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Biomedical subjects

C C Lee

Publications and source records attributed to C C Lee.

At least 145 records · Page 8Linked to original sources
PubMed2000

Mycotic aneurysm of the abdominal aorta in a patient undergoing hemodialysis: an unusual complication of Staphylococcus aureus bacteremia.

When Staphylococcus aureus is repeatedly positive in blood cultures even under effective antibiotics therapy (vancomycin, teicoplanin, or rifampin), computed tomography scan and sonography should be performed early to exclude mycotic aneurysm of the deeply seated arteries, especially in patients with abdominal aortic calcification. Before 1990, the most common causative organism of suprarenal aortic mycotic aneurysm was Salmonella; since 1990, it has been gram-positive cocci (i.e., Streptococcus and Staphylococcus) rather than gram-negative bacilli (i.e., Salmonella), possibly because of the more invasive procedures performed in clinical settings, but this hypothesis needs further investigation.

Aged↗
PubMed2000

Loss of heterozygosity assay for molecular detection of cancer using energy-transfer primers and capillary array electrophoresis.

Microsatellite DNA loci are useful markers for the detection of loss of heterozygosity (LOH) and microsatellite instability (MI) associated with primary cancers. To carry out large-scale studies of LOH and MI in cancer progression, high-throughput instrumentation and assays with high accuracy and sensitivity need to be validated. DNA was extracted from 26 renal tumor and paired lymphocyte samples and amplified with two-color energy-transfer (ET) fluorescent primers specific for loci associated with cancer-induced chromosomal changes. PCR amplicons were separated on the MegaBACE-1000 96 capillary array electrophoresis (CAE) instrument and analyzed with MegaBACE Genetic Profiler v.1.0 software. Ninety-six separations were achieved in parallel in 75 minutes. Loss of heterozygosity was easily detected in tumor samples as was the gain/loss of microsatellite core repeats. Allelic ratios were determined with a precision of +/- 10% or better. Prior analysis of these samples with slab gel electrophoresis and radioisotope labeling had not detected these changes with as much sensitivity or precision. This study establishes the validity of this assay and the MegaBACE instrument for large-scale, high-throughput studies of the molecular genetic changes associated with cancer.

DNA Primers↗
PubMed2000

p53 status in multiple human urothelial cancers: assessment for clonality by the yeast p53 functional assay in combination with p53 immunohistochemistry.

Multifocal synchronous or metachronous tumor development is a common observation in human urothelial cancer cases. However, the underlying mechanism has remained obscure. We have employed a new tool to investigate the p53 gene status, the yeast p53 functional assay, in combination with immunohistochemistry in a total of 50 tumor samples from 32 cases with urothelial cancers, including 8 with multiple synchronous tumor development and 2 demonstrating metachronous tumors. p53 mutations were found in 13 cases (9 with missense mutations, 3 with deletion, 1 with splicing mutation) by the yeast p53 functional assay. p53 protein overexpression was seen in all 9 cases with missense mutations, but in only one of the 4 cases with nonsense mutations. Two tumors without p53 mutation also showed positive p53 immunoreactivity. Overall, p53 abnormalities including mutations and/or protein overexpression were found in 15 (47%) cases. p53 abnormalities were significantly more frequent in non-papillary and in high grade tumors. Loss of the wild type allele in addition to a p53 mutation was suggested in 8 of the 15 (53%) cases. All 4 cases with mutations in multiple synchronous tumors had identical p53 mutations in the separate urothelial cancers, strongly suggestive of monoclonality. The one case with multiple metachronous tumors, in contrast, was characterized by variation in the p53 status, indicative of different clonal origins. In conclusion, combined assessment for p53 status as used here (yeast p53 functional assay plus immunohistochemistry) may provide insights into the molecular mechanisms of urothelial carcinogenesis.

Adult↗
PubMed2000

Polymorphisms of the parkin gene in sporadic Parkinson's disease among Chinese in Taiwan.

The role of genetics in Parkinson's disease (PD), previously controversial, is now documented by several studies. A major breakthrough has been the discovery of two single-gene defects in familial PD. A single base pair change at position 209 from G to A (G209A) in the fourth exon of the alpha-synuclein gene has been identified in cases of autosomal dominant familial PD. Mutations in the Parkin gene can induce autosomal recessive juvenile parkinsonism. A polymorphism of R/W366 in the Parkin gene was found to be associated with a protective factor for sporadic PD. We surveyed the polymorphisms of the Parkin gene, including S/N167, R/W366 and V/L380, in 92 cases of sporadic PD and 98 nonaffected individuals in Taiwanese Chinese. The allele frequencies of these polymorphisms are not significantly different between PD and nonaffected controls. We conclude that polymorphisms of the Parkin gene, S/N167, R/W366, V/L380, are not genetic factors for sporadic PD among Chinese in Taiwan.

