Biomedical subjects

T Saika

Publications and source records attributed to T Saika.

At least 73 records · Page 4Linked to original sources

PubMed1994

Differential regulation of phospholipase C isozymes in the rat facial nucleus following axotomy.

The expression of phospholipase C isozymes and phosphatidylinositol 4-kinase in the rat facial nucleus was studied using in situ hybridization at various times after unilateral crushing and resectioning the facial nerve. The level of phospholipase C alpha messenger RNA increased from three days to one week after the operation. On the other hand, an apparent reduction in the level of phospholipase C beta 1 occurred from three days to one week after resection. After either crushing or resection, phospholipase C gamma 1 messenger RNA levels were not noticeably changed. As phosphatidylinositol 4-kinase is the rate-limiting enzyme for the production of phosphatidylinositol 4,5-bisphosphate, which is the preferred substrate for phospholipase C, we investigated the expression of phosphatidylinositol 4-kinase messenger RNA. The level of phosphatidylinositol 4-kinase messenger RNA was decreased one day after axonal injury. Among phospholipase C isozymes, phospholipase C alpha is up-regulated. As the structure of phospholipase C alpha is different from other isozymes, phospholipase C alpha is supposed to have a different function. The present unique up-regulation of phospholipase C alpha may suggest a novel function in nerve regeneration. Phospholipase C beta 1 is down-regulated, as is phosphatidylinositol 4-kinase. This suggests that the signal transmission system using a G-linked receptor is broken down after nerve injury. On the other hand, phospholipase C gamma 1, which is related to the receptor tyrosine kinase, does not demonstrate any transcriptional regulation after nerve injury.

1-Phosphatidylinositol 4-Kinase↗

PubMed1994

Over-expression of metallothionein and drug-resistance in bladder cancer.

Metallothionein (MT) in tumor cells has been implicated as one of the factors involved in mechanisms of resistance to anti-cancer drugs, including cis-diaminedichroloplatinum (CDDP) and adriamycin (ADM). The relationship between the expression of MT and chemotherapy with anti-cancer drugs was studied in CDDP- and ADM-resistant human bladder cancer cell lines and tissue samples from clinical cases. In drug-resistant cell lines (T-24/ADM, CI-7/CDDP) established in our laboratory, MT expression was studied by immunohistochemistry using the avidin-biotin peroxidase complex (ABC) method and radioimmunoassay (RIA), using anti-MT antibody. In addition, other potential mechanisms of drug resistance, such as P-glycoprotein expression were examined and the levels of reduced glutathione (GSH), oxidized glutathione (GSSG) and glutathione-S-transferase (GST) determined in these cell lines. The results of these investigations demonstrate that the expression of MT in resistant cell lines increased 2.1- and 2.5-fold when compared with parent cell lines (CI-7, T-24). GSH, GSSG and GST levels were unchanged and P-glycoprotein was not over-expressed. A total of 120 tissue samples from 35 clinical cases of bladder cancer, before and after chemotherapy, were stained for MT which was detected in 10 of the 35 cases before chemotherapy. The incidence of MT expression was significantly higher (p < 0.05) in cases with lower pathological tumor grades.(ABSTRACT TRUNCATED AT 250 WORDS)

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1994

[Influential clinical and pathological factors on prognosis of renal cell carcinoma].

The clinical, pathological and survival data were analyzed for 42 patients with nephrectomy for renal cell carcinoma, who visited our department between 1987 and 1992. The factors influencing prognosis were evaluated. There were 33 males and 9 females with an average age of 59.1 years old. Forty-five percent (19 patients) of the cases were detected incidentally. These incidental cases showed a higher survival rate than the cases with symptoms although the difference was not statistically significant. Positive acute phase reactant, clinical stage, grade and type of infiltration were to be considerably predictive factors indicating poor prognosis. Embolization of renal artery for neo -adjuvant therapy could not improve the survival rate. Interferon-alpha for adjuvant therapy did not prolong the survival team clearly.

Acute-Phase Proteins↗

PubMed1993

Preferential repression of the H subunit of ferritin by adenovirus E1A in NIH-3T3 mouse fibroblasts.

