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Biomedical subjects

Y Mikami

Publications and source records attributed to Y Mikami.

At least 163 records · Page 9Linked to original sources
PubMed1997

Evidence for an elevation in serum interleukin-2 and tumor necrosis factor-alpha levels before the clinical manifestations of preeclampsia.

PROBLEM: The purpose of this study is to clarify whether the disruption of immune regulation occurs in early pregnancy before the clinical manifestations of preeclampsia. METHOD OF STUDY: The serum concentrations of interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-alpha) were determined by using enzyme-linked immunoadsorbent assay (ELISA) in the first trimester of pregnancy in women who had preeclampsia develop after 28 weeks of pregnancy (preeclamptic group) and in women who completed pregnancy uneventfully (control group). RESULTS: Serum concentrations of both IL-2 and TNF-alpha in the first trimester of the preeclamptic group were significantly higher than those of the control group. CONCLUSIONS: That the perturbation of feto-maternal immune regulation may precede the clinical manifestations of preeclampsia, which may be of relevance in the development of preeclampsia, is suggested.

Adult↗
PubMed1997

Tumorous necrotic nodule in the liver: unexpected effect of the microwave tissue coagulator.

The microwave tissue coagulator (MTC) is used in hepatectomy because it provides excellent haemostasis during the procedure. A 59 year old man underwent partial hepatic lobectomy with MTC, for metastasis from colon cancer. A tumorous necrotic nodule was discovered in the liver. The nodule measured 2.5 cm at its largest diameter. Microscopically, it showed extensive coagulation necrosis and massive sinusoidal dilatation. To date, such a necrotic mass clinically mimicking neoplasm has not been reported as a complication of hepatectomy using MTC. Although it is unknown how the rounded necrotic nodule was formed in this case, clinicians should be aware of this phenomenon to avoid unnecessary operations. Likewise, pathologists should recognise such histological changes and review the clinical history of the patient when coagulation necrosis with massive sinusoidal dilatation is observed in a biopsy or hepatectomy specimen.

Diagnosis, Differential↗
PubMed1997

Assessment of UDP-galactosyl-transferase activity in gastric mucosa of patients with chronic liver disease using an enzyme-linked peanut agglutinin binding assay.

Gastric mucin plays an important role in protecting mucosa from irritants such as acids and pepsin, and UDP-galactosyltransferase is a key enzyme in mucin synthesis. In order to study the synthesis of gastric mucin in patients with chronic liver disease, we developed a new assay using a peanut agglutinin lectin to measure this enzyme in human gastric mucosa obtained by endoscopic biopsy. Enzyme activity correlated well with that determined with a previous method using radiolabeled galactose. The enzyme activity in gastric mucosa of cirrhotic patients was significantly lower than in patients with chronic hepatitis or in normal controls and correlated with the amount of mucin in surface epithelial cells. Our findings suggest that the synthesis of gastric mucin is impaired in patients with liver cirrhosis.

Adult↗
PubMed1997

Results of nerve grafting for injuries of the axillary and suprascapular nerves.

We report the results in 33 patients who had nerve grafting of the axillary or the suprascapular nerve or of both. There were 32 men and one woman; their mean age was 21 years and the average interval between injury and operation was three months. At a mean follow-up of 27 months, the deltoid had recovered to M3 or better in 23 of 30 patients (77%) and the infraspinatus in 18 of 25 patients (72%). Shoulder elevation had reached 120 degrees or more in 27 patients (82%), with external rotation of 30 degrees or more in 27 (82%). Twenty-six patients (79%) could reach to the top of their head with their hand. Recovery of muscle strength, range of movement and shoulder function were satisfactory when surgery was performed within four months of the injury. Early exploration and nerve grafting can lead to a good functional recovery, but thorough exploration and careful repair of both nerves are essential.

Adolescent↗
PubMed1997

Full exposure of the axillary and suprascapular nerves.

We describe a method of exposing the whole length of the axillary and suprascapular nerves through a sabre-cut incision. The coracoid process is osteotomised and part of trapezius is detached from its insertions. The posterior deltoid is freed from its scapular origin to expose infraspinatus. We have used this approach to explore combined injuries of the axillary and suprascapular nerves with good results, and no serious complications. Its success depends on a meticulous surgical technique.

Axilla↗
PubMed1997

Geranylgeranylacetone and cetraxate hydrochloride increase UDP-galactosyltransferase activity in rat gastric mucosa.

