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Biomedical subjects

H Osada

Publications and source records attributed to H Osada.

At least 181 records · Page 10Linked to original sources
PubMed1995

In vivo occurrence of p16 (MTS1) and p15 (MTS2) alterations preferentially in non-small cell lung cancers.

Frequent homozygous deletions of the p16 (MTS1) gene encoding a cyclin-dependent kinase inhibitor were recently reported in various tumor cell lines including examples derived from lung cancers, but direct evidence for their occurrence in lung cancer patients has not been reported thus far. In the present study, alterations of p16 and/or p15, a p16-related cyclin-dependent kinase, were observed not only in lung cancer cell lines but also in the corresponding tumor specimens in vivo, excluding the possibility of in vitro artifacts. Interestingly, a clear specificity was also noted in terms of the affected histological subtype; i.e., only non-small cell lung cancers carried alterations (6 of 20 as compared to 0 of 20 small cell lung cancer cell lines).

Base Sequence↗
PubMed1995

A complete hydatidiform mole coexisting with a normal fetus was confirmed by variable number tandem repeat (VNTR) polymorphism analysis using polymerase chain reaction.

The diagnosis of a complete hydatidiform mole coexisting with a live fetus is often difficult because of the morphological similarity to a partial mole, but it is crucial to management in the postmolar course. We present a recent case in which DNA polymorphism analysis clearly revealed a different genetic origin for the fetal and molar parts. DNA polymorphisms on three different variable number tandem repeat loci, which were detected by polymerase chain reaction, indicated that the cord/placenta and molar tissue were parental and androgenetic, respectively. Subsequently, the patient was admitted for chemotherapy of metastatic trophoblastic disease.

Adult↗
PubMed1995

Cardio-pulmonary function of cyclists competing on an ascending mountain course between altitudes of 1400 m and 2800 m.

Physiological changes were investigated in the cardio-respiratory function of competitors in a bicycle race which involved not a flat course but ascending a mountain, from 1400 m to 2800 m. Heart rate throughout the race, arterial oxygen saturation and pulmonary function before and after the race of well trained competitors were measured. The individual's maximal heart rate during the race was designated as HRmax for the calculations. (1) There were significant correlations between the age and the mean %HRmax during the race, between mean %HRmax and time, and between age and time (n = 15); the mean %HRmax had a 3.90 times greater effect on time than did age. (2) The individuals who performed best had lower values of oxygen saturation just after finishing the race (n = 51). (3) At 1 min after reaching the finishing line, oxygen saturation levels had recovered to the value of 20 min after finishing the race, whereas the heart rate was still in the process of recovery (n = 18). (4) Maximum expiratory flow at 50% vital capacity measured 30 min after reaching the finishing line was significantly higher than at the starting point. The intensity of the load on the cardiac system produced by completion of this course was estimated to be almost the same as that of a full marathon on a flat course. The time depended on both the youth of the cyclist and on his ability to maintain a high value of %HRmax during the race.

Adolescent↗
PubMed1995

Differences in the characterization of the Ca2+ current in ventricular myocytes between spontaneously hypertensive rats and normotensive rats.

1. The slow inward Ca2+ current elicited at the membrane potential -30 mV in SHR and normotensive Wistar rats (WR) with voltage-clamp recording was examined for this study. 2. The maximal Ca2+ current of WR in the current-voltage relationship showed the unified membrane potential of +10 mV and the amplitude was -1.2 +/- 0.2 pA. In the case of SHR, however, the maximal Ca2+ current showed a lower and variable membrane potential between 0 and -20 mV. The amplitudes were -1.7 +/- 0.9 pA at 0 mV, -2.1 +/- 0.8 pA at -10 mV and -4.4 +/- 0.3 pA at -20 mV. 3. From the cell-attached patch-clamp recording, the conductance of unitary Ca2+ current and the slope value were the same in SHR and in WR. From the open-time histogram of the Ca2+ channel, the open state probability in SHR increased and the time constant from the exponential curve became slightly extended in SHR. 4. L-isoproterenol at 10(-6) mol/L increased the Ca2+ current in SHR and WR. The increased ratio of Ca2+ current by l-isoproterenol was smaller in SHR than that in WR. 5. The aspect of 1-4 suggests that the increase in Ca2+ current in SHR obtained by the voltage-clamp was explained partly by the increase of open-state probability of unitary Ca2+ channel activity, and that a possibility of Ca2+ channel being activated by phosphorylation through cAMP did not eventuate.

Adrenergic beta-Agonists↗
PubMed1995

RS-22A, B and C: new macrolide antibiotics from Streptomyces violaceusniger. I. Taxonomy, fermentation, isolation and biological activities.

Three novel 36-membered macrolide antibiotics, RS-22A, B and C produced by Streptomyces violaceusniger have been isolated. These antibiotics were purified from an acetone extract of the mycelia followed by butanol extraction, centrifugal partition chromatography and HPLC. RS-22A, B, C showed antimicrobial activity against fungi and Gram-positive bacteria.

Anti-Bacterial Agents↗
PubMed1995

[Relationship of physical condition and functional capacity to depressive status in person aged 75 years].

