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Biomedical subjects

S-J Lee

Publications and source records attributed to S-J Lee.

At least 19 recordsLinked to original sources
PubMed2006

Atmospheric deposition of polycyclic aromatic hydrocarbons in an urban and a suburban area of Korea from 2002 to 2004.

Atmospheric bulk samples (wet and dry) were collected monthly during 2002 to 2004 from an urban and a suburban area in Korea for assessment of depositional flux and seasonal variations in the concentrations of polycyclic aromatic hydrocarbons (PAHs). PAH depositional flux ranged from 64.1 to 610 microg/m2/y for the urban area and from 65 to 460 microg/m2/y for the suburban area. The fluxes of PAHs measured in this study were comparable with those reported for urban and suburban areas in other countries. The fluxes of particulates and PAHs were higher in winter than in summer, consistent with the greater per capita consumption of fossil fuel in winter than in summer. Ambient temperature played a major role in the seasonal variability in PAH fluxes. Photochemical degradation of PAHs appears to occur during the summer months. The relationship of PAH depositional fluxes with major air pollutants, such as ozone, sulfur dioxide, carbon monoxide, nitrogen dioxide, and presence of particulate matter up to 10 microm in size (PM10), was also investigated. Dominant PAH compounds in both the urban and the suburban locations were benzo[g,h,i]perylene, pyrene, and indeno[1,2,3-c,d]pyrene. Based on the PAH diagnostic ratios and a factor analysis, the major sources of PAHs in the urban and the suburban regions were found to be similar. Diesel exhaust, coal combustion, and gasoline emissions contributed predominantly to atmospheric PAH contamination.

Korea↗
PubMed2006

Promoter CpG hypermethylation and downregulation of XAF1 expression in human urogenital malignancies: implication for attenuated p53 response to apoptotic stresses.

XIAP-associated factor 1 (XAF1) is a new candidate tumor suppressor, which has been known to exert proapoptotic effects by interfering with the caspase-inhibiting activity of XIAP. To explore the XAF1's candidacy for a suppressor in urogenital tumorigenesis, we investigated the XAF1 status in a series of cancer cell lines and primary tumors derived from the bladder, kidney and prostate. Expression of XAF1 transcript was undetectable or extremely low in 60% (3/5) of bladder, 66% (10/15) of kidney, and 100% (3/3) prostate cancer cell lines. Abnormal reduction of XAF1 was also found in 33% (18/55) of primary bladder and 40% (8/20) of primary kidney tumors, and showed a correlation with advanced stage and high grade of bladder tumor. Hypermethylation at 14 CpG sites in the 5' proximal region of the XAF1 promoter was highly prevalent in cancers versus adjacent normal or benign tissues and tightly associated with reduced gene expression. XAF1 expression enhanced the apoptotic response of tumor cells to chemotherapeutic agents, such as etoposide or 5-FU. While XAF1 expression did not influence the subcellular distribution or expression of XIAP, it elevated the protein stability of p53 and its target gene expression. Moreover, the apoptosis-sensitizing and growth suppression function of XAF1 was markedly impeded by blockade of p53 function. Collectively, our study demonstrates that epigenetic alteration of XAF1 is frequent in human urogenital cancers and may contribute to the malignant progression of tumors by rendering tumor cells a survival advantage partially through the attenuated p53 response to apoptotic stresses.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Dexamethasone protects primary cultured hepatocytes from death receptor-mediated apoptosis by upregulation of cFLIP.

