Biomedical subjects

Y Okazaki

Publications and source records attributed to Y Okazaki.

At least 109 records · Page 6Linked to original sources

PubMed1998

Identification of stable RNA hairpins causing band compression in transcriptional sequencing and their elimination by use of inosine triphosphate.

To identify stable RNA secondary structure causing band compression, 30 lambda DNA clones and four cDNA clones (about 10 kb in total length) were sequenced using Transcriptional Sequencing, which is based on the phage RNA polymerase chain termination reaction with fluorescent 3' deoxynucleoside triphosphate, using the canonical set of rNTPs for the substrate. Electrophoresis was performed on acrylamide gel containing 7 M urea at 50 degrees C using ABI 377 DNA sequencer. A total of 159 band compressions were identified, and most compression sites seem to be due to hairpin structures. We also found that the presence of rITP in place of rGTP in the sequencing reaction can entirely eliminate all band compressions. The use of rITP gave a better peak uniformity and resolution in the sequencing gel in the case of lambda DNA than with c7rGTP, leading to improved accuracy in the sequence determination. Substitution of the base analog rITP for rGTP should be useful for accurate sequencing determination.

Bacteriophage lambda↗

PubMed1998

Penetration of cisplatin into mouse brain by lipopolysaccharide.

We investigated the penetration of cisplatin into the mouse cerebral cortex-rich region (CCR) induced by lipopolysaccharide (LPS). With the injection of cisplatin into mice 3 h after the LPS treatment, platinum was detected in the CCR during the 7 days after the injection, while platinum was not detected in the CCR of cisplatin-injected mice without LPS pretreatment and of mice simultaneous treated with cisplatin and LPS. The N(G)-nitro-L-arginine methyl ester dose-dependently lowered the platinum level. A dose of 5 mg/kg of aminoguanidine reduced the increase in the platinum level of the LPS-treated mouse, and platinum was no longer detected at doses of 20 mg/kg in the aminoguanidine-injected group. At doses of 500 mg/kg aminoguanidine, however, no effect was seen on the platinum level of the CCR induced by LPS. Regarding indomethacin, the injection of 5 mg/kg resulted in a decrease in the platinum content of the CCR, but not undetectable level. These results suggest that LPS increases the penetration of cisplatin into the mouse brain, and platinum may be accumulated in the CCR. Nitric oxide and prostaglandins contribute to the penetration of platinum into the cerebral cortex.

Animals↗

PubMed1998

Recognition sites of 3'-OH group by T7 RNA polymerase and its application to transcriptional sequencing.

When analyzing the elongation mechanisms in T7 RNA polymerase (T7 RNAP)by using site-directed mutagenesis and a protein expression system, we identified the recognition sites of the rNTP 3'-OH group in T7 RNAP. On the basis of three-dimensional crystal structure analysis, we selected and analyzed six candidate sites interacting with the 3'-OH group of rNTP in T7 RNAP. We found that the Phe-644 and Phe-667 sites are responsible for the high selectivity of T7 RNAP for rNTPs. Also, we constructed the protein mutations of these residues, F644Y and F667Y, which display a >200-fold higher affinity than the wild type for 3'-dNTPs. These findings indicate that the phenylalanine residues of 644 and 667 specifically interact with the 3'-OH group. Thus, these mutants, F644Y and F667Y, with incorporation of 3'-dNTP terminators, which is similar to native rNTPs, can offer low backgrounds and equal intensities of the sequencing ladders in our method, called "transcriptional sequencing. "

Amino Acid Sequence↗

PubMed1998

Experiences of 23 patients > or = 90 years of age treated with radiation therapy.

