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Biomedical subjects

M Kusunoki

Publications and source records attributed to M Kusunoki.

At least 109 records · Page 6Linked to original sources
PubMed1994

Functional properties of rotation-sensitive neurons in the posterior parietal association cortex of the monkey.

We studied the functional properties of rotation-sensitive (RS) neurons of the posterior parietal association cortex in detail. We classified 58 neurons as RS neurons on the basis of statistical analysis, to indicate that their responses to rotary movement were significantly greater (P < 0.01) than those to linear movement of the same stimulus. We calculated rotation index, 1-(L/R), in 82 cells, where L/R is the ratio of net response to linear movement to that to rotary movement. All the RS neurons had rotation index greater than or equal to 0.3. The recording site of these RS neurons was localized in the posterolateral part of area PG (area 7a of Vogt), on the anterior bank of the caudal superior temporal sulcus (STS), in the region partly overlapping the medial superior temporal (MST) area. We compared the response of RS neurons to rotation with that to shearing movement as well as to linear movement. In the majority of RS neurons the ratio of shearing response to rotation response (S/R) was smaller than the ratio of linear response to rotation response (L/R), indicating that the response to rotation was not due to a simple combination of linear movements in the opposite direction. Most of the RS neurons responded to the rotary movement of a single spot as well as that of a slit, although the response was smaller (average 70%) for the former. Most of the RS neurons had large receptive fields (60-180 degrees in diameter) and their responses were independent of the position within the receptive field. The responses of most RS neurons increased monotonically with the increase in angular velocity and were also dependent on the size of the stimulus, although the rate of increase was small when the length was more than 10 degrees. The majority of RS neurons (37/58) responded better to rotation in depth than to that in the frontoparallel plane. Some of them (12/37) responded to diagonal rotation rather than to sagittal or horizontal rotation. We found that some depth RS neurons showed reversal in the preferred direction when we used a trapezoidal window-like plate as the rotating stimulus in the monocular viewing condition, just as occurs in the case of the Ames window illusion. The response of some RS neurons (5/7) was enhanced by tracking eye movement.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1994

Loss of biological activity of human chorionic gonadotropin (hCG) by the amino acid substitution on the "CMGCC" region of the alpha-subunit.

In order to study the bioactive sites of the glycoprotein hormones, we have prepared five point mutants on the CMGCC (Cys28-Met29-Gly30-Cys31-Cys32) region of the human alpha-subunit by using site-directed mutagenesis. Each mutant human chorionic gonadotropin (hCG) agr; cDNA and a wild-type hCG beta cDNA were transcribed by T3 RNA polymerase, and the mixture of the hCG alpha mRNA and hCG beta mRNA was microinjected into Xenopus laevis oocytes. All five mutant hCGs produced in oocyte culture supernatants were detected as immunoreactive forms by enzyme immunoassay. In contrast, four mutants (Cys28-->Tyr28, Gly30-->Arg30, Ala30, Asp30) were devoid of biological activity in vitro bioassay using the production of testosterone with mouse Leydig cells. These results indicate that the CMGCC region in the alpha-subunit, particularly the cysteine residue at position 28 and the glycine residue at position 30, plays an important role in the biosynthesis of glycoprotein hormones.

Amino Acid Sequence↗
PubMed1994

Variable activity of protein tyrosine kinase in apparently normal thyroid glands.

We examined protein tyrosine kinase (PTK) activity in apparently normal thyroid tissue (n = 22) obtained from patients undergoing thyroid surgery for papillary thyroid cancer or benign disease. The PTK activity in apparently normal thyroid tissue from patients with papillary thyroid cancer progressively was elevated in the cytosolic fraction compared with that from patients without cancer (p < 0.05). The cytosolic proportion of PTK activity was also significantly increased in the normal thyroid tissue of patients with cancer (62% vs. 51%, p < 0.05). These findings suggest that alterations in PTK activity may indicate apparently normal thyroid tissue at increased risk of developing malignancy.

Adenocarcinoma, Papillary↗
PubMed1994

[Therapeutic effect of lisuride maleate on post-stroke depression].

Twenty post-stroke depressive patients who obtained more than 11 points on Self-Rating Questionnaire for Depression, were treated with 0.075 mg/day lisuride maleate for 12 weeks. The drug effect on depression was evaluated quantitatively by the Hamilton Rating Scale for Depression. The relationships between brain CT or MRI and SRQ-D score were investigated in 24 subjects. More than 80% of post-stroke depressive patients improved after lisuride maleate treatment for 8 or 12 weeks. In particular, depressed mood, hypobulia, sleep disturbance, anxiety, etc. were significantly improved compared to the baseline condition. As for the relationships with CT and/or MRI findings, the group with moderate to severe brain atrophy had a significantly higher grade of depressive state than those without.

Aged↗
PubMed1994

Preoperative detection of local extension of carcinoma of the rectum using magnetic resonance imaging.

BACKGROUND: We evaluated the ability of magnetic resonance imaging (MRI) to define local extension of rectal carcinoma. STUDY DESIGN: Thirty-three patients with rectal carcinoma were preoperatively assessed by MRI. RESULTS: When sagittal or coronal images, or both, were added to transverse images as needed, the sensitivity rate was 84.2 percent and the specificity rate was 92.9 percent. False-positive results when using only transverse images were mainly related to slight extramural spread, to an anterior location in the lower rectum (partial volume effect), and to massive extramural spread of the middle rectal tumors. CONCLUSION: Preoperative MRI was helpful to define tumor extension three-dimensionally.

