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Papers by iba baba

A protocol has been developed for the direct induction of adventitious shoots from leaf explants ... more A protocol has been developed for the direct induction of adventitious shoots from leaf explants of in vitro raised Anthemis xylopoda O.Schwarz, a critically endangered Turkish endemic. The Murashige and Skoog (MS) media supplemented with N 6 -benzyladenine (BA), kinetin (KIN), and thidiazuron (TDZ) were used in regeneration experiments. BA at 0.5 mg L -1 concentration was chosen as the optimal treatment because it yielded the maximal number of adventitious shoots with the best quality (6.70 ± 1.05 shoots/explant). The highest mean of maximum shoot length was observed in MS media containing 0.2 mg L -1 BA (4.30 ± 0.48 cm). Regenerated shoots rooted best on ½MS medium containing 0.5 mg L -1 indole-3-butyric acid (IBA). Flower buds also occurred during rooting. For this study, the existence of auxins in the medium was essential for in vitro flower bud induction. IBA was found to be more efficient than indole-3-acetic acid (IAA) in the induction of flower buds of A. xylopoda. The maximum flowering percentage was obtained when the shoots were cultured on ½MS medium containing 1.0 mg L -1 IBA. Flowers produced in vitro were morphologically normal and yellow.

Brain Research, 2011

Ischemic vulnerability in diabetic nerve plays a paramount role in the development of diabetic ne... more Ischemic vulnerability in diabetic nerve plays a paramount role in the development of diabetic neuropathy, yet little is known of the underlying mechanism. Diabetes enhances the inflammatory response to ischemia and reperfusion. We investigated pathological characteristics of nerve fibers and endoneurial macrophages along the length of sciatictibial nerves before and after ischemia (60 to 90 min) and reperfusion (6 h to 7 days) in 8 weeks of STZ-induced diabetic rats. Without ischemia, diabetic nerves revealed significantly increased the density of Iba-1-positive endoneurial macrophages when compared with controls. Most of macrophages appeared slim and triangular in shape, but in diabetic nerves, some were rounded with bromodeoxyuridine (BrdU) incorporation, suggesting proliferating macrophages. Seventy-five minutes of ischemia is the minimal ischemic time to cause pathological changes in diabetic nerves. Following 90 min of ischemia and 6 h of reperfusion in diabetic rats, the number of Iba-1-positive endoneurial macrophages was increased significantly at the thigh level of sciatic nerve when compared with those before ischemia. Endoneurial macrophages in diabetic nerves increased in number further significantly after 24 and 48 h of reperfusion and underwent morphological alterations; swollen and rounded including phagocytosis. After 90 min of ischemia and 7 days of reperfusion, severe pathological alterations, e.g., demyelination and endoneurial edema at proximal nerves and axonal degeneration distally, were observed in diabetic nerves, while control nerves showed normal morphology. We conclude that macrophage proliferation occurs in STZ-diabetic nerves. The acute inflammatory response after ischemia and reperfusion was intensified in diabetic nerves. Activation of resident macrophages and infiltration by recruited macrophages could be casually linked to ischemic susceptibility in diabetic nerve.

Geophysical Research Letters, 2007

We have derived far-field-to-current conversion factors for lightning strikes to tall objects for... more We have derived far-field-to-current conversion factors for lightning strikes to tall objects for (a) the initial peak current at the object top, (b) the largest peak current at the object top, and (c) the peak current at the object bottom. These far-field-to-current conversion factors are needed for proper interpretation of peak currents reported by lightning detection networks and are each expressed here as the product of (1) the far-magnetic-or electric-field-tocurrent conversion factor for lightning strikes to flat ground based on the transmission line model, F H_flat =2πcd/v or F E_flat =2πε 0 cd/v, and an appropriate correction factor, f, to account for the transient process in the strike object. In the above equations, c is the speed of light, d is the distance between the lightning channel and a far observation point, and v is the wavefront propagation speed of lightning return stroke. The correction factors for the three considered cases are: (a) f tall_ini.top =v/(v+c), (b) f tall_top =[1+ρ bot (1+ ρ top )] v/(v+c), and (c) f tall_bot =(1+ ρ bot ) v/(v+c), where ρ bot and ρ top are current reflection coefficients at the object bottom and at the object top for upward-propagating waves, respectively. The inverse of the correction factor for the initial peak current at the object top, (v+c)/v, differs from the far-field enhancement factor, k tall =[(1-ρ top )/(1+ρ gr )] (v+c)/v, in that the latter is influenced by current transmission coefficients, (1-ρ top ) and (1+ρ gr ), at the object top (for downward-moving waves) and at the channel base for the flat-ground strike, respectively, while the former is not.