Dexamethasone (DEX) pretreatment protected hepatocytes from TNF-alpha plus actinomycin D (ActD)-induced apoptosis by suppressing caspase-8 activation and the mitochondria-dependent apoptosis pathway. DEX treatment upregulated cellular FLICE inhibitory protein (cFLIP) expression, but did not alter the protein levels of Bcl-2, Bcl-xL, Mcl-1, and cIAP as well as Akt activation. The increased cFLIP mRNA level by DEX was inhibited by ActD, indicating that DEX upregulates cFLIP expression at the transcriptional step. DEX also inhibited Jo2-mediated hepatocyte apoptosis by blocking the formation of the death-inducing signaling complex and caspase-8 activation. Specific downregulation of cFLIP expression using siRNA reversed the antiapoptotic effect of DEX by increasing caspase-8 activation. Moreover, DEX administration into mice increased cFLIP expression in the liver and prevented Jo2-induced hepatic injury by inhibiting caspase-8 and -3 activities. Our results indicate that DEX exerts a protective role in death receptor-induced in vitro and in vivo hepatocyte apoptosis by upregulating cFLIP expression.

Animals↗
PubMed2005

Interaction analysis between 5-HTTLPR and TNFA -238/-308 polymorphisms in schizophrenia.

This study investigated the potential interaction between the polymorphisms of serotonin transporter gene (SLC6A4, a 44 base pair insertion/deletion in the promoter region, 5-HTTLPR) and tumor necrosis factor-alpha gene (TNFA; -238G/A and -308G/A polymorphisms) on the development of schizophrenia, as well as the interaction of the three polymorphisms in relation to symptomatology, family history, onset age and antipsychotic treatment response. Genomic DNA analyses with polymerase chain reaction (PCR) was used for the genotyping. One hundred and fifty-two (152) patients with schizophrenia and 152 normal controls participated in the study. Any associations between the individual polymorphism and schizophrenia were not found. However, marginal association between subjects with both TNFA -238 A allele (genotype AA plus AG) and 5-HTTLPR s allele (ss plus sl) and presence of family history was found (p = 0.023; p = 0.026). The subjects with TNFA -308 AG genotype showed higher change in PANSS total score (p = 0.028). No significant interaction effect between 5-HTTLPR and TNFA -238/-308 polymorphisms either on the development of schizophrenia or on antipsychotics treatment response and psychopathology was found, although a significant interaction effect for subjects carrying TNFA -238 AG and -308 AA genotypes on a positive family history was observed (p = 0.017). These results suggest that the interaction effects between 5-HTTLPR and TNFA -238/-308 polymorphisms gives no significant contribution to the susceptibility to schizophrenia, and is not associated with clinical variables, antipsychotic treatment response and psychopathological features, except for family history of disease, at least in the Korean population.

Adult↗
PubMed2005

HOXB13 is downregulated in colorectal cancer to confer TCF4-mediated transactivation.

Mutations in the Wnt signalling cascade are believed to cause aberrant proliferation of colorectal cells through T-cell factor-4 (TCF4) and its downstream growth-modulating factors. HOXB13 is exclusively expressed in prostate and colorectum. In prostate cancers, HOXB13 negatively regulates beta-catenin/TCF4-mediated transactivation and subsequently inhibits cell growth. To study the role of HOXB13 in colorectal tumorigenesis, we evaluated the expression of HOXB13 in 53 colorectal tumours originated from the distal left colon to rectum with their matching normal tissues using quantitative RT-PCR analysis. Expression of HOXB13 is either lost or diminished in 26 out of 42 valid tumours (62%), while expression of TCF4 RNA is not correlated with HOXB13 expression. TCF4 promoter analysis showed that HOXB13 does not regulate TCF4 at the transcriptional level. However, HOXB13 downregulated the expression of TCF4 and its target gene, c-myc, at the protein level and consequently inhibited beta-catenin/TCF-mediated signalling. Functionally, forced expression of HOXB13 drove colorectal cancer (CRC) cells into growth suppression. This is the first description of the downregulation of HOXB13 in CRC and its mechanism of action is mediated through the regulation of TCF4 protein stability. Our results suggest that loss of HOXB13 may be an important event for colorectal cell transformation, considering that over 90% of colorectal tumours retain mutations in the APC/beta-catenin pathway.

Cell Proliferation↗
PubMed2005

Buccal bone plate thickness of the Asian people.

