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Biomedical subjects

K Takada

Publications and source records attributed to K Takada.

At least 91 records · Page 5Linked to original sources

Cyclophosphamide for the treatment of systemic lupus erythematosus.

Aggressive immunosuppressive therapy with cyclophosphamide has improved the outcome of major organ disease in lupus patients. Controlled trials have shown that pulse cyclophosphamide is the treatment of choice for patients with moderate to severe proliferative nephritis. Long-term follow-up of patients participating in these controlled trials suggests that combining pulse cyclophoshamide with pulse methylprednisolone increases efficacy but not toxicity. Retrospective case series have also shown that pulse cyclophosphamide therapy may be effective for the management of severe or refractory to standard therapy neuropsychiatric, pulmonary, cardiovascular and hematologic disease. Pulse cyclophosphamide is associated with an increased risk for herpes zoster infections in the short term and with sustained amenorrhea in the long-term. Recent studies have also drawn attention to the lack of response (or incomplete response) and flare of lupus after an initial response. In an effort to circumvent these limitations, current investigations explore the therapeutic potential of high-dose, immunoablative cyclophosphamide therapy or low-dose cyclophosphamide in combination with nucleoside analogs or biologic response modifiers.

Cyclophosphamide↗

Application of pressure-controlled colon delivery capsule to oral administration of glycyrrhizin in dogs.

A colon delivery system has been used to improve the bioavailability of glycyrrhizin, a glycoside of glycyrrhetic acid. The bioavailability of glycyrrhizin is low when administered in conventional oral galenic dosage forms because glycyrrhizin is enzymatically hydrolysed both in the stomach and in the intestine. It was reasoned that if large amounts of glycyrrhizin were directly delivered to the colon, enzymatic activity should be reduced due to saturation so that intact glycyrrhizin could be absorbed into the systemic circulation. Based on this assumption, pressure-controlled colon delivery capsules (PCDCs) were used as a colon delivery system. Eight types of glycyrrhizin solution were prepared and were introduced into PCDCs. After oral administration of the test PCDCs to beagle dogs, blood samples were obtained over 24 h and plasma glycyrrhizin concentrations were measured by an HPLC method. With PCDCs containing aqueous glycyrrhizin and propylene glycol solutions, plasma glycyrrhizin levels were extremely low and the bioavailabilities of glycyrrhizin were 0.6% and 0.4%, respectively. When Labrasol was added to both types of glycyrrhizin solution, the bioavailability was improved to 4.6% for aqueous solution and 3.8% for propylene glycol solution. When a surfactant, Polysorbate 80, was added in combination with Labrasol, synergistic effects were not obtained. Furthermore, dose-dependent effects of Polysorbate 80 were not obtained. Labrasol, which is a component of self-emulsifying drug delivery systems (SEDDS), has been shown to strongly improve the bioavailability of glycyrrhizin from the colon.

Administration, Oral↗

Application of Eudragit P-4135F for the delivery of ellagic acid to the rat lower small intestine.

Based on the assumption that the delivery of ellagic acid to its site of action would show an antiinflammatory activity in inflammatory bowel disease (IBD), we have prepared microspheres using a new pH-sensitive polymer, Eudragit P-4135F (P-4135F), to deliver ellagic acid to the lower small intestine in rats. The microspheres were spherical in shape and the mean diameters were approximately 100-150 microm. The amount of ellagic acid released from the microspheres decreased by increasing the formulated amount of P-4135F. The release characteristics of ellagic acid were pH-dependent. By considering the factors loading efficiency and microsphere particle size distribution, ellagic acid-2 microspheres (P-4135F/ellagic acid = 1.65) were selected for further investigation. In a dissolution study, more than 95% ellagic acid was released within 0.5 h in pH 7.4 and 8.0 buffers. The release percent of ellagic acid was less than 40% in pH 6.8 and 7.0 and was less than 10% in pH 5.6 and 5.9. To observe the dissolution sites of the microspheres in the rat small intestine fluorescein was formulated in the microspheres as a tracer drug along with ellagic acid (50 mg kg(-1)). After intraduodenal administration of fluorescein-labelled microspheres to rats, the plasma fluorescein level started to increase at 0.5 h, by which time the microspheres had reached the middle part of the ileum. Microspheres started to dissolve within 1.0 h and the peak plasma fluorescein concentration was observed at 3.0 h, when the majority of the administered microspheres were dissolved in the terminal ileum. These results suggested that P-4135F microspheres could deliver ellagic acid to the lower part of the small intestine, and that the released ellagic acid would be distributed into the caecum and the ascending colon.