Aged↗
PubMed2000

Resting B cells are not antigen-presenting cells in the induction of oral tolerance of specific Th2 immune responses in mice.

BACKGROUND: It has been shown that antigen presentation by resting B cells can induce tolerance to intravenously administered protein antigens, but the role of resting B cells in the induction of oral tolerance is unclear. METHODS: Mice continuously treated since birth with rabbit anti-mouse IgM serum for 5 weeks were depleted of B cells. When 4 weeks old, B cell-depleted mice drank 10% chicken egg white (EW) for 5 days. Ten weeks later, they were immunized with 10 microgram of ovalbumin in alum and their T helper 2 (Th2) immune responses were tested. RESULTS: Th2 cell-mediated IgE and IgG1 antibody responses and spleen cell production of IL-4 and IL-5 were suppressed by prior EW feeding during anti-IgM treatment. When anti-IgM-treated spleen cells collected 1 week after EW ingestion were transferred to naïve recipients, active suppression of Th2 immune responses was also demonstrated. CONCLUSIONS: Although resting small B cells aggregate in the mantle zone of follicles of intestinal Peyer's patches, the present data suggest that they are not antigen-presenting cells in the induction of oral tolerance of Th2 immune responses to oral antigens.

Administration, Oral↗
PubMed2000

T2-Weighted fast MR imaging with true FISP versus HASTE: comparative efficacy in the evaluation of normal fetal brain maturation.

OBJECTIVE: This study compares the relative efficacy of two fast T2-weighted MR imaging techniques-fast imaging with steady-state free precession (true FISP) and half-Fourier acquisition single-shot turbo spin-echo (HASTE)-in the evaluation of the normal fetal brain maturation during the second and third trimesters of gestation. SUBJECTS AND METHODS: The brain maturation of 10 normal nonsedated fetuses (5 during the second trimester and 6 during the third trimester of gestation [1 fetus underwent 2 examinations]) was examined by both techniques using a Vision+ 1.5-T MR system. We specifically looked for developing events, including white matter myelination, neuronal migration, and cortical sulcation. Image quality was graded according to the presence or absence of undesirable blurring. RESULTS: The specific absorption rate was lower for true FISP than for HASTE by a factor of 3 at equivalent imaging conditions. HASTE and true FISP provide comparable image quality in the second trimester when myelination of the cerebrum has not begun. Neuronal migration could be recognized as hypodense bands on both sequences during the second trimester. Myelination beginning at the third trimester was better delineated with true FISP than with HASTE because of point spread function-related blurring effects inherent in HASTE that hampered visualization of short-T2 structures. Cortical sulcation was well delineated by both sequences. CONCLUSION: With relatively superior image quality and significantly lower radiofrequency absorption than HASTE, true FISP is a safer and more effective alternative in the prenatal evaluation of normal fetal brain.

Basal Ganglia↗
PubMed2000

Association of the ACE gene polymorphism with the progression of autosomal dominant polycystic kidney disease.

Renin-angiotensin system is considered important in the genesis of hypertension and development of end-stage renal disease (ESRD) in autosomal dominant polycystic kidney disease (ADPKD). The angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism has been associated with susceptibility to the development of some renal diseases. We investigated the association of ACE gene polymorphism with the progression to hypertension and ESRD in 108 patients with ADPKD. The ACE I/D polymorphism was amplified with the flanking primers by polymerase chain reaction. In patients genotyped for ACE gene polymorphism, the frequencies of DD (15%), ID (51%) and II (34%) genotypes were similar to those of the general population. Of the 108 patients, 64 (59%) developed hypertension and 24 (22%) reached ESRD at the time of study. The prevalence of hypertension was not significantly different among the three genotypes. The mean renal survival time was 53-6 yr in II genotype, 55+/-10 yr in ID genotype and 52+/-9 yr in DD genotype which was not significantly different among them. Cumulative renal survival was not significantly different either. There was no association of ACE gene polymorphism with the prevalence of hypertension and renal survival in ADPKD. We suggest that ACE I/D polymorphism is not an important modifying gene in the progression of ADPKD.

