Search PubMed⌕ Search

Biomedical subjects

K Kanaya

Publications and source records attributed to K Kanaya.

At least 37 records · Page 2Linked to original sources
PubMed1996

Stringently and developmentally regulated levels of a cytoplasmic double-stranded RNA and its high-efficiency transmission via egg and pollen in rice.

A very restricted amount of high-molecular-weight double-stranded RNA (dsRNA) has been found in healthy japonica rice plants. We discriminated dsRNA-carrying rice plants from noncarriers. The endogenous dsRNA was localized in the cytoplasm (about 100 copies per cell) and was transmissible to progeny plants by mating. In crosses between carriers and noncarriers, the RNA was transmitted efficiently to F1 plants via both egg and pollen. The rice dsRNA was maintained at an almost constant level by host plant cells from generation to generation. The high-efficiency transmission of the endogenous dsRNA to progeny plants appears to depend on the autonomously controlled replication of the dsRNA localized in cytoplasmic vesicles. However, an increase in copy number (about 10-fold) of the dsRNA was observed during the suspension culture of host cells. The number of copies of dsRNA returned to the original low value in regenerated plants, suggesting that the copy number is stringently and developmentally regulated in rice cells.

Crosses, Genetic↗
PubMed1996

Study of the accuracy of stance regulation.

In order to find a rule underlying the control of stance we recorded the center of pressure intermittently every 29 ms, first with subjects standing still for 30 s and then during shifting the center of gravity along the margin of the supporting area for 30 s to detect any movement. Subjects were 5 adult volunteers. They were examined with eyes open and closed as well as standing on one leg, closed legs, and legs 15 cm apart. The distribution of cumulated densities of the center of pressure, in a 3-D drawing, formed a very simple graph, i.e., a tower on a circle. As the difficulty of stance increased, the circle was reduced and the height of tower lowered, independently of visual or supporting condition. Since easy and difficult stances could be simulated by small and large values of SD in a regular distribution, stance may yield action-oriented computation based on probability.

Adult↗
PubMed1996

[Periodic decerebrate spasm with ocular dipping, Cheyne-Stokes respiration and hypersympathetic activity].

Decerebrate spasm is a generalized muscular spasm produced by some stimuli on decerebrate posture. Such spasm are called "tonic fit" or "decerebrate extensor spasm". We reported a 50-year-old man with periodic decerebrate spasm after cerebral hemorrhage. On admission, the patient was comatose. The pupils were round but anisocoric and did not react to light. Corneal reflexes were absent. The face, arms, and legs did not move voluntarily. Two weeks after admission, he was found in decerebrate rigidity. Periodic decerebrate spasms were also observed and were accompanied by ocular dipping. Cheyne-Stokes respiration, and hypersympathetic activity (transiently dilated pupils, hypertension, tachycardia). These symptoms persisted for two months and were induced by painful or sonic stimuli and suppressed by sleep, sedative or antiedematous drugs. The cycle was 0.6 approximately 0.7 per minute in accord with that of Cheyne-Stokes respiration. Magnetic resonance imaging revealed an area of low signal intensity in the midbrain to the bottom of the pons caused by the tentorial herniation on T1-weighted images. From the the clinical features and results of MRI studies, we considered that dysfunction of the midbrain to the pons in addition to diffuse cerebral dysfunction played some role in the manifestation of periodic decerebrate spasm with ocular dipping.

Cerebral Hemorrhage↗
PubMed1994

[Equilibrium of small animals in "drop shaft" experimentation--preliminary study on the frog with vestibular neurectomy].

We have newly designed instruments for equilibrium experimentation, using a drop shaft, and studied the behavior and EMG Patterns of frogs with or without unilateral vestibular neurectomy, as a preliminary study at JAMIC (Japan Microgravity Center). The results are reported herein and the efficacy of the drop shaft in equilibrium experimentation is also documented. 1) In unilateral vestibular neurectomized frogs, posture--head tilt, leg flexion on the affected side, and leg extension on the opposite side--is maintained and persists under microgravity. Rolling to the affected side was also observed. 2) The latencies of the EMG responses from M. tibialis anticus and M. longissimus dorsi were prolonged on the affected side. 3) The frog is suitable for use in equilibrium experiments utilizing a drop shaft. 4) The JAMIC drop shaft can be used to obtain constant and stable microgravity, 10(-4) G for 10 sec, which is similar to that in space. Drop shafts are suitable for equilibrium experimentation.

Animals↗
PubMed1994

[Therapeutic effectiveness of 131I-MIBG on malignant pheochromocytoma--results of long-term follow-up].

The therapeutic response of 131I-MIBG was evaluated in 4 patients with malignant pheochromocytoma who had been treated with 131I-MIBG and followed-up over 5 years. The patients were 2 men and 2 women with ages ranging from 41 to 69 years old (mean 53 years). The primary tumors in 3 of 4 patients had been resected four to eight years before 131I-MIBG treatment. One patient was diagnosed as adrenal pheochromocytoma, and two were retroperitoneal paraganglioma. And in one patient, the resection of primary mediastinal tumor was not performed due to the adhesion to pericardium but the diagnosis of paraganglioma was obtained by biopsy of bone lesion. All patients showed the clear accumulation of 131I-MIBG in tumor on scintigraphy. The number of doses of 131I-MIBG ranged from one to three times with 3.7 GBq per administration and a cumulative activity from 3.7 to 11.1 GBq. Treatment effect was obvious in one patient with lung, bone, and lymph node metastases whose cumulated absorbed dose with 11.1 GBq of 131I-MIBG exceeded over 150 Gy. At the present time, the duration of survival since the beginning of initial 131I-MIBG therapy is over 5 yrs. The other three patients, however, showed little effects, and died with the disease in 2.6 to 4.1 years after the initial 131I-MIBG therapy. 131I-MIBG will become a promising agent for therapy in patients with malignant pheochromocytoma with high degree of accumulation.

