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Biomedical subjects

N Kubo

Publications and source records attributed to N Kubo.

At least 91 records · Page 5Linked to original sources
PubMed1996

A promiscuous chloroplast DNA fragment is transcribed in plant mitochondria but the encoded RNA is not edited.

The RNA editing processes in chloroplasts and mitochondira of higher plants show several similarities which are suggestive of common components and/or biochemical steps between the two plant organelles. The existence of various promiscuous DNA fragments of chloroplast origin in plant mitochondrial genomes allowed us to test the possibility that chloroplast sequences are also edited in mitochondria. An rpoB fragment transferred from chloroplasts to mitochondria in rice was chosen as it contains several editing sites, two of which match sequence motifs surrounding even non-homologous editing sites in both chloroplast and mitochondrial transcripts. Rice chloroplast and mitochondrial rpoB DNA and cDNA sequences were selectively amplified and the editing status of the cDNA sequences was determined. Three of the four potential rpoB editing sites previously detected in maize were found to be edited in the rice chloroplast rpoB transcript, whereas the fourth was found to remain unedited. In mitochondria, however, all four editing sites remain unmodified at the cDNA level. This indicates that the editing processes of higher plant mitochondria and chloroplasts are not identical and that organelle-specific factors are required for eliciting the respective editing events.

Amino Acid Sequence↗
PubMed1996

A case of cranial meningocele associated with Joubert syndrome.

Joubert syndrome was first reported in 1969 as a rare, recessive autosomal syndrome associated with neuropathological abnormalities of the cerebellum and brain stem, partial or complete aplasia of the cerebellar vermis, and presenting with episodic hyperpnea and apnea, oculomotor abnormalities, and psychomotor retardation. Having experienced one case of this syndrome with associated cranial meningocele, we report the clinical course, MRI features, and surgical findings, and discuss the relevant literature.

Brain Stem↗
PubMed1996

Subclavian artery aneurysm associated with absence of the ipsilateral internal carotid artery.

A 48-year-old male presented with a rare subclavian artery aneurysm associated with absence of the ipsilateral internal carotid artery. The aneurysm was resected and replaced with a Gore Tex artificial graft. Computed tomography, angiography and cerebral blood flow findings suggest that defect of the right internal carotid artery occurred in the developmental stage. There was no past history of trauma, nor histological evidence of inflammatory or sclerotic changes in the aneurysmal wall. The two vascular lesions may have been influenced by a synchronous causative factor in his developmental stage.

Aneurysm↗
PubMed1996

[A study on the relationship between sources of health information concerning smoking and drinking, and health behavior].

To determine effective measures to popularize knowledge on the health effects of smoking and drinking and to change health behavior, an interview survey of 2000 persons aged 18 or older randomly chosen from national census forms throughout Japan was carried out. The coverage rates of the information concerning smoking and drinking were 97.3% and 92.5%, respectively. Television, newspapers and magazines were the major sources of health information concerning smoking and drinking. In addition, men who gave up or controlled smoking or drinking usually obtained health information from doctors, while those who had never controlled smoking usually obtained health information from their friends and families. Men who could not control drinking effectively usually obtained health information from the health examination consultant at the workplace. However, according to the answers from men who gave up or controlled drinking, the health information useful in changing health behavior was obtained from the health examination consultant at the workplace and from persons who had a disease history. Women who gave up or controlled drinking answered that the health information from their friends and families was helpful to change the health behavior.

Adolescent↗
PubMed1996

Schwannoma arising from the intermediate nerve and manifesting as hemifacial spasm. Case report.

This 35-year-old man presented with left facial spasm that had persisted for 10 months. Microvascular decompression was performed to relieve the symptom. No responsible vessel could be identified during surgery, but a small mass seeming to arise from the intermediate nerve and compressing the seventh cranial nerve was removed. The histological diagnosis was Antoni-B type schwannoma. This unique case of schwannoma arising from the intermediate nerve was recognized by means of an operative microscope, and supports the idea that portions of the seventh nerve schwannoma originate from the components of the intermediate nerve.

Adult↗
PubMed1996

[Selective thermocoagulation of unresectable malignant tumors using radiofrequency].

Based on our experimental findings on porcine liver, we have been conducting a clinical trial of selective hyperthermia by radiofrequency (RF) capacitive heating with laparotomy for patients with unresectable malignant tumors. In 10 patients with malignant tumors (8 carcinoma of the pancreas, 2 carcinoma of the gallbladder), laparotomy and RF heating were performed after informed consent. The local heat coagulation was produced by heating equipment using 13.56 MHz radiofrequency produced by Omron Corporation, Japan. Four 2-cm electrode needles were placed in the tumor in a square array at intervals of 2.0 cm. Hyperthermia was given for 30 min with a controlled temperature of 50 degrees C in the RF field (2 x 2 x 2 cm3). That of the surrounding area was maintained at less than 40 degrees C. The calculated volume treated by RF ranged between (2 x 2 x 2 cm3) x 1 and (2 x 2 x 2 cm3) x 6. We followed all patients by computed tomographic (CT) scan 2 weeks after coagulation. Tumor markers in the blood were assayed before and 14 days after heating. Follow-up CT scans demonstrated that after the tumor mass had been heterogeneously enhanced, it changed to a homogeneous low-density area in 6 of 10 patients. The levels of tumor markers decreased to lower than the pre-treatment values in 9 of 10 patients. In all patients, the changes in CT scans and/or decrease in the markers were confirmed. Complications such as bleeding or abscess formation were not observed. It was suggested that the selective hyperthermia was safely produced by this equipment. The encouraging results in these patients justify further clinical trials.

