Biomedical subjects

Y Akasaka

Publications and source records attributed to Y Akasaka.

At least 19 recordsLinked to original sources

PubMed2006

The human renal lymphatics under normal and pathological conditions.

AIMS: The renal lymphatics have not been fully documented in humans. The aim of this study was to clarify the morphology of the human renal lymphatic system under normal and pathological conditions by immunohistochemistry using anti-D2-40 antibody. METHODS AND RESULTS: Normal and pathological renal tissues obtained at autopsy as well as nephrectomy specimens with renal cell carcinoma (RCC) were used. Thin sections were immunostained with antibodies against D2-40 and CD31. In normal kidney, D2-40+ lymphatics were abundant in the interstitium around the interlobar and arcuate arteries/veins but sporadic in those around the glomeruli or between the tubules in the cortex. A few lymphatics contained erythrocytes in their lumina. Lymphatics were seldom present in the medulla. In RCC cases, lymphatics were evident at the tumour margin, whereas CD31+ capillaries were abundant throughout the tumour and lymphatics were increased in the fibrous interstitium around the tumour. Lymphatic invasion by RCC cells was also detectable. D2-40+ lymphatics were evident in other pathological conditions and end-stage kidney had a denser lymphatic distribution than normal kidney. CONCLUSIONS: Lymphatics are abundant around the arteries/veins and are also present in the renal cortex and medulla. D2-40 immunostaining is helpful for investigating the pathophysiological role of renal lymphatics.

Aged↗

PubMed2005

Regulation of neurokinin-1 receptor messenger RNA expression in synovial fibroblasts of patients with rheumatoid arthritis.

We examined whether soluble mediators regulate the expression of tachykinin receptor mRNAs in synovial fibroblasts of patients with rheumatoid arthritis (RA). mRNAs encoding long and short isomers of neurokinin 1 receptor (NK1R), and neurokinin 2 receptor (NK2R) were confirmed by reverse transcription-polymerase chain reaction (RT-PCR) analysis. Level of long, but not the short, of NK1R mRNA was increased by treatment with 10-100 ng/ml basic fibroblast growth factor (bFGF) or 20 ng/ml tumor necrosis factor-alpha (TNF-alpha), but not with 1ng/ml interleukin 1beta (IL-1beta). TNF-alpha upregulated NK2R mRNA as well as long NK1R mRNA whereas bFGF had no effect on NK2R mRNA. Expression of neurokinin 3 receptor (NK3R) mRNA was not observed in RA fibroblasts, and its expression was not induced by bFGF and TNF-alpha. The basal and increased levels of long NK1R mRNA were inhibited by treatment with 20 microM SU5402, an inhibitor of the tyrosine kinase activity of FGF receptor 1 (FGFR1), or 10 ng/ml transforming growth factor-beta1 (TGF-beta1). SU5402 and TGF-beta1 had no effect on the basal level of short NK1R mRNA. Immunocytochemistry revealed the enhancement by bFGF of immunoreactive NK1Rs in the cells at 24 h after treatment. These results suggest that bFGF, TGF-beta1, and TNF-alpha in synovial tissue and fluid play a role in the regulation of long NK1R expression in synovial fibroblasts of RA patients. It appears that the pathway of downregulation by TGF-beta1 is more dominant in the long NK1R mRNA expression than that of upregulation by bFGF or TNF-alpha. Furthermore, the regulation of short NK1R mRNA expression seems to be performed via a different pathway from that of long isomer mRNA.

Arthritis, Rheumatoid↗

PubMed2005

Expression of a candidate marker for progenitor cells, Musashi-1, in the proliferative regions of human antrum and its decreased expression in intestinal metaplasia.

AIM: Reliable makers for progenitor cells in the human stomach have not been elucidated. The aim of the present study was to clarify whether Musashi-1 (Msi-1), which has recently been proposed as a stem cell marker in mouse intestine, serves as a marker for progenitor cells in human stomach. METHODS AND RESULTS: Immunohistochemistry revealed that Msi-1+ cells were detected especially in the isthmus/neck region (the putative position of stem cells) of the adult antrum, but were limited to the basal regions of fetal pyloric glands during the early stages of development. These results suggest that Msi-1 expression occurs specifically in the stem cell-containing regions. Msi-1+ cells were intermingled with proliferating cell nuclear antigen (PCNA)+ cells in the isthmus/neck region of the adult antrum, but did not coexpress PCNA or Ki 67. Msi-1 expression overlapped partly with expression of MUC 5 AC and MUC 6, indicating that Msi-1+ cells retain some features of both foveolar and pyloric gland cell differentiation phenotypes. In contrast, Msi-1 expression in gastric glands showing intestinal metaplasia (IM) became weaker than that in the glands without IM. CONCLUSION: The specific expression of Msi-1 within the proliferative regions suggests that Msi-1 is a marker of cells with progenitor characteristics before active proliferation in human antrum.