Diabetologia, 1981

The level of the glycosylated haemoglobin HbAlc was measured in (1) subjects with normal renal fu... more The level of the glycosylated haemoglobin HbAlc was measured in (1) subjects with normal renal function, (2) patients with renal failure and (3) patients on intermittent haemodialysis. In 60 subjects with normal renal function but with a varying degree of glucose tolerance, there was a significant correlation between HbAI~ and fasting blood-glucose. In 20 patients with renal failure the mean value of HbAlc was 6.6 _+ 1.3% (mean _+ SD) whereas in 17 subjects with normal renal function, but with the same degree of glucose tolerance, this value was 4.7 + 0.9%. In 30 patients on intermittent dialysis the mean level of HbAlc was 6.3 _+ 1.5%. This level did not fall after 3 months of dialysis with a glucose-free fluid. In both groups of patients with renal failure there was no correlation between HbA~ and fasting blood-glucose. -It is concluded that renal failure itself causes an increase in HbAlc.

Plant Biotechnology Reports, 2007

Liquid cultures were successfully generated from cotyledons of two Sonneratia species, S. alba an... more Liquid cultures were successfully generated from cotyledons of two Sonneratia species, S. alba and S. caseolaris in Murashige and Skoog (MS) medium containing 0.1 μmol L−1 2,4-dichlorophenoxyacetic acid (2,4-D). Adventitious roots differentiated from cotyledons of S. alba. Proliferated cells were subcultured and a large volume of suspension cells was subsequently established in 100-mL flasks. All the cytokinins tested inhibited cell proliferation. After three years of culture, the potential to differentiate was tested as indicated by greening of the cells. Greening occurred when suspension cells were transferred to solid MS medium with and without 0.1 μmol L−1 2,4-D. Greening was stimulated by low concentrations of the weak auxins indolebutyric acid (IBA) and naphthaleneacetic acid (NAA) while 2,4-D stimulated late-stage greening. Abscisic acid (ABA) inhibited greening. Gibberellic acid (GA3) at 1.0 μmol L−1 stimulated callus greening and was not inhibitory even when tested at high concentrations. Cytokinins were inhibitory in combination with 0.1 μmol L−1 of either IBA or NAA. The cause of different effects of plant hormones on growth and differentiation was discussed. Small-scale liquid media and 24-well culture plates of solid media methods developed in this paper are suitable for the optimization of hormonal conditions for cell proliferation and differentiation.

BMC Neuroscience, 2008

Background Parkinson's disease (PD) is a neurological disorder characterized by the degeneration ... more Background Parkinson's disease (PD) is a neurological disorder characterized by the degeneration of nigrostriatal dopaminergic systems. Free radicals induced by oxidative stress are involved in the mechanisms of cell death in PD. This study clarifies the neuroprotective effects of edaravone (MCI-186, 3-methyl-1-phenyl-2-pyrazolin-5-one), which has already been used for the treatment of cerebral ischemia in Japan, on TH-positive dopaminergic neurons using PD model both in vitro and in vivo. 6-hydroxydopamine (6-OHDA), a neurotoxin for dopaminergic neurons, was added to cultured dopaminergic neurons derived from murine embryonal ventral mesencephalon with subsequet administration of edaravone or saline. The number of surviving TH-positive neurons and the degree of cell damage induced by free radicals were analyzed. In parallel, edaravone or saline was intravenously administered for PD model of rats receiving intrastriatal 6-OHDA lesion with subsequent behavioral and histological analyses. Results In vitro study showed that edaravone significantly ameliorated the survival of TH-positive neurons in a dose-responsive manner. The number of apoptotic cells and HEt-positive cells significantly decreased, thus indicating that the neuroprotective effects of edaravone might be mediated by anti-apoptotic effects through the suppression of free radicals by edaravone. In vivo study demonstrated that edaravone-administration at 30 minutes after 6-OHDA lesion reduced the number of amphetamine-induced rotations significantly than edaravone-administration at 24 hours. Tyrosine hydroxylase (TH) staining of the striatum and substantia nigra pars compacta revealed that edaravone might exert neuroprotective effects on nigrostriatal dopaminergic systems. The neuroprotective effects were prominent when edaravone was administered early and in high concentration. TUNEL, HEt and Iba-1 staining in vivo might demonstrate the involvement of anti-apoptotic, anti-oxidative and anti-inflammatory effects of edaravone-administration. Conclusion Edaravone exerts neuroprotective effects on PD model both in vitro and in vivo. The underlying mechanisms might be involved in the anti-apoptotic effects, anti-oxidative effects, and/or anti-inflammatory effects of edaravone. Edaravone might be a hopeful therapeutic option for PD, although the high therapeutic dosage remains to be solved for the clinical application.