Administration, Oral↗

Role of hypertension, dyslipidemia and diabetes mellitus in the development of coronary atherosclerosis in Japan.

The present study evaluated the effect of hypertension (HT), dyslipidemia and diabetes mellitus (DM) on the development of coronary atherosclerosis in the Japanese population, using a cross-sectional study of 433 patients (254 men and 179 women) aged 30 years or older who underwent coronary angiography for suspected or known coronary heart disease angina at 5 cardiology departments in the Fukuoka area between September 1996 and August 1997. Patients with a disease duration of 6 months or more were excluded. The main outcome measure was angiographically defined coronary artery stenosis and was found to a significant degree in 146 patients (33.7%). HT, DM, low levels of high-density lipoprotein cholesterol (HDL-C) and hypertriglyceridemia remained as significant coronary artery disease (CAD) risk factors even after controlling for age, sex, hospital, smoking, alcohol use, body mass index and leisure time physical activity. However, hypercholesterolemia was not a significant risk factor after adjusting for these variables. After controlling for these variables, DM, low HDL-C and hypertriglyceridemia were significant CAD risk factors for men, but only DM was a significant CAD risk factor in women. These results indicate that in Japan DM, low HDL-C and hypertriglyceridemia may be more important CAD risk factors than hypercholesterolemia.

Adult↗

Morphological and histochemical changes in the secretory granules of mucous cells in the early postnatal mouse parotid gland.

It has previously been known that the developing parotid glands in humans and rats contain mucous cells in their terminal clusters and acini, but these cells disappear within a short period of time. Using rat parotid glands, IKEDA and AIYAMA (1997, 1999) suggested that the mucous cells might change into serous cells in the early postnatal period, but it is uncertain whether mucous cells appear only in the developing parotid gland of a few species such as humans and rats, or whether the cell transformation actually occurs. To clarify these points, the present study investigated the developing mouse parotid glands. Light microscopy showed cells with secretory granules that stained extensively with PAS and alcian blue in the terminal clusters of a 1-day-old mouse parotid gland. Mucous cell numbers in the terminal clusters and the acini reached a peak on day 5 and decreased on day 7. By day 10, the mucous cells had disappeared altogether. Thus, the presence of mucous cells in the developing mouse parotid gland was confirmed. Electron microscopy showed granules of low-electron-density and bipartite granules in the mucous cells. Bipartite granules and highly electron-dense granules sometimes co-existed in a single cell. Immuno-electron microscopy revealed a positive reaction for amylase to the low-electron-density granules and the low-electron-density portions of the bipartite granules, in addition to the highly electron-dense granules and the electrondense cores of the bipartite granules. No mucous cells with nuclei displaying characteristics of apoptosis were recognizable. Lectin histochemistry both at the light and electron microscopic levels showed that the secretory granules in the mouse parotid gland mucous cells had sugar residues similar to those of the mature serous granules. These findings demonstrate that mucous cells appear in the early postnatal mouse parotid gland, and that almost all of these cells may be converted into serous cells.

Amylases↗

Immediate remission obtained by minocycline in a patient with histiocytic necrotizing lymphadenitis.

