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Biomedical subjects

K Onishi

Publications and source records attributed to K Onishi.

At least 55 records · Page 3Linked to original sources
PubMed1996

Verb comprehension deficits in probable Alzheimer's disease.

Studies of lexical comprehension in probable Alzheimer's disease (pAD) have focused almost exclusively on nouns. In the following preliminary study, we examined whether lexical comprehension for verbs is also impaired in 25 pAD patients. The semantic meaning of motion verbs, cognition verbs, and perception verbs was assessed with a triadic comparison task. Structural meaning associated with these verbs was evaluated by asking the patients to judge the coherence of sentence frames that accept these verbs naturally or awkwardly. We found that pAD patients are significantly impaired at identifying semantic relations among verbs. pAD patients also encountered significantly more difficulty judging the coherence of sentences than control subjects. Correlation and regression analyses demonstrated that semantic characteristics of verbs are projected from the verb's sentence frames in control subjects, but there was minimal evidence for such a structural-semantic relationship in pAD. We consider several possible explanations for our preliminary observations of an impairment that has consequences for processing both semantic and structural aspects of verb meaning.

Aged↗
PubMed1996

Serial position and temporal cue effects in multiple sclerosis: two subtypes of defective memory mechanisms.

Neurocognitive studies of multiple sclerosis (MS) have identified a robust long-term memory deficit. We hypothesized that this is due in part to the limited representation and use of serial order information. MS patients and controls were studied with a supraspan list learning procedure with post-encoding retrieval and recognition trials. MS patients demonstrated post-encoding negative recency with normal recognition, and word order recall was impaired. These findings appear to be in part to difficulty using temporal order cues in long-term memory. Two dissociable memory deficits were identified, suggesting that there are at least two neurocognitive mechanisms underlying memory impairment in MS.

Adult↗
PubMed1996

Changes in calcium transient and left ventricular function during positive inotropic stimulation and myocardial ischemia in indo-1-loaded beating guinea pig heart.

To elucidate the issues such as excitation-contraction coupling and myocardial ischemia, it is necessary to measure intracellular free Ca2+ concentration and mechanical function of hearts perfused via the normal arterial circulation. For this purpose, we simultaneously measured Ca(2+)-dependent indo-1 fluorescence and left ventricular (LV) pressure on a beat-to-beat basis in Langendorff guinea-pig hearts, and investigated the changes in Ca2+ transient and LV function during inotropic stimulation and myocardial ischemia. The indo-1 fluoresence ratio and LV developed pressure increased the perfusate [Ca2+] increased from 1.6 to 3.2 mmol/L, and there was a good correlation between Ca2+ transient and LV contractility. Digoxin (10(-6) mol/L) and milrinone (10(-5) mol/L) increased LV contractility with a concomitant increase in Ca2+ transient, and the relative increase of Ca2+ transient produced by milrinone was much more than that by digoxin. The reduction of coronary perfusion pressure from 80 to 40 mm Hg decreased LV contractility with an increase in indo-1 fluorescence ratio. These results suggest that Ca2+ responsiveness of contractile apparatus declines during inotropic stimulation by milrinone and during myocardial ischemia. Thus, this experimental technique is useful to investigate the interrelation of Ca2- regulation and LV function during a variety of pharmacological and physiologic perturbations.

Animals↗
PubMed1996

Transversely designed dorsal metacarpal V-Y advancement flaps for dorsal hand reconstruction.

Five successful cases of transversely designed dorsal metacarpal V-Y advancement flaps for reconstructing defects on the dorsum of the hand are reported. The flaps were supplied by dorsal metacarpal vessels. Proximally based flaps were used in 2 cases, one of which was supplied by two dorsal metacarpal arteries. Distally based flaps were used in 3 cases. All flaps survived completely.

Adolescent↗
PubMed1996

Freehand drawing impairments in probable Alzheimer's disease.