Adult↗
PubMed2000

Simple bone cyst in cervical vertebral spinous process and laminae: report of a case.

Simple (unicameral or solitary) bone cysts are the only true cysts of primary intraosseous origin. These cysts involve the metaphysis of long tubular bones such as the proximal humerus and proximal femur and, occasionally, the proximal tibia, distal femur, patella, ilium, rib, and calcaneus. They are very rarely found in vertebrae, especially in the cervical vertebral spinous process and laminae. We report a 14-year-old boy with an expansile, bubbly cystic lesion in the spinous process and laminae of the seventh cervical vertebra. Histopathologic examination showed a cyst surrounded by thin fibrous or fibro-osseous wall without any lining epithelial cells, compatible with a simple bone cyst. As far as we know, this is the first case of simple bone cyst involving the spinous process and laminae of a cervical vertebra reported in Taiwan.

Adolescent↗
PubMed2000

Case reports of nocardiosis in patients with human immunodeficiency virus (HIV) infection.

INTRODUCTION: We present 4 local cases of nocardiosis in HIV-infected patients and discuss the diagnosis, clinical syndromes and therapy of nocardiosis. CLINICAL PICTURE: Two cases presented with pulmonary nocardiosis, one had a cervical lymph node abscess and one had disseminated nocardiosis with pulmonary, cerebral and soft tissue involvement. TREATMENT: Combination therapy is often employed. Sulphonamides or co-trimoxazole, amikacin, imipenen, minocycline and ceftriaxone are some of the drugs that could be used. OUTCOME: Outcome hinges on the early recognition and optimal treatment of this infection. CONCLUSIONS: Clinical presentations vary and diagnosis is difficult and frequently delayed. Nocardiosis should be suspected in patients who present with pulmonary lesions with soft tissue and/or cerebral abscesses.

Adult↗
PubMed2000

Artificial insemination. Role of endometrial thickness and pattern, of vascular impedance of the spiral and uterine arteries, and of the dominant follicle.

OBJECTIVE: To assess the roles of endometrial thickness and pattern, as well as vascular impedance of the spiral and uterine arteries and dominant follicle in predicting the pregnancy rate in women receiving controlled ovarian hyperstimulation (COH) following by intrauterine insemination (IUI). STUDY DESIGN: All idiopathically infertile couples who accepted COH + IUI for the first time were prospectively included. The COH agents included clomiphene citrate and human menopausal gonadotropins. Endometrial thickness and pattern (trilaminar, nontrilaminar) and vascular impedance (pulsatility index [PI], resistance index [RI]) of the spiral and uterine arteries and ovarian dominant follicle were measured on the day of IUI. Analyses were made of the influences on pregnancy outcomes by endometrial thickness and pattern as well as Doppler surveys of the spiral and uterine arteries and dominant follicle. RESULTS: A total of 110 couples with 110 cycles were enrolled, and there were 16 resulting pregnancy cycles. Trilaminar endometrium appeared in 87.5% and 57.4% of pregnant and nonpregnant women (P = .022), respectively. The pregnancy rates in trilaminar and nontrilaminar groups were 17.9% and 6.3%, respectively (P = .022). Endometrial thickness and PI/RI values for the spiral artery and uterine arteries and dominant follicle in pregnant women (12.1 +/- 2.6; 1.28 +/- 0.33/0.68 +/- 0.12; 2.67 +/- 0.51/0.72 +/- 0.32; 0.71 +/- 0.19/0.54 +/- 0.06 mm, respectively) were not statistically different from those for nonpregnant women (11.0 +/- 2.9; 1.46 +/- 0.49/0.71 +/- 0.21; 2.81 +/- 0.65/0.88 +/- 0.34; 0.74 +/- 0.24/0.55 +/- 0.09, respectively). CONCLUSION: A trilaminar endometrium on the day of IUI provides a favorable prediction of pregnancy. Endometrial thickness and Doppler surveys of the spiral and uterine arteries and dominant follicle do not have useful predictive value in COH + IUI.

Adult↗
PubMed2000

The mental health of the peers of suicide completers and attempters.

