EEG-EMG coherence changes in postural tasks.

PURPOSE: Recent studies have investigated the possible function of synchronous oscillatory activity within the sensorimotor cortex of monkeys and humans that is thought to arise from synchronous discharge of large numbers of cortical neurons. There has been found clear task-dependent changes in 15-30 Hz oscillations. In leg muscles, coherence also occurs in the same frequency band during voluntary static contraction. Therefore we investigated changes in coherence in leg muscles during several postural tasks. METHODS: We examined the coherence between EEGs and soleus EMGs during voluntary contraction and in various postural tasks. RESULTS: There was a significant coherence during voluntary static contraction, but not during standing, forward bending, or standing on one foot; whereas, there was significant coherence during stamping the ground. CONCLUSION: These results suggest that the coherence at 15-30 Hz originates from the motor cortex during voluntary contraction, not when doing postural tasks. Coherence analysis indicates that during postural tasks the motor cortex would not produce the synchronous discharge of large numbers of cortical neurons or might not induce soleus EMG activity.

Increased expression of cyclooxygenase-2 protein in 4-nitroquinoline-1-oxide-induced rat tongue carcinomas and chemopreventive efficacy of a specific inhibitor, nimesulide.

Expression of cyclooxygenase (COX)-2 protein in 4-nitroquinoline-1-oxide (4-NQO)-induced rat tongue lesions and the postinitiation chemopreventive potential of a selective COX-2 inhibitor, nimesulide (NIM), were examined in Fischer 344 male rats. NIM was administered in the diet at doses of 150, 300, and 600 ppm for 14 weeks after treatment with 25-35 ppm 4-NQO in the drinking water for 12 weeks. Western blot analysis revealed COX-2 protein to be barely expressed in the normal tongue epithelia, whereas it was increased approximately 6-fold in squamous cell carcinomas (SCCs). Immunohistochemically, COX-2 protein was diffusely present in SCCs and dysplasia but expressed only in basal cells in hyperplasia and papillomas. In basal cells of normal epithelia, it was also occasionally weakly stained. NIM dose-dependently decreased at doses of 150 and 300 ppm, the incidences of SCCs to 4 of 12 (33.3%) and 1 of 13 (7.7%) and their multiplicity to 0.33+/-0.49 and 0.08+/-0.28 per rat, respectively, as compared with 4-NQO alone group values of 9 of 11 (81.8%) and 1.00+/-0.77. A lesser decrease was observed with 600 ppm, the values being 5 of 12 (41.7%) and 0.50+/-0.67. NIM did not significantly affect the development of hyperplasias, dysplasias, and papillomas. These results clearly indicate chemopreventive potential of a selective COX-2 inhibitor against the postinitiation development of SCCs in rat tongue carcinogenesis.

Reversible changes in the composition of the population of mtDNAs during dedifferentiation and regeneration in tobacco.

Differences in the composition of the population of mtDNAs between green plants and calli of tobacco were detected by DNA filter hybridization analysis. The altered composition of the population of mtDNAs observed in calli returned to the composition typical of green plants during the process of regeneration. Quantitative assays revealed that the changes were associated with the differentiation and dedifferentiation of cells since the extent of the change in composition depended on the degree of differentiation of a population of cells. The sequence that accumulated in dedifferentiated cells was shown to be a product of recombination mediated by a 9-nucleotide repeated element, one of which is located at the 5' region of atp6. Although the recombinant sequence was not detected by a hybridization procedure in green plants, its presence was identified by a more sensitive polymerase chain reaction method. The recombination event was shown to result in a deletion that prevents reverse recombination. Therefore, the reversion from the altered composition to the normal state of the population of mtDNAs during regeneration is explained not by recombination but by the preferential amplification of subgenomic mtDNA molecules.

Molecular and cellular characterizations of a cDNA clone encoding a novel isozyme of aldehyde dehydrogenase from rice.

