Biomedical subjects

M Murakami

Publications and source records attributed to M Murakami.

At least 667 records · Page 37Linked to original sources

PubMed1995

Gene expressions of oxytocin and oxytocin receptor in cumulus cells of human ovary.

Oxytocin (OT) has been detected in mammalian granulosa-luteal cells during the early stages. The purpose of this study was to explore gene expressions of OT and OT receptor (OTR) in human cumulus cells. Cumulus cells enclosing a mature oocyte were obtained from 6 women undergoing clinical in vitro fertilization and embryo transfer programs. OT and OTR gene expressions were investigated by employing reverse transcription polymerase chain reaction and reverse transcription polymerase chain reaction/single-strand conformation polymorphism methods. OT gene expression in the cumulus cells was positive in 5 women and weakly positive in the remaining patient. The structure of OT mRNA in the cumulus cells was equivalent to that in human hypothalamus. OTR gene expression was also observed in the cumulus cells. This study is the first to describe the simultaneous expression of both OT and OTR genes in human cumulus cells. It is suggested that local OT plays some important roles in fertility through modification of the micro-environment around the oocyte.

Base Sequence↗

PubMed1995

Effects of antiepileptic drugs on EEG background activity in children with epilepsy: initial phase of therapy.

The effects of antiepileptic drugs (AED) on EEG background activity were evaluated in 37 newly treated children with epilepsy, compared with 46 age-matched healthy controls. Before AED therapy, the children with epilepsy, both partial (treated with carbamazepine, CBZ group) and generalized seizures (treated with valproic acid, VPA group), already exhibited significant slowing of EEG with increased delta and decreased alpha power. Following 3 to 6 months of AED therapy, this EEG slowing was enhanced in the CBZ group and reduced in the VPA group. Following 1 year of AED therapy, an increase in frequency was recognized in the CBZ group. These results suggest that 1) most children with epilepsy already exhibit slowing of the EEG at the onset of seizures, which may reflect CNS developmental deficit, 2) the short-term effects on EEG are different between CBZ and VPA, and 3) EEG development with age continues under continuous AED administration. The EEG background activity in children with epilepsy is affected by many factors, which include the underlying CNS dysfunction of the epilepsy itself and also AED therapy (type of AEDs, duration of therapy, etc).

Alpha Rhythm↗

PubMed1995

Synergistic anti-tumor effects of mitomycin C and bile salts against L1210 cells.

The effects of various adjuvants on the cytotoxicity of mitomycin C (MMC) were studied in L1210 mouse leukemia cells. Adjuvants examined in this study were sodium glycocholate (Na-GC), sodium deoxycholate (Na-DC), O-n-dodecyl-beta-D-maltopyranoside (LM), and sodium salicylate. Among various additives, bile salts such as Na-GC and Na-DC were the most effective for increasing the cytotoxicity of MMC against L1210 cells. A dose-dependent increase in cytotoxic effect of MMC was observed in the presence of these bile salts. To elucidate a possible mechanism for enhancing the cytotoxic effect of MMC by the bile salts, the cellular uptake of MMC with or without Na-GC was examined using L1210 cells. The cellular concentration of MMC was determined by a reversed-phase HPLC. When Na-GC was coadministered with MMC, the uptake of MMC into L1210 cells was significantly enhanced as compared with MMC alone. Furthermore, the membrane fluidity of L1210 cells, as determined by fluorescence polarization, was increased in the presence of Na-GC. These results suggested that the enhancement of cytotoxicity of MMC by the addition of Na-GC could be attributed to the increasing cellular uptake of MMC due to the increasing membrane fluidity of L1210 cells.

Animals↗

PubMed1995

Effect of a hematopoietic promoting factor derived from porcine kidney on the proliferation of mouse hematopoietic progenitor cells in liquid culture.

