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Biomedical subjects

K Onishi

Publications and source records attributed to K Onishi.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Determination of sennoside A and sennoside B in formulation using capillary electrophoresis].

The determination of sennoside A (SA) and sennoside B (SB) by capillary zone electrophoresis was developed. The separation of SA and SB was performed in 100 mM of the 3-[cyclohexylamino]-1-propanesulfonic acid (CAPS) buffer (pH 10.0), and the migration time of SA and SB was found to be both less than 7 min. This method was applied to the analyses of seven commercial formulations containing SA and SB without previous treatment. The statistical comparison of the results obtained from both capillary electrophoresis and HPLC methods revealed an absolute correlation.

Anthraquinones↗
PubMed1999

Endogenous endothelin-1 depresses left ventricular systolic and diastolic performance in congestive heart failure.

Endothelin-1 (ET-1) is a positive inotrope in normal hearts; however, the direct cardiac effects of endogenous ET-1 in congestive heart failure (CHF) are unknown. We evaluated the cardiac responses to endogenous ET-1 using an ETA and ETB receptor blocker (L-754,142) in seven conscious dogs before and after pacing-induced CHF. Before CHF, when the plasma ET-1 was 7.3 +/- 1.7 fmol/ml, L-754,142 caused no significant alterations in heart rate, left ventricular (LV) end-systolic pressure, total systemic resistance, and the time constant of LV relaxation (tau). LV contractile performance, measured by the slopes of LV pressure (P)-volume (V) relation (EES), dP/dtmax-end-diastolic V relation (dE/dtmax), and stroke work-end-diastolic V relation, was also unaffected. After CHF, when the plasma ET-1 was significantly increased to 14.1 +/- 3.0 fmol/ml (p <.05), L-754,142 produced a significant decreases in LV end-systolic pressure (101 +/- 11 versus 93 +/- 8 mm Hg) and total systemic resistance (0.084 +/- 0.022 versus 0.065 +/- 0.15 mm Hg/ml/min). The tau (42 +/- 12 versus 38 +/- 10 ms), mean left atrial P (22 +/- 5 versus 18 +/- 4 mm Hg) (p <.05), and minimum LVP were also significantly decreased. After CHF, the slopes of P-V relations, EES (3.4 +/- 0.4 versus 4.8 +/- 0.8 mm Hg/ml), dE/dtmax (42.4 +/- 7.8 versus 50.0 +/- 7.8 mm Hg/s/ml), and stroke work-end-diastolic V relation (58.1 +/- 3.3 versus 72.4 +/- 5.2 mm Hg) (p <.05) all increased after L-754,142, indicating enhanced contractility. Before CHF, low levels of endogenous ET-1 have little cardiac effect. However, after CHF, elevated endogenous ET-1 produces arterial vasoconstriction, slows LV relaxation, and depresses LV contractile performance. Thus, elevated endogenous ET-1 may contribute to the functional impairment in CHF in this canine model.

Animals↗
PubMed1998

Endoscopic osteosynthesis for frontal bone fracture.

Endoscopic surgery to repair a frontal bone fracture is described. This operation is less invasive than the conventional open technique, which is performed under direct vision through a bicoronal or eyebrow incision. Endoscopic surgery leaves no conspicuous scars in the forehead and is free from complications such as nerve or vascular injuries, and appears to be of significant clinical value.

Adult↗
PubMed1998

The dorsal metacarpal flap for secondary digital artery flap donor sites.

The effective approach of the reverse digital artery flap for reconstruction of the distal phalanges, fingertips, and finger pulp is used widely in a clinical setting. However, the most potential problem is that digital artery flap donor sites cannot be closed primarily. We have used distally based dorsal metacarpal flaps to cover secondary digital artery flap donor sites in 12 patients. The use of adjacent tissue provided the best possible texture and color match for the dorsal half of the lateral side of the finger. This allowed aesthetically superior wound closure to that achieved by conventional methods employing skin grafts.

Adolescent↗
PubMed1998

Combination latissimus dorsi and rectus abdominis musculocutaneous flap for primary repair of a large upper limb defect.

The usefulness of flap transfer in reconstructive surgery is well established, and various types of flaps have been reported. However, concomitant use of skin grafts or repair by plural flaps must be utilized for large defects. We have obtained satisfactory results in the primary repair of a large defect covering the entire length of the upper limb by using a combination flap consisting of latissimus dorsi and rectus abdominis musculocutaneous flaps. This surgical procedure is relatively easy, safe, and reliable. Moreover, it is possible to harvest a combination flap possessing a wide arc of rotation with either the latissimus dorsi muscle or the rectus abdominis muscle as a pedicle. This reconstructive method should be considered for large defects.

Adult↗
PubMed1998

Language comprehension and regional cerebral defects in frontotemporal degeneration and Alzheimer's disease.