Distances from the apex to the buccal bone plate were measured on the computed tomography (CT) images of 1806 teeth from 66 patients, using an image analyzer program (Image-Pro Plus, Ver. 4.0, Media Cybernetics). In the mandible, the mean distance from the distal apex of the mandibular second molar to the buccal bone plate was the largest distance measured, at 8.51 mm, followed by distance from the mesial root to the buccal bone (7.34 mm). In the mandibular first molar, the mean distal and mesial bone thicknesses were 5.18 mm and 4.09 mm, respectively. However, when there were two distal roots, the distance of the disto-lingual root to the buccal plate was found to be 9.52 mm, which constitutes the greatest measured thickness. In the maxillary buccal roots, the distances from the mesio-buccal and disto-buccal root of the second molar to the buccal bone plate were the largest, at 4.63 mm and 3.61 mm, respectively. The average distances from the palatal apex of the maxillary first and second molars to the buccal bone plate were 10.69 mm and 10.17 mm, respectively, while, from the palatal bone plate, average distances of 3.15 mm and 3.08 mm were measured. Special considerations, such as bony lid approach, lingual approach, or intentional replantation may be required, especially when a patient has a surgical need in the second molars and the disto-lingual root of the mandibular first molar, or in the palatal root of the maxillary molars.

Adolescent↗
PubMed2005

Difference in root canal length between Asians and Caucasians.

AIM: To investigate whether there is a racial difference in canal length between the Asians and Caucasians. METHODOLOGY: Five hundred and fifteen Asian patients who had received root canal treatment at the Yonsei University Hospital, Korea between 1995 and May 2001 and 324 Caucasoid patients who had received root canal treatment at the Graduate Endodontic Clinic at the University of Pennsylvania, US were selected. The clinical endodontic procedures at both clinics were similar. An electronic apex locator (Root-ZX; J. Morita Co., Kyoto, Japan) was used to measure the initial working lengths and this was verified by conventional radiography. The measurements from both Asian and Caucasian teeth were compared using a Student's t-test and a Mann-Whitney test. RESULTS: The mean difference in canal length of pooled teeth between the Asian and Caucasian teeth was 1.2 mm, with a range from 0 to 2.5 mm. The greatest difference was in the distobuccal canal (2.5 mm) of maxillary first molar teeth followed by the mesiolingual canal (2.3 mm) of mandibular second molar, the buccal canal (2.1 mm) of the maxillary second premolar, the maxillary first molar and the mandibular second molar. CONCLUSION: Tooth lengths in Asians were shorter than Caucasians.

Asian People↗
PubMed2005

Genetic basis of hearing loss associated with enlarged vestibular aqueducts in Koreans.

Sensorineural hearing loss associated with enlargement of the vestibular aqueduct (EVA) can be associated with mutations of the SLC26A4 gene. In western populations, less than one-half of the affected individuals with EVA have two mutant SLC26A4 alleles, and EVA is frequently caused by unknown genetic or environmental factors alone or in combination with a single SLC26A4 mutation as part of a complex trait. In this study, we ascertained 26 Korean probands with EVA and performed nucleotide sequence analysis to detect SLC26A4 mutations. All subjects had bilateral EVA, and 20 of 26 were sporadic (simplex) cases. Fourteen different mutations were identified, including nine novel mutations. Five mutations were recurrent and accounted for 80% of all mutant alleles, providing a basis for the design and interpretation of cost-efficient mutation detection algorithms. Two mutant alleles were identified in 21 (81%), one mutant allele was detected in three (11%), and zero mutant allele was detected in two (8%) of 26 probands. The high proportion of Korean probands with two SLC26A4 mutations may reflect a reduced frequency of other genetic or environmental factors causing EVA in comparison to western populations.

Adolescent↗
PubMed2004

Serum bioactive lysophospholipids prevent TRAIL-induced apoptosis via PI3K/Akt-dependent cFLIP expression and Bad phosphorylation.