The purpose of the present study is to examine cross-sectionally and longitudinally the relationship of physical conditions and functional capacity to depressive status in the elderly. Subjects comprised 308 men and women aged 75 years and over living at home in a rural community. Geriatric Depression Scale (GDS) was employed to assess depressive status, and physical conditions and functional capacity were simultaneously investigated. The results obtained were as follows; 1. There was no significant difference in GDS score by age or sex. 2. Cross-sectionally, the depressive status was significantly associated with weakened grip strength and poor locomotion in men, and it was associated with experience of falls, poor chewing ability, and low levels in high functional capacity as measured by the TMIG Index of Competence. 3. Longitudinally over a 2 year period, bereavement, decline of locomotion, and persistent anxiety about physical conditions significantly influenced aggravation of the depressive status in men. In women, high systolic blood pressure and visual and/or hearing impairment influenced the aggravation. Decline in functional capacity as measured by the TMIG Index of Competence appeared to influence the aggravation in both men and women.

Aged↗
PubMed1995

Bilateral intralobar pulmonary sequestration.

A 34-year-old male presented with an infected intralobar pulmonary sequestration of the left lower lobe. Aortography revealed bilateral anomalous systemic arteries, originating in the lower level of the descending thoracic aorta, to the lower lobe on each side. The portion of the right lower lobe, which was perfused by the anomalous systemic artery was seen otherwise normal in anatomy without any recognizable sequestered lung tissue. The patient underwent a left postero-lateral thoracotomy on June 22, 1994. Each aberrant artery was recognized to take off from a common branch of the descending aorta at the level of the diaphragm. A left lower lobectomy with division of the left aberrant artery as well as ligation of the right anomalous artery were done. A postoperative pulmonary perfusion scan depicted normal uptake of radioactivity in the right lower lobe, suggesting normal pulmonary arterial perfusion to the area receiving previously the anomalous systemic arterial flow. An anomalous systemic artery perfusing an otherwise normal lung can be classified as one of the forms of intralobar pulmonary sequestration and could be ligated without resection of the involved area of the lung.

Adult↗
PubMed1995

[Surgical treatment of posterior mediastinal teratoma].

A 22-year-old male patient was admitted to our hospital because of an abnormal shadow on a chest X-ray taken for routine examination. Preoperative diagnostic work up including chest computed tomography and magnetic resonance imaging suggested that the tumor would most likely to be a posterior mediastinal lipoma. Through a right thoracotomy the tumor was removed successfully. Histologically it proved to be a mature teratoma. The incidence, etiology and diagnostic procedure of the mediastinal teratoma was discussed.

Adult↗
PubMed1994

[Measurement of cerebral blood flow in normal subjects by phase contrast MR imaging].

Global cerebral blood flow (CBF) was quantitatively measured with a two-dimensional phase contrast cine magnetic resonance (MR) imaging technique in 24 normal subjects (mean age, 38.6 years; range, 12-70 years). Cine transverse images of the upper cervical region (32 phases/cardiac cycle) were acquired with a 1.5 Tesla MR imaging unit. In five subjects, measurement of CBF was performed before and after intravenous administration of acetazolamide (DIAMOX, 15 mg/kg). Inter- and intraobserver variations in flow volume measurement were small (r = 0.970, standard error of the estimate (SEE) = 2.9 ml/min, n = 80; r = 0.963, SEE = 4.6 ml/min, n = 40, respectively). In measuring flow velocity, they were inferior to those of flow volume measurement. On a visually determined setting of region of interest (ROI), reproducibly of the measurement of flow velocity was not satisfactory in this study. Thus only the results of flow volume measurement are presented. Mean summed vertebral flow volume (171 ml/min, SD = 40.6) was significantly less than mean summed internal carotid flow volume (523 ml/min, SD = 111). Total blood flow volume showed a significant decline with age (r = 0.45, p < 0.05). The mean proportions of carotid and vertebral flow volume to total flow volume were 75.3% and 24.7%, respectively, and showed no significant change with age. The left-to-right ratio of vertebral flow volume (1.39) was significantly higher than that of internal carotid flow volume (0.99, r = 0.05). After DIAMOX i.v., the mean rate of increase in total flow volume was 157%. Mean rates of increase in carotid and vertebral flow volume were 154% and 166%, respectively, which were not significantly different. In conclusion, this method is useful for estimating carotid and vertebral flow volume.

Acetazolamide↗
PubMed1994

Specific in vivo association between the bHLH and LIM proteins implicated in human T cell leukemia.

The protein products of proto-oncogenes implicated in T cell acute lymphoblastic leukemia include two distinct families of presumptive transcription factors. RBTN1 and RBTN2 encode highly related proteins that possess cysteine-rich LIM motifs. TAL1, TAL2 and LYL1 encode a unique subgroup of basic helix-loop-helix (bHLH) proteins that share exceptional homology in their bHLH sequences. We have found that RBTN1 and RBTN2 have the ability to interact with each of the leukemogenic bHLH proteins (TAL1, TAL2 and LYL1). These interactions occur in vivo and appear to be mediated by sequences within the LIM and bHLH domains. The LIM-bHLH interactions are highly specific in that RBTN1 and RBTN2 will associate with TAL1, TAL2 and LYL1, but not with other bHLH proteins, including E12, E47, Id1, NHLH1, AP4, MAX, MYC and MyoD1. Moreover, RBTN1 and RBTN2 can interact with TAL1 polypeptides that exist in assembled bHLH heterodimers (e.g. TAL1-E47), suggesting that the RBTN proteins can influence the functional properties of TAL1. Finally, we have identified a subset of leukemia patients that harbor tumor-specific rearrangements of both their RBTN2 and TAL1 genes. Thus, the activated alleles of these genes may promote leukemia cooperatively, perhaps as a result of bHLH-LIM interactions between their protein products.

Amino Acid Sequence↗