We have partially purified a factor from porcine kidney, hematopoietic-promoting factor (HPF), which enhances granulocyte-macrophage colony-forming units (CFU-GM) and erythropoietic burst-forming unit (BFU-E) colony formation in the presence of various exogenous colony-stimulating factors (CSF) or erythropoietin (Epo) from mouse bone marrow cells. In this paper we examine the combined effects of HPF and/or stem cell factor (SCF) with interleukin-3 (IL-3) and interleukin-6 (IL-6) on the proliferation of primitive hemopoietic progenitor cells in liquid cultures for 7 or 14d. The combination of IL-3+IL-6+HPF could not increase the number of CFU-GM, BFU-E, and day-8 colony forming units in spleen (CFU-S) in cultures of unfractionated bone marrow cells, while this combination resulted in a marked increase of progenitors in cultures of c-kit+ enriched cells. In contrast, expansion of progenitors was observed by IL-3+IL-6+SCF or IL-3+IL-6+SCF+HPF in the culture of both unfractionated bone marrow cells and c-kit(+)-enriched cells after 7d. The number of CFU-GM and BFU-E in the combination of IL-3+IL-6+SCF+HPF for c-kit+ cells showed the largest increase, 109-fold and 38-fold respectively after 14d. These results show that HPF has promoting activity on hematopoietic stem cells and acts synergistically with SCF in early stages of hematopoiesis.

Animals↗

PubMed1995

Intestinal absorption of azetirelin, a new thyrotropin-releasing hormone (TRH) analogue. II. In situ and in vitro absorption characteristics of azetirelin from the rat intestine.

Intestinal absorption characteristics of azetirelin, a new thyrotropin-releasing hormone (TRH) analogue, were studied in rats by means of in situ closed loop and in vitro everted sac experiments. Plasma concentrations of azetirelin obtained in the in situ closed loop experiments were not significantly different among the intestinal segments. Area under the plasma concentration-time curve (AUC) of azetirelin following administration into the duodenal loop increased in proportion to the dose. The serosal to mucosal concentration ratio of the analogue in the everted sac experiment was constant over the mucosal drug concentration range of 0.01-10 mM. There was no directional difference in the transfer rate of azetirelin across the everted and non-everted sacs of the duodenum. Furthermore, its transport across the duodenum was not influenced by low incubation temperature (25 degrees C), addition of dipeptide (Gly-Gly), or pretreatment of the mucosal surface with 2,4-dinitrophenol, while that of TRH was inhibited under these conditions. These results suggest that the intestinal absorption mechanism of azetirelin is different from that of TRH, and that azetirelin is predominantly transported via a passive diffusion.

Amino Acid Sequence↗

PubMed1995

Differences in heavy-ion-induced DNA double-strand breaks in a mouse DNA repair-deficient mutant cell line (SL3-147) before and after chromatin proteolysis.

DNA double-strand breaks induced by X- or neon beam-irradiation in a DNA double-strand break-repair-deficient mutant cell line (SL3-147) were examined. The increase in the number of DNA double-strand breaks was dose depend after irradiation with X-rays and neon beams and was enhanced by chromatin-proteolysis treatment before irradiation. These results suggest that the induction of DNA double-strand breaks by ionizing radiation, including heavy-ions, is influenced by the chromatin structure.

Animals↗

PubMed1995

Western blot analysis of rat pituitary antigens recognized by human antipituitary antibodies.

Antipituitary antibodies have been reported to exist in sera of patients with autoimmune endocrine disorders. In order to investigate the pituitary antigens recognized by antipituitary antibodies, we studied the autoantigens in rat pituitary membrane and cytosolic fractions recognized by human antipituitary antibodies and anti-human pituitary hormone antibodies. Sera from 6 patients which showed positive antipituitary antibodies by immunofluorescence methods were studied. Each serum identified some proteins with 14.5, 22, 47, 49, 65, 84 and 97.5 kDa. Anti-GH antibodies and anti-PRL antibodies identified a positive band with 22 kDa, suggesting that anti-GH and anti-PRL antibodies may be present in patients' sera. These results indicate that Western blot analysis of rat pituitary antigens recognized by human antipituitary antibodies is a useful method to elucidate the pathophysiology of autoimmune endocrine disorders.

Animals↗

PubMed1995

Modulation of angiotensin II type 1 receptor mRNA expression in human blood cells: comparison of platelets and mononuclear leucocytes.