Serum contains a variety of biomolecules, which play an important role in cell proliferation and survival. We sought to identify the serum factor responsible for mitigating tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis and to investigate its molecular mechanism. TRAIL induced effective apoptosis without serum, whereas bovine serum decreased apoptosis by suppressing cytochrome c release and caspase activation. Indeed, albumin-bound lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) inhibited TRAIL-induced apoptosis by suppressing caspase activation and cytochrome c release. LPA increased phosphatidylinositol 3-kinase (PI3K)-dependent Akt activation, cellular FLICE-inhibitory protein (cFLIP) expression, and Bad phosphorylation, resulting in inhibition of caspase-8 activation and Bad translocation to mitochondria. The antiapoptotic effect of LPA was abrogated by PI3K inhibitor, transfection with dominant-negative Akt, and specific downregulation of cFLIP expression using siRNA and further increased by siRNA-mediated suppression of Bad expression. Moreover, sera from ovarian cancer patients showed more protective effect against TRAIL-induced apoptosis than those from healthy donors, and this protection was suppressed by PI3K inhibitor. Our results indicate that albumin-bound LPA and S1P prevent TRAIL-induced apoptosis by upregulation of cFLIP expression and in part by Bad phosphorylation, through the activation of PI3K/Akt pathway.

Adult↗
PubMed2004

Determination of polychlorinated dibenzo-p-dioxins and dibenzofurans and comparison of extraction methods for edible freshwater fish and frogs in South Korea by using a high-resolution GC/MS.

Three different extraction methods were evaluated: Soxhlet extraction, accelerated solvent extractor extraction and alkali digestion with high-resolution gas chromatography/high-resolution mass spectrometry, for the analysis of edible freshwater fish and frogs. The recovery efficiencies for the different extraction methods were also compared. Using these extraction methods, the concentrations and spatial distributions of these compounds in freshwater fish and frogs (n = 99), collected from 31 locations on four major river systems (Han, Nakdong, Kum and Youngsan) and two wetlands in South Korea, were examined. The concentrations of total polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in all the freshwater fish and frog samples were analysed. The toxic equivalency (TEQ) concentration of PCDD/Fs in fish ranged from 0 (n.d.) to 1.309 pg I-TEQ g(-1) wet weight. Detailed concentrations for different types of fish were as follows (pg I-TEQ g(-1) wet weight): 0 (n.d.)-1.309 for crucian (mean 0.331, n = 28), 0.004-0.743 for carp (0.244, n = 10), 0.004-0.592 for dace (0.198, n = 8), 0.187-0.400 for cornet fish (0.287, n = 3), 0.164-0.410 for Korean piscivorous chub (0.303, n = 6), 0.105-0.516 for bass (0.310, n = 2), 0.451-0.812 for mullet (0.631, n = 2), 0.082 for long-nosed barbell, 0.100 for common Korean bitterling and 0.995 for dark chub. The total TEQ concentration ranged from 0 (n.d.) to 1.258 pg I-TEQ g(-1) wet weight for the two kinds of frogs (n = 36) investigated: 0 (n.d.)-1.258 pg I-TEQ g(-1) (mean 0.346, n = 29) for the bullfrog and from 0 (n.d.)-0.474 pg I-TEQ g(-1) (0.185, n = 7) for the mountain frog.

Animals↗
PubMed2004

Epstein-Barr virus-associated lymphoproliferative lesions presenting as a hydroa vacciniforme-like eruption: an analysis of six cases.