Aged↗
PubMed1994

Clinicopathological study of anorectal mucosa in total colectomy with mucosal proctectomy and ileoanal anastomosis.

OBJECTIVE: To find out whether the extent of inflammation of the anorectal mucosa affects the quality of the mucosectomy and postoperative function in patients undergoing total colectomy with mucosal proctectomy and ileoanal anastomosis. DESIGN: Prospective study. SETTING: University hospital. SUBJECTS: 33 patients with ulcerative colitis and 17 with familial adenomatous polyposis. INTERVENTIONS: With the patient in the prone jackknife position, the anorectal columnar mucosa above the dentate line was removed transanally by the forceps coagulation technique. MAIN OUTCOME MEASURES: Score of histological appearance on light microscopy. RESULTS: All the patients with ulcerative colitis had moderate (n = 17, 52%) or severe (n = 16, 48%) inflammation, and their mean histological score was 12 (range 7-16). The patients with polyposis had little or no inflammation, and a mean histological score of 0.4 (range 0-2). The mucosectomy became more difficult as the severity of the inflammation increased, but there were no significant differences between the two groups in operating time, blood loss, or bowel function postoperatively. CONCLUSION: Though mucosectomy is technically more difficult in the presence of severe inflammation, there were no adverse effects on bowel function postoperatively.

Adenomatous Polyposis Coli↗
PubMed1993

Flash induced XANES spectroscopy for the Ca-depleted Mn-cluster in the photosynthetic O2-evolving enzyme.

Flash-induced changes of the Mn K-edge absorption spectra have been studied in the oxygen-evolving complex depleted of Ca. The Mn K-edge energy for the Ca-depleted S1-state was lower by 1.5 eV than that for the normal S1-state. The K-edge energy upshifted by 1 eV after one flash, indicative of an oxidation of Mn. After two flashes, the K-edge was elevated as well by 0.4 eV, and then reached a steady-state high level after continuous illumination where the K-edge energy was higher by 0.9 eV than that after one flash. The results indicate that the Mn-cluster and/or its direct ligand could be oxidized up to two electrons but further events are blocked.

Calcium↗
PubMed1993

Anorectal function after preoperative intraluminal brachytherapy and colonic J pouch-anal anastomosis for rectal carcinoma.

The effects of preoperative intraluminal brachytherapy on bowel function after anoabdominal rectal resection and colonic J pouch-anal anastomosis were studied. The patients included eight not receiving irradiation (group 1), eight who received 30 Gy (group 2) and eight who received 80 Gy (group 3). Stool frequency and the incidence of soiling were significantly greater in group 3 than in the other groups. Anal resting pressure was lower in group 3 during the study period but J pouch distensibility was not reduced. The maximum tolerated volume, threshold volume and squeeze pressure were significantly lower in group 3 than in the other groups in the early postoperative period. These results suggest that high-dose brachytherapy affects the anal sphincters and colonic J pouch. A moderate dose of 30 Gy may be more suitable before restorative anorectal surgery.

Adult↗
PubMed1993

Cineradiographic study of wrist motion after fracture of the distal radius.

Residual dorsal tilt is one of the main deformative factors in the malunion of fractures of the distal radius. We investigated the effect of such tilt on the range of wrist motion and on carpal alignment in a cineradiographic study of wrist motion in 30 patients with extra-articular Colles' fracture. With increased dorsal tilt, the range of wrist motion became more restricted and abnormalities of carpal alignment during wrist motion became apparent. When the dorsal tilt was less than 10 degrees, the effects on the range of motion and on the dynamic carpal alignment were small.

Adolescent↗
PubMed1993

Muscle glucose uptake during and after exercise is normal in insulin-resistant rats.

It is not generally known whether impaired stimulation of muscle glucose metabolism in insulin-resistant states is specific to insulin stimulation. Our aim was to examine whether glucose uptake responded normally to exercise and postexercise recovery in insulin-resistant high-fat-fed (HFF) rats. Three-week HFF or Chow-fed [control (Con)] adult rats were studied 5 days after cannulation. Before, during, or immediately after (recovery) 50 min of treadmill exercise, bolus 2-deoxy-[3H]glucose and [14C]glucose were administered to estimate muscle glucose uptake (R'g) and glycogen incorporation rates. Mean exercise and recovery plasma glucose levels were similar in HFF and Con rats. In hindlimb muscles sampled, exercise and recovery R'g were similar in HFF and Con (e.g., red quadriceps exercise 104 +/- 13 vs. 113 +/- 8, recovery 45.3 +/- 3.9 vs. 47.7 +/- 4.5 mumol.100 g-1.min-1, respectively). Moreover, muscle glucose transporter (GLUT-4) content was not reduced in HFF rats. Glycogen resynthesis accounted almost entirely for R'g during recovery and was equivalent between groups. We conclude that impaired muscle glucose uptake and glycogen synthesis in HFF rats are characteristic of insulin but not of exercise or postexercise stimulation.

Analysis of Variance↗