A 29-year-old man was admitted because of fever, arthralgia and swelling of the cervical lymph nodes. A diagnosis of histiocytic necrotizing lymphadenitis (HNL) was made based on the findings of a lymph node biopsy. At first, piperacillin sodium (PIPC) was started, but a spiking fever persisted. We therefore changed the PIPC treatment to minocycline. On the following day, his clinical and laboratory findings were dramatically improved. After administering minocycline for 10 days, the HNL symptoms completely disappeared. He has been in good health for 3 years since undergoing treatment. This case strongly indicates that minocycline-sensitive microorganism(s) may be related, at least in part, to the etiology of HNL.

Adult↗

Rapid improvement of osteomalacia by treatment in a case with Sjögren's syndrome, rheumatoid arthritis and renal tubular acidosis type 1.

We present here a case of Sjögren's syndrome (SjS) with osteomalacia based on renal tubular acidosis type 1 (RTA-1). A 53-year-old woman, diagnosed as having rheumatoid arthritis (RA) at the age of 33, was admitted to our hospital because of sicca complex, fatigability and worsening general aching. The activity of RA had been low, but it was complicated by SjS, RTA-1 and remarkable osteomalacia. Acidosis was corrected by alkali supplement therapy. By treatment with a regimen consisting of alfacalcidol, calcium L-aspartate, elcatonin and ipriflavone, her bone mineral density (BMD) was remarkably improved within months and the generalized aching gradually diminished.

Acidosis, Renal Tubular↗

Lipid microspheres incorporated by U937 cells via their specific receptors.

Lipid microspheres (LM), currently in clinical use as drug carriers, mainly consist of soybean oil as a core and lecithin as a surfactant. The purpose of our study wass to determine whether or not LM incorporation is receptor-mediated. U937 cells resuspended in a serum-free medium abundantly took up unmodulated LM. A binding study showed that U937 cells had a single binding site for LM (410 sites/cell at 24 degrees C; 100 sites/cell at 4 degrees C). Inhibition assays revealed that lecithin liposome, lysophosphatidylcholines, activated alpha2-macroglobulin, and HDL did not affect the binding of LM to U937 cells. VLDL strongly, and LDL and AcLDL moderately, inhibited the binding of LM to U937 cells. Ligand blotting analysis revealed that unmodulated LM in an apoprotein-free buffer directly bound to a 40 kDa protein in the cell membrane fraction. These results suggest that LM that is not modulated by any protein is incorporated by specific cells via receptor-mediated processes.

Binding Sites↗

[Hepatic and splenic arterial infusion chemotherapy after transcatheter peripancreatic arterial embolization for patients with inoperable adenocarcinoma of the pancreas].

Thirty-one patients with advanced pancreatic carcinoma and liver metastases were treated by hepatic and splenic arterial infusion chemotherapy after transcatheter peripancreatic arterial embolization. The response rate for these 31 patients was 61.3%, with a mean survival period of 17.8 +/- 3.2 months and a 50% survival period of 12 months. By site of the primary tumor, the response rate for pancreatic head and body carcinoma was 81%, with a mean survival period of 21.6 +/- 4.0 months and a 50% survival period of 17 months, whereas the response rate for pancreatic caudal carcinoma was 20%, with a mean survival period of 6.1 +/- 0.5 months and a 50% survival period of 6 months. We believe that the current chemotherapy is an effective treatment for advanced pancreatic cancer with liver metastases.

Adenocarcinoma↗

[Implantation of a dual chambers port for hepatic and splenic arterial infusion chemotherapy in advanced pancreatic carcinoma with multiple liver metastasis].

Dual chambers ports were implanted in 7 patients with advanced pancreatic carcinoma and metastatic liver tumors to connect a 3.3 Fr catheter as an indwelling catheter. In comparison with the implantation of a pair of Single chamber ports, implanting a Dual chambers port entails some technical difficulties, but has some benefits in terms of stabler placement, a smaller incision, reduction of medical fees, and improved QOL of patients.

Catheters, Indwelling↗

[A case of cerebellar glioblastoma with massive cerebellar hemorrhage].