Biomarkers, Tumor↗
PubMed1995

Creation of an initiation codon by RNA editing in the coxI transcript from tomato mitochondria.

Nucleotide-sequence analysis showed that the gene for cytochrome oxidase subunit I (coxI) from tomato mitochondrial DNA has an ACG codon at a conserved position corresponding to an ATG initiation codon in other higher-plant coxI genes. cDNA-sequence analysis of the coxI transcripts showed that 15 positions in the genomic DNA were converted from C to U in the transcripts by RNA editing. One of the editing events is observed at the indicated ACG codon, producing an ATG initiation codon. The nucleotide sequences of 37 cDNA clones showed that the initiation codon was created in 32 out of the 37 clones, while nucleotide positions 254 and 11 were edited in 37 and 34 of the 37 clones examined, respectively, suggesting that creation of the initiation codon is a post-transcriptional event. The BamHI site at nucleotide position 757-762 within the coxI genomic DNA was altered in all 97 cDNA clones examined, demonstrating that RNA editing at this site in the transcripts is very common. RNA editing takes place to a lesser extent at the initiation codon, compared with editing at internal position 254. This indicates that editing is either a random process or that it involves a mechanism favoring less RNA editing in the initiation codon than in internal sites.

Amino Acid Sequence↗
PubMed1995

Dysautoregulation in patients with hypertensive intracerebral hemorrhage. A SPECT study.

In patients with hypertensive intracerebral hemorrhage, changes in regional cerebral blood flow (rCBF) following drug-induced blood pressure reduction were examined by SPECT. METHODS. The subjects were 68 patients with hypertensive intracerebral hemorrhage. The site of cerebral hemorrhage was the thalamus in 28 patients, and the putamen in 40 patients. RCBF was measured by SPECT using the 133Xe inhalation method. To reduce blood pressure, trimethaphan camsilate (an autonomic ganglion blocker) and diltiazem hydrochloride (a calcium antagonist) were used. RESULTS. 1. In the acute period, mean CBF declined as the mean arterial blood pressure declined by more than 20% in both the putaminal and the thalamic hemorrhage group (p < 0.01). 2. During the chronic period, a greater reduction in blood pressure was needed to induce mean CBF reduction. 3. Neither of the two drugs significantly reduced the mean arterial blood pressure, but the group receiving trimethaphan demonstrated a 7.9 approximately 7.5% decreased in CBF, group while the receiving diltiazem showed a 2.2 approximately 2.4% decrease (p < 0.05). CONCLUSIONS. In patients with hypertensive intracerebral hemorrhage, a 20% or more drug-induced decrease in blood pressure resulted in a decrease in mean CBF. During the acute period of intracerebral hemorrhage, blood pressure showed reduced by 20%. Clinically, diltiazem was more effective than trimethaphan.

Adult↗
PubMed1995

Carbon dioxide gas replacement of chronic subdural hematoma using single burr-hole irrigation.

In order to achieve complete irrigation, reduce air in the hematoma cavity, and obtain rapid reduction of the cavity without drainage, we use burr-hole evacuation of the hematoma followed by irrigation using physiologic saline solution and replacement of the hematoma with carbon dioxide (CO2) gas. We have treated 19 cases between the ages of 41 and 84. With the exception of one case with dementia of 5 years' duration, all cases were asymptomatic postoperatively. Computed tomography (CT) scans obtained immediately postoperatively showed the gas to fill the hematoma cavity, but on the following day, the gas and the hematoma cavity had nearly disappeared. There was no surgical mortality nor morbidity and there were no side effects of the CO2 gas. Recurrence was found in one case (5.3%). By filling the hematoma cavity with CO2, disappearance of the cavity is rapid and drainage is not needed. Moreover, this technique implies no restrictions on postoperative motility, and is thus suitable for elderly patients.

Adult↗
PubMed1995

Biochemical evidence of platelet-activating factor (PAF) in human middle ear effusions.