A protocol has been developed for the direct induction of adventitious shoots from leaf explants ... more A protocol has been developed for the direct induction of adventitious shoots from leaf explants of in vitro raised Anthemis xylopoda O.Schwarz, a critically endangered Turkish endemic. The Murashige and Skoog (MS) media supplemented with N 6 -benzyladenine (BA), kinetin (KIN), and thidiazuron (TDZ) were used in regeneration experiments. BA at 0.5 mg L -1 concentration was chosen as the optimal treatment because it yielded the maximal number of adventitious shoots with the best quality (6.70 ± 1.05 shoots/explant). The highest mean of maximum shoot length was observed in MS media containing 0.2 mg L -1 BA (4.30 ± 0.48 cm). Regenerated shoots rooted best on ½MS medium containing 0.5 mg L -1 indole-3-butyric acid (IBA). Flower buds also occurred during rooting. For this study, the existence of auxins in the medium was essential for in vitro flower bud induction. IBA was found to be more efficient than indole-3-acetic acid (IAA) in the induction of flower buds of A. xylopoda. The maximum flowering percentage was obtained when the shoots were cultured on ½MS medium containing 1.0 mg L -1 IBA. Flowers produced in vitro were morphologically normal and yellow.

Brain Research, 2011

Ischemic vulnerability in diabetic nerve plays a paramount role in the development of diabetic ne... more Ischemic vulnerability in diabetic nerve plays a paramount role in the development of diabetic neuropathy, yet little is known of the underlying mechanism. Diabetes enhances the inflammatory response to ischemia and reperfusion. We investigated pathological characteristics of nerve fibers and endoneurial macrophages along the length of sciatictibial nerves before and after ischemia (60 to 90 min) and reperfusion (6 h to 7 days) in 8 weeks of STZ-induced diabetic rats. Without ischemia, diabetic nerves revealed significantly increased the density of Iba-1-positive endoneurial macrophages when compared with controls. Most of macrophages appeared slim and triangular in shape, but in diabetic nerves, some were rounded with bromodeoxyuridine (BrdU) incorporation, suggesting proliferating macrophages. Seventy-five minutes of ischemia is the minimal ischemic time to cause pathological changes in diabetic nerves. Following 90 min of ischemia and 6 h of reperfusion in diabetic rats, the number of Iba-1-positive endoneurial macrophages was increased significantly at the thigh level of sciatic nerve when compared with those before ischemia. Endoneurial macrophages in diabetic nerves increased in number further significantly after 24 and 48 h of reperfusion and underwent morphological alterations; swollen and rounded including phagocytosis. After 90 min of ischemia and 7 days of reperfusion, severe pathological alterations, e.g., demyelination and endoneurial edema at proximal nerves and axonal degeneration distally, were observed in diabetic nerves, while control nerves showed normal morphology. We conclude that macrophage proliferation occurs in STZ-diabetic nerves. The acute inflammatory response after ischemia and reperfusion was intensified in diabetic nerves. Activation of resident macrophages and infiltration by recruited macrophages could be casually linked to ischemic susceptibility in diabetic nerve.

Geophysical Research Letters, 2007

We have derived far-field-to-current conversion factors for lightning strikes to tall objects for... more We have derived far-field-to-current conversion factors for lightning strikes to tall objects for (a) the initial peak current at the object top, (b) the largest peak current at the object top, and (c) the peak current at the object bottom. These far-field-to-current conversion factors are needed for proper interpretation of peak currents reported by lightning detection networks and are each expressed here as the product of (1) the far-magnetic-or electric-field-tocurrent conversion factor for lightning strikes to flat ground based on the transmission line model, F H_flat =2πcd/v or F E_flat =2πε 0 cd/v, and an appropriate correction factor, f, to account for the transient process in the strike object. In the above equations, c is the speed of light, d is the distance between the lightning channel and a far observation point, and v is the wavefront propagation speed of lightning return stroke. The correction factors for the three considered cases are: (a) f tall_ini.top =v/(v+c), (b) f tall_top =[1+ρ bot (1+ ρ top )] v/(v+c), and (c) f tall_bot =(1+ ρ bot ) v/(v+c), where ρ bot and ρ top are current reflection coefficients at the object bottom and at the object top for upward-propagating waves, respectively. The inverse of the correction factor for the initial peak current at the object top, (v+c)/v, differs from the far-field enhancement factor, k tall =[(1-ρ top )/(1+ρ gr )] (v+c)/v, in that the latter is influenced by current transmission coefficients, (1-ρ top ) and (1+ρ gr ), at the object top (for downward-moving waves) and at the channel base for the flat-ground strike, respectively, while the former is not.