BACKGROUND: There are many reports of patients with a severe hydroa vacciniforme (HV)-like eruption in which cutaneous lesions occur in both sun-exposed and non-exposed areas, unlike in true HV. Several patients have died from a malignant haematological neoplasm. In most cases, a latent Epstein-Barr virus (EBV) infection has been detected in the skin lesions. OBJECTIVES: To describe the clinical and laboratory features of six additional patients with an EBV-associated HV-like eruption. METHODS: The clinical, histological and immunohistochemical features were reviewed. T-cell receptor gamma gene rearrangements were studied using polymerase chain reaction (PCR) and heteroduplex analysis. In-situ hybridization was performed to detect mRNA for EBV in skin biopsy specimens. PCR was performed to screen for EBV infection in the skin lesions of three patients and blood of two patients. Photoprovocation with repeated ultraviolet (UV) A exposure was performed in three patients. RESULTS: The severity of the skin lesions and the clinical course varied among the patients. Skin lesions were induced by repeated UVA exposure in three patients and a latent EBV infection was demonstrated in the photoprovoked lesions. CONCLUSIONS: Three different clinical courses were found in six patients with an HV-like eruption associated with chronic EBV infection: (i) spontaneous remission; (ii) clearing after photoprotection; and (iii) continuous recurrence irrespective of sun exposure. It is possible that there are two patterns of HV-like eruption associated with chronic EBV infection. One is characterized by recurrent necrotic papulovesicles of the face and the other by nodules and facial swelling. It was demonstrated that the skin lesions could be triggered by repeated UVA exposure in the patients showing recurrent necrotic papulovesicles of the face.

Adolescent↗
PubMed2004

Upregulation of the NNP-1 (novel nuclear protein-1, D21S2056E) gene in keloid tissue determined by cDNA microarray and in situ hybridization.

BACKGROUND: A keloid results from excessive collagen deposition, the cause of which remains elusive. A thorough understanding of the pathophysiology of keloid tissue can help determine the most appropriate treatment strategy. OBJECTIVES: To assess the differences in gene expression between keloids and adjacent normal skin in order to define the genes involved in keloid formation. METHODS: Three Korean patients with keloids underwent excision of the keloid and adjacent normal skin, which was used as the control. We investigated expression patterns of genes in the keloids and the normal skin using cDNA microarray and in situ hybridization techniques. RESULTS: Nine genes in the keloid tissue were consistently upregulated over the 2.0 ratio compared with the normal control from the cDNA microarray composed of 3063 clones: collagen type I alpha1 (NM_000088), DNA segment on chromosome 21 (unique) 2056 expressed sequence (D21S2056E, NNP-1, NM_003683), suppressor of Ty 5 homologue (NM_003169), phosphoglycerate dehydrogenase (NM_032692), adenosine triphosphate synthase beta (NM_001686), serine (or cysteine) proteinase inhibitor, clade H (heat shock protein 47, NM_001235), LIV-1 protein, oestrogen regulated (LIV-1, NM_012319), interleukin-11 receptor alpha (IL11RA, NM_004512) and carbonyl reductase 3 (CBR3, NM_001236). From the in situ hybridization study, the staining signals in the keloid tissue hybridized with anti sense probes of NNP-1 mRNA were stronger than signals in normal controls. Further, endothelial epithelium, but not the epidermis, expressed the signal equally in both keloid and normal control tissue. CONCLUSIONS: We identified nine upregulated genes in keloid tissue using cDNA microarray. Of the nine, the NNP-1 gene was confirmed by topological information using the in situ hybridization technique. We conclude that these nine genes, especially NNP-1, probably contribute either directly or indirectly to keloid formation.

Adolescent↗
PubMed2004

The effectiveness of syringe irrigation and ultrasonics to remove debris from simulated irregularities within prepared root canal walls.