Adult↗

PubMed2005

Expression of type V secretory phospholipase A in myocardial remodelling after infarction.

AIMS: Secretory phospholipase A2 is associated with ischaemic injury in the human heart, but the distribution of type V secretory phospholipase A2 (sPLA2-V) remains unknown. The significance of sPLA2-V in myocardial infarction was investigated histopathologically. METHODS: Sequential changes in the localization of sPLA2-V and its mRNA in myocardial tissues obtained from 30 autopsied hearts were examined by immunohistochemistry and in situ hybridization and compared with those of fibronectin, vascular endothelial growth factor (VEGF), interleukin (IL)-1beta, tumour necrosis factor (TNF)-alpha, and cyclooxygenase-2 (COX-2). RESULTS: No expression of sPLA2-V was observed in normal heart, but it was promptly expressed in wavy myofibres positive for fibronectin just after the onset of infarction. sPLA2-V was subsequently expressed in ischaemic cardiomyocytes around the lesion. The expression decreased at the granulation tissue and disappeared at the chronic stage with scar formation. The distribution of the signal for sPLA2-V mRNA paralleled that of the protein. Ischaemic myocytes around the lesion expressed VEGF, IL-1beta, TNF-alpha and COX-2 at all stages. CONCLUSIONS: sPLA2-V production in myocardium is limited to the acute phase of infarction. sPLA2-V may play a dual role, acting both to remove degraded cell-membrane through cooperative activity with COX-2 in necrotic areas and to attack ischaemic myocytes around the lesion via degradation of membrane phospholipids.

Adult↗

PubMed2004

Expression of cholesteryl ester transfer protein (CETP) in germinal centre B cells and their neoplastic counterparts.

AIMS: Cholesteryl ester transfer protein (CETP) is known to facilitate the transfer of lipids between plasma lipoproteins. Previous studies on human tissues have determined that the spleen contains large amounts of CETP mRNA, while the exact location of CETP in such organs remains unknown. In the present study, our aim was to locate CETP protein expression at the cellular level in human normal and neoplastic lymphoid organs. METHODS AND RESULTS: In-situ hybridization (ISH) and immunohistochemistry were applied to pathology specimens. A specific rabbit anti-CETP antibody was used for immunohistochemical analysis, together with another CETP-specific monoclonal antibody. A riboprobe for ISH was derived from CETP cDNA. Immunohistochemically, CETP was localized in germinal centre B cells and a proportion of marginal zone B cells. ISH showed that CETP mRNA was located mostly in the same areas. When 141 malignant lymphomas of various subtypes were studied, high expression of CETP, equivalent to that found in normal germinal centre B cells, was demonstrated in lymphoma subtypes that are currently regarded as the neoplastic counterparts of primarily germinal centre B cells. CONCLUSION: CETP localizes B cells in germinal centres, a proportion of post-germinal centre B cells and their neoplastic counterparts.

Animals↗

PubMed2003

Changes in the distribution pattern of gelatin-binding protein of 28 kDa (adiponectin) in myocardial remodelling after ischaemic injury.

AIMS: Gelatin-binding protein of 28 kDa (GBP28) is a collagen-like plasma protein having a binding capacity with collagens. We investigated GBP28 role on myocardial remodelling as well as the diagnostic significance of GBP28 immunostaining in myocardial infarction. METHODS AND RESULTS: Myocardial tissues obtained from 47 autopsied hearts with infarction were immunostained with antibodies against GBP28, fibronectin, type III and IV collagens, and prolyl 4-hydroxylase. GBP28 was distributed in interstitium of infarcted lesions at an early stage. GBP28 was linearly found both along the border with vital myocardium and at the periphery of surviving cardiomyocyte around the lesion at granulative stage. However, it was not observed in the scar. GBP28 distribution patterns were similar to those of fibronectin in infarcted lesions and those of type IV collagen at the periphery of cardiomyocyte. Type III collagen was not recognized in the early-stage lesion but increased along with scar maturation. Prolyl 4-hydroxylase was found in surviving cardiomyocytes around the lesion during all stages and in interstitial cells appeared in granulation tissue. CONCLUSION: GBP28 plays a role as a scaffold of newly formed collagen in myocardial remodelling after ischaemic injury, and GBP28 immunostaining may assist in a diagnosis of healing stage.