Aldehyde dehydrogenases (ALDHs) are a group of enzymes catalyzing the conversion of aldehydes to the corresponding acids. In mammals and yeasts, at least two isozymes of ALDH are known to be involved in ethanol metabolism (cytosolic ALDH1 and mitochondrial ALDH2). Although mitochondrial ALDH isozymes have previously been identified in several plants, such as maize and tobacco, it is unclear whether cytosolic ALDH isozymes also exist in plants. In this study, we identified and characterized a cDNA clone encoding aldehyde dehydrogenase (ALDH1a) from rice (Oryza sativa L. cv. Nipponbare). The open reading frame of this clone did not contain a typical mitochondrial targeting signal. Analysis of the subcellular localization of ALDH1a using green fluorescent protein (GFP) suggested that ALDH1a is a cytosolic enzyme rather than a mitochondrial enzyme. A genomic Southern hybridization indicated that sequences homologous to the ALDH1a gene are present in at least two regions of the rice genome. Amplification by RT-PCR showed that ALDH1a is expressed strongly in roots, but not in leaves, of rice seedlings, suggesting that ALDH1a functions in roots.

Characterization and expression of the genes for cytochrome c oxidase subunit VIb (COX6b) from rice and Arabidopsis thaliana.

Many of the subunits of cytochrome c oxidase (COX) in the mitochondria of higher plants are encoded by nuclear genes. These genes are less characterized compared to mitochondrial-encoded genes. We previously isolated a cDNA encoding COX6b (designated OsCOX6b1 in this study) from the rice nuclear genome and analyzed its expression. The deduced protein had an extended N-terminus compared with human and yeast COX6b proteins. In this study, we identified another COX6b gene (OsCOX6b2) in rice and revealed that it was actually expressed. The deduced protein of this gene did not have an extended N-terminus and had about the same size as the human and yeast proteins. Genomic Southern hybridization analysis revealed that there was at least one OsCOX6b-homologus sequences in the rice genome other than OsCOX6b1 and OsCOX6b2. Furthermore, we identified three COX6b genes in a dicotyledonous plant, Arabidopsis thaliana. One of these genes (AtCOX6b1) was relatively long, with a length similar to that of OsCOX6b1, and the other two (AtCOX6b2 and AtCOX6b3) were shorter, with lengths similar to the length of OsCOX6b2. Genomic Southern hybridization analysis indicated there were no additional COX6b genes in the Arabidopsis genome. The coding regions of OsCOX6b1 and AtCOX6b1 were separated by four introns and those of OsCOX6b2, AtCOX6b2 and AtCOX6b3 were separated by three introns. A Northern hybridization analysis showed that OsCOX6b1, AtCOX6b1 and AtCOX6b3 were expressed in all organs examined, although with some differences in the amount of expression among the organs. OsCOX6b2 and AtCOX6b2 were strongly expressed in roots but most of the transcripts of AtCOX6b2 were degraded. The evolution of COX6b genes from rice and Arabidopsis is discussed.

Transcript levels of tandem-arranged alternative oxidase genes in rice are increased by low temperature.

We identified two genes for alternative oxidase (AOX) from rice. One AOX gene (designated AOX1a) is located approx. 1.9 kb downstream of another AOX gene (designated AOX1b). Comparison of the genomic and cDNA sequences of the two AOX genes showed that the AOX1a gene is interrupted by three introns, as are AOX genes of other plants. On the other hand, two introns are inserted in the AOX1b gene. The predicted AOX1a and AOX1b precursor proteins consist of 332 and 335 amino acid residues, respectively. A genomic Southern hybridization analysis indicated that rice has several AOX genes other than the two tandem-arranged AOX genes. Steady-state mRNA levels of both of the genes for AOX1a and AOX1b were increased under low temperature (4 degrees C). However, no difference in the pattern of induction of transcription between the genes for AOX1a and AOX1b was observed.

Transcript levels of the nuclear-encoded respiratory genes in rice decrease by oxygen deprivation: evidence for involvement of calcium in expression of the alternative oxidase 1a gene.

We investigated the effect of oxygen on the expressions of respiratory genes encoded in the nuclear and mitochondrial genomes of rice (Oryza sativa L.). Hypoxic treatment decreased the transcript levels of nuclear-encoded, but not mitochondrial-encoded respiratory genes. The effects of ruthenium red (an inhibitor of Ca(2+) fluxes from organelles) and/or CaCl(2) on plants under hypoxic conditions suggested that Ca(2+) is a physiological transducer of a low-oxygen signaling pathway for expression of the alternative oxidase 1a gene (AOX1a), but not for expressions of genes involved in the cytochrome respiratory pathway, in rice.

A novel plant nuclear gene encoding chloroplast ribosomal protein S9 has a transit peptide related to that of rice chloroplast ribosomal protein L12.

