Biomedical subjects

W L Lin

Publications and source records attributed to W L Lin.

At least 37 records · Page 2Linked to original sources

PubMed2000

Protective effect of Hibiscus anthocyanins against tert-butyl hydroperoxide-induced hepatic toxicity in rats.

Hibiscus anthocyanins (HAs), a group of natural pigments occurring in the dried flowers of Hibiscus sabdariffa L., which is a local soft drink material and medical herb, were studied for antioxidant bioactivity. The preliminary study showed that HAs were able to quench the free radicals of 1,1-diphenyl-2-picrylhydrazyl. This antioxidant bioactivitiy was further evaluated using the model of tert-butyl hydroperoxide (t-BHP)-induced cytotoxicity in rat primary hepatocytes and hepatotoxicity in rats. The results demonstrated that HAs, at the concentrations of 0.10 and 0.20 mg/ml, significantly decreased the leakage of lactate dehydrogenase and the formation of malondialdehyde induced by a 30-min treatment of t-BHP (1.5 mM). The in vivo investigation showed that the oral pretreatment of HAs (100 and 200 mg/kg) for 5 days before a single dose of t-BHP (0.2 mmol/kg, ip) significantly lowered the serum levels of hepatic enzyme markers (alanine and aspartate aminotransferase) and reduced oxidative liver damage. The histopathological evaluation of the liver revealed that Hibiscus pigments reduced the incidence of liver lesions including inflammatory, leucocyte infiltration, and necrosis induced by t-BHP in rats. Based on the results described above, we speculate that Hibiscus pigments may play a role in the prevention of oxidative damage in living systems.

Alanine Transaminase↗

PubMed2000

Changes in circulating levels of an anti-inflammatory cytokine interleukin 10 in burned patients.

In order to understand the role of an anti-inflammatory cytokine interleukin 10 (IL-10) in the pathophysiology of burn injury, IL-10 levels in serial serum samples of 22 burned patients were analyzed. The total body surface areas (TBSA) of the burn injury ranged from 30 to 90%. Among these 22 patients, 14 recovered and the other eight, who were septic, expired. A significant difference in serum IL-10 values on admission (5-20 h postburn) was found (P<0.05) between patients who survived or died from burn injury as analyzed by the Student's t test. In addition, a significant difference in serum IL-10 on admission was also found (P<0.05) between patients with TBSA of greater or less than 50%. An initial peak serum IL-10 response was detected within 2.5 days postburn. Significant differences in the peak serum IL-10 levels were not found between patients with TBSA of greater or less than 50% and patients who survived or expired from burn injury. Afterwards, serum IL-10 remained low in the survivors, while an increase in serum IL-10 could be detected in the non-survivors with proven sepsis. Levels of circulating IL-6 in these non-surviving patients showed a tendency to increase starting from about 1-2 weeks postburn which coincided temporally with the detection of infections. However, marked increases in circulating IL-10 levels were observed just before death in four of the eight non-survivors. The serum samples of these four patients were collected at 31 h (404.8 pg/ml), 2 h (773.9 pg/ml), 5 days (150.7 pg/ml) and 12 h (177.1 pg/ml) before the expiration of these patients, respectively. IL-10 levels of 28.6, 27. 5 and 13.5 pg/ml were detected in sera of three of the remaining four non-survivors that were collected at 2.5 h, 36 h and 30 h before the expiration of these patients, respectively. There was one non-surviving patient who suffered an 80% burn (patient D4 in Table 1 and Fig. 4) and his IL-10 level at 20 days postburn was 13.4 pg/ml. The serum sample of this patient was collected 22 days before death and he was not suffering from sepsis at this stage. In conclusion, an initial increase in serum levels of IL-10 was detected postburn. A marked increase in serum levels of IL-10 was detected in four of the eight septic patients just before their death. It was considered that a lack and/or a delay in the increase of circulating IL-10 may play a significant role in the pathophysiology of sepsis in burned patients.

Adolescent↗

PubMed2000

Theoretical study of convergent ultrasound hyperthermia for treating bone tumors.