Adiponectin↗

PubMed2001

The effect of myocardial bridging of the coronary artery on vasoactive agents and atherosclerosis localization.

The relationship between alterations in the immunohistochemical expression of three vasoactive agents [endothelial nitric oxide synthase (eNOS), endothelin-1 (ET-1), and angiotensin-converting enzyme (ACE)] and the occurrence human atherosclerosis was investigated in relation to the myocardial bridge (MB) of the left anterior descending coronary artery (LAD), an anatomical site that experiences increased shear stress. Five millimetre cross-sections of LADs with MB from 22 autopsied cases were taken from the left coronary ostium to the cardiac apex and were immunohistochemically stained with antibodies against eNOS, ET-1, and ACE. The extent of atherosclerosis in each section was calculated using the atherosclerosis ratio (intimal cross-sectional area/medial cross-sectional area) determined by histomorphometry. The results were analysed according to their anatomical location relative to the MB, either proximal, beneath, or distal. The extent of atherosclerosis was significantly lower beneath the MB, compared with proximal and distal segments. The expression of eNOS, ET-1, and ACE was also significantly lower beneath the MB. The expression of these agents correlated significantly with the extent of atherosclerosis. Because nitric oxide, after its production by eNOS, is believed to be degraded by superoxide radicals, the effect of eNOS expression on atherosclerosis remains controversial. However, the present findings clearly indicate that the expression of ET-1 and ACE is directly related to the development of human coronary atherosclerosis in vivo through shear stress.

Adult↗

PubMed2001

The distribution and production of cholesteryl ester transfer protein in the human aortic wall.

Cholesteryl ester transfer protein (CETP) has been considered to mediate the transfer of cholesteryl ester from arterial wall, however, the distribution and production of CETP in human arterial wall remains unclear. Present study histopathologically demonstrated the distribution of CETP and CETP mRNA in the human aortic wall by immunohistochemistry and in situ hybridization. While CETP was constantly distributed in the media, the protein was recognized within the intima with fibrocellular thickening and atherosclerotic intima. Double immunostaining methods demonstrated CETP expression in smooth muscle cells in the intima and media. CETP mRNA was detected not only in intimal cells but medial smooth muscle cells. Intimal cells expressing CETP mRNA were considered to be monocyte-derived macrophages and smooth muscle cells by immunohistochemistries using two antibodies against smooth muscle actin and human macrophage on the subserial sections. Our in vivo study provides that CETP is produced by smooth muscle cells in the intima and media of human aorta, and it is suggested that arterial smooth muscle cells positively participate in the removal of excessive cholesteryl ester from the arterial wall by CETP production.

Aorta↗

PubMed2001

Immunolocalization of apolipoproteins in aortic atherosclerosis in American youths and young adults: findings from the PDAY study.

The immunohistochemical distribution of apolipoproteins in the abdominal aortas of 142 men, 15-34 years of age, collected in a cooperative multicenter study group (Pathobiological Determinants of Atherosclerosis in Youth) was examined in relationship to serum VLDL+LDL+HDL cholesterol levels. ApoB deposits were limited to the intima of specimens with intimal fibro cellular thickening or atherosclerotic lesions. Apo A-I, E and J were observed in both the intima and media of the aortas with intimal lesions. The pattern of apoJ distribution was similar to that of apoA-I and E. The distribution patterns of these apolipoproteins in these young adults were very similar to those in adults and old men seen in an earlier study. The extent of apolipoprotein distribution in the intima and media increased with age and the stage of atherosclerosis development, but was not correlated significantly with serum VLDL+LDL or HDL cholesterol levels. The infiltration of lipoprotein particles into the aortic wall seems to be more strongly associated with the progression of intimal lesions rather than with serum cholesterol levels.

