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Biomedical subjects

L A Lee

Publications and source records attributed to L A Lee.

At least 19 recordsLinked to original sources
PubMed2003

Cerebral autoregulation in children during sevoflurane anaesthesia.

INTRODUCTION: Little is known about cerebral autoregulation in children. The aim of this study was to examine cerebral autoregulation in children. METHODS: Cerebral autoregulation testing was performed during less than 1 MAC sevoflurane anaesthesia in children (from 6 months to 14 yr) and in adults (18-41 yr). Mean middle cerebral artery flow velocities (V(MCA)) were measured using transcranial Doppler ultrasonography. Mean arterial pressure (MAP) was increased to whichever was greater: 20% above baseline or (i) 80 mm Hg for less than 9 yr, (ii) 90 mm Hg for 9-14 yr, and (iii) 100 mm Hg for adults. Cerebral autoregulation was considered intact if the autoregulatory index was > or =0.4. RESULTS: There were 13 subjects less than 2 yr old (Group 1), 13 subjects 2-5 yr (Group II), 14 subjects 6-9 yr (Group III), 12 subjects 10-14 yr (Group IV), and 12 adults (Group V; control group). All subjects had an autoregulatory index > or =0.4. There was no difference in autoregulatory index between children in Groups I-IV or between children and adults. DISCUSSION: We found no age-related differences in autoregulatory capacity during low-dose sevoflurane anaesthesia. We report no differences in autoregulatory capacity between children and adults.

Adolescent↗
PubMed2003

Efficacy of radiofrequency volumetric tissue reduction of the soft palate in the treatment of snoring.

Traditional surgery for snoring often leads to intolerable postoperative pain. A new surgical treatment, radiofrequency volumetric tissue reduction (RVTR) of the soft palate, was carried out and its effect and safety in the management of snoring were evaluated. Thirty-two patients received a single treatment of RVTR with a mean follow-up period of 4.5 months. All patients were assessed by a questionnaire using the Snore Outcomes Survey (SOS) and the Epworth Sleepiness Scale (ESS). Postoperative pain, speech and swallowing disturbances were also evaluated. The postoperative scores of SOS and ESS all significantly improved (p<0.05). Postoperative pain, speech and swallowing disturbances were all mild 1-3 days after treatment. With the success of treatment defined as a postoperative snoring index (SI) of <3 or a reduction of the SI by >5 points by the visual analogue scale, the success rate was 81.3% in patients with a respiratory disturbance index (RDI) of <20, and 50% in those with an RDI of >20. We conclude that RVTR of the soft palate is an effective treatment for snoring, resulting in only mild postoperative discomfort. A patient whose RDI was <20 had a higher success rate with a single RVTR treatment.

Adult↗
PubMed2002

Endoscopic findings predict the histologic diagnosis in gastrointestinal graft-versus-host disease.

BACKGROUND AND STUDY AIMS: Graft-versus-host disease (GvHD) of the gastrointestinal tract is a major cause of morbidity and mortality after allogeneic bone marrow transplantation (BMT). Whether endoscopic findings predict the histologic diagnosis of GvHD in the gastrointestinal tract remains controversial. We performed a study to determine the diagnostic accuracy of macroscopic endoscopy findings in the diagnosis of acute and chronic histologically proven gastrointestinal GvHD (GI-GvHD). PATIENTS AND METHODS: Endoscopic images from the intestinal mucosa of post-BMT patients were blindly graded as positive or negative for GI-GvHD and compared with corresponding histological findings, which were used as the gold standard. RESULTS: 44 BMT patients were referred for 96 endoscopic evaluations. Using 162 endoscopy-biopsy pairs, a positive association between endoscopic grading and histologic grading of GI-GvHD (odds ratio [OR] = 11.97, 95% CI 3.86, 37.16) was observed. Endoscopic diagnosis correctly predicted histologic diagnosis in both acute and chronic GI-GvHD (OR = 9.3 vs. 23.1, P = 0.31). CONCLUSIONS: The diagnostic accuracy of endoscopy was high in both acute and chronic histologically proven GI-GvHD. Accurate diagnosis of GI-GvHD might be obtained with mucosal biopsies from either the upper or lower gastrointestinal tract. Endoscopy may play a significant role in establishing early diagnosis and treatment for GI-GvHD in patients following BMT, but histologic evaluation of the gastrointestinal mucosa is needed to confirm the final diagnosis.

Adult↗
PubMed2002

Unilateral tumid lupus erythematosus.