We evaluated freehand picture production of familiar objects in patients with probable Alzheimer's disease. The overall recognizability of their drawings was significantly compromised. Error analyses revealed the production of category violations and the frequent inclusion of incorrect features in a picture that were borrowed from semantically related objects, suggesting difficulty distinguishing between items with overlapping features sets in semantic memory. Analyses of individual patient drawing profiles also revealed that some patients are disproportionately compromised in expressing a particular perceptual feature, implicating difficulty at the level of perceptual processing. Regression analyses demonstrated the contribution of limited visual attentional resources. We conclude that impaired freehand drawing in probable Alzheimer's disease is multifactorial in nature.

Aged↗
PubMed1996

Endoscopic extraction of lipomas using an ultrasonic suction scalpel.

Lipomas were extracted with an ultrasonic suction scalpel, assisted by an endoscope, with good results. The combined surgical technique is described in this paper. Preoperative clinical findings and diagnostic imaging of the patients provided a preoperative diagnosis of lipomas. For the procedure, the endoscope was inserted through a small incision immediately above the tumor. The tumor was endoscopically confirmed and then extracted with an ultrasonic scalpel. Complete lipoma extraction was achieved in all patients without recurrence. The patients had good cosmetic results with only minimal postoperative scarring. The endoscopic extraction of lipomas with an ultrasonic scalpel is proven to be highly useful, especially for large tumors, and permits a less invasive and more reliable surgical operation.

Adult↗
PubMed1996

Compound rib-latissimus dorsi osteomusculocutaneous flap in reconstruction of the upper arm.

Reconstruction of humeral defects with a pedicled compound rib-latissimus dorsi osteomusculocutaneous flap is described. This flap consists of a latissimus dorsi musculocutaneous flap and segments taken from two ribs. In addition to the advantages of the conventional latissimus dorsi musculocutaneous flap, it enables multiple ribs to be transferred to the recipient site. This compound flap transfer can be used as a choice for a reconstructive procedure of the upper arm combined with humeral defects.

Bone Neoplasms↗
PubMed1996

Endoscope-assisted rectus abdominis muscle flap harvest for chest wall reconstruction: early experience.

We performed endoscope-assisted rectus abdominis muscle flap harvests on 2 patients with anterior chest wall defects. For the procedure, a spindle-shaped anterior fascia and the upper two-thirds of the rectus abdominis muscle were elevated endoscopically from an incision at the umblicus and transferred to the chest wall defect through a subcutaneous tunnel. Endoscopic harvest of the rectus abdominis muscle flap minimizes postoperative scarring caused by cutting off the flap, affording expectations of good cosmetic results. Furthermore, this surgical procedure is less invasive, relieves postoperative pain, and enables reduction of donor site morbidity.

Adult↗
PubMed1996

The originally designed TM HAKEN plate and its use in craniofacial surgery.

Rigid internal fixation using mini/microplates has become a frequent application in craniomaxillofacial surgery. To make plate fixation easier and reduce surgical time, the TM HAKEN plate, a kind of microplate, was devised and applied to craniofacial surgery. Advantages and indications of this plate are virtually the same as those of microplates of other types. And it permits positive fixation of artificial bone firmly without causing damage. We believe that the TM HAKEN plate serves as an excellent adjunct in craniofacial surgery.

Bone Plates↗
PubMed1996

Simple intermaxillary fixation for maxillomandibular osteosynthesis.

A simple intermaxillary fixation technique for the maxillomandibular osteosynthesis is devised using miniscrews and surgical wires. Using this technique, we have treated 13 cases of maxillomandibular fractures and osteotomies. Sufficient intermaxillary fixation was provided at surgery, and satisfactory results were obtained in all patients. This technique is quite simple and easy to use and requires no special instruments. Positive occlusion during surgery is obtained for the osteosynthesis, providing a very useful auxiliary technique for rigid internal fixation. The details of this technique are described.

Bone Screws↗
PubMed1996

Differences in nausea, vomiting, and retching between younger and older outpatients receiving cancer chemotherapy.