PURPOSE: To present 23 patients > or = 90 years old treated with radiotherapy, and to retrospectively evaluate the results of radiotherapy and tolerance in these patients. METHODS AND MATERIALS: The clinical records of 27 patients over 90 years of age who were treated with radiotherapy at the Department of Radiology, Shinshu University Hospital, and eight affiliated general hospitals from 1990 until 1995 were reviewed. The strategy of radiotherapy was individually planned depending on the stage of the disease and performance status (PS) of the patient; however, it was not modified, based solely on chronologic age. The overall survival rate and disease-free survival rate were determined using the Kaplan-Meier method. The Radiation Therapy Oncology Group scoring criteria of acute and late reactions of radiation therapy were used. RESULTS: This group of patients accounted for 0.37% of all patients treated with radiotherapy in these hospitals. Of these, 23 patients in whom cancer was pathologically confirmed and whose follow-up data were available for retrospective analysis were included in the final evaluation of data. The age of the 23 patients ranged from 90 to 96 years (median 93). Tumor was untreated and in the early stage in five patients, locoregionally advanced in 13, recurrent in four, and systemic in one. Definitive radiation therapy was administered in 12 patients (13 sites), preoperative intent in one, and palliative intent in 10. The period of observation ranged from 2.5 to 6 years (median 18 months). Seven patients were alive for 15-67 months. Fourteen patients died because of intercurrent diseases or senility associated with active cancer, and two because of senility without evidence of cancer. The overall and relapse-free survival rates were 65% and 30% at 1 year and 30% and 21% at 2 years, respectively. Definitive radiation therapy was completed in 13 of 13 patients (100%), and local control was attained in 9 of 13 patients at 6 months (62%). Palliative radiation therapy was completed as intended in 7 of 11 (64%), and effects of palliation were observed in 9 of 11 patients (81%). Acute dermatitis, mucositis, pharyngitis, esophagitis, and cystitis of grade 2-3 related to the definitive radiation therapy were tolerable for the patients with good PS. It took 3-7 weeks (median 5) for acute moist desquamation of six lesions of skin cancer to heal. Depending on the radiation doses, grade 1-2 atrophy of skin and telangiectasia were documented for eight patients followed up for more than 1 year. A brief description of representative case is presented. CONCLUSION: Patients older than 90 years with good PS may tolerate the acute effects of radiotherapy administered according to conventional fractionation schedules. Definitive radiation therapy should be considered, when applicable, even for patients older than 90 years.

Aged↗

PubMed1998

Metallothionein-mediated resistance to multiple drugs can be induced by several anticancer drugs in mice.

We examined the role of metallothionein in the chemosensitivity of transplanted tumors in mice. The antitumor activities of cisplatin, adriamycin, bleomycin, peplomycin, cyclophosphamide, and melphalan were significantly suppressed when the concentration of metallothionein in the tumor was increased to only twice the control level. On the other hand, the antitumor activities of mitomycin C, 5-fluorouracil, and vinblastine were hardly affected by increases in the concentration of metallothionein in the tumors in mice. Moreover, all the antitumor drugs examined increased the concentration of metallothionein in transplanted tumors to a level that was high enough to suppress the antitumor activity of these drugs. These observations suggest that treatment of patients with certain antitumor drugs might result in the resistance of their tumors to multiple drugs.

Animals↗

PubMed1998

Characterization of gene expression in mouse blastocyst using single-pass sequencing of 3995 clones.

To study the gene expression profile in the mouse blastocyst and to identify embryonic stage-specific genes, we randomly selected cDNAs derived from mouse blastocysts and sequenced a total of 3995 clones from one or both ends. Excluding the uninformative clones, 3395 clones were grouped as 937 different kinds of genes. Among these, 465 and 406 species showed similarity to known genes and expressed sequence tags (ESTs), respectively, whereas 66 species showed no significant similarity to any genes in known databases. Analysis of these cDNAs revealed that this library contained a variety of functional genes as well as genes that have not been detected in the human EST database; it should provide us with a useful resource for molecular analysis of developmental mechanisms. Although the human EST project is considered to represent roughly half of all genes, our findings indicate that many early stage developmental genes remain to be identified.

Animals↗

PubMed1998

Transcriptional sequencing: A method for DNA sequencing using RNA polymerase.