UDP-galactosyltransferase (UDP-Gal-T) is a key enzyme in the synthesis of mucus glycoprotein which plays an important role in gastric mucosal defensive mechanisms. Analysis of gastric UDP-Gal-T activity should clarify the mechanisms of the action of antiulcer drugs regarding gastric defensive factors. Here, we examined UDP-Gal-T activity in rat gastric mucosa treated with the antiulcer drugs geranylgeranylacetone (GGA) and cetraxate hydrochloride (CET). The effects of coadministration of indomethacin and exogenous administration of prostaglandins (PGs) were also studied. GGA and CET significantly increased UDP-Gal-T activity, and coadministration of indomethacin inhibited the increase of enzyme activity. UDP-Gal-T activity level with GGA was significantly higher than the control level, even in the presence of indomethacin. With CET, however, this was not the case. Among PGs, PGE1 significantly increased enzyme activity. Concomitant administration of PGE1 and GGA or CET increased UDP-Gal-T activity even with indomethacin to the levels achieved when these antiulcer drugs were administered without indomethacin. Our findings suggest that GGA and CET exert antiulcer effects by increasing mucus glycoprotein synthesis and that endogenous PG synthesis may be involved in this process. However, mechanisms not mediated by endogenous PGs may also exist in the stimulatory action of GGA on UDP-Gal-T activity.

Animals↗
PubMed1997

Brasilinolide A, a new macrolide antibiotic produced by Nocardia brasiliensis: producing strain, isolation and biological activity.

A new 32-membered macrolide antibiotic, brasilinolide A was isolated from the fermentation broth of Nocardia sp. IFM 0406. The producer was identified as Nocardia brasiliensis. The antibiotic was only active against Aspergillus niger, but not active against other fungi including yeasts as well as other filamentous like fungi and bacteria. Brasilinolide A exerted an immunosuppressive activity in the assay system of a mixed lymphocyte reaction (MLR).

Animals↗
PubMed1997

Brasiliquinones A, B and C, new benz[alpha]anthraquinone antibiotics from Nocardia brasiliensis. I. Producing strain, isolation and biological activities of the antibiotics.

New benz[alpha]anthraquinone antibiotics (brasiliquinones A, B and C) with an ethyl group at C-3 were isolated. The producer was identified as Nocardia brasiliensis. The antibiotics were active against Gram-positive bacteria including Mycobacterium sp., but not active against Gram-negative bacteria or fungi. They were also active against multiple drug-resistant P388/ADR tumor cells.

Animals↗
PubMed1997

Nocardicyclins A and B: new anthracycline antibiotics produced by Nocardia pseudobrasiliensis.

Nocardicyclins A (1) and B (2), new anthracycline antibiotics have been isolated from the mycelial cake of Nocardia pseudobrasiliensis IFM 0624 (JCM 9894). The molecular formulae of 1 and 2 have been determined as C30H35NO11 and C32H37NO12, respectively, and the structures were characterized by 1- and 8-methoxyl groups, a 10-carbonyl group and a novel carbon-methylated aminosugar constituent. Nocardicyclin A (1) exerts cytotoxic activity against L1210 and P388 leukemia. Nocardicyclins A (1) and B (2) are active against Gram-positive bacteria including Mycobacterium spp. and Nocardia spp., but inactive against Gram-negative bacteria.

Anthracyclines↗
PubMed1997

[A case of unresectable pancreatic cancer successfully treated with continuous venous daily infusion of 5-FU and low-dose CDDP].

This case was a 61-year-old male diagnosed with pancreatic cancer who had a celiotomy. The tumor invasion involved the pancreas body and head. Ultrasonograph examination revealed that all the celiac artery, supramesenteric artery, and portal vein were occluded in the tumor. Because of the unresectability of the tumor, a palliative operation was carried out, and during the following 9 months he was given UFT 300 mg daily. Because abdominal ascites accompanied the tumor growth, the patient underwent combination chemotherapy of cisplatin 5 mg/day x 5/week and continuous infusion of 5-fluorouracil 250 mg/day for 4 weeks. Remarkable reduction of the abdominal ascites and decline of the tumor markers (CEA, CA19-9) was observed in the course of the chemotherapy. Bone marrow function was suppressed by the agents, but granulocyte colony stimulating factor (G-CSF) was very effective for recovery from the damage. Two months after discharge, abdominal ascites recurred. The patient received the same serial chemotherapy for 6 weeks, and now is followed as an outpatient.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Extraorbital giant cell angiofibromas.