Platelet-activating factor (PAF) is one of the most potent biological lipid mediators. This is especially true in relation to inflammation. In order to characterize the biochemical features of otitis media with effusion, the authors characterized and determined the concentration of the PAF present in human middle ear effusions obtained from 23 patients with otitis media with effusion. Each sample of middle ear effusion was divided into two groups: serous (n = 12) and mucoid effusions (n = 11). The platelet-activating factor activity was found mainly in mucoid middle ear effusions, and the amounts of PAF were higher in mucoid type (3.55 +/- 1.19 ng/g, mean +/- standard deviation [SD]) than in the serous type (0.44 +/- 0.19 ng/g). Phospholipids obtained from the middle ear effusions contained a large amount of lyso-platelet-activating factor, the biologically inactive precursor or breakdown product of platelet-activating factor. Based on these findings, it is suggested that platelet-activating factor may play an important role as a mediator of the inflammatory responses in the pathogenesis of otitis media with effusion.

Arachidonic Acids↗
PubMed1995

Infralabyrinthine approach to vestibular neurectomy in Menière's disease.

The infralabyrinthine approach to vestibular neurectomy was performed in 9 patients with unilateral Menière's disease. According to the AAOO (1972) criteria, 7 of 9 cases were graded as class B and the remaining 2 cases as class C. Otherwise, according to the AAO-HNS (1985) criteria, 6 patients who could be followed over 2 years were all graded as 'complete' at the vertigo control. The compensation of the spontaneous vestibular signs was rapid in the first 2 postoperative weeks, though an occasional imbalance on movement persisted even 3 years after the operation. No specific caloric reaction was elicited in any patient after warm or cold water irrigation of the operated side in any postoperative period. There have been no serious complications except a delayed facial palsy that appeared in one case one week after surgery. This approach offers access to the vestibular nerve with minimal risk and morbidity.

Adult↗
PubMed1995

Evidence of cellular supplies to the endolymphatic sac from the systemic circulation.

Donor T lymphocytes injected into the host systemic circulation were observed to infiltrate into the host endolymphatic sac in mice. These findings suggest that the endolymphatic sac, a major immune organ in the inner ear, is supplied with immunocompetent cells from the systemic circulation. This concept is consistent with clinical reports that inner ear disorders accompany certain systemic autoimmune diseases. Bone marrow transplantation to replace autoreactive immunocompetent cells with normal cells should be considered as a potential therapy for inner ear autoimmune diseases and an alternative to conventional treatments.

Animals↗
PubMed1995

[Efficacy and complications of topical cocaine anesthesia in functional endoscopic sinus surgery].

A 4% cocaine (total dose; 200 mg) solution with 1 mg epinephrine was used as a topical anesthetic for 178 cases undergoing functional endoscopic sinus surgery. Complications were investigated before and during surgery. Bleeding amount and operative duration were compared between patients with and without topical cocaine application. Tachycardia (26 cases) was the only complication encountered in this study. Tachycardia occurred at a high incidence in cases which used atropine as a premedication. Total bleeding amount did no differ significantly between those with and without topical cocaine. However, minimum bleeding cases (less than 20 ml) were found in the cocaine group more frequently than in the non-cocaine group. Operative durations of cases with cocaine anesthesia were significantly shorter than cases without cocaine anesthesia. Those findings suggest that cocaine is effective for prevention of bleeding from micro-vessels and/or mucosal oozing, whereas bleeding from macro-vessels was not controlled by topical cocaine application. Topical cocaine anesthesia produced no major complications, even at 200 mg, in the presence of 1 mg epinephrine and when atropine use was avoided.

Adolescent↗
PubMed1995

[Restoration filtering based on projection power spectrum for single-photon emission computed tomography].

To improve the quality of single-photon emission computed tomographic (SPECT) images, a restoration filter has been developed. This filter was designed according to practical "least squares filter" theory. It is necessary to know the object power spectrum and the noise power spectrum. The power spectrum is estimated from the power spectrum of a projection, when the high-frequency power spectrum of a projection is adequately approximated as a polynomial exponential expression. A study of the restoration with the filter based on a projection power spectrum was conducted, and compared with that of the "Butterworth" filtering method (cut-off frequency of 0.15 cycles/pixel), and "Wiener" filtering (signal-to-noise power spectrum ratio was a constant). Normalized mean-squared errors (NMSE) of the phantom, two line sources located in a 99mTc filled cylinder, were used. NMSE of the "Butterworth" filter, "Wiener" filter, and filtering based on a power spectrum were 0.77, 0.83, and 0.76 respectively. Clinically, brain SPECT images utilizing this new restoration filter improved the contrast. Thus, this filter may be useful in diagnosis of SPECT images.

Brain↗
PubMed1994

Rapid identification of the common apo E isoform genotype using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP).

Polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) was used to identify the common apoprotein E (apo E) isoform genotypes. DNA from the target sequence on apo E was amplified by PCR from peripheral blood genomic DNA. Non-radiolabelled natural PCR products were electrophoresed on a polyacrylamide gradient gel and automatically silver-stained. Bands compatible with each of the three common apo E isoforms were obtained. This method, which does not require restriction enzymes or DNA purification, is a rapid and useful means of detecting the apo E isoform genotype.

Apolipoproteins E↗