We have cloned a novel nuclear gene for a ribosomal protein of rice and Arabidopsis that is like the bacterial ribosomal protein S9. To determine the subcellular localization of the gene product, we fused the N-terminal region and green fluorescent protein and expressed it transiently in rice seedlings. Localized fluorescence was detectable only in chloroplasts, indicating that this nuclear gene encodes chloroplast ribosomal protein S9. The N-terminal region of rice ribosomal protein S9 was found to have a high sequence similarity to the transit peptide region of the rice chloroplast ribosomal protein L12, suggesting that these transit peptides have a common lineage.

Effect of KCA-098 on the function of osteoblast-like cells and the formation of TRAP-positive multinucleated cells in a mouse bone marrow cell population.

KCA-098 (3,9-bis(N,N-dimethylcarbamoyloxy)-5H-benzofuro[3,2-c]quinol ine-6-one), an analogue of coumestrol (a naturally occurring weak phytoestrogen), dose-dependently increased alkaline phosphatase activity of osteoblastic ROS 17/2.8 cells and freshly-isolated osteoblasts from neonatal mouse calvaria, and reduced cell proliferation. In addition, KCA-098 increased the synthesis of collagenese-digestible protein (CDP) of ROS 17/2.8 cells. On the other hand, KCA-098 had no effect on the basal synthesis of osteocalcin but reduced the 1 alpha,25-dihydroxyvitamin D3 (1 alpha,25(OH)(2)D3)-induced increase in osteocalcin synthesized by ROS 17/2.8 cells. Therefore, KCA-098 had a bidirectional effect on the differentiation of osteoblasts (i.e., stimulating both alkaline phosphatase activity and synthesis of CDP and inhibiting osteocalcin synthesis). However, as KCA-098 stimulated the mineralization of chick embryonic bone in organ culture and recovered the bone density reduced by ovariectomy of rats, it would serve overall to stimulate the differentiation of osteoblasts. On the other hand, KCA-098 inhibited the formation of tartrate-resistant, acid phosphate-positive multinucleated cells (TRAP(+)MNC) induced by 1 alpha,25(OH)(2)D(3), parathyroid hormone (PTH), and prostaglandin E2 (PGE2) in cultures of mouse bone marrow cells, showing that it inhibits the formation of osteoclast-like cells. Coumestrol and 17beta-estradiol had no effect on the proliferation and alkaline phosphatase activity of ROS 17/2.8 cells. They did, however, dose-dependently inhibit osteoclast-like cell formation as well as KCA-098 did, indicating that the main action of coumestrol and 17beta-estradiol on bone tissue is the inhibition of bone resorption.

Enhancing effect of ethanol on aflatoxin b1-induced DNA-damage in glutathione-depleted rat hepatocytes.

The effect of reduced glutathione (GSH) and ethanol on aflatoxin B1 (AFB1)-induced DNA single strand breaks was studied in primary cultured hepatocytes. Buthionine sulfoximine (BSO) which decreased intracellular GSH to 13% of those of the control levels increased DNA fragmentation of AFB1-treated hepatocytes by over 17% of those without BSO. Thus, a decrease in hepatocyte GSH levels increased AFB1-induced DNA damage. Although ethanol in itself did not induce DNA damage, a combination of BSO and ethanol increased the percentage by over 23% of that with BSO only. Ethanol did not affect the amount of GSH, total cytochrome P-450 (P450), glutathione S-transferase (GST) and epoxide hydrolase (EHase) in cultured hepatocytes. However, GSH-depleted rat hepatocytes exposed to ethanol significantly increased the level of P450IIIA, which activates AFB1. The enhancing effects of ethanol in the presence of BSO are probably due to the induction of this isozyme in rat hepatocytes. The GSH-depleted hepatocytes are more susceptible to chemical carcinogens in the presence of ethanol.

RNA editing of transcripts of the gene for apocytochrome b (cob) in rice mitochondria.

RNA editing was examined in rice mitochondrial apocytochrome b (cob) transcripts. Nineteen C-U conversions were found, and most of them changed the polypeptide sequence encoded by genomic DNA sequence. Evidence for partial and excess editing was also found.

The gene for alternative oxidase-2 (AOX2) from Arabidopsis thaliana consists of five exons unlike other AOX genes and is transcribed at an early stage during germination.