This study examined the prevalence and risk of psychiatric disturbances and suicidal behaviours among the peers of suicide attempters and completers. The subjects were selected from high schools with and without history of student suicides in the past 3 years. The psychiatric disturbances (as measured by the YSR and CBCL), suicidal behaviours, drug use, and a wide range of potential risk factors were measured. About a quarter of the peers of suicide completers and attempters were probable psychiatric cases and 15-21% of them reported suicidal acts. The increased risk of psychiatric disturbances and suicidal behaviours were still evident after controlling for age, sex, and potential risk factors. The presence of psychiatric disturbances could not wholly account for the increased odds of suicidal behaviours. Peers of suicide attempters carried a higher risk than peers of suicide completers. The close friends of suicide completers were particularly at risk of internalising problems, whereas the close friends of suicide attempters were at high risk of externalising problems. The peers of suicide completers and attempters represent a high-risk group for psychiatric disturbances and suicidal behaviours. The specific association of different types of psychiatric disturbances in the peers of suicide completers and attempters suggested that different risk mechanisms might be in operation within these peer groups.

Adolescent↗
PubMed2000

Prenatal diagnosis of inherited satellited non-acrocentric chromosomes.

We report on the prenatal diagnosis of two sib female fetuses with a satellited short arm of chromosome 4 and a male fetus with a satellited long arm of chromosome X. The first two fetuses had a cryptic balanced translocation (4;15)(p16;p11.1) inherited from a mother carrying a satellited 4p and having an affected child with the Wolf-Hirschhorn syndrome. The third fetus had a satellited Xq, with a deletion of subtelomeric region of Xq. The mother was subsequently found to have the same satellited Xq but without the presence of a reciprocal translocation. She decided to continue the pregnancy. The proband with a satellited Xq manifested developmental delay, mental retardation, hypertelorism, ptosis of one eye, low-set ears, and hearing disturbance at age 6 months. Fluorescence in situ hybridization (FISH) with a specific telomeric or subtelomeric probe, and genetic marker analyses were used to confirm the diagnosis. Pregnant women with satellited non-acrocentric chromosomes are at risk for carrying fetuses with chromosome abnormalities. If the X chromosome is involved, the fetuses can be affected with X-linked recessive disorders including mental retardation. Detailed genetic counselling, cytogenetic studies, FISH and genetic marker analyses are useful in prenatal detection of abnormal chromosome rearrangements.

Adult↗
PubMed2000

Analysis of an SMN gene-like DNA fragment.

Part of a survival motor neuron (SMN) gene-like DNA fragment has been identified. This DNA fragment was accidentally isolated from cDNA by RT-PCR using primers specific for the region between exon 3 and 6 of the SMN gene. This fragment was used as a probe to hybridize the mRNA from several tissues, but we have been unable to detect any transcript of this SMN-like gene in these tissues. Thus, we have inferred this SMN gene-like fragment was a genomic product contaminant that was amplified in the reaction. Sequencing analysis of this fragment, which contains several stop codons, revealed a 74.6% nucleotide homology with the SMN gene. From these results, we believe that this DNA fragment is not a mutated form of SMN gene. Rather, it is an SMN-like pseudogene, which is variably present even in normal individuals.

Base Sequence↗
PubMed2000

Effects of VEGF121 and/or VEGF165 gene transfection on collateral circulation development.

BACKGROUND AND PURPOSE: Angiogenesis is regulated by various factors, including vascular endothelial growth factor (VEGF). Five isoforms of VEGF have been discovered: VEGF121, VEGF145, VEGF165, VEGF189, and VEGF206. The teleologic basis for the various VEGF isoforms remains unclear, but different VEGF isoforms may mediate distinct endothelial cell functions such as angiogenesis, vascular permeability, and differentiation. We sought to determine the effects of various VEGF isoforms on angiogenesis under ischemic conditions in rabbits. METHODS: The effects of VEGF121 and/or VEGF165 gene transfection on collateral circulation development in ischemic rabbit hindlimb muscles were investigated by using naked plasmids encoding VEGF121 or VEGF165 (pVEGF121 or pVEGF165), either individually or in combination. pCMV beta was used as the control plasmid. The femoral artery on one side of New Zealand White rabbits was ligated. Ten days later, the ischemic muscles received direct intramuscular injection of pVEGF121 (500 micrograms), pVEGF165 (500 micrograms), or pVEGF121 (250 micrograms) + pVEGF165 (250 micrograms) in experimental groups, while pCMV beta (500 micrograms) was used in the control group. Therapeutic effects were evaluated 30 days later by anatomic and physiologic analysis. RESULTS: Internal iliac angiography showed strong development of collateral circulation in all of the pVEGF-treated groups. In contrast, collateral arteries developed weakly in the control group. Combination treatment with both pVEGF121 and pVEGF165 did not result in additional improvement compared with pVEGF121 or pVEGF165 treatment alone (angiographic scores: pVEGF121 = 0.85 +/- 0.10; pVEGF165 = 0.81 +/- 0.11; pVEGF121 + pVEGF165 = 0.83 +/- 0.09; control = 0.53 +/- 0.09; p < 0.01). A favorable response in the development of circulation at the capillary level with pVEGF121 and/or pVEGF165 versus pCMV beta was also found. Blood pressure measurement and regional blood flow measurement using colored microspheres revealed similar results. CONCLUSIONS: Our results show that direct intramuscular injection of naked DNA encoding VEGF121 or VEGF165, individually or in combination, is an effective method for gene transfer in an animal model of ischemic limbs and results in augmented collateral vascular development and tissue perfusion.