Adolescent↗

PubMed2001

Gene gun-mediated oral mucosal transfer of interleukin 12 cDNA coupled with an irradiated melanoma vaccine in a hamster model: successful treatment of oral melanoma and distant skin lesion.

Malignant melanoma involving the oral cavity has a highly metastatic potential. Curative surgery is required to resect extensive oral tissues and often results in dysfunction as well as a severe cosmetic deformity in patients with the disease. An alternative technology for the local and sustained delivery of cytokines for cancer immunotherapy has been shown to induce tumor regression, suppression of metastasis, and development of systemic antitumor immunity. However, local immunization of the oral cavity has not previously been studied. In this study, we examined the efficacy of particle-mediated oral gene transfer on luciferase and green fluorescent protein production. The results showed that these proteins were more significantly expressed in oral mucosa than the skin, stomach, liver, and muscle. Using an established oral melanoma model in hamsters, particle-mediated oral gene gun therapy with interleukin (IL) 12 cDNA was then conducted. The results indicated that direct bombardment of mouse IL-12 cDNA suppressed tumor formation and improved the survival rate. The skin tumor model created by inoculation of melanoma cells was also significantly inhibited by the oral bombardment of IL-12 cDNA coupled with an irradiated melanoma vaccine administrated to the oral mucosa, compared to treatment with a percutaneous vaccine. IL-12 gene gun therapy, combined with an oral mucosal vaccine, induced interferon-gamma mRNA expression in the host spleen for a long time. These results suggest that immunization of oral mucosa may induce systemic antitumor immunity more efficiently than immunization of the skin and that oral mucosa may be one of the most suitable tissues for cancer gene therapy by means of particle-mediated gene transfer.

Animals↗

PubMed2001

[The early hemorrhage and development of a bacterial aneurysm after a cerebral ischemic attack caused by a septic embolism--a case report].

A 71-year-old female was admitted with the complaints of dysarthria and right hemiparesis. CT scan revealed subarachnoid hemorrhage in the left cerebral sulcus. The first angiography was performed 3 days after the onset and left carotid angiography revealed a small aneurysm arising from the left middle cerebral artery. After 3 weeks of antibiotic therapy, the second angiography showed the aneurysm to be clearly enlarged, so it was resected. The patient complained of marked dysarthria a day after the operation and CT scan revealed a new infarction in the right frontal lobe. The third angiography showed an aneurysm arising from the right middle cerebral artery and the fact that two peripheral arteries of the aneurysm had disappeared 3 weeks after the first operation. The second operation was performed and a bacterial aneurysm was resected. The patient left the hospital without any neurological deficits. Septic embolism is the most important complication of infective endocarditis and it is usually presented with subarachnoid hemorrhage and intracerebral hemorrhage caused by ruptured bacterial aneurysms. In this case the septic embolism occurred two times. At each time cerebral ischemic attacks were presented. The reason why this case presented with ischemic symptoms was suspected to be that embolisms occurred at the trifurcation of the distal middle cerebral arteries. We were able to detect a bacterial aneurysm angiographically 3 days after the ischemic attack and we suspected that a bacterial aneurysm had been able to develop within 3 days after the septic embolism.

Aged↗

PubMed2001

[Temporary placement of inferior vena cava filter prior to transcatheter arterial embolization (TAE) for hepatocellular carcinoma with IVC tumor thrombus--prevention of pulmonary tumor emboli after TAE].

A 66-year-old-man with a right huge hepatocellular carcinoma (HCC) extending into both the right portal vein and the right atrium underwent transcatheter arterial embolization (TAE) via the right hepatic artery. Prior to the TAE, a temporary inferior vena cava (IVC) filter was placed suprarenally for prevention of pulmonary tumor emboli. When we replaced the temporary IVC filter with a new one 7 days after the TAE, the filter which was pulled out of the IVC captured a fragment of the tumor thrombus. A histopathological specimen demonstrated only ghost cells. The patient has been followed at our outpatient clinic without any tumor thrombus or pulmonary infarction for 13 months after this procedure.

Aged↗

PubMed2000

Improved plant regeneration from cultured leaf segments in peanut (Arachis hypogaea L.) by limited exposure to thidiazuron.