Ferritin is the major intracellular iron-storage protein in eucaryotic cells and plays a prominent role in maintaining intracellular iron homeostasis. We observed that transfection of NIH-3T3 mouse fibroblasts with the adenovirus E1A oncogene specifically repressed the mRNA for one of the subunits of ferritin, ferritin H. This occurred in the absence of any effect of E1A on the mRNA for the L subunit of ferritin. The repression of ferritin H was not a general feature of oncogene expression since transfection of NIH-3T3 cells with H-ras did not affect ferritin composition. Deletion of the conserved regions of E1A responsible for immortalization and transcriptional repression impaired the ability of E1A to repress ferritin H. Immunoprecipitation of ferritin in E1A transfectants demonstrated that the decrease in the ferritin H/L ratio observed at the mRNA level was also exhibited at the protein level. The E1A-dependent inhibition of ferritin H was also observed in a chimeric gene containing the ferritin H promoter ligated to the chloramphenicol acetyltransferase reporter gene, but was not observed in control genes in which chloramphenicol acetyltransferase activity was dependent on promoters derived from SV40 or the interleukin-3 gene. This suggests that E1A may repress ferritin H at the transcriptional level. These results demonstrate that the adenovirus E1A oncogene specifically modulates ferritin H expression. They also suggest that alterations in cellular iron metabolism may be among the diverse array of cellular responses induced by E1A.

3T3 Cells↗

PubMed1993

Autoradiographic localization of somatostatin mRNA in the adult rat lower brainstem: observation by the double illumination technique.

Using in situ hybridization histochemistry and observation with a double (dark and bright) illumination apparatus, the precise localization of preprosomatostatin mRNA was studied in the adult rat lower brainstem and cerebellum. It has previously been hard to localize the somatostatin precursor gene in the adult rat brainstem, because the level of expression is low or undetectable in some brain areas in adulthood, in contrast to the high levels in the neonatal period. The present study in adult rats showed the clear localization of this mRNA in the same areas where it is found in the perinatal period. The results showed that somatostatin neurons in such areas continue the minimal production of the precursor gene even at the adult stage.

Animals↗

PubMed1993

Expression of muscarinic and nicotinic receptor mRNA in the salivary gland of rats: a study by in situ hybridization histochemistry.

Expression of muscarinic receptor mRNA subtypes (m1-5) and nicotinic receptor subunits (alpha 2-4, and beta 2) was examined in the rat submandibular gland by in situ hybridization histochemistry, using oligonucleotide probes for the muscarinic receptor and RNA probes for the nicotinic receptors. m2, alpha 3, and beta 2 mRNA were strongly expressed in the submandibular ganglion, and m3, alpha 2, alpha 3, alpha 4, and beta 2 were expressed in the striated and interlobular duct cells. Both muscarinic and nicotinic receptors were coexpressed in the same ganglion neurons, while none of these mRNA were detected in the terminal secretory units.

Animals↗

PubMed1993

Changes in preproenkephalin mRNA after unilateral and bilateral labyrinthectomy in the rat medial vestibular nucleus.

We examined the expression of preproenkephalin (PPE) mRNA in the vestibular nuclei in rats using in situ hybridization histochemistry. In normal rats, PPE mRNA-positive cells were observed in the medial and spinal vestibular nuclei. After unilateral labyrinthectomy, PPE mRNA was increased in the medial vestibular nucleus on the operated side from the 1st through the 3rd day after the surgery. It is suggested that the changes in PPE mRNA level after labyrinthectomy are involved in vestibular compensation.

Animals↗

PubMed1993

GAP-43 mRNA expression in facial motoneurons during regeneration: in situ hybridization histochemistry study using an alkaline phosphatase-labelled probe.

By means of in situ hybridization histochemistry using an alkaline phosphatase-labelled probe, we found an increase of mRNA for the growth-associated protein GAP-43 in rat facial motoneurons following axotomy of the facial nerve. After nerve resection, the increased level of GAP-43 mRNA was maintained for at least 8 weeks, while it returned to almost undetectable levels by 8 weeks after nerve crush injury. Thus, expression of GAP-43 mRNA in motor neurons paralleled the process of axonal regeneration. However, the increase of GAP-43 mRNA after resection was more pronounced than after crushing, in this way being different from the pattern of low-affinity nerve growth factor receptor mRNA expression.