We investigated the expressions of genes for alternative oxidase (AOX1a, AOX1b, AOX1c and AOX2) and genes for cytochrome c oxidase (COX5b and COX6b) during germination of Arabidopsis thaliana, and examined oxygen uptakes of the alternative respiration and the cytochrome respiration in imbibed Arabidopsis seeds. A Northern blot analysis showed that AOX2 mRNA has already accumulated in dry seeds and subsequently decreased, whereas accumulation ofAOX1a mRNA was less abundant from 0 hours to 48 hours after imbibition and then increased. The increase of the capacity of the alternative pathway appeared to be dependent on the expressions of both AOX2 and AOX1a. On the other hand, steady-state mRNA levels of COX5b and COX6b were gradually increased during germination, and the capacity of the cytochrome pathway was correlated with the increase of expressions of the COX genes. Antimycin A, the respiratory inhibitor, strongly increased the expression of AOX1a but had no effect on the expression of AOX2. A 5'RACE analysis showed that AOX2 consists of five exons, which is different from the case of most AOX genes identified so far. Analysis of subcellular localization of AOX2 using green fluorescent protein indicated that the AOX2 protein is imported into the mitochondria.

Effects of ethanol on the DNA-damage induced by 2 carcinogenic nitrosamines.

We studied the DNA single-strand breaks (DNA SSBs) induced by two nitrosamines using rat hepatocytelin situ nick translation assay. In the hepatocytes treated with 20 mu M of N-nitrosodimethylamine (NDMA), 100 mM ethanol enhanced DNA SSBs 3 times higher than those of control. However, there was no significant difference between the DNA SSBs with and without ethanol in 300 mu M of N-nitrosodiethylamine (NDEA) treated groups. Pretreatment of 100 mM ethanol increased P450IIE1 levels determined by Western blotting, whereas the amount of total P450 was not affected. Although NDMA is possibly activated by P450IIE1, there could be other isozymes responsible for the activation of NDEA. Phenobarbital inducible isozymes such as P450IIB1 and IIB2, or P450IIA3 may be primarily responsible.

Reduced rejoining ability of DNA strand breaks with differentiation in barley root cells.

To investigate the relationship between differentiation and the rejoining ability of DNA strand breaks, DNA strand breaks induced by gamma-rays were analyzed in barley roots using the alkaline unwinding assay. The extent of unwinding in an alkaline solution containing 0.5 M NaCl was found to be significantly inhibited at the root tip consisting of meristematic cells but not in the remainder of the root consisting of differentiated cells immediately after 100 Gy of gamma-irradiation. The difference in the extent of unwinding was diminished when the alkaline solution contained 2 M NaCl, suggesting a difference of chromosome structure and/or cell skeleton between the two regions. The rejoining kinetics of DNA strand breaks consisted of a fast and a slow component in both regions. DNA strand breaks were rejoined to the level of unirradiated control at the root tip but remained partly unrejoined in the remainder of the root during 6 h post-irradiation incubation. The difference of rejoining ability observed between the two regions originated from the different efficiency of rejoining at the slow component. The rejoining at the slow component in the root tip was found to be inhibited in the presence of the protein synthesis inhibitor cycloheximide, suggesting that de novo synthesized proteins are involved in the rejoining of DNA strand breaks. In contrast, the slow component in the remainder of the root was not inhibited by cycloheximide. These results suggest that the reduced rejoining ability of DNA strand breaks of differentiated cells may result from a deficiency of rejoining DNA strand breaks by inducible repair at the slow component. In addition, the lack of an apparent correlation between rejoining ability and growth inhibition of the root is discussed.

Hepatopancreatoduodenectomy for squamous and adenosquamous carcinoma of the gallbladder.

The characteristics of squamous or adenosquamous cell carcinoma of the gallbladder differ quite markedly from those of adenocarcinoma, although the incidence is extremely low. Recently, we encountered both of the former types of gallbladder carcinoma: a 77-year-old man with squamous cell carcinoma and a 70-year-old man with adenosquamous cell carcinoma of the gallbladder. Both had a large mass in the gallbladder fossa region with infiltration to the liver and invasion of the duodenum. Hepatopancreatoduodenectomy was performed on both of these patients. The TNM stage of the former was IV (T4N0M0) and of the latter IV (T4N0M0) and of the latter IV (T4N1bM0). The former has remained well without recurrence for about 1 year and 4 months after the operation, while the latter died of recurrent disease 6 months after operation. The true reason for the difference in the prognosis of these two patients was not known. However, hepatopancreatoduodenectomy is considered to be a most adaptable operative procedure for squamous or adenosquamous cell carcinoma of the gallbladder in view of their mode of spread, and the presence of lymph node metastasis might be a factor of poor prognosis.