A case is reported of glioblastoma multiforme (GM) of the cerebellum associated with an intracerebellar hemorrhage. A 54-year-old male was admitted to our hospital with sudden onset of headache and nausea. CT scan showed right intracerebellar hemorrhage. The patient received conservative therapy and was discharged without any neurological deficits. However a second cerebellar hemorrhage attacked him ten days after discharge. His level of consciousness deteriorating, he underwent suboccipital craniectomy and the hematoma with the surrounding elastic tissues was excised. There were no findings suggesting hemorrhage within the tumor on the preoperative neuroimagings, but histological examination confirmed GM with massive hemorrhage. To our knowledge, only 2 cases of cerebellar GM with massive hemorrhage have been reported in the literature. Our case indicates cerebellar GM should be taken into account as a possible cause of cerebellar hemorrhage.

Cerebellar Diseases↗

Calpain inhibitor inhibits secretory granule maturation and secretion of GH.

Clathrin- and AP-1-coated buds are present on immature secretory granules of endocrine cells that mature into clathrin-uncoated granules. The mechanism of clathrin and adaptor protein uncoating has remained obscure. Benzyloxycarbonyl-L-leucyl-L-leucinal (ZLLal), a calpain inhibitor, reduced growth hormone (GH) secretion with intracellular accumulation, in a GH-secreting rat pituitary tumor cell. Pulse and chase demonstrated that ZLLal retarded the turnover of clathrin (Clt.H) and adaptins. ZLLal-treatment co-immunoprecipitated the increased amounts of GH with Clt.H and adaptins compared to control cells, suggesting the intracellular accumulation of immature secretory granules. Clt.H and adaptins were limited-proteolyzed by m-calpain in vitro, indicating that calpain may be involved partly in the maturation of secretory granules in endocrine cells via the process of clathrin uncoating.

Adaptor Protein Complex alpha Subunits↗

Epstein-Barr virus-encoded poly(A)(-) RNA supports Burkitt's lymphoma growth through interleukin-10 induction.

Akata and Mutu cell lines are derived from Burkitt's lymphoma (BL) and retain the in vivo phenotype of Epstein-Barr virus (EBV) expression that is characterized by expression of EBV-determined nuclear antigen 1 (EBNA1), EBV-encoded RNAs (EBERs) and transcripts from the BAM:HI A region (BARF0). We found that EBV-positive Akata and Mutu cell clones expressed higher levels of interleukin (IL)-10 than their EBV-negative subclones at the transcriptional level. Transfection of an individual EBV latent gene into EBV-negative Akata cells revealed that EBERs were responsible for IL-10 induction. Recombinant IL-10 enabled EBV-negative Akata cells to grow in low (0.1%) serum conditions. On the other hand, growth of EBV-positive Akata cells was blocked by treatment either with an anti-IL-10 antibody or antisense oligonucleotide against IL-10. EBV-positive BL biopsies consistently expressed IL-10, but EBV-negative BL biopsies did not. These results suggest that IL-10 induced by EBERs acts as an autocrine growth factor for BL. EBERs, EBER1 and EBER2, are non-polyadenylated RNAs and are 166 and 172 nucleotides long, respectively. The present findings indicate that RNA molecules could regulate cell growth.

Burkitt Lymphoma↗

Epstein-Barr virus lacking glycoprotein gp85 cannot infect B cells and epithelial cells.

To evaluate whether the BXLF2 gene of Epstein-Barr virus (EBV), which codes gp85 protein, is essential for infection of B cells and epithelial cells, we analyzed the infectivity of an EBV recombinant lacking gp85. The cells that were infected with the BXLF2-disrupted virus were unable to express gp85 proteins that could be detected by mouse monoclonal antibody E1D1, specific for gp85/gp25 complexes. The BXLF2-disrupted EBV had the ability to attach to, but not infect, B cells. On the other hand, the same virus failed to bind to and infect NU-GC-3, a human gastric adenocarcinoma cell line that is susceptible to EBV infection. The results indicate that the gp85 is used for infection of not only B cells but also epithelial cells and suggest that the gp85 is necessary for attaching the virus to epithelial cells.

Animals↗