Diabetologia, 1981

The level of the glycosylated haemoglobin HbAlc was measured in (1) subjects with normal renal fu... more The level of the glycosylated haemoglobin HbAlc was measured in (1) subjects with normal renal function, (2) patients with renal failure and (3) patients on intermittent haemodialysis. In 60 subjects with normal renal function but with a varying degree of glucose tolerance, there was a significant correlation between HbAI~ and fasting blood-glucose. In 20 patients with renal failure the mean value of HbAlc was 6.6 _+ 1.3% (mean _+ SD) whereas in 17 subjects with normal renal function, but with the same degree of glucose tolerance, this value was 4.7 + 0.9%. In 30 patients on intermittent dialysis the mean level of HbAlc was 6.3 _+ 1.5%. This level did not fall after 3 months of dialysis with a glucose-free fluid. In both groups of patients with renal failure there was no correlation between HbA~ and fasting blood-glucose. -It is concluded that renal failure itself causes an increase in HbAlc.

Plant Biotechnology Reports, 2007

Liquid cultures were successfully generated from cotyledons of two Sonneratia species, S. alba an... more Liquid cultures were successfully generated from cotyledons of two Sonneratia species, S. alba and S. caseolaris in Murashige and Skoog (MS) medium containing 0.1 μmol L−1 2,4-dichlorophenoxyacetic acid (2,4-D). Adventitious roots differentiated from cotyledons of S. alba. Proliferated cells were subcultured and a large volume of suspension cells was subsequently established in 100-mL flasks. All the cytokinins tested inhibited cell proliferation. After three years of culture, the potential to differentiate was tested as indicated by greening of the cells. Greening occurred when suspension cells were transferred to solid MS medium with and without 0.1 μmol L−1 2,4-D. Greening was stimulated by low concentrations of the weak auxins indolebutyric acid (IBA) and naphthaleneacetic acid (NAA) while 2,4-D stimulated late-stage greening. Abscisic acid (ABA) inhibited greening. Gibberellic acid (GA3) at 1.0 μmol L−1 stimulated callus greening and was not inhibitory even when tested at high concentrations. Cytokinins were inhibitory in combination with 0.1 μmol L−1 of either IBA or NAA. The cause of different effects of plant hormones on growth and differentiation was discussed. Small-scale liquid media and 24-well culture plates of solid media methods developed in this paper are suitable for the optimization of hormonal conditions for cell proliferation and differentiation.

BMC Neuroscience, 2008

Background Parkinson's disease (PD) is a neurological disorder characterized by the degeneration ... more Background Parkinson's disease (PD) is a neurological disorder characterized by the degeneration of nigrostriatal dopaminergic systems. Free radicals induced by oxidative stress are involved in the mechanisms of cell death in PD. This study clarifies the neuroprotective effects of edaravone (MCI-186, 3-methyl-1-phenyl-2-pyrazolin-5-one), which has already been used for the treatment of cerebral ischemia in Japan, on TH-positive dopaminergic neurons using PD model both in vitro and in vivo. 6-hydroxydopamine (6-OHDA), a neurotoxin for dopaminergic neurons, was added to cultured dopaminergic neurons derived from murine embryonal ventral mesencephalon with subsequet administration of edaravone or saline. The number of surviving TH-positive neurons and the degree of cell damage induced by free radicals were analyzed. In parallel, edaravone or saline was intravenously administered for PD model of rats receiving intrastriatal 6-OHDA lesion with subsequent behavioral and histological analyses. Results In vitro study showed that edaravone significantly ameliorated the survival of TH-positive neurons in a dose-responsive manner. The number of apoptotic cells and HEt-positive cells significantly decreased, thus indicating that the neuroprotective effects of edaravone might be mediated by anti-apoptotic effects through the suppression of free radicals by edaravone. In vivo study demonstrated that edaravone-administration at 30 minutes after 6-OHDA lesion reduced the number of amphetamine-induced rotations significantly than edaravone-administration at 24 hours. Tyrosine hydroxylase (TH) staining of the striatum and substantia nigra pars compacta revealed that edaravone might exert neuroprotective effects on nigrostriatal dopaminergic systems. The neuroprotective effects were prominent when edaravone was administered early and in high concentration. TUNEL, HEt and Iba-1 staining in vivo might demonstrate the involvement of anti-apoptotic, anti-oxidative and anti-inflammatory effects of edaravone-administration. Conclusion Edaravone exerts neuroprotective effects on PD model both in vitro and in vivo. The underlying mechanisms might be involved in the anti-apoptotic effects, anti-oxidative effects, and/or anti-inflammatory effects of edaravone. Edaravone might be a hopeful therapeutic option for PD, although the high therapeutic dosage remains to be solved for the clinical application.