The objective of the present study was to quantify the expression of angiotensin II type 1 (AT1) receptor transcripts in human blood cells--platelets and mononuclear leukocytes--from 10 normal healthy volunteers during the alterations in the renin-angiotensin system. A quantitative assay employing reverse transcription-polymerase chain reaction (RT-PCR) was utilized. Oral administration of furosemide, 40 mg for 2 days, under mild salt restriction (50 mEq NaCl/day) for 6 days stimulated the renin-angiotensin system resulting in significant increases in plasma renin activity (PRA) (1.84 +/- 0.12 vs. 1.05 +/- 0.17 ng/l/s; P < 0.01), plasma angiotensin II concentration, and plasma aldosterone concentration (PAC). The ratio of AT1 receptor mRNA to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA expression in mononuclear leucocytes was significantly (P < 0.05) increased from the basal level (0.49 +/- 0.05 vs. 0.29 +/- 0.03) (P < 0.01), while in platelets these changes were opposite (0.11 +/- 0.05 vs. 0.25 +/- 0.05) (P < 0.01). Compared to these significant changes, salt loading (200 mEq NaCl/day) for 6 days decreased PRA(0.49 +/- 0.10 vs. 1.05 +/- 0.17 ng/l/s; P < 0.01) and induced the opposite changes in the ratio of AT1 receptor/GAPDH mRNA. These data suggest that AT1 receptors in human blood cells may be of two different types--platelets and mononuclear leucocytes.

Adult↗

PubMed1995

Clinical usefulness of thyroid-stimulating antibody measurement using Chinese hamster ovary cells expressing human thyrotropin receptors.

Human thyrotropin (TSH) receptors were expressed in Chinese hamster ovary (CHO) cells using eukaryotic expression plasmid pCXN2, which contains beta-actin promoter. We measured cAMP stimulation in CHO cells expressing human TSH receptors (CHO-hTSH-R cells) by immunoglobulin G (IgG) of patients with Graves' disease and Hashimoto's thyroiditis, and compared the results with a conventional thyroid-stimulating antibody (TS-Ab) assay using porcine thyroid cells and a TSH-binding inhibiting immunoglobulin (TBII) assay. Nineteen untreated patients with Graves' disease, including a case who developed hyperthyroidism after interferon -alpha therapy for chronic hepatitis C, and 13 treated patients with Graves' disease, 10 patients with Hashimoto's thyroiditis and 8 control subjects were studied. In 19 untreated patients with Graves' disease, 17 patients showed positive CHO-hTSH-R cell stimulation, 11 patients showed positive porcine thyroid cell stimulation and 15 patients showed positive TBII. All the untreated patients showed positive results in at least one assay. Although significantly positive correlations were observed among CHO-hTSH-R cell stimulation, porcine thyroid cell stimulation and TBII activities, the IgG of several patients showed significant discrepancy in the assay results. In a patient with interferon-induced hyperthyroidism only CHO-hTSH-R cell stimulation was positive, while porcine thyroid cell stimulation and TBII were negative. After the treatment with propylthiouracil for 6 months, CHO-hTSH-R cell stimulation became negative. The IgG of patients with Hashimoto's thyroiditis did not show significant stimulation of CHO-hTSH-R cells. These results suggest that the CHO-hTSH-R cell stimulation assay is clinically useful for the diagnosis and follow-up of patients with Graves' disease.

Animals↗

PubMed1995

Interactions between angiotensin II and norepinephrine on renin release by juxtaglomerular cells.

While the interactions between angiotensin II (Ang II) and norepinephrine (NE) on cardiovascular responses are well known, their effects on renin responses are not. We determined the renin secretion rate (RSR) and intracellular calcium level in juxtaglomerular cells harvested from Sprague-Dawley rats using a radioimmunoassay and a two-dimensional calcium analyzer. The effect of Ang II and NE was inhibitory on RSR and stimulatory on intracellular calcium. The NE-induced RSR response was amplified in the presence of Ang II (20 nmol/l). The NE-induced intracellular calcium response was also potentiated by the Ang II. There was a significant correlation (r = 0.994, p < 0.0001) between the changes in the RSR and those in intracellular calcium levels. Losartan (0.1 mumol/l). an Ang II type 1 receptor antagonist, blocked the Ang II threshold RSR responses and completely abolished the Ang II-related enhancements. The exclusion of calcium from the buffer reduced the maximal RSR response to NE but did not prevent the enhancement, suggesting the importance of the mobilization of intracellular calcium in the mechanism. The Ang II-induced RSR was amplified in the presence of NE (0.2 mumol/l). The Ang II-induced intracellular calcium response was also potentiated by the NE. A significant correlation (r = 0.996, p < 0.0001) between the changes in the RSR and the changes in intracellular calcium levels was also noted. Prazosin (1 mumol/l), an alpha 1-adrenoceptor antagonist, blocked the NE threshold RSR responses and abolished the agonist-related enhancements. The calcium-free buffer diminished this amplication with a slight decrease in the maximum RSR response to Ang II.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-1 Receptor Antagonists↗

PubMed1995

Restricted diffusion of an 19F-labelled organic acid in human erythrocytes analyzed by 19F pulsed field gradient NMR.