AIM: To compare the ability of syringe irrigation and ultrasonic irrigation to remove artificially placed dentine debris from simulated canal irregularities within prepared root canals. METHODOLOGY: After canal enlargement, twelve canines were split longitudinally into two halves. On the wall of one half of each root canal a standard groove of 4 mm in length, 0.2 mm in width and 0.5 mm in depth was cut, 2-6 mm from the apex, to simulate uninstrumented canal extensions. On the wall of the other half, three standard saucer-shaped depressions of 0.3 mm in diameter and 0.5 mm in depth were cut at 2, 4 and 6 mm from the apex to simulate uninstrumented canal irregularities. Each groove and depression were filled with dentine debris mixed with 2% NaOCl to simulate a situation when dentine debris accumulates in uninstrumented canal extensions and irregularities during canal preparation. Each tooth was re-assembled by reconnecting the two halves, using wire and an impression putty material. Two per cent NaOCl was then delivered into each canal either using syringe irrigation (n = 8) or using ultrasonic irrigation (n = 8). Before and after irrigation, images of the two halves of the canal wall were taken, using a microscope and a digital camera, after which they were scanned into a PC as TIFF images. The amount of remaining dentine debris in the grooves and depressions was evaluated by using a scoring system between 0-3: the higher the score, the more the debris. The data were analysed by means of the Mann-Whitney U-test. RESULTS: Both forms of irrigation reduced the debris score significantly. The debris score was statistically significantly lower after ultrasonic irrigation than after syringe irrigation (P = 0.002 for grooves, P = 0.047 for depressions). CONCLUSION: Ultrasonic irrigation ex vivo is more effective than syringe irrigation in removing artificially created dentine debris placed in simulated uninstrumented extensions and irregularities in straight, wide root canals.

Cuspid↗
PubMed2004

The efficacy of ultrasonic irrigation to remove artificially placed dentine debris from different-sized simulated plastic root canals.

AIM: To investigate the influence of diameter and taper of root canals on the effectiveness of ultrasonic irrigation to remove artificially placed dentine debris from simulated uninstrumented extensions in simulated root canals. METHOD: Three groups of standard canals were cut in resin blocks using either size 20, .04 taper ProFile instruments, size 20, .06 Greater Taper (GT) rotary instruments or size 20, .08 GT instruments, respectively. Each resin block was then split longitudinally through the canal, forming two halves. In one canal wall, a standard groove 4 mm in length was cut 2-6 mm from the apical end of the canal, to simulate uninstrumented canal extensions. Each groove was filled with dentine debris mixed with 2% NaOCl to simulate a situation when dentine debris accumulates in the uninstrumented canal extensions. Each canal was reassembled by joining the two halves of the resin block by means of wires and sticky wax. In each canal ultrasonic irrigation was performed for 3 min using 2% NaOCl as irrigant. Before and after irrigation, images of each half of the canal with a groove were taken using a microscope and a digital camera, after which they were scanned into a PC as TIFF images. The quantity of dentine debris in the groove was evaluated using a scoring system: the higher the score, the larger the amount of debris remaining. The score data were analysed by means of Kruskal-Wallis and Mann-Whitney U-tests. RESULTS: After ultrasonic irrigation, the debris score for the size 20,.04 taper group was significantly higher than that for the size 20,.06 group (P = 0.040) and the size 20,.08 group (P = 0.006) groups. However, no significant difference was found between the size 20,.06 and the size 20,.08 groups (P = 0.320). CONCLUSION: In simulated plastic root canals, the diameter and taper of root canal influenced the effectiveness of ultrasonic irrigation to remove artificially placed dentine debris.

Dental Instruments↗
PubMed2004

Modes of transmission of Glugea plecoglossi (Microspora) via the skin and digestive tract in an experimental infection model using rainbow trout, Oncorhynchus mykiss (Walbaum).

Glugea plecoglossi (Microspora) is a significant cause of economic loss in cultured ayu, Plecoglossus altivelis, in Japan, due to the unsightly appearance of infected fish harbouring xenomas in the body cavity. Modes of transmission of G. plecoglossi via the skin and digestive tract were studied in an experimental infection model using rainbow trout, Oncorhynchus mykiss. Combined with Uvitex 2B and in situ hybridization (ISH) assays, the early development of G. plecoglossi was successfully traced. Following a bath exposure of fish Uvitex 2B-labelled G. plecoglossi spores were observed to attach to microscopic injuries (trypan blue-positive sites) of fish skin, after which ISH-positive sporoplasms were found to invade the epidermis as early as 5 min post-infection (PI), migrating rapidly to the subdermis. It was also shown that G. plecoglossi entering via the skin does not spread into the internal organs but develops into subdermal xenomas. After rainbow trout were exposed to G. plecoglossi spores by oral intubation, spores germinated in the intestinal lumen, followed by penetration of sporoplasms into the gut mucosal epithelium 5 min PI. In vitro trials determining stimulation factors (fish mucus, changes in pH, digestive enzymes) for the extrusion of the polar tube were inconclusive. The present study indicates that skin wounds and the gut epithelium can be portals of entry of G. plecoglossi and that natural infection in fish seems to occur perorally rather than via the skin.