Angiography↗
PubMed2000

Clinical characteristic of parenteral iron supplementation in hemodialysis patients receiving erythropoietin therapy.

BACKGROUND: Iron deficiency constitutes the major cause of erythropoietin hyporesponse in uremic patients receiving erythropoietin therapy; therefore, iron supplementation is necessary for these patients. Recent data suggested that intravenous iron supply is a preferable route for iron supplementation. However, it remains unclear whether a single large dose or multiple small doses are a better way of administering an intravenous iron supply. METHODS: To determine the effect of different dosing schedules of intravenous iron therapy on the hematocrit level, we randomly assigned 18 patients to 3 groups. The first group of patients (n = 6) received a single dose of 800 mg intravenous fesin (ferric saccharate). The second group of patients (n = 6) received 400 mg intravenous fesin once weekly for 2 successive weeks. The third group of patients (n = 6) received 120 mg of intravenous fesin for 7 successive hemodialysis sessions. EPO was given at a fixed dose for all individuals in the study period. RESULTS: The results showed that all 3 groups of patients had a progressive increase in hematocrit (Hct) level following intravenous iron therapy. Serum ferritin levels increased rapidly following iron therapy and then declined gradually in all 3 groups. But no statistical significance could be found among the 3 groups because of the small patient number. Also, no differences were observed in Hct or serum ferritin levels among these 3 groups of patients at all stages. CONCLUSION: In this study, we found that a large single dose as well as small multiple doses of parenteral iron therapy had similar effects in correcting the iron deficiency in hemodialysis patients treated with erythropoietin. To save manpower and costs, we recommend the large single dosing schedule.

Anemia↗
PubMed2000

Prolonged paralysis associated with succinylcholine--a case report.

Prolonged paralysis is a rare complication of succinylcholine. We report a case of palmar hyperhidrosis who underwent transthoracic endoscopic sympathetic ganglionectomy under general anesthesia with a facemask developed prolonged paralysis following the operation. The prolonged paralysis supposedly caused by intraoperative use of succinylcholine was recognized and confirmed by laboratory examination which showed low pseudocholinesterase activity. In this report, we describe the course of the event and discuss the causes of delayed awakening associated with anesthesia and its management.

Adolescent↗
PubMed1999

Human FRAG1 encodes a novel membrane-spanning protein that localizes to chromosome 11p15.5, a region of frequent loss of heterozygosity in cancer.

We have previously identified a chromosomal rearrangement between fibroblast growth factor receptor 2 (FGFR2) and a novel gene, FRAG1, in a rodent model of osteosarcoma. To assess the potential role of FRAG1 in disease further, we have isolated cDNA and genomic clones of human FRAG1. Sequence analysis of the cDNA revealed the presence of an insertion not contained in the original FRAG1 sequence. This insertion in human FRAG1 encoded a region highly homologous to and immediately following the first 55 amino acids of the protein, indicating the presence of a repetitive domain within FRAG1, designated the FRAG1 homology (FH) domain. Analysis of FRAG1 gene structure revealed that the FH domains were encoded by tandem duplicated exons. Database searches identified several transmembrane proteins displaying homology to the FH domain of FRAG1. In addition, hydropathy analysis predicted FRAG1 to encode an integral membrane protein with multiple membrane-spanning segments. FRAG1 mRNA was ubiquitously expressed in human adult tissues and several tumor cell lines at varying levels of abundance. Human FRAG1 was mapped by fluorescence in situ hybridization and radiation hybrid analysis to chromosome 11 at band p15.5, a region implicated in Beckwith-Wiedemann syndrome and a region of frequent loss of heterozygosity in multiple tumor types. These results suggest that FRAG1 may be a useful candidate gene for genetic disorders associated with alterations at 11p15.5.

Adult↗