This study investigates the optimal external parameters for using an ultrasound applicator for treating bone tumors. This system utilized spherically arranged applicators such as scanned focused ultrasound, and spherically focused multielement applicators. The power deposition pattern is modeled as geometric gain with exponential attenuation. The specific absorption rate ratio (SARR) criteria have been used to determine the proper heating domain of ultrasound driving frequency and therapeutic tumor diameter. The results demonstrate that the optimal driving frequency depends on tumor depth, ultrasound absorption of bone marrow, and diameter of bone, but it is independent of the acoustic window area and SARR. The treatable diameter of bone tumor increased when the absorption ratio of bone marrow to tumor, acoustic window of surface skin, and diameter of bone were elevated. However, the treatable diameter of bone tumor decreased when muscle thickness, SARR of bone tumor site to the surface skin, bone marrow, and bone declined. To deliver the ultrasound energy into the tumor site and to avoid the potential damage to the normal tissue as much as possible, the specific absorption rate (SAR) in the bone tumor site has to be three times higher than that in the surface skin, tumor/marrow, and marrow/bone interfaces. The temperature distributions can verify the SARR criteria in this model. This study provides the information for choosing the optimal operating frequency of the ultrasound transducer and the acoustic window on the skin surface, and for designing the ultrasound applicator for clinical implementation.

Biomedical Engineering↗

PubMed2000

Comparison of the effect of fish oil and corn oil on chemical-induced hepatic enzyme-altered foci in rats.

The effects of fish oil and corn oil diets on diethylnitrosamine initiation/phenobarbital promotion of hepatic enzyme-altered foci in female Sprague-Dawley rats were investigated. Groups of 12 rats were initiated with diethylnitrosamine (15 mg/kg) at 24 h of age. After weaning, they received diets containing either 13.5% fish oil plus 1. 5% corn oil or 15% corn oil for 24 weeks. Rats fed fish oil had significantly greater liver weight, relative liver weight, spleen weight, and relative spleen weight than rats fed corn oil (p < 0.05). Hepatic phospholipid fatty-acid profile was significantly affected by the type of dietary lipid. The rats fed fish oil had significantly greater hepatic phospholipid 20:5 and 22:6 than rats fed corn oil; in contrast, the rats fed corn oil had significantly greater hepatic phospholipid 18:2 and 20:4 than rats fed fish oil (p < 0.05). Rats fed fish oil had significantly lower hepatic vitamin E and PGE(2) content but significantly greater hepatic lipid peroxidation than rats fed corn oil (p < 0.05). The hepatic levels of antioxidant enzymes (GSH reductase and GST) were significantly greater in rats fed fish oil than in rats fed corn oil (p < 0.05). Except for PGST-positive foci (foci area/tissue area), all the other foci parameters (GGT-positive foci area/tissue area, GGT-positive foci no./cm(2), GGT-positive foci no./cm(3), PGST-positive foci no. /cm(2), and PGST-positive foci no./cm(3)) measured in the fish oil group were 10-30% of those in the corn oil group (p < 0.05). Analyses of Pearson correlation coefficient revealed a positive correlation between hepatic GGT- or PGST-positive foci number (no. /cm(2)) and PGE(2) content (r = 0.66, P = 0.01; r = 0.56, P = 0.02, respectively) but a negative correlation between GGT- and PGST-positive foci (no./cm(2)) and lipid peroxidation (r = -0.8, P = 0.0006; r = -0.58, P = 0.01, respectively), GSH/(GSH + GSSG) ratio (r = -0.61, P = 0.05; r = -0.4, P = 0.14, respectively), GSH reductase (r = -0.75, P = 0.002; r = -0.53, P = 0.02, respectively), and GST activities (r = -0.65, P = 0.01; r = -0.44, P = 0.07, respectively). Similar correlation between foci number (no./cm(3)) and PGE(2), lipid peroxidation, GSH/(GSH + GSSG) ratio, GSH reductase, and GST activities were obtained. The results of this study show that dietary fish oil significantly inhibited hepatic enzyme-altered foci formation compared with corn oil in rats. These results suggest that the possible mechanisms involved in this process are the stimulation of hepatic detoxification system, changes in membrane composition, inhibition of PGE(2) synthesis, the enhancement of GSH-related antioxidant capacity, and the enhancement of lipid peroxidation by fish oil.

Animals↗

PubMed2000

Neurofibrillary tangles, amyotrophy and progressive motor disturbance in mice expressing mutant (P301L) tau protein.