We related profiles of language comprehension difficulty to patterns of reduced cerebral functioning obtained with high-resolution single photon emission computed tomography (SPECT) in patients with neurodegenerative conditions. We found different patterns of reduced relative cerebral perfusion in patients with frontotemporal degeneration (FD) and patients with Alzheimer's disease (AD). Cognitive assessments also showed different patterns of impaired comprehension in patients with FD and patients with AD. Grammatical comprehension difficulty in FD correlated with relative cerebral perfusion in left frontal and anterior temporal brain regions; impaired semantic processing in AD correlated with relative cerebral perfusion in inferior parietal and superior temporal regions of the left hemisphere. These findings are consistent with the hypothesis that a neural network distributed throughout the left hemisphere subserving different aspects of language comprehension, rather than a single brain region, is responsible for understanding language.

Aged↗
PubMed1998

Functional effects of endogenous bradykinin in congestive heart failure.

OBJECTIVES: The purpose of this study was to determine the level and functional effects of endogenous bradykinin in congestive heart failure (CHF). BACKGROUND: There is experimental evidence that bradykinin is increased in several cardiac disease states. However, it is unknown whether plasma levels of bradykinin are elevated in CHF. Further, the cardiac and vascular responses to bradykinin in CHF are unclear. METHODS: The circulating levels of bradykinin and the effects of endogenous bradykinin were assessed in eight instrumented, conscious dogs both before and after pacing-induced CHF. RESULTS: Before CHF, the plasma bradykinin level was 53.1 +/- 12.4 pg/ml. Blocking endogenous bradykinin with HOE-140 (0.3 mg/kg), a specific bradykinin B2-receptor antagonist, produced no significant alterations in heart rate, left ventricular (LV) end-systolic pressure (Pes), total systemic resistance (TSR), the time constant of LV relaxation (tau) or the maximal rate of LV filling (dV/dt(max)). However, coronary blood flow was significantly reduced (p < 0.05). LV contractile performance measured by the slopes of pressure-volume relations was unaffected. After induction of CHF, the plasma bradykinin level increased to 234.2 +/- 19.4 pg/ml (p < 0.05). Blocking endogenous bradykinin with HOE-140 reduced coronary blood flow and produced significant increases in Pes and TSR, prolonged tau, decreased dV/dt(max) and elevated minimal LV pressure and mean left atrial pressure. Furthermore, the slopes of pressure-volume relations (p < 0.05) were decreased, indicating depressed contractility with HOE-140 after CHF. CONCLUSIONS: Before CHF, endogenous bradykinin results in coronary dilation but has no effect on systemic arterial vasodilation or cardiac performance. After CHF, endogenous bradykinin is significantly increased and, acting through B2-receptors, produces coronary and arterial vasodilation and improves LV relaxation and contractile performance. Thus, endogenous bradykinin may play an important role in preserving cardiovascular function in CHF.

Animals↗
PubMed1997

Lexical acquisition in probable Alzheimer's disease.

Patients with probable Alzheimer's disease (pAD) were exposed to a new verb in a naturalistic fashion. We probed their knowledge of the word's semantic and grammatical characteristics for several minutes following this exposure, and compared this with their performance on parallel measures assessing known words. Significant differences were seen between pAD patients and controls in the acquisition of the new verb's semantic meaning and its argument structure, but pAD patients did not differ from controls in the acquisition of the new word's grammatical form class. Individual patient analyses demonstrated parallel deficits restricted to the semantic meaning and argument structure of the new word and known words in several pAD patients, suggesting that a selective language impairment contributed to their word learning deficit. This pattern is consistent with an intimate relationship between semantic meaning and argument structure in semantic memory. Other pAD patients had difficulty learning about all aspects of the new word, despite good performance with known words, suggesting that compromised memory may have limited their lexical acquisition.

Aged↗
PubMed1997

Endoscopic harvest of the tensor fasciae latae muscle flap.

Endoscopic harvest of the tensor fasciae latae muscle flap is presented. Two cases of abdominal wall hernia were treated with reinforcement of the abdominal wall using endoscopically harvested, pedicled tensor fasciae latae muscle flaps. The scars of the thigh after flap harvest were much shorter than the scar of the conventional open technique and the results were satisfactory. As the tensor fasciae latae muscle is easily undermined, we think it is appropriate to harvest the flap using an endoscope. Fascial grafts can also be harvested in the same manner as the pedicled flap.

Endoscopy↗
PubMed1997

Bilobed fasciocutaneous flap for primary repair of a large upper arm defect with secondary closure of the donor site without a skin graft.

Primary repair of 2 patients with large upper arm defects with the bilobed fasciocutaneous flap is reported. In this procedure the repair of a large soft-tissue defect with a flap prepared adjacent to the defect and closure of the flap donor site are performed at the same time without a skin graft. This procedure enabled regional reconstruction and provided excellent aesthetic results. It is simple and reliable. In addition, primary repair of large upper arm defects can be expected.