Bud primordia were induced from leaf segments, which were harvested from young seedlings of Spanish type peanut (Arachis hypogaea L. cv. Chico), on 0.8% agar-solidified medium containing Murashige and Skoog (MS) basal salts supplemented with B5 vitamins, 1 mg/l NAA and various cytokinins such as benzyladenine (BA), isopentenyladenine (2ip), kinetin (KIN), chloropyridylphenylurea (4PU), thidiazuron (TDZ), zeatin (ZTN) in different concentrations. Among the cytokinins tested, TDZ was found to be the most efficient for inducing bud primordia. However, continuous culture on TDZ-containing media induced abnormal development of these primordia, and they failed to grow into plantlets. Histological observations revealed that the malformation most often obtained was a shoot-like structure which lacked shoot apical meristem (SAM) and had disorganized vascular bundles. For normal shoot regeneration, it was necessary to limit the culture period of the explants on TDZ-containing medium to 7 days at 10 mg/l or 21 days at 1 mg/l and then transfer them onto plant growth regulator-free medium. The percentage of conversion from shoot buds to shoots was 34.7%. When shoots were removed from the explants and transferred onto basal medium containing 1 mg/l NAA, all regenerated shoots readily rooted and successfully acclimatized. All of the acclimatized plants produced viable seeds in the greenhouse condition.

Journal Article↗

PubMed2000

Intratumoral pyrimidine nucleoside phosphorylase (PyNPase) activity predicts a selective effect of adjuvant 5'-deoxy-5-fluorouridine (5'DFUR) on breast cancer.

BACKGROUND: Pyrimidine nucleoside phosphorylase (PyNPase) is the enzyme that converts 5'-deoxy-5-fluorouracil (5'DFUR) to 5-fluorouracil (5FU). Its activity in cancer tissue may correlate with the selective antitumor activity of 5'DFUR in breast cancer. METHODS: Two hundred and sixteen T2 breast cancer patients were treated consecutively with surgery followed by 5'DFUR (600 mg/body/day) + tamoxifen (20 mg/body/day) for 2 years. PyNPase activity in breast cancer tissue, determined by high-performance liquid chromatography, ranged from 4.2-626.0 micrograms FU/mg protein/hr (mean +/- SD, 203.5 +/- 122.4), and the examined patients were divided into two groups: group A (high PyNPase group), cases with the PyNPase activity equal to or more than the mean value of 203.5 micrograms FU/mg protein/hr, and group B (low PyNPase group), cases with activity less than the mean value. RESULTS: Although there was no difference in relapse-free survival (RFS) between groups A and B, among node-positive patients (n = 83) those in group A tended to have a longer RFS. When divided into subgroups according to estrogen receptor (ER) status, among node-positive and ER-positive tumors (n = 49), the RFS was significantly better in group A than in group B (p < 0.05). CONCLUSION: Intratumoral PyNPase activity might be of use as a predictor of the effect of adjuvant 5'DFUR on breast cancer.

Adult↗

PubMed2000

Collagen alteration in vascular remodeling by hemodynamic factors.

The collagen alterations in the vascular wall remodeled by hemodynamic change were investigated by electron microscopy and immunohistochemistry. The left anterior descending coronary artery (LAD) without a myocardial bridge (MB) showed both lower matrix metalloproteinase-1 (MMP-1) expression and a smaller extent of spiraled collagen (SC) distribution than the LAD wall with MB, in which the intima was influenced by high shear stress. In the wall of the varicose great saphenous vein (GSV) the expression of MMP-1 was lower, while the expression of prolyl 4-hydroxylase was higher, than in the normal GSV. The extent of SC distribution in the intima and media of the varicose GSV was smaller than that in the normal GSV. An analogous difference in results was demonstrated between the portal vein (PV) of patients with liver cirrhosis and normal PV. However, the levels of expression of MMP-2, MMP-9 and tissue inhibitors of MMP (TIMPs) in these pathologic vessels were not different from those in the corresponding normal vessels. The results indicate that hemodynamic forces such as shear stress and increased intravascular blood pressure contribute to the collagen alterations in the vascular wall, which may lead to vascular wall remodeling.

Arteries↗

PubMed2000

Enhanced expression of caspase-3 in hypertrophic scars and keloid: induction of caspase-3 and apoptosis in keloid fibroblasts in vitro.