Neurofibrillary tangles (NFT) composed of the microtubule-associated protein tau are prominent in Alzheimer disease (AD), Pick disease, progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). Mutations in the gene (Mtapt) encoding tau protein cause frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), thereby proving that tau dysfunction can directly result in neurodegeneration. Expression of human tau containing the most common FTDP-17 mutation (P301L) results in motor and behavioural deficits in transgenic mice, with age- and gene-dose-dependent development of NFT. This phenotype occurred as early as 6.5 months in hemizygous and 4.5 months in homozygous animals. NFT and Pick-body-like neuronal lesions occurred in the amygdala, septal nuclei, pre-optic nuclei, hypothalamus, midbrain, pons, medulla, deep cerebellar nuclei and spinal cord, with tau-immunoreactive pre-tangles in the cortex, hippocampus and basal ganglia. Areas with the most NFT had reactive gliosis. Spinal cord had axonal spheroids, anterior horn cell loss and axonal degeneration in anterior spinal roots. We also saw peripheral neuropathy and skeletal muscle with neurogenic atrophy. Brain and spinal cord contained insoluble tau that co-migrated with insoluble tau from AD and FTDP-17 brains. The phenotype of mice expressing P301L mutant tau mimics features of human tauopathies and provides a model for investigating the pathogenesis of diseases with NFT.

Amino Acid Substitution↗

PubMed2000

Production and characterization of monoclonal antibodies to serine proteinase allergens in Penicillium and Aspergillus species.

BACKGROUND: Alkaline and/or vacuolar serine proteinases are major allergens in prevalent airborne Penicillium and Aspergillus species. OBJECTIVE: The object of this study is to generate and characterize monoclonal antibodies against these serine proteinase allergens. METHODS: BALB/c mice were immunized individually with the Penicillium citrinum culture medium or the crude extract and culture medium preparations of Aspergillus fumigatus. Hybridoma cells that secrete monoclonal antibodies against serine proteinase allergens were selected by immunoblotting. Antigens in three different Penicillium (P. citrinum, P. notatum and P. oxalicum) and two different Aspergillus species (A. fumigatus, and A. flavus) recognized by these monoclonal antibodies were analysed by sodium dodecyl sulphate and two-dimensional polyacrylamide gel electrophoresis immunoblotting and N-terminal amino acid sequence analysis. RESULTS: Four (PCM8, PCM10, PCM16 and PCM39) and one (FUM20) monoclonal antibodies against serine proteinase allergens were generated after fusion of NS-1 cells with spleen cells obtained from BALB/c mice immunized with antigens from P. citrinum and A. fumigatus, respectively. Immunoblotting results showed that PCM8 reacted with an alkaline serine proteinase allergen in P. citrinum and P. notatum. PCM10 and PCM39 reacted with the alkaline serine proteinase in two Penicillium (P. citrinum, P. notatum) and two Aspergillus species (A. fumigatus, and A. flavus) tested. PCM16 reacted with the alkaline serine proteinase allergen in P. citrinum, A. fumigatus and A. flavus but not with that in P. notatum. MoAb FUM20 reacted with the alkaline serine proteinase allergen in two Aspergillus species (A. fumigatus and A. flavus) but not with that in two different Penicillium species (P. citrinum, P. notatum) tested. Among these five monoclonal antibodies generated, only PCM39 and FUM20 can react with the vacuolar serine proteinase allergen in P. notatum, P. oxalicum and in A. fumigatus. The 35 kDa P. citrinum component that reacted with FUM20 has an N-terminal amino acid sequence of DSPSVEKNAP. CONCLUSION: Five monoclonal antibodies against different epitopes of the serine proteinase major allergens in prevalent Penicillium and Aspergillus species were generated in the present study. Antibodies obtained may be useful in the characterization and standardization of serine proteinase allergens in crude fungal extracts.

Allergens↗

PubMed2000

Complementary DNA cloning and immunologic characterization of a new Penicillium citrinum allergen (Pen c 3).