We have developed a sequencing method based on the RNA polymerase chain termination reaction with rhodamine dye attached to 3'-deoxynucleoside triphosphate (3'-dNTP). This method enables us to conduct a rapid isothermal sequencing reaction in <30 min, to reduce the amount of template required, and to do PCR direct sequencing without the elimination of primers and 2'-dNTP, which disturbs the Sanger sequencing reaction. An accurate and longer read length was made possible by newly designed four-color dye-3'-dNTPs and mutated RNA polymerase with an improved incorporation rate of 3'-dNTP. This method should be useful for large-scale sequencing in genome projects and clinical diagnosis.

DNA↗

PubMed1998

Thermostabilization and thermoactivation of thermolabile enzymes by trehalose and its application for the synthesis of full length cDNA.

The advent of thermostable enzymes has led to great advances in molecular biology, such as the development of PCR and ligase chain reaction. However, isolation of naturally thermostable enzymes has been restricted to those existing in thermophylic bacteria. Here, we show that the disaccharide trehalose enables enzymes to maintain their normal activity (thermostabilization) or even to increase activity at high temperatures (thermoactivation) at which they are normally inactive. We also demonstrate how enzyme thermoactivation can improve the reverse transcriptase, reaction. In fact, thermoactivated reverse transcriptase, which displays full activity even at 60 degrees C, was powerful enough to synthesize full length cDNA without the early termination usually induced by stable secondary structures of mRNA.

DNA, Complementary↗

PubMed1998

High accumulation of minerals in the human arteries of lower limb.

To elucidate accumulation of minerals in the human arteries, the relative contents (RCs) of minerals in the arteries of the upper and lower limbs were analyzed by inductively coupled plasma atomic emission spectrometry. It was found that the RCs of calcium and phosphorus in the femoral and popliteal arteries of the lower limb increased with aging, whereas those in the axillary and radial arteries of the upper limb did not increase with aging. This result indicates that higher accumulation of calcium and phosphorus occurs in the arteries of the lower limb with aging as compared with that in the arteries of the upper limb, and the prevalence of arteriosclerosis increases in the arteries of the lower limb with aging but not in the arteries of the upper limb.

Adult↗

PubMed1998

Effect of the lipid peroxide reaction caused by repeated cold stress on cisplatin-induced nephrotoxicity.

The peroxide reaction in mouse kidney was examined in order to determine the relationship between the lipid peroxide reaction caused by SART (specific alternation of rhythm in temperature) stress and that caused by drug administration. After exerting SART stress for one wk on 6-wk-old male ddY mice (stress group), the peroxide reaction generated by the administration of a single dose of cis-diamminedichloroplatinum (cisplatin: CDDP, 10 mg/kg, i.p.) into SART-stressed mice (stress + CDDP group) was compared with the reaction of CDDP-administered nonstressed mice (CDDP group), saline-administered nonstressed mice (saline group), and saline-administered SART-stressed mice (stress + saline group). Lipid peroxidation in the kidneys was significantly higher in the stress group upon cessation of stress exertion than in the normal group. However, no significant difference in the lipid peroxide level after administration of CDDP was observed between the CDDP groups. The renal glutathione levels were significantly different between the CDDP groups and the saline administered groups. These results indicate that the peroxide reaction is generated in the kidneys by stress, but stress has no effect on the peroxide damage caused by CDDP administration. However, the contribution of stress to renal function impairment requires further evaluation.

Animals↗

PubMed1998

Age-related changes of element contents in the human meniscus.

The relative contents (RCs) of elements in the human menisci from 23 subjects in the age range between 65 and 93 yr were analyzed by inductively coupled plasma atomic emission spectrometry. The RCs of sulfur, calcium, and phosphorus in menisci increased progressively until the 80s, being the highest in the 80s, and thereafter decreased. The RCs of magnesium in menisci increased progressively until the 90s. Regarding the medial and lateral menisci, higher RCs of magnesium and iron, and a lower RC of phosphorus were found in lateral menisci in comparison with those in medial menisci. There were sexual differences in the RCs of calcium and phosphorus of medial and lateral menisci. The RCs of calcium and phosphorus were about 50% higher in women's menisci than in men's. Histological examinations showed that structureless mucoid masses were observed in the menisci, with very high RCs of calcium and phosphorus being detected.