Alkaline Phosphatase↗

PubMed1993

[Tissue concentration of intravesically instilled (2"R)-4'-o-tetrahydropyranyl-adriamycin or adriamycin in superficial bladder cancer].

Twenty-one patients with superficial bladder cancer entered an analysis of single dose (2'R)-4'-O-tetrahydropyranyladriamycin (THP) or adriamycin (ADM) administration. The patients in each group that have been or not have been treated previously with anti-cancer drugs were randomized into two groups, one was given THP and the other ADM. Thirty-mg of THP or ADM dissolved in 30 ml of physiologic saline was instilled into the bladder, and retained for 1 hour. After 1 hour retention of the drugs, tumor tissues and normal mucosas were removed by punch biopsy forceps transurethrally. The tissue concentrations of THP and ADM were estimated by high performance liquid chromatography. The tissue concentrations of THP and ADM in the tumors were significantly greater (p < 0.05) than those in the normal bladder mucosas. The tissue concentration of THP in the tumors were greater than that of ADM. The tissue concentrations of THP and ADM in the tumor of patients who have been treated with anti-cancer drugs previously were less than those of patients who have not. This results demonstrated that prior therapy with anti-cancer drug may cause a resistance for intravesical instillation chemotherapy. However in patients with prior therapy, the tissue concentration of THP in the tumors were greater than that of ADM. Based on these findings, THP has been shown to be were effective as an intravesical instillating agent especially, in cases with prior chemotherapy.

Administration, Intravesical↗

PubMed1992

[Prophylactic intravesical instillation therapy in patients with superficial bladder cancer--results of a randomized prospective study].

A randomized prospective study was conducted for the purpose of investigating the efficacy of intravesical chemoprophylaxis of superficial bladder cancers. Eligible patients were randomized into three groups: 1) adriamycin (ADM) group; intravesical instillation with 50 mg of ADM dissolved in 100 ml physiological saline, 2) mitomycin C (MMC) group; intravesical instillation with 30 mg of MMC dissolved in 100 ml of physiological saline, 3) control group; transurethral resection or transurethral coagulation only. The characteristic features of our protocol consisted of frequent (six times) instillations of the drugs within two weeks after transurethral resection, followed by instillations on two consecutive days at four-week intervals for two years. Furthermore, large quantities (100 ml) of instillation fluid containing relatively low concentrations of the drugs (500 micrograms/ml for ADM or 300 micrograms/ml for MMC) were employed. One hundred and forty-four patients have been submitted to the study; 110 patients were fully evaluable for recurrence and 34 patients were eliminated as non-evaluable patients. The cumulative five-year non-recurrence rates of the patients with multiple tumors were 32% in the MMC group, 25% in the ADM group and 7% in the control group. The cumulative non-recurrence rates of the ADM and MMC groups were significantly higher than that of the control group. It is considered that this instillation therapy with ADM and MMC is useful for preventing the recurrence of superficial bladder cancers.

Administration, Intravesical↗

PubMed1992

[Histopathological study of metallothionein in bladder cancer and renal cell carcinoma].

Metallothionein (MT) is a low molecular-metal binding protein with multiple biological functions. Recently, MT has been implicated as a factor involved in resistance to anticancer drugs, which presumably inactivates anticancer drugs, including cisplatin, and doxorubicin. In this report, we investigated the relationship of MT expression with the clinical features in bladder cancer and renal cell carcinoma. In 35 cases of bladder cancer, 10 cases of renal cell carcinoma and 3 cases of normal mucosa of bladder, the expression of MT was immunohistologically examined by avidinebiotin-peroxidase (ABC) staining of paraffin-embedded tissue specimens with anti-MT antibody. Intense MT expression was noted in all cases of normal mucosa of bladder. MT was detected in 10 of 35 cases of bladder cancer, with the incidence of MT expression being significantly higher increases with lower pathological tumor grade. MT was detected in 8 of 10 cases of renal cell carcinoma, and all of the their normal renal tubules showed more intense staining. A number of hypotheses can be proposed from these observations. First, our observation of decreased MT expression in poorly differentiated carcinomas, which are the more proliferating tumors, this suggests correlation of MT expression with proliferative status of cancer. Second, the higher incidence of MT expression in renal cell carcinoma than in bladder cancer may suggest that it is a factor responsible for the lower efficacy of chemo-therapy in renal cell carcinoma than in bladder cancer.