BACKGROUND: Penicillium citrinum has been identified as the most prevalent airborne Penicillium species in the Taipei area. It is important to understand the allergenic composition of this ubiquitous fungal species. OBJECTIVE: The complementary DNA (cDNA) clone of an allergen from P citrinum was isolated and expressed in Escherichia coli as a fusion protein. mAbs were prepared with the recombinant protein as antigen. The corresponding natural allergen in the fungal extracts was identified with the mAbs. METHODS: A Uni-Zap XR P citrinum cDNA library was screened with sera from asthmatic patients. An IgE-binding cDNA clone was isolated and expressed as a glutathione-S-transferase fusion protein. The frequency of IgE binding to the expressed protein was analyzed by immunoblotting. Spleen cells from BALB/c mice immunized with the recombinant protein were fused with NS-1 cells for mAb generation. RESULTS: A P citrinum cDNA library was screened with a mixture of serum samples from 4 asthmatic patients. An IgE-binding cDNA clone was obtained and designated as PCE2. PCE2 has a 694-bp insert that contains a 167 amino acids open reading frame. The deduced amino acid sequence of the encoded protein has 82.6% (138 amino acids) identity with an Aspergillus fumigatus peroxisomal membrane protein allergen (Asp f 3). PCE2 was expressed in E coli as a fusion protein and designated as Pen c 3. Sera from 13 (46%) of the 28 Penicillium-sensitized asthmatic patients demonstrated IgE binding to Pen c 3. In addition, 11 of the 13 Pen c 3-positive serum samples have IgE immunoblot reactivity to recombinant Asp f 3. The presence of IgE cross-reactivity between Pen c 3 and Asp f 3 was also detected by immunoblot inhibition. Four of the 6 mAbs generated against Pen c 3 cross-react with Asp f 3. The presence of the corresponding 18-k natural allergens in the crude extracts of P citrinum and A fumigatus were detected by immunoblot with use of the mAbs and sera from asthmatic patients. CONCLUSION: Results obtained suggest that the peroxisomal membrane protein (Pen c 3) is an important allergen of P citrinum. PCE2 is a full-length cDNA clone encoding this allergen. In addition, the mAbs generated may be useful in standardizing the diagnostic allergenic extracts.

Adult↗

PubMed2000

A qualitative and quantitative study of grumose degeneration in progressive supranuclear palsy.

Grumose degeneration (GD) of the dentate nucleus is a common feature in progressive supranuclear palsy (PSP), but its pathogenesis has not been well studied, and its clinical significance remains unknown. This report describes a quantitative study of GD in 9 cases of PSP using image analysis with single- and double-immunolabeling, as well as histochemical stains for myelin and axons. GD was associated with demyelination, axonal loss, glial tau pathology, and microgliosis in regions juxtaposed to the dentate nucleus (DN). Specifically, demyelination and microgliosis were prominent in the superior cerebellar peduncle (SCP), dentate hilus, and cerebellar hemispheric white matter. Tau pathology and microgliosis were less prominent in the DN itself. The degree of myelin loss correlated with the tau burden in the SCP. GAP-43, which is a phosphoprotein known to be involved in axonal growth and sprouting, was decreased in the DN of PSP, and the degree of GAP-43 loss correlated with severity of GD. These results suggest that GD may be related to progressive pathology in the dentatorubrothalamic tract as well as the cerebellar hemispheric white matter, and that GD may be a consequence of concurrent degeneration in both output from and input to the DN. The results further suggest a possible role for oligodendroglial and myelin pathology in the pathogenesis of PSP.

Aged↗

PubMed2000

Theoretical study of temperature elevation at muscle/bone interface during ultrasound hyperthermia.

This paper examines the distributions of the SAR (specific absorption rate) ratio and temperature elevation when an ultrasound beam propagates through the interface of muscle and bone. This interface is regarded as a flat boundary to partition the energy of the ultrasound beam, and the analytical solution of temperature distribution is based on the steady-state bio-heat transfer equation. The parameters considered are the incident angle of ultrasound beam, the ultrasound frequency, the acoustic attenuation coefficients of refracted longitudinal and shear waves in bone, and the blood perfusion in muscle. The results show that the peak of the SAR ratio is always at the interface of muscle and bone, while the peak of temperature is located in the bone region beyond the interface. A muscle with lower perfusion or a bone with higher acoustic attenuation results in the shifting of the temperature peak closer to the interface. It is more difficult to heat a higher perfused muscle in front of a bone using a lower frequency ultrasound since the temperature elevation for bone relative to muscle is greater.

Acoustics↗

PubMed2000

Suppression of altered hepatic foci development by a high fish oil diet compared with a high corn oil diet in rats.

