. Non-functioning adrenal tumors of a diameter smaller than 3.0 cm generally tended not to require surgery. Ultrasonography is useful for screening and evaluating patients with an adrenal mass without surgery as well as is computed tomographic scan.

Adenoma↗
PubMed1989

[Changes in production of platelet activating factor by adherent hepatocytes of mice with experimental liver failure].

It is thought that the platelet activating factor (PAF) enhances the immune response and inflammatory reaction. We studied the production of PAF from liver adherent cells. As a result, liver adherent cells produced PAF, when they were stimulated with calcium ionophore. In addition, when mice were treated with heat-killed Propionibacterium acnes and the mononuclear cells were infiltrated into the liver, a significantly larger amount of PAF was produced compared to normal mice.

Acute Disease↗
PubMed1989

[Effect of glycyrrhizin on the production of platelet-activating factor from rat peritoneal exudate cells].

We examined the effect of glycyrrhizin (GL) on the production of platelet-activating factor (PAF) from rat peritoneal exudate cells. GL was shown to significantly suppress the production of PAF from the rat peritoneal exudate cells stimulated with calcium ionophore A23187. This result suggests that GL have an anti-inflammatory or allergic action by the suppression of PAF production.

Animals↗
PubMed1988

Monoclonal antibodies to the thyrotropin receptor bind to a 56-kDa subunit of the thyrotropin receptor and show heterogeneous bioactivities.

Four monoclonal antibodies to the thyrotropin (TSH) receptor were established by fusing human peripheral lymphocytes of patients from Graves' disease with a human myeloma cell line. Of two antibodies with TSH-binding inhibitory immunoglobulin activity (TBII), one inhibited TSH stimulation of adenylate cyclase and another stimulated adenylate cyclase. These antibodies showed competitive and noncompetitive modes of binding inhibition, respectively. Of the other two antibodies without TBII activity, one stimulated adenylate cyclase and the other inhibited TSH stimulation of adenylate cyclase. Of the two antibodies, which inhibited TSH stimulation of adenylate cyclase, one with TBII activity inhibited stimulation of adenylate cyclase by stimulating antibody with TBII activity, but another without TBII activity inhibited stimulation by both stimulating antibodies with or without TBII activity. These inhibitory antibodies did not influence the stimulation of adenylate cyclase by Forskolin and guanosine 5'-(beta,gamma-imido)triphosphate compounds which are known to affect other parts of the receptor-adenylate cyclase system than the receptor unit. Four antibodies with heterogeneous potencies to the TSH receptor reacted with glycoproteins extracted from thyroid membranes. One stimulating antibody without TBII activity also interacted with the glycolipid fraction of the membrane preparation, and the binding decreased after desialylation or deglycosylation of the membrane components. In order to identify the binding sites of these monoclonal antibodies, receptor proteins interacting with antibodies were visualized by Western blot analysis and by the label transfer cross-linking method. All of these antibodies with different characteristics reacted with a 56-kDa molecule.

Adenylyl Cyclases↗