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Biomedical subjects

K Mitamura

Publications and source records attributed to K Mitamura.

157 records · Page 9Linked to original sources

Quantitative determination of 25-hydroxyvitamin D3 3-sulphate in human plasma using high performance liquid chromatography.

The quantitative determination of 25-hydroxyvitamin D3 3-sulphate in human plasma was completed using reversed phase high performance liquid chromatography with UV detection (265 nm) and an internal standard method. The vitamin D sulphate fraction was obtained from a plasma specimen with the combined use of a Bond Elut C18 cartridge for solid-phase extraction and a piperidinohydroxypropyl Sephadex LH-20 column for lipophilic ion-exchange chromatography. Separation of the compounds was performed on a YMC-Pack ODS-AM column. The limit of quantitation was 5 ng/mL and the assay was linear from 5 to 50 ng/mL. The proposed method is satisfactory in its accuracy and precision.

Calcifediol↗

Androgen and estrogen receptors in hepatocellular carcinoma and in the surrounding noncancerous liver tissue.

Both androgen and estrogen receptors were studied in human hepatocellular carcinoma and noncancerous liver tissue surrounding it. Androgen receptor was detected in the cytosol and/or nucleosol of 4 of 8 cancerous tissues and 1 of 6 noncancerous tissues. The levels of androgen receptor in hepatocellular carcinomas ranged from 3.4 to 37.6 fmoles per mg protein with dissociation constants (Kd) of 0.226 - 51.3 X 10(-9) M. That in the surrounding noncancerous tissue was 2.1 fmoles per mg protein with Kd of 0.941 X 10(-9) M. Estrogen receptor was detected in the cytosol of 1 of 7 cancerous tissues, while it was detected in the cytosol and/or nucleosol of 3 of 7 noncancerous tissues. The level of estrogen receptor in hepatocellular carcinoma was 4.9 fmoles per mg protein with Kd of 1.20 X 10(-9) M, and those in the surrounding noncancerous tissues ranged from 2.6 to 1,073 fmoles per mg protein with Kd of 0.223 - 3.15 X 10(-9) M. The results suggest that the expression of androgen receptor may be augmented in association with malignant transformation of hepatocytes while the expression of estrogen receptor may be rather suppressed and that some of hepatocellular carcinomas may be androgen-dependent.

Adult↗

IgM anti-HBc in anti-HBe positive chronic type B hepatitis with acute exacerbations.

IgM anti-HBc was measured by radioimmunoassay in serially collected serum samples during 20 acute exacerbations which developed in 14 patients with anti-HBe positive chronic type B hepatitis. IgM anti-HBc became positive in 12 of the 14 (86%) patients and in 18 of the 20 (90%) exacerbations, and elevation of IgM anti-HBc which was believed to be significant was also observed in the remaining two patients. In most of the patients who also had determinations of serum hepatitis B virus DNA, the hepatitis B virus DNA became positive. These results suggest that ALT elevation in anti-HBe positive chronic type B hepatitis is associated with active replication of hepatitis B virus. It is considered to be useful to measure IgM anti-HBc for the purpose of identifying the causes of ALT elevation in anti-HBe positive chronic type B hepatitis.

Adult↗

Increased soluble CD4 molecules and the role of soluble CD4 production in patients with rheumatoid arthritis.

We investigated the concentration of soluble CD4 molecules (sCD4) in serum, and the mechanism of sCD4 production from T lymphocytes, in patients with rheumatoid arthritis (RA). The concentration of sCD4 molecules was determined using a solid-phase enzyme-linked immunosorbent assay method. Using reverse transcription polymerase chain reaction (RT-PCR) techniques, we studied the presence of alternatively spliced mRNA encoding the transmembrane site of CD4, and the mRNA encoding a conservative region of the CD4 binding site of the human immunodeficiency virus (HIV), in the serum of RA patients. Levels of sCD4 found in RA patients were higher than in normal controls (199 U/ml compared with 8.4 U/ml, respectively), and correlated with additional medical parameters. The results of RT-PCR suggested that the higher sCD4 levels may be due to shedding from the cell membrane after protease digestion, not to alternative splicing or a reaction to viral binding to sCD4.