The diffusion coefficient of an 19F-labelled organic acid (3-trifluoromethylhippurate: TFMH) was measured in intact human red blood cells (RBCs) and sealed right-side-out ghosts at 22.5 +/- 0.05 degrees C. Diffusion coefficients were measured using stimulated echo and spin-echo pulsed field gradient sequences. The apparent diffusion coefficient (Da) of TFMH in the intracellular space was much smaller than in the extracellular medium. This was due to restricted diffusion of intracellular TFMH since i) the intracellular Da decreased when the diffusion time was increased, and ii) the smaller Da component disappeared when the membrane was permeabilized with saponin. From the intracellular Da values obtained over a range of diffusion times, from 5 ms to 1 s, the apparent radius of the diffusion barrier was estimated to be 3 +/- 1.1 micron assuming spherical geometry. Despite the high protein concentration in the intracellular space of the intact RBC, the intracellular values of Da were similar to the values obtained in the ghosts at the same diffusion times. We therefore conclude that the small diffusion coefficient of intracellular TFMH is mainly explained by the restricted diffusion due to the cell boundary.

Biological Transport↗

PubMed1995

Human interferon-beta therapy for cerebral primitive neuroectodermal tumors--two case reports.

A 5-year-old girl and a 2-year-old boy presented with recurrent cerebral primitive neuroectodermal tumor (PNET) and were treated with intravenous administration of human fibroblast interferon (HuIFN-beta) which was continued as outpatient maintenance therapy. Both patients showed a partial response and were still alive 14 months and 2 years after diagnosis. Our results suggest that HuIFN-beta is an effective therapy for PNET, and can be used as long-term maintenance therapy without serious side effects.

Brain↗

PubMed1995

High-resolution MRI of the human cochlea.

The majority of magnetic resonance imaging (MRI) studies in neurotology concern the evaluation of retrocochlear pathologies or temporal bone lesions. Recently, quite a number of investigators have attempted to use imaging diagnosis to obtain a diagnosis and manifest the pathological findings of Meniere's disease. However, there is no evidence that endolymphatic hydrops in patients with Meniere's disease can be identified by imaging techniques. In this study we could depict Reissner's membrane clearer than before with the use of image processing. At the present time, we cannot apply the 2.11T MRI machine to patients under FDA regulation. We believe that MRI diagnoses of endolymphatic hydrops and small lesions of the internal structures of the inner ear will be possible in the near future.

Adult↗

PubMed1995

[Evaluation of early colorectal cancer with submucosal invasion based on histological architecture].

To clarify the clinicopathological features of tumors with submucosal invasion, especially superficial elevated and sessile ones, histological architectures of 32 cases of submucosal invasive cancers were analyzed. They were classified into 3 types based on cross-section view: PG and NPG of Shimoda's classification and PG'. Histological architectures were drawn in accordance with these findings. In 7 PG-Ca which consisted of PG only, no apparent correlation was found between the tumor sizes and invasion depth of submucosal layer. However, 12 NPG-Ca which consisted of NPG only and 12 Mixed-Ca which include various cross-section views both showed massive invasion into the submucosa with 1 cm or more in tumor size. Therefore these two types were similar in biological behavior in terms of invasion depth. And degree of submucosal invasion tended to increase in the order of PG-Ca, Mixed-Ca and NPG-Ca. Examinating histological architectures of the Mixed-Ca tumors in details, all of these cancers were consisted of both PG and PG'. Of the 12 Mixed-Ca, 91.7% were proved to be PG dominant type. Macroscopically, I s and II a contained 88.9% and 40.0% of Mixed-Ca, respectively. In conclusion, these results suggest that PG' is a subtype of PG, and PG-Ca have a correlation between tumor invasion and alteration from PG to PG' in histological architectures among submucosal cancers. It is important to clarify morphological features of PG' in margin of I s and II a tumors in diagnosing the depth of early colorectal cancers.

Colon↗

PubMed1995

[Computed radiography in X-ray examination of stomach: evaluation by phantom experiments and clinical studies].