Recent studies have suggested that the regulation of apoptosis during wound healing is important in scar establishment and development of pathological scarring. To examine the phenomenon of apoptosis and its involvement in the process of pathological scarring, we immunohistochemically quantified differential levels of expression of caspase-3 and -2, which are activated during apoptosis in vitro, in surgical resected scar tissues. We divided 33 cases of normally healed flat scars and 18 cases of pathological scars (15 cases of hypertrophic scars and 3 cases of keloid) into three groups (S1 = <10 months' duration; S2 = 10 to 40 months' duration; and S3 = >40 months' duration) according to the duration of scar. In all three groups examined, the semiquantitative scores for caspase-3 staining were significantly higher for the combination of hypertrophic scars and keloid as a group compared with normally healed flat scars, suggesting reduced cell survival and increased apoptotic cell death in hypertrophic scars and keloid. Apoptosis and caspase proteolytic activities were examined in vitro using two flat scar-derived fibroblast lines (FSFB-1 and -2) and two keloid-derived fibroblast lines (KFB-1 and -2). After 24 hours of serum deprivation, apoptotic cells were significantly increased in both KFB lines, whereas serum deprivation of FSFB-1 cells did not result in a significant increase in apoptotic cell number. After serum deprivation, significant increases in caspase-3 proteolytic activities were detected in both KFB lines compared with both FSFB lines. In contrast, no significant differences with caspase-8 activity were observed between similarly treated KFB and FSFB lines. Furthermore, serum deprivation-induced apoptosis of KFB-2 cells was significantly inhibited by the caspase-3 inhibitor Ac-Asp-Glu-Val-Asp-fluoromethyl ketone (DEVD-FMK), indicating that caspase-3 is important for serum deprivation-induced apoptosis in KFB-2 cells. Considering the role of caspase-3 as a key effector molecule in the execution of apoptotic stimuli, our results suggested that enhanced expression of caspase-3 in hypertrophic scars and keloid induces apoptosis of fibroblasts, which may play a role in the process of pathological scarring.

Adolescent↗

PubMed2000

Sequential changes in localization of repair-related proteins (heat shock protein 70, ubiquitin and vascular endothelial growth factor) in the different stages of myocardial infarction.

AIMS: The myocardium expresses vascular endothelial growth factor (VEGF), heat shock protein 70 (HSP70), and ubiquitin immediately after the onset of cardiac ischaemia. This study demonstrated the sequential changes in localization of these proteins, in addition to fibronectin and troponin T (TnT), in human hearts with myocardial infarction (MI). METHODS AND RESULTS: Myocardial tissues from 40 autopsied MI cases were immunostained with the five antibodies against VEGF, HSP70, ubiquitin, fibronectin and TnT. Fibronectin was recognized only in the cardiomyocytes with infarction. Although TnT, HSP70, ubiquitin and VEGF were detected in the affected myocardium in the early stages, their expression in cardiomyocytes around infarcted foci were more intense. The cardiomyocytes with coagulative myocytolysis were positive for fibronectin, but negative or weakly positive for TnT, HSP70, ubiquitin and VEGF. In contrast, the cardiomyocytes with colliquative myocytolysis were strongly positive for TnT, HSP70, ubiquitin and VEGF, but negative for fibronectin. CONCLUSIONS: Immunostaining using antibodies to fibronectin, TnT, HSP70, ubiquitin and VEGF is useful for the discrimination between infarcted myocytes and ischaemia-damaged myocytes in the human heart with MI at autopsy.

Adult↗

PubMed2000

Time course of the size of the dark area in macular holes by scanning laser ophthalmoscopy.

To investigate the time course of idiopathic macular hole development by scanning laser ophthalmoscopy (SLO), we examined 28 eyes of 25 patients with macular holes. Cases included four eyes with stage 1-B disease (foveal detachment), 3 with stage 2 (break at the fovea), 13 with stage 3 (full-thickness macular hole), and 8 with stage 4 (hole with pseudo-operculum, posterior vitreous detachment), according to Gass's classification. The diameter of the dark area around the macular holes was recorded by SLO using a helium-neon laser. We compared the percent difference of dark area recorded between initial findings and these after three months. The size of the dark area increased after three months in eyes with stages 1, 2, and 3 disease. The size of the dark area in stage 4 disease decreased after 3 months. In the stage before posterior vitreous detachment (PVD), the dark areas increased. Once PVD occurred, these areas decreased. These findings suggested that the time course of the dark area may be related to the development of PVD.

Aged↗