The purpose of this study was to determine whether there were differences in the side effects of nausea, vomiting, and retching (N, V, and R) between younger ( < 65 years, n = 102) and older ( > or = 65 years, n = 25) persons receiving outpatient chemotherapy. A longitudinal 4-month study was used for the 127 participants recruited from 18 settings. Participants completed two questionnaires (Inventory of N, V, and R and Behavior Checklist) over the course of the study. The pattern between the younger and older patients' N, V, and R subscale scores was consistent in that the younger patients' scores were consistently (except on one occasion) higher than the older patients' scores, but this difference was statistically insignificant. This study furthers our understanding of N, V, and R and has several clinical implications.

Adult↗
PubMed1996

Mechanisms and management of gastric cancer. A comparison between the Japanese and U.S. experiences.

While gastric cancer is on the decline in the United States, this cancer has been the leading cause of death in Japan since 1981. Although the mechanisms underlying the development of gastric cancer are not completely understood, certain epidemiological factors, particularly diet, are associated with this disease. This article presents information on the differences in disease classification, diagnostic and screening procedures, treatment approaches, and mortality statistics between the United States and Japan. In addition, the clinical manifestations of gastric cancer are summarized, and the nursing care of the patient is outlined using a nursing diagnosis format.

Aged↗
PubMed1996

Decrease in oxygen cost of contractility during hypocapnic alkalosis in canine hearts.

Ca2+ sensitization of contractile machinery could theoretically enhance the mechanoenergetics of the heart. We studied the effects of alkalosis with Ca2+ sensitization on mechanoenergetics within the framework of the relationships of left ventricular pressure-volume area (PVA; a measure of the total mechanical energy), myocardial oxygen consumption per beat (VO2), and the contractility index [E(max) (slope of end-systolic pressure-volume relation)] in 10 excised, cross-circulated canine hearts. Alkalosis was stably maintained without hypoxia (mean pH 7.66). Alkalosis increased E(max) without changing the slope of the VO2-PVA relation, a reflected contractile efficiency. The incremental ratio of unloaded VO2 to E(max) in alkalosis was significantly lower than that in Ca2+ sensitization (0.0012 +/- 0.0010 vs. 0.0062 +/- 0.0030 ml O2 . mmHg-1 . ml . beat-1 . 100 g LV-2; P < 0.01). Basal metabolism under KCl arrest was unchanged by alkalosis, indicating the decreased energy cost of the excitation-contraction coupling by alkalosis. Compared with the control, alkalosis increased E(max) during the Ca2+ infusion of various concentrations without any further increase in unloaded VO2. Thus we demonstrated a decreased oxygen cost of contractility during alkalosis, presumably due to Ca2+ sensitization.

Alkalosis, Respiratory↗
PubMed1996

Differential effects of EMD-53998 on calcium-pressure relationship in normal and ischemic guinea pig heart.

We investigated the effects of EMD-53998 and digoxin on Ca2+ transients and left ventricular (LV) function in indo 1-loaded Langendorff guinea pig hearts. EMD-53998 (10(-9) to 10(-5) M) and digoxin (10(-10) to 10(-6) M) increased +dP/dt and Ca2+ transients in normal hearts. The relative increase in Ca2+ transients by EMD-53998 was similar to digoxin. At 10(-5) M, EMD-53998 increased LV end-diastolic pressure. Low-flow ischemia decreased +dP/dt by 50%, while indo 1 ratio increased by 10-25%. EMD-53998 (10(-9) to 10(-6) M) effectively restored the depressed +dP/dt with little effect on indo 1 ratio, but at 10(-5) M, it markedly elevated LV end-diastolic pressure and the beneficial effect on contractile dysfunction disappeared. Digoxin (10(-10) to 10(-7) M) failed to improve LV function, but at 10(-6) M, it restored contractile dysfunction with a large increase in indo 1 ratio. The relation between indo 1 ratio and +dP/dt clearly showed that EMD-53998 restored contractile dysfunction by Ca2+ sensitization. These findings suggest that Ca2+ sensitization by EMD-53998 is an advantageous approach for ischemic contractile failure but impairs diastolic function.