Animals↗
PubMed2002

Reliability of perfusion MR imaging in symptomatic carotid occlusive disease. Cerebral blood volume, mean transit time and time-to-peak.

PURPOSE: Perfusion MR imaging offers an easy quantitative evaluation of relative regional cerebral blood volume (rrCBV), relative mean transit time (rMTT) and time-to-peak (TTP). The purpose of this study was to investigate the reliability of these parameters in assessing the hemodynamic disturbance of carotid occlusive disease in comparison with normative data. MATERIAL AND METHODS: Dynamic contrast-enhanced T2*-weighted perfusion MR imaging was performed in 19 patients with symptomatic unilateral internal carotid artery occlusion and 20 control subjects. The three parameters were calculated from the concentration-time curve fitted by gamma-variate function. Lesion-to-contralateral ratios of each parameter were compared between patients and control subjects. RESULTS: Mean +/- SD of rrCBV, rMTT and TTP ratios of patients were 1.089 +/- 0.118, 1.054 +/- 0.031 and 1.062 +/- 0.039, respectively, and those of control subjects were 1.002 +/- 0.045, 1.000 +/- 0.006, 1.001 +/- 0.006, respectively. The rMTT and TTP ratios of all patients were greater than 2 SDs of control data, whereas in only 6 patients (32%), rrCBV ratios were greater than 2 SDs of control data. The three parameter ratios of the patients were significantly high compared with those of control subjects, respectively (p < 0.01 for rrCBV ratios, p < 0.0001 for rMTT ratios, and p < 0.0001 for TTP ratios). CONCLUSION: Our results indicate that rMTT and TTP of patients, in contrast to rrCBV, are distributed in narrow ranges minimally overlapped with control data. The rMTT and TTP could be more reliable parameters than rrCBV in assessing the hemodynamic disturbance in carotid occlusive disease.

Arterial Occlusive Diseases↗
PubMed2002

Comparative evaluation of cerebral blood volume and cerebral blood flow in acute ischemic stroke by using perfusion-weighted MR imaging and SPECT.

PURPOSE: To investigate the relationship between relative cerebral blood volume (CBV) measured with perfusion-weighted (PW) MR imaging and relative cerebral blood flow (CBF) measured with SPECT in acute ischemic stroke. MATERIAL AND METHODS: Fifteen patients who had acute unilateral middle cerebral artery occlusion underwent both PW MR imaging and 99mTc-HMPAO SPECT with an interval less than 20 min between the two examinations within 6 h after stroke onset. Lesion-to-contralateral relative CBV and CBF ratios measured in multiple regions of interest were compared to evaluate the relationship of the two parameters. RESULTS: An overall linear relationship was found between relative CBV and relative CBF ratios (R2 = 0.54, p < 0.0001). The two parameters correlated linearly to each other in regions with evolving infarction (R2 = 0.43, p<0.0001), but not in regions without evolving infarction (R2 = 0.001, p>0.05). Regions with evolving infarction had more severe hypoperfusion (mean relative CBF ratio, 0.38 +/- 0.22) than regions without (mean relative CBF ratio, 0.70+/-0.13) (p<0.0001). CONCLUSION: A significant linear relationship existed between relative CBV and relative CBF in acute ischemic stroke, although relative CBV did not change linearly to relative CBF in mild hypoperfusion. Relative CBV can be used as an alternative to relative CBF within 6 h after stroke onset, particularly in regions with severe hypoperfusion proceeding to infarction.

Brain↗