Adult↗

A new tactile skin sensor for measuring skin hardness in patients with systemic sclerosis and autoimmune Raynaud's phenomenon.

We used a new tactile sensor to measure the elastic properties of skin in patients with systemic sclerosis or Raynaud's phenomenon. The sensor consists of a piezoelectric vibrator with vibration pickup to measure frequency changes when the sensor is placed on the skin. The mean frequency change at the skin surface of the proximol third phalanx in patients with systemic sclerosis was significantly lower than in age- and sex-matched controls. The results in systemic sclerosis patients were statistically correlated to the Modified Rodnan Skin Thickness Score. This technique was also used to measure the therapeutic efficacy of salpogrelate, a new specific serotonin receptor antagonist. A greater mean frequency change was seen after treatment. We conclude that this new tactile sensor is useful for quantitatively measuring skin sclerosis and may help determine the efficacy of therapeutic treatments.

Benzene Derivatives↗

Detection of Grb-2-related adaptor protein gene (GRAP) and peptide molecule in salivary glands of MRL/lpr mice and patients with Sjögren's syndrome.

The pathogenesis of Sjögren's syndrome (SS) is poorly understood. In this study we used an in-house mouse spleen cDNA microarray to analyse genes in spleens from MRL/lpr (an SS mouse model) mice. We have previously demonstrated that GRAP genes were up-regulated in salivary glands of the same mice. The microarray analysis showed that seven out of 2304 genes were highly expressed in spleens from the MRL/lpr mice, one of which was the GRAP gene. In other words, the GRAP gene is highly expressed in the salivary glands and spleen of MRL/lpr mice. We also carried out immunohistochemical studies. Mouse and human Grb-2-related adaptor protein (GRAP) antigens were expressed on ductal cells and infiltrating lymphocytes in salivary glands of MRL/lpr mice and SS patients, but only weakly in controls (MRL/+ mice and individuals with salivary cysts). These results suggest that the GRAP gene might have a role in the pathogenesis of SS.

Adaptor Proteins, Signal Transducing↗

Two cases of Pneumocystis carinii pneumonia occurred in human immunodeficiency virus infected patients: supplemental treatment with aerosolised pentamidine isethionate.

Two cases of Pneumocystis carinii pneumonia occurred in human immunodeficiency virus infected patients who were diagnosed by the aspiration-lung-biopsy. They were treated with 4 mg/kg of pentamidine isethionate intravenously administered followed by pentamidine aerosol inhalation. Although clinical and laboratory findings were improved by the fifth or seventh day of intravenous therapy, substantial leukocytopenia, from 3,000/cmm to 600/cmm and from 2,700/cmm to 1,000/cmm, occurred. At this point, the method of pentamidine administration was switched to inhalation. Pentamidine 600 mg in 30 ml distilled water was aerosolised using ultrasonic nebuliser and exposed for a 30-minute period once daily. In both cases, chest x-rays showed improvements: The disappearance of P. carinii were obtained in two weeks. Mild coughing was the sole adverse reaction encountered during the course of aerosol inhalation.

Administration, Inhalation↗

Three cases of acquired immunodeficiency syndrome complicated with toxic epidermal necrolysis.

Co-trimoxazole (trimethoprim-sulfamethoxazole) and pyrimethamine-sulfadoxine have been recommended for treatment and prophylaxis, respectively, of Pneumocystis carinii pneumonia (PCP). However, toxic epidermal necrolysis (TEN) occurred in three of four patients with acquired immunodeficiency syndrome (AIDS) during the course of treatment or prophylaxis of PCP with these agents. On the other hand, 14 patients with PCP treated with pentamidine never developed TEN. Because the incidence of adverse skin reactions is higher among patients with AIDS than those without AIDS, and TEN is a severe, potentially fatal skin reaction, sulfonamide-containing drugs should be given cautiously to patients with AIDS.

Acquired Immunodeficiency Syndrome↗

Gastrointestinal lesions in an adult patient with Henoch-Schönlein purpura.