Animals↗
PubMed1996

Blood pressure and its regulation in spontaneously hypertensive rats bred on the lowest sodium diet for normal growth.

To investigate the effects of dietary sodium restriction from conception to adulthood on blood pressure and its regulatory mechanisms, male offspring were derived from inbreeding in spontaneously hypertensive rats fed a diet containing sodium of 175 mumol/g food (control) or 22 mumol/g (low sodium), which is the least sodium content for normal growth. While urinary sodium excretion was markedly less, the low sodium diet did not inhibit body growth and failed to blunt the development of hypertension. Neither plasma catecholamine concentration nor depressor response to hexamethonium was different between the two groups at any age examined (8, 12, and 20 weeks). Plasma renin concentration was not elevated, whereas urinary excretion of aldosterone was increased at any age in the low sodium group compared with that in the control group. Other sets of rats were fed a diet containing sodium of 175 mumol/g plus mefruside (a diuretic) of 0.001% in the same manner as in the other two groups. Urinary sodium excretion per creatinine was higher than in the other groups. The diuretic treatment inhibited body growth and suppressed adult blood pressure. While the sympathetic function was not affected, both plasma renin concentration and urinary excretion of aldosterone were elevated. These results indicate that dietary sodium restriction with the least sodium for normal growth from conception cannot blunt either the sympathetic nervous function or the development of hypertension in spontaneously hypertensive rats. Aldosterone appears to play an important role in maintaining sodium homeostasis under the dietary sodium restriction.

Aldosterone↗
PubMed1996

Language comprehension profiles in Alzheimer's disease, multi-infarct dementia, and frontotemporal degeneration.

We assessed language functioning in 116 age-, education-, and severity-matched patients with the clinical diagnosis of Alzheimer's disease (AD), multi-infarct dementia (MID) due to small-vessel ischemic disease, or a frontotemporal form of degeneration (FD). Assessments of comprehension revealed that patients with AD are significantly impaired in their judgments of single word and picture meaning, whereas patients with FD had sentence comprehension difficulty due to impaired processing of grammatical phrase structure. Patients with MID did not differ from control subjects in their comprehension performance. Traditional aphasiologic measures did not distinguish between AD, MID, and FD. Selective patterns of comprehension difficulty in patients with different forms of dementia emphasize that language deficits cannot be explained entirely by the compromised memory associated with a progressive neurodegenerative illness.

Aged↗
PubMed1996

Calcium sensitization in perfused beating guinea pig heart by a positive inotropic agent MCI-154.

We investigated the effects of MCI-154, a positive inotropic agent that increases the myofilament response to Ca++, on Ca++ transients, left ventricular (LV) function and phosphodiesterase (PDE) III activity of guinea pig heart, and compared them with the effects of pimobendan and milrinone. In Langendorff guinea pig hearts loaded with a fluorescent Ca++ probe indo-1, LV pressure and Ca++ transient were measured simultaneously. MCI-154 (10(-10)-10(-6) M) increased LV developed pressure, +dP/dt and -dP/dt with a reduction of LV end-diastolic pressure, although it did not affect coronary flow. The positive inotropic activity of MCI-154 was more potent than that of pimobendan and milrinone; EC50 values (concentrations for increasing +dP/dt by 50% from base line) were 4.31, 41.5 and 294 x 10(-9) M, respectively. The positive inotropic effect of MCI-154 was accompanied by the increase in systolic, diastolic and amplitude of indo-1 fluorescence ratio. The relative increase in Ca++ transients against the increase in LV contractility produced by MCI-154, however, was significantly less than that by increasing perfusate [Ca++], pimobendan or milrinone. MCI-154 (3 x 10(-7)-10(-4) M) inhibited the activity of PDE III isolated from guinea pig LV tissues, but the inhibitory effect of MCI-154 was less than pimobendan and milrinone; IC50 values were 10.1, 3.5 and 2.4 x 10(-6) M, respectively. These findings suggest that MCI-154 exerts a positive inotropic effect mainly through Ca(++)-sensitizing action in intact beating whole hearts.

Animals↗