Few cases of inflammatory blaschkolinear dermatoses have been described. We report a case of blaschkolinear cutaneous tumid lupus erythematous and discuss the potential association between cutaneous genetic mosaicism, Blaschko lines and lupus susceptibility.

Adrenal Cortex Hormones↗
PubMed2001

A novel c-Myc-responsive gene, JPO1, participates in neoplastic transformation.

We have identified a novel c-Myc-responsive gene, named JPO1, by representational difference analysis. JPO1 responds to two inducible c-Myc systems and behaves as a direct c-Myc target gene. JPO1 mRNA expression is readily detectable in the thymus, small intestine, and colon, whereas expression is relatively low in spleen, bone marrow, and peripheral leukocytes. We cloned a full-length JPO1 cDNA that encodes a 47-kDa nuclear protein. To determine the role of JPO1 in Myc-mediated cellular phenotypes, stable Rat1a fibroblasts overexpressing JPO1 were tested and compared with transformed Rat1a-Myc cells. Although JPO1 has a diminished transforming activity as compared with c-Myc, JPO1 complements a transformation-defective Myc Box II mutant in the Rat1a transformation assay. This complementation provides evidence for a genetic link between c-Myc and JPO1. Similar to c-Myc, JPO1 overexpression enhances the clonogenicity of CB33 human lymphoblastoid cells in methylcellulose assays. These observations suggest that JPO1 participates in c-Myc-mediated transformation, supporting an emerging concept that c-Myc target genes constitute nodal points in a network of pathways that lead from c-Myc to various Myc-related phenotypes and ultimately to tumorigenesis.

Amino Acid Sequence↗
PubMed2001

A strategy to identify differentially expressed genes using representational difference analysis and cDNA arrays.

Representational difference analysis (RDA) combined with cDNA arrays is an effective approach to identify differentially expressed genes. To identify differentially expressed genes in c-Myc transgenic mouse liver, we compared the virtues of probing commercially available cDNA arrays with either radiolabeled cDNA pools or radiolabeled difference products (DP2) derived from RDA using c-Myc transgenic and normal mouse liver. Probing commercial and custom arrays with DP2 products led to the identification of transcripts of low abundance that were missed when the arrays were initially probed with PCR-amplified cDNA pools. Although DP2 probes also detected abundant transcripts that are highly differentially expressed, they failed to identify abundant transcripts with low differential expression that were detected with cDNA pools. The combined use of radiolabeled cDNA and DP2 products to probe arrays allows a more comprehensive identification of differentially expressed transcripts that are abundant or rare. Our method has the additional benefit of eliminating false-positive transcripts that lack true differential expression and frequently contaminate DP2 pools. Using this method we identified 16 differentially expressed genes in c-Myc transgenic liver, one of which is novel.

Animals↗
PubMed2001

Neonatal lupus: clinical features, therapy, and pathogenesis.

Neonatal lupus is a disease characterized by one or more of the following findings: congenital heart block, cardiomyopathy, cutaneous lupus lesions, hepatobiliary disease, and thrombocytopenia. Accumulating evidence indicates that the disease is probably caused by maternal autoantibodies, particularly autoantibodies of the Ro family. While often initially asymptomatic, mothers tend to develop symptoms of connective tissue disease. This review discusses the recent advances in the understanding of neonatal lupus, its clinical features, therapy, and pathogenesis.

Adrenal Cortex Hormones↗
PubMed2001

CUSP/p63 expression in rat and human tissues.

The human homolog of KET, p63, bears strong homology to the tumor suppressor p53 and plays an essential role in epithelial development. CUSP, the most abundant cutaneous product of p63, has been identified as an autoantigen in chronic ulcerative stomatitis (CUS). The original report of KET expression at least partially contradicts p63 expression subsequently reported by many different groups. We have examined p63 expression by Northern analysis of RNA from multiple human tissues and by indirect immunofluorescence of rat tissue with CUS patient sera. Northern analysis reveals p63 RNA in skin, thymus, placenta, skeletal muscle, kidney, and lung, with non-transactivating p63 RNA in skin, thymus, and placenta. Reverse transcriptase polymerase chain reaction (rtPCR) assays show abundant non-transactivating p63 RNA, and little to no transactivating p63 RNA, in human basal cell carcinoma as well as in normal skin adjacent to the tumors. p63 RNA expression was not detected in brain, heart, colon, spleen, liver, or small intestine. Immunofluorescence reveals p63 expression in skin, oral epithelium, tongue, kidney, and trachea, but not in liver, large intestine, testis, skeletal muscle, or heart. Focal p63 expression within tissues, the complex array of isoforms encoded by the gene, and the specificity of the probes and antibodies utilized, may all contribute to contradictory accounts of CUSP/p63 expression.