Aged↗

PubMed1992

[Immunological study of induction of metallothionein in bladder cancers].

Metallothionein (MT) in tumor cell has been indicated as one of the factors involved in the mechanism of resistance to anticancer drugs. The relationship between expression of MT and chemotherapy with anticancer drugs was studied with bladder cancer culture cell lines and tissue samples from clinical cases. In drug-resistance cell lines, MT expression was studied by immunohistological staining of the avidin -biotin peroxidase complex (ABC) method, and by the radioimmunoassay (RIA) method, using an anti-MT antibody. As for tissue samples from clinical cases, 114 paraffin embedded samples of 29 cases before and after chemotherapy were subjected to immunohistological staining of MT. Human-bladder cancer cell lines with resistance to anticancer drugs (C1-7/CDDP, T-24/ADM) showed increased of expression of MT compared to each parental cell lines (C1-7, T-24), suggesting relationship of resistance to anticancer drugs and MT expression. In the clinical cases, those with continuous administration such as intra-vesicle chemotherapy or oral administration chemotherapy showed greater incidence of positive staining of MT expression in comparison with cases with fewer administrations, such as intra-arterial infusion therapy or intravenous administration chemotherapy. These results demonstrated that repetitive and continuous administration of anticancer drugs cause increase of MT in bladder cancer cell, which may be a possible mechanism of acquired resistance to anticancer drugs.

Adult↗

PubMed1991

Postnatal ontogeny of cells expressing prepro-neurotensin/neuromedin N mRNA in the rat forebrain and midbrain: a hybridization histochemical study involving isotope-labeled and enzyme-labeled probes.

The postnatal ontogeny of cells expressing prepro-neurotensin/neuromedin N messenger RNA (prepro-NT/NN mRNA) in the rat forebrain and midbrain was investigated by in situ hybridization histochemistry. According to the pattern of expression during development, the cells which express prepro-NT/NN mRNA can be roughly divided into 2 groups. In type I cells, prepro-NT/NN mRNA expression reaches a maximum in terms of content during the postnatal period. After this early peak, cells of this type express the same or less prepro-NT/NN mRNA, reaching a plateau at an adult level that still contains a high level of expression. In type II cells, prepro-NT/NN mRNA appears during the postnatal period, and the expression decreases dramatically after the first postnatal week, being almost undetectable by a few weeks after birth. Type I cells were observed in the following areas: the piriform cortex, field CA1 of Ammon's horn, subiculum, vertical, and horizontal limbs of the diagonal band of Broca, intermediate part of the lateral septal nucleus, bed nucleus of the stria terminalis, medial preoptic area, lateral hypothalamus, caudal part of the caudate putamen, medial, cortical, and central amygdaloid nuclei, ventral tegmental area, deep mesencephalic nucleus, cuneiform nucleus, dorsal raphe nucleus, laterodorsal tegmental nucleus, parabrachial nucleus, and oral part of the pontine reticular nucleus. Cells of type II were observed in the following areas: the mitral cell layer of the olfactory bulb, rostral part of the caudate putamen, (anterior) cingulate cortex, and retrosplenial cortex (posterior cingulate cortex).

Aging↗

PubMed1991

Localization and ontogeny of cells expressing preprodynorphin mRNA in the rat cerebral cortex.