Aged↗
PubMed1997

Use of endoscopic surgery for forehead recontouring.

Forehead recontouring in endoscopic surgery is presented. Eleven cases of protruded forehead deformity caused by benign tumor and one case of concave deformity caused by depressed frontal bone fracture were treated. All lesions were approached through incisions made in the hair-bearing area and operated on endoscopically. This method left no scars on the forehead, and the results were satisfactory. It is considered to be an excellent procedure with regard to cosmetic results.

Endoscopy↗
PubMed1997

Constraints on the cerebral basis for semantic processing from neuroimaging studies of Alzheimer's disease.

OBJECTIVE: Functional activation studies of semantic processing in healthy adults have yielded conflicting results. The purpose was to evaluate the relative role of the brain regions implicated in semantic processing with converging evidence from imaging studies of patients with impaired semantic processing. METHODS: Semantic memory was assessed in patients with Alzheimer's disease using two measures, and these performance patterns were related to profiles of reduced cerebral functioning obtained with high resolution single photon emission computed tomography (SPECT). Patients with frontotemporal degeneration were similarly evaluated as a control group. RESULTS: Reduced relative cerebral perfusion was seen in parietal and posterior temporal brain regions of patients with Alzheimer's disease but not patients with frontotemporal degeneration. Impairments on semantically guided category membership decision tasks were also seen in patients with Alzheimer's disease but not those with frontotemporal degeneration. Performance on the semantic measures correlated with relative cerebral perfusion in inferior parietal and superior temporal regions of the left hemisphere only in Alzheimer's disease. Relative perfusion was significantly lower in these regions in patients with Alzheimer's disease with semantic difficulty compared with patients with Alzheimer's disease with relatively preserved semantic processing. CONCLUSION: These findings provide converging evidence to support the contribution of superior temporal and inferior parietal regions of the left hemisphere to semantic processing.

Aged↗
PubMed1997

MCI-154, a Ca2+ sensitizer, decreases the oxygen cost of contractility in isolated canine hearts.

An increase in the responsiveness of the contractile machinery to Ca2+ could theoretically enhance the mechanoenergetics of the heart. To clarify this unresolved issue, we studied the effects of MCI-154, a Ca2+ sensitizer, on the mechanoenergetics in terms of the left ventricular contractility index [slope of end-systolic pressure-volume relationship (Emax)] and the relationship between myocardial oxygen consumption (VO2) and left ventricular pressure-volume area in excised cross-circulated canine hearts. MCI-154 increased Emax by 42 +/- 31% (SD), although the slope of the VO2-PVA relationship (an indicator of contractile efficiency) was unchanged by MCI-154. Despite equal increases in Emax, the relative increase in unloaded VO2 (delta VO2/delta Emax) during infusion of MCI-154 was, however, significantly less than that during CaCl2 infusion (0.0016 +/- 0.0018 vs. 0.0059 +/- 0.0054; P < 0.05). By contrast, delta VO2/delta Emax for milrinone was the same as that for CaCl2 (0.0043 +/- 0.0041 vs. 0.0039 +/- 0.0045; P > 0.05). Basal metabolism in KCl-arrested hearts was unchanged by MCI-154, indicating that MCI-154 consumes less energy than CaCl2 for excitation-contraction coupling. These findings suggest that MCI-154 acts energetically as a Ca2+ sensitizer in beating canine whole hearts.

Animals↗
PubMed1997

[Usage of intra-operative scalp expansion for primary wound closure in cranio-facial operation].

The size of detects in scalp for which primary wound closure can be applied is limited. Cases with a scalp defect for which primary wound closure is difficult to perform are frequently seen. In these cases, an attempt is made to close the wound by extending the margin of an incision produced by extensive subgaleal undermining or galeal incisions. However, its effectiveness is limited. We performed in such cases intra-operative scalp expansion with a tissue expander for primary wound closure, and this technique has yielded good results. A case with craniosynostosis and five cases with cranioplasty received this procedure. Four of these cases had a previous history of undergoing surgery for carvarial bone defect three to five times from the same incision. The scalp at the carvarial bone defect had a scar and was atrophic with great depression. It was expected that the expansion of cranium resulting from cranioplasty would make it difficult to perform primary wound closure. During the surgery, a tissue expander was placed subgaleally in an osseous area prior to the bone operation, and intermittent air expansion was carried out for 20 to 30 minutes by means of air inflation and deflation to expand the scalp. In all of these cases little tension was generated by the wound closure despite the lapse of time during the bone operation. In consequence, primary wound closure was accomplished easily, and the reliable closure of the galea made it possible to prevent the scar widening. This is a simple and easy technique combining primary wound closure of the scalp with intra-operative scalp expansion. We believe that the technique should be considered for cases for whom primary closure of compression deformity is difficult or in whom there is a wound at the carvarial reconstruction site. The technique and typical cases are reported.

Aged↗