We herein describe two unusual neoplasms showing histopathologic features consistent with those of giant cell angiofibroma, which was originally described as a neoplasm arising in the orbit in adults: one of them arose in the right submandibular region of a 48-year-old woman and the other in the right parascapular region of a 49-year-old woman. Macroscopically, although the latter was characterized by a lymphangioma-like cystic appearance, both tumors were well circumscribed and encapsulated. Microscopically, in both cases, pseudovascular spaces lined by a discontinuous row of multinucleated cells were seen against a background of spindle-shaped fibroblastic cell proliferation. In the second case, the tumor presented increased cellularity and plump and somewhat atypical nuclei of proliferating fibroblastic cells, compared with the tumor in the first case. Immunohistochemically, the mononuclear and multinucleated cells within these tumors were positive for vimentin and CD 34 but negative for any other antigens, including Factor VIII-related antigen, desmin, alpha smooth muscle actin, myoglobin, S-100 protein, LeuM1, lysozyme, alpha-1-antitrypsin, and cytokeratins (AE1/AE3 and CAM5.2). The features in these cases indicate that giant cell angiofibroma can arise in an extraorbital site in middle-aged patients and presents some histopathologic diversity.

Angiofibroma↗
PubMed1996

Hepatocyte growth factor as a key to modulate anti-ulcer action of prostaglandins in stomach.

Although the clinical efficacy of prostaglandins (PGs), especially on gastric mucosal injuries induced by nonsteroidal antiinflammatory drugs, is widely appreciated, their mechanism of action, apart from acid suppression, is quite unclear. In this study, we have established a primary culture system of human gastric fibroblasts and clearly demonstrated that PGs strongly induce the expression of hepatocyte growth factor (HGF) in the fibroblasts, which is mediated by PGE specific receptor, EP2 or EP4. Since HGF facilitates repair and protection of gastric epithelial cells in a paracrine manner, it is assumed that some of the beneficial effects of PGs may be mediated by HGF. To confirm this assumption, we established a simplified in vitro culture gastric mucosal model which consists of gastric epithelial cells and gastric fibroblasts. Using the model, we performed a round wound restitution assay. PGE1 remarkably accelerated restitution which was completely inhibited by anti-HGF antibody, indicating that the action was mediated by HGF. To confirm these in vitro data, we further demonstrated that HGF mRNA expression is downregulated at the edges of nonsteroidal antiinflammatory drug-induced gastric ulcers where PGs should be depleted. In summary, we proposed that gastric fibroblasts are newly recognized targets of PGs, and HGF produced by human gastric fibroblasts may be a key factor for anti-ulcer action of PGs in the stomach.

Adult↗
PubMed1996

Intracellular signaling pathway of substance P-induced superoxide production in human neutrophils.

We examined the intracellular mechanisms of substance P-induced superoxide anion (O2-) production in human neutrophils. Addition of substance P (30 microM) caused O2- production and biphasic increases in intracellular Ca2+ concentrations ([Ca2+]i) (early transient and subsequent sustained components) associated with the formation of inositol 1,4,5-trisphosphate (IP3). O2- and [Ca2+]i were assayed by using ferricytochrome C and fura 2-AM, respectively. These responses were abolished by tachykinin NK1 receptor antagonists, [D- Pro9[spiro-gamma-lactam],Leu10,Trp11]physalaemin-(1-11) (GR82334) or [D-Arg1,D-Trp7,9,Leu11]substance P (spantide), and an intracellular Ca2+ chelator, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA-AM). Inhibition of IP3 formation by GTP-binding protein (G-protein) inactivators such as guanosine 5'-O-(2-thiodiphosphate) (GDP beta S) and islet-activating protein (IAP), or a phospholipase C inhibitor, 1-[6-[[17 beta-3-methoxyestra-1,3,5(10)- trien-17-yl]amino]hexyl]1 H-pyrrole-2,5-dione (U-73122), blocked the substance P-induced O2- production and biphasic increases in [Ca2+]i. An IP3 receptor antagonist, heparin, reduced both the substance P-induced O2- production and the transient increase in [Ca2+]i without any significant effects on the sustained increase in [Ca2+]i. Protein kinase C inhibitors, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7) and calphostin C, only slightly suppressed O2- production, and abolished the sustained increase in [Ca2+]i without any significant effects on the transient increase in [Ca2+]i. A Ca2+ entry blocker, nicardipine, completely inhibited the sustained increase in [Ca2+]i without affecting O2- production and the transient increase in [Ca2+]i. These results suggest that the tachykinin NK1 receptor/G-protein-linked IP3 formation with the resulting IP3-induced transient increase in [Ca2+]i is the main signal transduction pathway for substance P-stimulated O2- production in neutrophils.