The regional distribution of preprodynorphin (PPD) mRNA-containing cells (PPD cells) in the rat cerebral cortex was investigated by in situ hybridization histochemistry using a synthetic oligonucleotide probe. In the isocortex, PPD cells were small or medium-sized and were mainly located in layer V. While they were less numerous in the allocortex than in the isocortex. Only a few labeled cells were seen in the piriform and entorhinal cortices. In the hippocampal formation, labeled cells were observed in the granular layer of the dentate gyrus. An ontogenetic study revealed that PPD mRNA-containing cells appeared on postnatal day 7 in the isocortex and the allocortex and on day 14 in the dentate gyrus. Thereafter, they increased in number and signal intensity to reach a plateau on postnatal day 14 in both the isocortex and the allocortex and on day 35 in the dentate gyrus. The time-course of development of PPD mRNA-containing neurons in the cerebral cortex suggested that PPD-derived peptide has a neuromodulator and/or neurotransmitter role in these regions of the brain.

Animals↗

PubMed1991

Changes in expression of peptides in rat facial motoneurons after facial nerve crushing and resection.

In situ hybridization histochemistry was used to study changes in mRNAs coding neuropeptides such as alpha-calcitonin gene-related peptide (CGRP), beta-CGRP, cholecystokinin (CCK) and galanin, in rat facial motoneurons following axotomy of the facial nerve. In control rats, 38%, 55% and 7% of the facial motoneurons expressed alpha-CGRP, beta-CGRP and CCK mRNAs, respectively. No galanin mRNA-containing motoneurons were observed in these animals. The levels of mRNA for alpha-CGRP, CCK and galanin were increased while the beta-CGRP mRNA level was decreased after axotomy. The levels of mRNAs for these peptides returned to the control values by 2-4 weeks after nerve crush, whereas nerve resection had more prolonged effects. Within 3-4 weeks after injury, nerve resection had greater effects on beta-CGRP, CCK and galanin mRNAs than did nerve crush. Thus, there appear to be differences in the regulation of mRNA expression of these peptides in axotomized motoneurons.

Animals↗

PubMed1991

Effects of nerve crush and transection on mRNA levels for nerve growth factor receptor in the rat facial motoneurons.

We found that the level of nerve growth factor receptor (NGF-R) mRNA in facial motoneurons was increased after both facial nerve crushing and transection by means of in situ hybridization histochemistry. The increased level of NGF-R mRNA was maintained for at least 8 weeks after facial nerve transection, while facial nerve crushing caused only a transient increase. Thus, expression of NGF-R mRNA paralleled the axonal regeneration process. In addition, the increase of NGF-R mRNA with crushing was more pronounced than with transection from the 3rd to the 14th day after the insult.

Animals↗

PubMed1991

Localization of glycine receptor alpha 1 subunit mRNA-containing neurons in the rat brain: an analysis using in situ hybridization histochemistry.

The localization of glycine receptors in the rat brain was examined by means of in situ hybridization histochemistry using an oligonucleotide probe to the sequence of the alpha 1 subunit. Strongly- or moderately-labeled neurons were found in the cranial nuclei, sensory nuclei such as the spinal trigeminal nucleus, principal trigeminal nucleus, gracile and cuneate nuclei, dorsal and ventral cochlear nuclei, superior olivary nucleus, medial and lateral trapezoid nuclei, lateral lemniscus and vestibular nuclei, red nucleus, parabrachial area, cerebellar nuclei, dorsal tegmental nucleus, reticular formation and parafascicular nucleus. This study thus demonstrated the localization of neurons which are regulated by glycine via strychnine-sensitive glycine receptors in the rat brain.

Animals↗

PubMed1991

Analysis of saccadic eye movements using an infrared video system in human subjects.

Horizontal and vertical saccades were recorded and quantitatively analyzed with an infrared video recording system in 6 normal human subjects. Peak and mean saccade velocities increased exponentially as the amplitude increased. Peak velocity of horizontal saccade was significantly larger than that of vertical saccade (p less than 0.05, ANOVA test). On the other hand, duration and latency showed a linear relationship with saccade amplitude. Latency was constant (i.e. 0.21 s) irrespective of saccade amplitude in the regular eye tracking mode; however, latency slightly increased as the amplitude became larger in the randomized eye tracking mode. As a result, a slight positive correlation could be found between saccade amplitude and latency: r = 0.50 and 0.35 in horizontal and vertical saccades, respectively.

Adult↗