The usefulness and clinical applicability of computed radiography (FCR) in X-ray examination of the stomach were evaluated in comparison with film-screen (FS) radiography by both phantom experiments and clinical studies. Receiver operating characteristic (ROC) curve analysis consisting of 25 normal and 25 artificially created simulated lesions on an originally created Styrofoam phantom showed no difference in lesion detectability between FCR and FS radiography. Both were also equal in evaluation of the internal structure and margin of the 25 lesions by visual ranking. ROC curve analysis of clinical cases was performed in 30 cases, 20 normal and 10 abnormal, while evaluation by visual ranking was performed on 18 lesions. There was no significant difference between FCR and FS radiography either with ROC curve analysis or visual ranking, although the variations were somewhat greater in the clinical cases than in the phantom studies. I conclude that FCR is equal to FS radiography in X-ray examination of the stomach regarding both the detectability and visual conspicuity of the lesion. In view of the other advantages of FCR, it can safely replace conventional FS radiography in X-ray examination of the stomach.

Humans↗

PubMed1995

[Effects of separate administration of low-dose CDDP on antitumor immune reactivity for treatment of malignant glioma].

Recently, it has been reported that CDDP modifies the immune responses of tumor bearing hosts, but problem of the most appropriate treatment with CDDP to augment the host immunity remains unresolved. The purpose of this study was to determine the most advantageous administration of CDDP to increase both its cytotoxic effect and antitumor immune reactivity. Cell growth inhibition in vitro was assessed by MTT assay after treatment of U-251MG cells with various concentrations of CDDP for 24 or 120 hours. The results of this experiment showed that the growth of U-251MG cells in vitro was suppressed by CDDP in a dose-dependent as well as a time-dependent manner. Ten days after subcutaneous inoculation of human glioma cells, GL-9, in the rear flank of nude mice, they were assessed for growth suppression by CDDP. Totally, 20 ml/kg of CDDP was administered to each mouse; in one group (high-dose CDDP group), 5 ml/kg of CDDP on every fifth day, and in the other group (low-dose CDDP group), 2 ml/kg on every day. Measurement of the tumor volume in each group revealed no significant difference between the two groups in terms of the efficacy of tumor growth suppression. Twenty-one days after inoculation, we measured the splenic natural killer(NK) cell activity in each mouse. The results showed that NK cell activity was significantly increased in the low-dose cisplatin (2 ml/kg) group, and significantly decreased in the high-dose cisplatin (10 mg/ml) group, as compared to the control group. The results of our study suggest that the separate administration of low-dose CDDP is a useful treatment strategy for malignant glioma, because it increases the antitumor immune reactivity of hosts without decreasing the direct tumor cytotoxicity of CDDP.

Animals↗

PubMed1995

[Measurement of serum TSH receptor antibodies in thyroid patients using TRAb Dade kits].

TRAb Dade kit is a radioreceptor assay that detects autoantibodies in serum of patients with thyroid diseases which interfere with the binding of 125I labeled TSH to its receptor. In this paper we examined the basic and clinical usefulness of newly developed TRAb assay kits. The intra and inter assay coefficients of variation were 7.9% and 8.4%, respectively. There was no significant effect of temperature and incubation time on TRAb values. The influence of conjugated, unconjugated bilirubin, hemoglobin and turbidity was not so significant on TRAb values. TRAb values in serum of 68 untreated Graves' disease were above the normal range, but most (78%) treated Graves' patients who became euthyroid after receiving antithyroid drug, showed the normal range. In patients with chronic renal failure TRAb values were also within the normal range. A significant correlation (y = 1.0x-0.88, r = 0.95) was observed between this TRAb kit and TRAb Cosmic values in various thyroid conditions. This new assay for TRAb was simple, rapid and reproducible. The measurement of serum TRAb values was useful for the evaluation of physiological and pathological function and seemed to be helpful in the management of patients with thyroid disease.

Autoantibodies↗

PubMed1995

[Alexia-agraphia of kanji (Japanese morphogram) after left posterior-inferior temporal lesion].

Several cases of selective alexia with agraphia of kanji have been reported in Japan in this decade. It is well known that the lesion in the posterior inferior temporal lobe of the dominant hemisphere is responsible for this cognitive syndrome. Neuropsychological data in our patient suggest that the postero-inferior region of the temporal lobe of the dominant hemisphere may be the visuo-verbal association area for the analysis of the complex visuo-verbal information. The symptoms caused by the same lesion in western patients might be subangular alexia (alexia without agraphia). Alexia with agraphia of kanji and subangular alexia would appear to be distinct entities, but a dual processing hypothesis of visuo-verbal information and the concept of the visuo-verbal association area might well explain both syndromes.

Agraphia↗