Aged↗

PubMed1998

Age-related changes of mineral contents in the human aorta and internal thoracic artery.

To elucidate accumulations of minerals in the human aorta and internal thoracic artery, their relative contents (RCs) of minerals were analyzed by inductively coupled plasma atomic emission spectrometry. Aortas from 47 men and 24 women subjects were examined. The ages of these subjects ranged from newborn to 99 yr. After the age of 40 yr, RCs of calcium and phosphorus began to increase, and thereafter increased stepwise in the 50s and 70s. In the 70s, their accumulations were markedly increased. Internal thoracic arteries from 16 men and 7 women subjects were examined. These subjects ranged in age from 65-93 yr. It was found that all the RCs of calcium were low, <5.0 mg/g dry wt, and there was no age-dependent increase of calcium contents in internal thoracic arteries.

Adolescent↗

PubMed1998

Effect of monoclonal anti-human gp130 antibody (GPX7) on bone turnover in normal and ovariectomized rats.

We examined the effects of a monoclonal antihuman gp130 antibody (GPX7), which is known to inhibit interleukin-6 (IL-6) and leukemia inhibitory factor-mediated responses in human cells on the bone metabolism in normal and ovariectomized (OVX), 7-month-old, Wistar rats for 8 weeks. After confirming the cross-reactivity of the antibody in suppressing the IL-6-mediated proliferation of rat liver cells, GPX7 was injected once a week at doses of 1 (low dose) or 4 (high dose) mg/kg body weight (BW). In the lumbar body, bone mineral density values and the trabecular bone volume (BV/TV) were maintained in the GPX7 groups. The values of the trabecular osteoclast surface and number in the GPX7 high-dose group were significantly smaller than those in the OVX controls. The double-labeled surface and bone formation rates in the GPX7 high-dose group were significantly increased. In the proximal tibia, however, the bone mineral content and BV/ TV values in the GPX7 groups were smaller, but the trabecular thickness value in the GPX7 high-dose group was larger than in the OVX control. The single-labeled surface in the GPX7 high-dose group was significantly larger than that in the OVX control rats. Though the parameter values of trabecular osteoclasts were apparently smaller, the differences were not significant. 17-beta estradiol (0.125 mg/kg BW a week) administration prevented the bone loss by reducing the parameters of bone formation and resorption in both the lumbar and the proximal tibia. The antibody administration to the normal rats did not cause any significant changes in the parameters of bone mass and turnover. These data demonstrate that while GPX7 modulates the bone turnover after ovariectomy in rats, it does not compensate for the action of estrogen after ovariectomy in rats.

Alkaline Phosphatase↗

PubMed1998

An automatic image analysis system for RLGS films.

The RLGS (Restriction Landmark Genome Scanning) method was originally developed as a powerful method for enabling viewing of thousands of restriction landmarks. It offers a tool for obtaining information about genetic loci, with a single RLGS profile displaying approximately 2000 restriction landmarks as spots. One of the most useful applications is RLGS spot mapping, which allows the efficient, low-cost construction of the genetic map of any organism. However, analyses of the profiles depend mainly on human visual observation and are tedious and laborious. Although several commercially available image analyzing systems for profile comparison have been examined, they cannot be used for the RLGS spot mapping system owing to the background characteristics of the RLGS profiles, unsatisfactory rates of correspondence, and inefficient correction of informative genetic data. We therefore developed a novel automatic image analysis system for RLGS spot mapping, using an original algorithm based on the binary image transferred from the original RLGS profile. This system was employed for identifying non-polymorphic and parental strain-specific polymorphic spots of the F1 mouse profile and yielded efficient initial screening of RLGS profiles.

Animals↗

PubMed1998

Genetic profile of the SMXA recombinant inbred mouse strains revealed with restriction landmark genomic scanning.