Effects of low corn oil, high corn oil, and high fish oil diets on altered hepatic foci development in female Sprague-Dawley rats were investigated. Rats assigned to Groups 1-4 were initiated with saline as the control and those assigned to Groups 5-7 were initiated with diethylnitrosamine (DEN 15 mg/kg) at 24 hours of age. After weaning, all rats, except those in Group 1, received 500 ppm phenobarbital (PB) in their diet as tumor promoter for three months. Altered hepatic foci development was significantly lower in DEN-initiated rats fed the high fish oil + PB diet than in DEN-initiated rats fed the high corn oil + PB diets. Liver weight and relative liver weight were significantly greater in rats fed the high fish oil + PB diet than in rats fed the other diets, and hepatic biotransformation/detoxification enzyme activities were greater in rats fed the fish oil + PB diets than in rats fed the other diets. These results suggest that the effect of a high fish oil diet on altered hepatic foci may occur through regulation of hepatic biotransformation/detoxification enzyme activities, leading to alteration in the tumor-promoting action of PB. Dietary lipid significantly affected the hepatic phospholipid fatty acid composition of rats. n-3 polyunsaturated fatty acids were incorporated into membrane phospholipid at the expense of n-6 polyunsaturated fatty acids. A high fish oil diet caused greater oxidative stress in rats, as measured by plasma vitamin E level, red blood cell glutathione status, liver lipid peroxidation, and hepatic glutathione reductase activity. Pearson's correlation analysis indicated that the foci number was negatively correlated to the liver thiobarbituric acid-reactive substance and 7-pentoxyresorufin O-dealkylase activity, and the foci area was negatively correlated to the liver thiobarbituric acid-reactive substance activity (p < 0.05) in rats of groups that developed foci. These results suggest that the type of dietary lipid is the more important determinant for gamma-glutamyl transpeptidase-positive foci development than the amount of dietary lipid when rats consumed approximately the same amount of calories in all the dietary groups, and the underlying mechanisms may be partially ascribed to the antioxidant/oxidation status and biotransformation/detoxification system of rats.

Animals↗

PubMed1999

Melatonin promotes osteoblast differentiation and bone formation.

Prior studies have demonstrated that the pineal hormone, melatonin, can stimulate chloramphenicol acetyltransferase activity in Drosophila SL-3 cells transfected with a chloramphenicol acetyltransferase reporter construct containing the response element of rat bone sialoprotein (BSP). Based on these findings, studies were performed to determine whether melatonin could similarly modulate the expression of BSP in two cell lines, the MC3T3-E1(MC3T3) pre-osteoblast and rat osteoblast-like osteosarcoma 17/2.8 cell. Initial studies demonstrated that MC3T3 cells grown in the presence of 50 nM melatonin underwent cell differentiation and mineralization by day 12 instead of the 21-day period normally required for cells grown in untreated media. Melatonin increased gene expression of BSP and the other bone marker proteins, including alkaline phosphatase (ALP); osteopontin; secreted protein, acidic and rich in cysteine; and osteocalcin in MC3T3 cells in a concentration-dependent manner. Levels of melatonin as low as 10 nM were capable of stimulating transcription of these genes when cells were grown in the presence of beta-glycerophosphate and ascorbic acid. Under these conditions, melatonin induced gene expression of the bone marker proteins; however, this does not occur until the 5th day after seeding the culture dishes. Thereafter, MC3T3 cells responded to melatonin within 2 h of treatment. The fully differentiated rat osteoblast-like osteosarcoma 17/2.8 cells responded rapidly to melatonin and displayed an increase in the expression of BSP, ALP, and osteocalcin genes within 1 h of exposure to the hormone. To determine whether melatonin-induced osteoblast differentiation and bone formation are mediated via the transmembrane receptor, MC3T3 cells were treated in the presence and absence of melatonin with either luzindole, a competitive inhibitor of the binding of melatonin to the transmembrane receptors, or pertussis toxin, an uncoupler of G(i) from adenylate cyclase. Both luzindole and pertussis toxin were shown to reduce melatonin-induced expression of BSP and ALP. These results demonstrate, for the first time, that the pineal hormone, melatonin, is capable of promoting osteoblast differentiation and mineralization of matrix in culture and suggest that this hormone may play an essential role in regulating bone growth.