A 28 year-old man was admitted because drug toxication, due to a high dose of antipsychotic drugs, presented purpuric rash on both legs, lower abdominal pain, arthralgia, and fresh-bloody stool. Colonoscopy observed numerous small ring-like petechiae in the rectum and in the sigmoid colon. Upper gastrointestinal endoscopy found a few petechiae in the antrum of the stomach and in the duodenal second portion. He was treated with coagulation factor X III after admission. After 38 days, there was no abnormal mucosa in the colorectum, the duodenal second portion, or the antrum of the stomach. The disappearance of gastrointestinal lesions correlated with the course of the illness. Gastrointestinal tracts should be thoroughly observed in patients with Henoch-Schönlein purpura.

Adult↗

Involvement of p38 MAP kinase in apoptotic and proliferative alteration in human colorectal cancers.

Mitogen-activated protein kinases (MAPKs) have been thought to be involved in tumor development, and recently implicated in the regulation of apoptosis. We assessed the activation of p38 MAPK and extracellular signal-regulated kinases (ERKs) in human colorectal adenocarcinoma by immunoblotting with antibodies raised against each activated form. We also assessed the alteration of proliferative and apoptotic states, and analyzed the association of p38 MAPK with these alterations. The incidence of p38 MAPK activation in the cancer nucleus was significant (p = 0.0215), while ERKs activation was not significant. Proliferating cell nuclear antigen (PCNA)-labeling index and apoptotic index were increased in all cancer tissues. These findings suggested that p38 MAPK was constitutionally activated and was associated with increased proliferative and apoptotic states in colorectal cancers. Serum-deprivation-induced apoptosis in colonic adenocarcinoma cell line was significantly inhibited by SB203580, a specific p38 MAPK inhibitor, suggesting that apoptosis was mediated by the p38 MAPK pathway.

Adenocarcinoma↗

Mechanism of growth-inhibitory effect of cisplatin on human pancreatic cancer cells and status of p53 gene.

Pancreatic cancer is a devastating malignant tumor in humans and the development of new modalities of treatment is needed. We studied the mechanism of the growth-inhibitory effect of cisplatin (CDDP) on human pancreatic cancer cells in connection with the status of the p53 gene and expression of the bcl-2 family. COLO-357 cells with wild-type p53 gene and T3M4, Panc-1 and AsPC-1 cells with mutant-p53 gene were used. Growth of these cells was inhibited by CDDP in a dose-dependent manner in both serum-deprived and serum-supplemented conditions. CDDP induced apoptosis of COLO-357 and T3M4 cells in the serum-supplemented condition, whereas necrosis of these cells was induced by CDDP at high concentrations in the serum-deprived condition. Although expression of bax mRNA and its protein product were enhanced, while bcl-2 protein was decreased by CDDP in COLO-357 cells, expression of mRNA of the bcl-2 family and protein product were not influenced by CDDP in T3M4 cells. Increased expression of bax and reduced expression of bcl-2 are involved in the growth-inhibitory effect of CDDP on pancreatic cancer cells with wild-type p53 gene.

Antineoplastic Agents↗

Histological findings after placement of a self-expanding stent in rectal carcinoma with complete obstruction--case report.

Patients with acute obstruction due to colorectal carcinomas frequently require emergency surgery. However, such emergency procedures are associated with various complications, a high mortality rate and a poor prognosis. If the obstruction could be immediately relieved, the patient could later undergo an elective operation with a much better prognosis. Recently, expanding metallic stents have been used to treat obstruction due to colorectal carcinoma. In the case reported here, we initially inserted a colonoscopic retrograde bowel drainage tube per anus to achieve decompression. We then placed a self-expanding metallic stent, since we anticipated a prolonged preoperative period due to high fever, congestive heart failure, cerebral infarction, and persistent high blood sugar concentrations. The patient had no complications for 57 days after placement of the stent, and eventually underwent an elective operation. Histologically, the side of the cancerous lesion compressed by the stent was thin and consisted solely of a serosal layer. Implantation of a metallic stent is safe for the treatment of acute malignant obstruction. Stent placement is indicated not only as a palliative treatment for inoperable or recurrent cases, but also as a preoperative procedure before elective surgical resection.

Aged↗