We have applied the restriction landmark genomic scanning (RLGS) method to the SMXA recombinant inbred (RI) mouse strain set to reveal its detailed genetic profile. A total of 663 polymorphic RLGS spot loci were identified, 576 of which were assigned to chromosomes. Strain distribution patterns (SDPs) at 55 microsatellite marker loci were also obtained. As a result, the total number of loci with distinct SDPs on chromosomes increased to 400. These loci were dispersed on all chromosomes, except for the Chromosome (Chr) Y, and effectively covered the genome with an average spacing of 4 cM. The SMXA RI strain set, hereby, would be of value for genetic study.

Animals↗

PubMed1998

Dimensions of schizophrenic positive symptoms: an exploratory factor analysis investigation.

Current psychopathology classifies schizophrenic positive symptoms into four groups: delusions, hallucinations, formal thought disorder, and catatonic symptoms. The present study explores the factor structure of different positive symptoms to refine this classification. The 35 positive symptoms of 429 psychiatric patients, consecutively admitted to any of 95 mental hospitals, with diagnosis of the ICD-10 F20 schizophrenia, were studied. After excluding those items with a base rate of 10% or less, factor analysis yielded six factors. The first factor was loaded by most of Schneider's first-rank symptoms and two specific auditory hallucinations; the second by all the catatonic symptoms and incoherence; the third by bodily delusions/hallucinations; the fourth by delusions of persecution and reference; the fifth by grandiose and religious delusions; and the sixth by visual and miscellaneous hallucinations. The finding that schizophrenic positive symptoms may have more than four dimensions suggests the need for reclassification of schizophrenic symptoms and for reconsideration of evidence-based diagnostic criteria for the disorder.

Adolescent↗

PubMed1998

Metastatic malignant meningioma of the liver with hypoglycemia: report of a case.

We herein present the case of a 68-year-old male who suffered an episode of hypoglycemic shock 2 years after undergoing total removal of a bifrontal parasagittal malignant meningioma. Imaging studies revealed three giant hypervascular tumors with a cystic portion in the right lobe, but no confirmed preoperative diagnosis could be made. At laparotomy, liver tumors were found in the medial segment of the left lobe as well as in the right lobe, and thus an extended right lobectomy was performed. All the resected tumors were histologically diagnosed as metastatic malignant meningiomas of the liver. Despite subsequent transarterial chemoembolization for a recurrence in the residual liver, the patient died 11 months after surgery. To the best of our knowledge, only one other case of a hepatectomy for liver metastases from an intracranial malignant meningioma has been reported in the literature, but there has never been any report of surgical treatment for a metastatic meningeal tumor in the liver associated with hypoglycemia. Although our surgical treatment provided effective palliation, the prognostic significance of a surgical strategy for such patients has yet to be established.

Aged↗

PubMed1998

Anticipation in Japanese families with schizophrenia.

The identification of anticipation in schizophrenia is a recent focus in the genetic epidemiology of schizophrenia, although it involves some controversial methodological issues. We explored the evidence of anticipation among 44 Japanese two-generation pairs with schizophrenia found by reviewing nine years of admission records (1986-1994) at the Department of Neuropsychiatry, Nagasaki University Hospital and Michino-o Hospital, Nagasaki. The 44 pairs consisted of 27 two-generation pairs of first-degree relatives group (FDRG) and 17 pairs of second-degree relatives group (SDRG). On pairwise comparison and a life table analysis, the age at onset (AO) was significantly earlier in the lower generation (G2) than in the upper generation (G1) in all of the pairs and in the two subgroups, FDRG and SDRG. Earlier AO was shown in G2 even after minimizing some statistical biases for the study of anticipation in schizophrenia. A significant earlier mean AO was found in G2 even when a cohort effect was controlled for. There was no marked difference in AO between paternal and maternal transmission. These results provide further evidence for epidemiological anticipation, suggesting biological anticipation such as the involvement of trinucleotide repeats expansion in G2. The limitations of the study are also discussed.

Adolescent↗