3T3 Cells↗

PubMed1999

Interleukin-1beta-induced release of matrix proteins into culture media causes inhibition of mineralization of nodules formed by periodontal ligament cells in vitro.

The mechanism by which interleukin-1beta (IL-1) inhibits the formation of mineralized tissue nodules by periodontal ligament (PDL) cells in vitro was investigated through the processes of morphological analysis, immunoprecipitation, and Northern blot analysis. PDL cells were obtained from a 2-day-old coagulum in tooth socket and cultured in Dulbecco's Modified Eagle Medium (DMEM) containing 10% fetal bone serum (FBS) and antibiotics. Confluent cells were grown for up to 3 weeks in the presence of ascorbic acid (AA), beta-glycerophosphate (GP), and dexamethasone (Dex), or IL-1. PDL cells cultured in the presence of GP and AA did not differentiate, but those treated with Dex, GP, and AA (Dex group) underwent differentiation, showing four stages (confluent, multilayer, nodule, and mineralization) of disparate morphological characteristics. In contrast, the cells treated with IL-1, Dex, GP, and AA (IL-1 group) did form multilayers but failed to form mineralized nodules. Electron microscopy demonstrated that the Dex-induced mineralized nodules contain multilayers of fibroblastic cells, numerous collagen fibrils, and dense globular as well as fused electron dense patches that are associated with numerous apatite crystals. The nodule-like structures in the IL-1 group were also comprised of multilayered fibroblastic cells, but they contained only a small number of collagen fibrils, and no dense globular or fused patches. Von Kossa staining confirmed the presence of numerous mineralized nodules in the Dex group and their scarceness in the IL-1 group. Northern blot analysis of IL-1-treated cells, however, revealed the presence of mRNAs for type I collagen (Col I), secreted protein, acidic and rich in cysteine (SPARC), osteopontin (OPN), alkaline phosphatase (ALP), bone sialoprotein (BSP), and osteocalcin (OC), whose expression patterns and levels were comparable to those of the Dex group. Immunoprecipitation analysis of OPN and BSP in the cell/matrix layers and the culture media after [35S]-methionine labeling showed their deposition primarily in the mineralized nodules of the Dex group, and their release into the media in the IL-1 group. Immunogold labeling demonstrated the location of OPN and BSP in mineralized nodules of the Dex group, but no significant labeling occurred in the nodule-like structures from the IL-1 group. Interestingly, IL-1 treatment increased the expression of collagenase mRNA by sevenfold, compared with that of the Dex group. These data suggest that the IL-1-induced formation of unmineralized nodules by PDL cells results not so much from the downregulated formation of matrix proteins, which plays a crucial role in the mineralization process, as from their release into the culture media. Finally, collagenase synthesis upregulated by IL-1 may be involved in this process.

Animals↗

PubMed1999

Changes in circulating levels of interleukin 6 in burned patients.

Interleukin 6 (IL-6) levels in serial serum samples of 10 burned patients were analyzed. The total body surface areas (TBSA) of the burn injury varied from 30 to 85%. Among these 10 patients, five recovered and the other five, who were septic, expired. A significant difference in serum IL-6 values on admission (5-13 h postburn) was found (p < 0.05) between patients who survived or died from burn injury as analyzed by the Wilcoxon's rank sum test. In addition, a significant difference in serum IL-6 on admission was also found (p < 0.05) between patients with TBSA of greater or less than 50%. Afterwards, an initial peak serum IL-6 response was detected within 4 days postburn. Significant differences in the peak serum IL-6 levels were not found between patients with TBSA of greater or less than 50% and patients who survived or expired from burn injury. In the survivors, serum IL-6 remained low, while IL-6 increased markedly starting at about one to two weeks postburn in four of the five nonsurvivors with proven sepsis. Except for the patient who expired 42 days postburn, the maximum serum IL-6 values of the other four nonsurvivors were all greater than those of the five survivors from burn injury. Significant correlation (p < 0.05) relating the change in serum IL-6 and body temperature was observed in only two (one survivor and one nonsurvivor) of the ten patients. Changes in serum IL-6 were also compared with changes in circulating TNF-alpha and IL-8 determined previously. A similar pattern in the dynamic changes of circulating TNF-alpha, IL-8 and IL-6 was observed in the individual burned patient. An increase in serum levels of all three cytokines was detected postburn. Serum levels of three cytokines were significantly higher in the septic patients, who all died. It was considered that all three cytokines analyzed may play a significant role in the pathophysiology of sepsis in burned patients.