Growth inhibition of K-ras-expressing tumours by a new vinca alkaloid, conophylline, in nude mice.

Conophylline, a new vinca alkaloid isolated from the plant Ervatamia microphylla induced normal flat morphology in K-ras-NRK and K-ras-NIH cell lines, and lowered the increased uptake of 2-deoxyglucose in K-ras-NRK cells. Conophylline inhibited the growth of K-ras-NRK cells, but this inhibition was reversible. The alkaloid also inhibited the growth of K-ras-NRK and K-ras-NIH3T3 tumours transplanted into nude mice. On the other hand, it showed no effect on survival of the mice loaded with L1210 leukaemia. Thus, conophylline is a new antitumour vinca alkaloid that induced normal phenotypes in ras-expressing cells.

[A case of pulmonary edema after electroconvulsive therapy under propofol anesthesia].

Electroconvulsive therapy (ECT) was scheduled for a 61-yr-old woman with major depression who had been taking a beta-blocker for hypertension. She underwent the first ECT under thiamylal anesthesia uneventfully. The second ECT was performed under propofol anesthesia on the next day. Immediately after ECT, the heart rate dropped from 56 to 19 beats.min-1, which was remedied by intravenous atropine. Then, the blood pressure increased to 204/108 mmHg but it was controlled by nicardipine. However, the SpO2 decreased to 84-88% under oxygen administration by mask at a rate of 3 l.min-1. The patient complained of chest discomfort and had a bloody secretion from the trachea. A chest X-ray showed a butterfly shadow. The patient was diagnosed as having neurogenic pulmonary edema and was treated in the ICU by artificial ventilation and administration of diuretics and catecholamines. These treatments proved to be successful, and the patient was discharged from the ICU 4 days later uneventfully. This case indicates that hemodynamics should be carefully monitored following ECT and that care should be taken to prevent the occurrence of complications after ECT.

[Perioperative management of life-threatening intra-abdominal bleeding with intra-aortic balloon occlusion catheter].

Intra-thoracic aortic clamping using an intra-aortic balloon occlusion catheter (IABOC) is employed for patients with life-threatening intra-abdominal and/or extra-abdominal bleeding in spite of massive transfusion. For perioperative management, we inserted an IABOC preoperatively into a 59-year-old man with life-threatening intra-abdominal bleeding from an abscess formed around his traumatically injured pancreas. We could perform a safe operation in which bleeding was controlled by intermittently occluding the IABOC and the patient was thus prevented from developing into severe hemorrhagic shock. We experienced a usefulness of IABOC for a patient with life-threatening intra-abdominal bleeding uncontrolled due to intra-abdominal adhesion during the perioperative period. However, organ dysfunctions caused by ischemia and reperfusion following intra-aortic balloon occlusion must be prevented by shortening the occlusion time through use of an intermittent method such as described above.

[Hepatic arterial infusion therapy in a patient with multiple hepatic metastases from gastric cancer].

A patient with multiple hepatic metastases (H3) from advanced gastric cancer was treated with pre- and post-operative arterial infusion therapy. A Port-A-Cath was cannulated into the gastroduodenal artery after total gastrectomy. Repeated arterial infusions were performed monthly in the outpatient ward. The volume of hepatic tumors was remarkably decreased to 12% of the pretreatment level. The patient has been alive for 15 months after the operation without any complaint. Arterial infusion chemotherapy through implantable reservoir is useful for the treatment of unresectable hepatic metastasis without decreasing the quality of life.

[A comparative study on the serum and tissue 5-FU concentrations in patients with hepatocellular carcinoma after preoperative oral administration of UFT and 5'-DFUR].

UFT or 5'-DFUR was orally administered to the patients with hepatocellular carcinoma preoperatively and the concentrations of these drugs and 5-FU in the serum, liver tissue and cancer tissue obtained at the time of operation were measured. The unchanged 5'-DFUR was not detected in any of these samples. The concentration of 5-FU in cancer tissue was significantly higher in UFT treated group (0.409 microgram/g) than that in 5'-DFUR group (0.040 microgram/g). However, the 5-FU levels in the serum and noncancerous liver tissue were also higher than those in the patients with other organ cancers. Although UFT is a useful drug for the adjuvant chemotherapy of hepatocellular carcinoma, the dose was considered to be minimized to avoid the side effects since the activity of drug-metabolizing enzymes may be decreased in hepatocellular carcinoma complicated with liver cirrhosis.