Calcium↗
PubMed1996

Peritumoral angiogenesis in carcinomas of the head and neck.

In the present study, the relationship between peritumoral angiogenesis and the clinical stage or the DNA ploidy pattern in 37 cases of squamous cell carcinomas of the head and neck was examined. Vascular endothelial cells of biopsy specimens were immunohistochemically stained for factor VIII-related antigen and the number of micro-vessels counted. The DNA ploidy pattern was determined by flow cytometry. The number of micro-vessels increased significantly (p < 0.05) as the regional lymph node metastasis advanced. In terms of the DNA ploidy pattern, the tumors of aneuploid pattern contained a greater number of micro-vessels than did those of diploid pattern. These findings suggest that the number of micro-vessels at the primary site of squamous cell carcinoma of the head and neck may be closely associated with the metastatic potential to the regional lymph node.

Adult↗
PubMed1996

Different rifampicin inactivation mechanisms in Nocardia and related taxa.

Mycolic acid-containing bacteria inactivate rifampicin in a variety of ways such as glucosylation, ribosylation, phosphorylation and decolorization. These inactivations were found to be a species-specific phenomena in Nocardia and related taxa. Gordona, Tsukamurella and fast-growing Mycobacterium modified rifampicin by ribosylation of the 23-OH group of the antibiotic. Such ribosylation was not observed in Rhodococcus and Corynebacterium, but phosphorylation of the 21-OH group of rifampicin was observed in one strain of Rhodococcus. Nocardia modified the antibiotic by glucosylation (23-OH group) and phosphorylation, but ribosylation was not observed.

Actinomycetales↗
PubMed1996

Immunopotentiating activity of Clostridium butyricum in mice.

Bacterial vaccine, as generated by heat-inactivated Clostridium butyricum cells, displayed antitumor activity against sarcoma 180 in DDY mice and antimetastatic activity against B16-F10 melanoma in BDF1 mice. According to our results, the vaccine has no direct growth inhibitory effect toward the tumor cell lines tested in this study. The vaccine increased gamma-interferon production, elicited delayed type hypersensitivity reaction, and enhanced IgM antibody formation and mitogenicity. The phagocytic activity of macrophage and killing activity of NK cells from mice were enhanced in a dose-dependent manner by stimulating with the heat-inactivated vaccine. Among those responses in the mice treated with CB, elevated NK cell activity may play a prominent role in manifesting antitumor activity in the B16-F10 metastasis experiment.

Adjuvants, Immunologic↗
PubMed1996

[Standardization of quantitative measurement of rheumatoid factor].

Recently many automated methods have been developed for a quantitative measurement of rheumatoid factor (RF). As they are widely used, it has been claimed that estimated values of RF are quite different among institutions. Standardization of quantitative measurement of RF is, therefore, required. The subcommittee for standardization of RF of the Ministry of Health and Welfare of Japan, worked from 1988 to 1994 in order to obtain an appropriate national standard of RF and has reached the conclusion that murine monoclonal rheumatoid factor (mRF) would be recommended as a new national standard of RF, which allows new expression of RF value (microgram/ml equivalent to the mRF instead of unit/ml referred to the WHO standard). There are two types of methods widely used for the quantification of RF. The first type is a method of light scattering analysis which is based on interaction of RF with particle-coated or aggregated human IgG (Fc) in nepherometry or turbidimetry, RF being expressed as unit/ml referred to the WHO standard. The second is a radioimmunoassay or an enzyme immunoassay in which RF is expressed as index compared to arbitrary standard. The former expression of RF is recognized to indicate agglutination titer of RF and the latter expresses the concentration of RF. The subcommittee decided to target on the former type of methods because of rapid prevalence with large inter-laboratory variations. The mRF is able to agglutinate proportionally IgG-complex with various features in wide range (x x microgram/ml to more than 1 mg/ml). It can be measured by nepherometry and turbidimetry with sufficient stability. The mRF has no misgivings in present and future supply and in immutability after a century. One of the largest advantages of the use of mRF national standard is expected to be able to eliminate the inter-laboratory variations of RF values which are considered to be mainly derived from different methods of laboratory instruments as well as from biological properties of polyclonal RF. The use of microgram/ml equivalent to mRF instead of unit/ml referred to the WHO standard makes it possible to determine the exact RF value of test serum since the mRF preparation could be adjusted to the best concentration to be requested by any available method of instrument to measure agglutination titer of RF.

Animals↗