Adolescent↗

PubMed1999

The genotype and epigenotype synergize to diversify the spatial pattern of expression of the imprinted H19 gene.

Little is known of how the genetic background effects the phenomenon of genomic imprinting. The H19 gene belongs to a cluster of imprinted genes on human chromosome 11. Here we show that the alternative splicing of a human H19 transcript is genotype-specific. Moreover, this variant transcript, which lacks exon 4, is either not found at all, is widely expressed or is confined to extra-villous cytotrophoblasts in first trimester placenta, depending on a combination of the genotype and the sex of the transmitting parent.

Alleles↗

PubMed1999

Characterization of allergens from Penicillium oxalicum and P. notatum by immunoblotting and N-terminal amino acid sequence analysis.

BACKGROUND: Penicillium species are important causative agents of extrinsic bronchial asthma. However, little is known about the allergens of these ubiquitous fungal species. Objective The object was to analyse the composition, the allergenic cross-reactivity and the N-terminal sequences of allergens from two prevalent airborne Penicillium species, P. oxalicum and P. notatum. METHODS: The allergenic composition and the immunoglobulin (Ig)E cross-reactivity were analysed by immunoblot and immunoblot inhibition, respectively, using sera from asthmatic patients. The N-terminal amino acid sequences of major allergens were determined by Edman degradation. Allergens identified were also characterized by immunoblotting using monoclonal antibody (MoAb) PCM39 against the alkaline serine proteinase major allergen of P. citrinum. RESULTS: Among the 70 asthmatic sera tested, 18 (26%) and 17 (24%) had IgE immunoblot reactivity towards components of P. oxalicum and P. notatum, respectively. Major allergens (> 80% frequency of IgE-binding) from both species are the 34 and 30 kDa proteins of P. oxalicum and the 34 and 32 kDa proteins of P. notatum. IgE cross-reactivity among these major allergens and the 33 kDa major allergen of P. citrinum can be detected by immunoblot inhibition studies. The N-terminal amino acid sequences of the 34 kDa allergen of P. oxalicum and of the 32 and the 28 kDa allergens of P. notatum share homology with sequences of the vacuolar serine proteinase from Aspergillus fumigatus. The N-terminal amino acid sequence of the 34 kDa allergen of P. notatum shows sequence homology with that of alkaline serine proteinase from P. citrinum. Results obtained from immunoblotting showed that MoAb PCM39 reacted with the 34, 30 and 16 kDa IgE-binding components of P. oxalicum, and with the 34, 32 and 28 kDa IgE-binding components of P. notatum. CONCLUSIONS: Results obtained suggest that the 34 kDa major allergen of P. oxalicum may be a vacuolar serine proteinase. The 34 and the 32 kDa major allergens of P. notatum may be the alkaline and the vacuolar serine proteinases of P. notatum, respectively. The 30 and 16 kDa IgE-binding components of P. oxalicum and the 28 kDa IgE-binding component of P. notatum may be breakdown products of the 34 and the 32 kDa major vacuolar serine proteinase allergens of P. oxalicum and P. notatum, respectively.

Adult↗

PubMed1999

Expression of TGF-beta isoforms and their receptors during mineralized nodule formation by rat periodontal ligament cells in vitro.