3-Iodobenzylguanidine↗
PubMed1994

Accumulation enhancement of human monoclonal antibody HB4C5 to lung tumor xenografts by N-deglycosylation.

UNLABELLED: The fractional uptake of intact monoclonal antibodies by tumors is relatively low. Various methods to alter the molecular structure have been used to augment tumor uptake. These chemical manipulations, however, may alter the specificity of antibody binding. METHODS: Comparative studies of biodistribution, radioimmunoimaging and macroautoradiography in LC-6 xenografted mice were conducted with the 125I-labeled intact and N-terminal deglycosylated monoclonal antibodies to evaluate the effect on deglycosylation on antibody binding. RESULTS: The removal of N-glycosyl residues from this monoclonal antibody significantly enhanced specific localization of the radioactivity to the tumor, especially to its necrotic fraction. Nonspecific accumulation of radioactivity to the necrotic fraction of the tumor was excluded by biodistribution studies demonstrating selective accumulation of 125I-labeled monoclonal antibody after coadministration of 125I-monoclonal antibody (intact or N-deglycosylated) with 131I-labeled control IgM. CONCLUSION: The lung cancer-associated human monoclonal antibody HB4C5, which recognizes histone H2B as the antigen, accumulates specifically to the necrotic fraction of tumor. The uptake is enhanced by removal of N-terminal glycosyl residues from the antigen-binding site of the light chain.

Animals↗
PubMed1993

Vestibular compensation in vestibular neuronitis: evaluation of positional nystagmus and caloric nystagmus.

We evaluated the vestibular functions, especially for positional nystagmus and caloric nystagmus, in 43 cases of vestibular neuronitis for long periods after its onset. It is shown that in the cases of vestibular neuronitis that were studied more than 10 years after the onset of the disease, the completed vestibular compensation changed or the vestibular compensation was still incomplete.

Caloric Tests↗
PubMed1993

Vestibular neuronitis evaluated by the combined galvanic test.

Forty-two patients with unilateral vestibular neuronitis were examined by the combined galvanic test (CGT), consisting of the galvanic eye movement test (GEMT) and the galvanic body sway test (GBST). Results of the CGT were evaluated with respect to the time period from the onset of vestibular neuronitis. A favorable recovery was observed earlier with the GBST than the GEMT. We believe that this discrepancy may be due to the difference in compensation between the vestibulo-ocular reflex and the vestibulo-spinal reflex.

Adult↗
PubMed1993

Interpretation of the combined galvanic test. Findings from cases with vestibular neuronitis.

The combined galvanic test (CGT) was developed in our department for simultaneous recording of galvanic eye movement test (GEMT) and galvanic body sway test (GBST). Twelve cases of vestibular neuronitis were studied first with the caloric test, and then with the CGT. The findings of the caloric test corresponded to those of the GEMT, but did not always correspond to those of the GBST. Thus we suggest that the GBST reflects an abnormality in a system different from that reflected by the caloric test and GEMT. It is likely that the caloric response mainly originates from the semicircular canal system. Thus the GEMT may reflect an abnormality in the semicircular canal system, while the GBST reflects an abnormality in the otolithic system. The CGT may thus be a feasible method of differentiating the disorders of the semicircular canal system from those of the otolithic system in the vestibular nervous system.

Adult↗
PubMed1993

[131I-therapy of differentiated thyroid carcinoma with distant metastases--relation between absorbed dose by quantitative SPECT and outcome of the patients in thyroid carcinoma].

The correlation of absorbed doses of tumors in 18 patients of differentiated thyroid carcinoma with distant metastases, who were treated by 131I and followed over 5 years, with their outcome were analyzed and the clinical significance of determination of absorbed dose was discussed. Radioactivities of 131I in the tumors were measured by using SPECT at the time of therapy. Absorbed dose was calculated based on the MIRD equation. Outcome of 8 patients were evaluated as good and their absorbed dose was 10-630 Gy with 2-22 g of tumor volume, 1.2-3.5 days of effective half life (EHL) and follow-up term was 8.6 +/- 0.9 years. The absorbed dose of 10 patients whose outcome were evaluated as poor, was 5-81 Gy with 7-215 g of tumor volume, 1.3-5.3 days of EHL and follow-up term was 5.6 +/- 2.5 years. The initial treatment seemed to be important for 131I therapy, since the absorbed doses in the following therapy became reduced. When the absorbed dose of the tumor exceeded over 94 Gy at initial treatment, good clinical courses were obtained. These results indicate that the quantitative SPECT for 131I therapy is clinically valid and that the calculated absorbed doses correlate well with outcome of the patients.

Adenocarcinoma↗