Biomedical subjects

T Iwahara

Publications and source records attributed to T Iwahara.

30 records · Page 2Linked to original sources

PubMed1991

[The influence of spine distraction on cat spinal cord blood flow and evoked potentials].

The changes of spinal cord blood flow (SCBF) and spinal cord evoked potential (SCEP) due to spine distraction were analyzed in 30 cats. Spine distraction was performed at L1/2 level at which spinal bodies were separated surgically. SCBF was measured by means of a microsphere technique before, during and after spine distraction and SCEP elicited by spinal cord electrical stimulation was recorded simultaneously. With slight spine distraction (SCEP amplitude 80-100%), SCBF was increased significantly over normal value. SCBF was decreased significantly by further distraction (SCEP 50-80%), but was recovered over normal value after the release of distraction. When severe distraction (SCEP less than 50%) was applied, decreased SCBF around L1 level was irreversible. These results suggested that the disorder of SCBF regulating system due to spine distraction could be expected by analyzing changes of the SCEP.

Animals↗

PubMed1990

[A combined anti-emesis therapy of oral prednisolone and alprazolam for cisplatin-induced delayed emesis].

To evaluate the efficacy of a combined therapy of prednisolone and alprazolam for controlling cisplatin-induced delayed emesis, a study involving 14 non-small cell lung cancer patients receiving cisplatin (80 mg/m2) was conducted. Seven of these patients were given oral prednisolone at a dose of 30 mg/day for 5 days, then, 15 mg/day for 2 days, and with alprazolam at a dose 1.2 mg/day for 7 days. The other 7 patients were given an oral metoclopramide at a dose of 1 mg/kg/day for 5 days, and at 0.5 mg/kg/day for 2 days. All patients received 2 courses of chemotherapy and the same assigned regimen. Five of the 7 patients who had received prednisolone and alprazolam experienced no emesis, in contrast to only 1 patient who experienced no emesis from taking oral metoclopramide (p less than 0.05). Further, the duration of anorexia was shorter in those who received oral prednisolone with alprazolam. Thus, a combined therapy of oral prednisolone and alprazolam appears to be effective for controlling cisplatin-induced delayed emesis. Further evaluation and study, however, are necessary.

Administration, Oral↗

PubMed1990

[Simultaneous bilateral spontaneous pneumothoraces].

Seven cases (1.9%) of simultaneous bilateral pneumothoraces were found in a retrospective study of 377 patients with spontaneous pneumothorax during the period from July, 1977 to June, 1989. Their symptoms were essentially those of unilateral pneumothorax, but with more severe dyspnea. All but two cases, both young, had underlying pulmonary diseases. Three (two lung cancers and one metastatic lung disease) had malignant pulmonary disease. During this period, five lung cancer patients were complicated with pneumothorax, and two of them had simultaneous bilateral pneumothoraces. Therefore the frequency of bilateral pneumothoraces in the lung cancer patients associated with pneumothorax is high. In these three patients with malignant disease, tube drainage was carried out but all died of respiratory failure. Two senile patients had small bilateral pneumothoraces. Bed rest without invasive treatment led to successful cure. Two younger patients without underlying pathology initially underwent tube drainage, followed by operation. We conclude that many patients with simultaneous bilateral spontaneous pneumothoraces have underlying pulmonary disease, the frequency of lung cancer being particularly high. Young patients without underlying disease should be operated on following alleviation of symptoms by tube drainage. Older patients and patients with malignancy should be treated with great care and individually.

Adolescent↗

PubMed1989

Automated spinal cord monitoring for spinal surgery.

A microcomputer-based automated spinal cord monitoring system was developed and 56 spinal operations have been carried out with it since 1986. The system comprises an electrodiagnostic system (Dantec 2000M), an FM tape recorder, a channel selector, an electrical relay, a Modem and a microcomputer which controls all of the elements. The program allowed for automated recording and analysis of evoked potentials during spinal surgery and alarm signals were generated according to the criteria of amplitude decrease and latency delay. It was demonstrated that automated spinal cord monitoring in the operating room was performed easily, reliably and safely allowing the surgeon to react quickly to possible compromise of the spinal cord. The design and usefulness of the system is described in this report.

Diagnosis, Computer-Assisted↗

PubMed1988

Lumbar degenerative kyphosis. Clinical, radiological and epidemiological studies.

We suggest that lumbar degenerative kyphosis be included as one of the abnormal sagittal curvatures in which a kyphosis or a marked loss of lordosis is seen in the lumbar spine, caused by degenerative changes in middle-aged and elderly. One hundred and five consecutive patients were investigated, most of whom complained of low-back pain, often with a long history. They all walked in a forward bending posture, either all the time or only when exhausted. In roentgenograms, most cases showed a marked loss of the sacral inclination, as well as multiple disc narrowing and/or vertebral wedging in the lumbar region. These subjects showed a definite weakness of the lumbar extensors compared to the flexors, and therefore a reversed ratio of extensors/flexors muscle power compared with normal controls and other types of spinal curvatures. Weakness of the lumbar extensors was clearly shown by isokinetic measurement and a marked atrophy of these muscles with fatty infiltration was demonstrated by CT scanning.

Aged↗

PubMed1983

Intraosseous ganglion of the lunate.

The case of a thirty-year-old woman with a cystic lesion in the right lunate is reported. The cyst was an intraosseous ganglion which is a relatively rare entity in that location.

Adult↗

PubMed1982

Studies on reconstituted myoglobins and hemoglobins. I. Role of the heme side chains in the oxygenation of myoglobin.

To clarify the functional role of the 2- and 4-side chains of heme in myoglobin oxygenation, we synthesized several new hemins carrying nonnatural side chains at positions 2 and 4, reconstituted myoglobins with them, and investigated their optical, ionization, and oxygen-binding properties. The absorption maxima for most of the reconstituted myoglobins except those reconstituted with hemins having carbonyl groups, no matter whether they are oxy-, deoxy-, or carbon monoxy-form, shifted by at most 20 nm toward shorter wavelengths than protoheme-myoglobin. The absorption spectrum is more affected by resonance effects than by inductive effects of the peripheral side chains of heme. Differences in optical and oxygenation properties between isomeric myoglobins carrying hemes with different side chains at positions 2 and 4 indicate that the 2- and 4-side chains of heme are functionally nonequivalent, as previously shown by Sono and Asakura [(1975) J. Biol. Chem. 250, 5227-5232] for monoformyl-monovinylheme myoglobins. Modification of the 4-side chain exerts greater influence on the oxygen affinity than that of the 2-side chain. The extrapolation method proposed by Sono and Asakura to correct for the protein factor seems to be applicable only as a special case and does not apply to the isomeric myoglobins studied by us. There was not correlation between pKa of the met-form and the oxygen pressure at half saturation, implying that the electronic effect of the side chains is not decisive for the oxygen affinity of myoglobin. The bulkiness of the 2- and 4-side chains, on the other hand, appear to have a certain relation to the affinity but is not a dominant factor. In addition to these factors, specific stereochemical considerations are required to explain all the oxygenation data for the various reconstituted myoglobins. We have proposed a stereochemical mechanism based on the movement of the heme group upon ligation of native myoglobin.

Acylation↗

PubMed1972