Transforming growth factor-betas (TGF-beta s) and bone morphogenetic proteins (BMPs), members of a TGF-beta superfamily, are known to play an important role in osteogenic cell differentiation and consequently bone formation. We have reported previously that periodontal ligament (PDL) cells differentiate and form mineralized nodules when cultured in the presence of dexamethasone (Dex), beta-glycerophosphate (GP) and ascorbic acid (AA). To understand the roles of TGF-beta isoforms (TGF-beta 1, 2 and 3) and TGF-beta type I receptors (activin receptor-like kinase (ALK)-2, -3, -5 and -6) in PDL cell differentiation, their expression was investigated using Northern blot analysis. Rat PDL cells, derived from coagulum in the tooth socket, were cultured in the presence of Dex (5 microM), GP (10 mM) and AA (50 micrograms/ml) for up to 21 d. Total RNA was isolated from PDL cells after 0, 7, 14 and 21 d and used for northern blot analysis of mRNAs for matrix proteins, TGF-beta isoforms and their receptors using 32P-labeled cDNAs as probes. Four stages showing distinct morphological characteristics and matrix expression during development of mineralized nodules were identified. Type I collagen (Col I) and SPARC (secreted protein, acidic and rich in cysteine) mRNAs were expressed at the confluent stage, but decreased during the mineralization stage. Osteopontin (OPN) and alkaline phosphatase (ALP) transcripts were initially observed at multilayer stage, while bone sialoprotein (BSP) and osteocalcin (OC) at the nodule stage and all 4 were expressed thereafter. TGF-beta 1 mRNA expression increased with the progression of PDL cell differentiation, while a relatively high level of TGF-beta 3 transcript decreased slightly during their differentiation. TGF-beta 2 mRNA was not expressed. The expression of TGF beta-RI mRNA decreased, whereas that of TGF beta-RIII increased dramatically with PDL cell differentiation. TGF beta-RII gene activities remained high throughout all stages. ALK-2, ALK-3 and ALK-6 mRNA expression increased with the progression of PDL cell differentiation, suggesting that these receptors may play important roles in Dex-induced PDL cell differentiation and mineralized nodule formation.

Animals↗

PubMed1999

Relationship between acoustic aperture size and tumor conditions for external ultrasound hyperthermia.

External ultrasound hyperthermia is a very flexible modality for heating deep-seated tumors due to its deep penetration and focusing ability. However, under the constraints of the available acoustic aperture size for the ultrasonic beam, ultrasonic attenuation, as well as other anatomic properties, it may not be able to deliver sufficient ultrasonic energy to heat a large tumor located in a deep region without overheating the normal tissue between the tumor and the aperture. In this work, we employ a simulation program based on the steady-state bioheat transfer equation and an ideal ultrasound power deposition (a cone with convergent/divergent shape) to examine the relationship between the minimal diameter of the acoustic aperture and the tumor conditions. Tissue temperatures are used to determine the appropriate aperture diameter and the input power level for a given set of tumor conditions. Due to the assumed central axis symmetry of the power intensity deposition and anatomic properties, a two-dimensional (r-z) simulation program is utilized. Factors determining the acoustic aperture diameter and the input power level considered here are the tumor size, tumor depth, ultrasonic attenuation in tissue, blood perfusion, and temperature of the surface cooling water. Simulation results demonstrate that tumor size, tumor depth, and ultrasonic attenuation are major factors affecting the aperture diameter of the ultrasonic beam to obtain an appropriate temperature distribution, while blood perfusion and the temperature of the surface cooling water are the minor factors. Plots of the effects of these factors can be used as the guideline for designing an optimal ultrasound heating system, arranging the transducers, and planning further treatments.

Humans↗

PubMed1999

Self-tuning fuzzy logic control for ultrasound hyperthermia with reference temperature based on objective functions.

The purpose of this paper is to develop and evaluate a self-tuning fuzzy logic controller for a scanned focused ultrasound hyperthermia system with the reference temperature (Tr) determined from objective functions. This work employs simulation programs to develop the power deposition for the scanned focused ultrasound system and to solve the responses of temperature profiles based on the transient bioheat transfer equation. A fuzzy logic control algorithm is employed to determine the output power level for the heating system and an observer for blood perfusion variation is used to enhance the capability of the controller to adjust the required output power level for the treatment due to the drastic change of the blood perfusion. The reference temperature (Tr) for the controller is based on objective functions to tune its value during the heating process, while a control temperature (Tc) from the thermosensors located in the tumor region is used as the input for the controller. The objective function based on the entire temperature profile is used to evaluate the appropriateness of the heating temperature distribution for a time-variational blood perfusion. Simulation results demonstrate that the tumor region can be rapidly heated to the desired temperature level and maintained at that level despite blood perfusion variation. The resulting temperature profile, the objective function, and the output power level are related to the magnitude of blood perfusion, but are almost independent of the Tc location and the initial setting value of Tr. The fuzzy logic control algorithm with Tr determined from objective functions can be used for controlling the entire temperature distribution through a single control temperature, and the combination of control and optimization allows appropriate temperature fields to be created during the entire heating process. The control algorithm does not require the accurate prior knowledge of the locations of the thermosensors and the appropriate setting value for Tr.

Fuzzy Logic↗