Animals↗
PubMed2001

Behçet disease.

Behçet's disease is a multisystem inflammatory disorder of unknown origin, characterized by recurrent oral and genital ulcerations, ocular and cutaneous lesions, arthritis, central nervous system, and vascular disease. There is no pathognomonic laboratory test, but there are clinical criteria to assist in establishing the diagnosis. Behçet's is most common along the Silk Road. It is particularly common among persons who have the HLA-B51 major histocompatibility type. Cutaneous lesions include pustules, erythema nodosum-like lesions, Sweet's-like lesions, pyoderma gangrenosum-ike lesions, and pathergy. The major cutaneous findings may be classified as neutrophilic vascular reactions. There is considerable morbidity resulting from Behçet's disease, most notably a high risk of blindness from ocular involvement. Mortality may occur as a result of neurologic or vascular disease or gastrointestinal perforation.

Behcet Syndrome↗
PubMed2001

A genetic screen for suppressors and enhancers of the Drosophila PAN GU cell cycle kinase identifies cyclin B as a target.

The early cell cycles of Drosophila embryogenesis involve rapid oscillations between S phase and mitosis. These unique S-M cycles are driven by maternal stockpiles of components necessary for DNA replication and mitosis. Three genes, pan gu (png), plutonium (plu), and giant nuclei (gnu) are required to control the cell cycle specifically at the onset of Drosophila development by inhibiting DNA replication and promoting mitosis. PNG is a protein kinase that is in a complex with PLU. We employed a sensitized png mutant phenotype to screen for genes that when reduced in dosage would dominantly suppress or enhance png. We screened deficiencies covering over 50% of the autosomes and identified both enhancers and suppressors. Mutations in eIF-5A and PP1 87B dominantly suppress png. Cyclin B was shown to be a key PNG target. Mutations in cyclin B dominantly enhance png, whereas png is suppressed by cyclin B overexpression. Suppression occurs via restoration of Cyclin B protein levels that are decreased in png mutants. The plu and gnu phenotypes are also suppressed by cyclin B overexpression. These studies demonstrate that a crucial function of PNG in controlling the cell cycle is to permit the accumulation of adequate levels of Cyclin B protein.

Animals↗
PubMed2001

Upper gastrointestinal tract injury in patients receiving kayexalate (sodium polystyrene sulfonate) in sorbitol: clinical, endoscopic, and histopathologic findings.

Kayexalate (sodium polystyrene sulfonate) in sorbitol has been demonstrated to cause colonic necrosis in a subset of uremic patients who are administered the cation exchange resin for treatment of hyperkalemia. Upper gastrointestinal damage associated with Kayexalate in sorbitol is reported far less frequently, and the clinicopathologic spectrum of disease in cases with upper gastrointestinal damage has not been investigated previously. The authors studied the clinical, endoscopic, and histologic features of 11 patients with Kayexalate crystals in biopsies from the esophagus (n = 7), stomach (n = 6), and duodenum (n = 2). The endoscopic appearance was markedly abnormal in all 11 patients. The effects of the medication closely mimicked other endoscopic and radiologic diagnoses in three cases, including esophageal carcinoma, Candidal esophagitis, and gastric bezoar. Histologic and/or endoscopic evidence of mucosal injury in the form of an ulcer or erosion was present in nine patients (82%). In four patients with mucosal injury, no other etiology apart from Kayexalate in sorbitol could be identified. In comparison with a cohort of patients with Kayexalate crystals in lower gastrointestinal specimens identified during the same period (11 patients) the frequency of associated mucosal damage was not significantly different (55%, p = 0.19), but no patient with upper gastrointestinal Kayexalate required surgical resection or died as a result of Kayexalate-induced mucosal injury. The results of this study provide evidence that Kayexalate in sorbitol can induce damage to the upper gastrointestinal tract. Recognition of Kayexalate crystals in histologic sections as a marker for sorbitol-induced mucosal damage may aid in establishing the correct diagnosis for clinically or endoscopically misleading lesions.

Aged↗
PubMed2001

Epidemiologic study of the prevalence and severity of myopia among schoolchildren in Taiwan in 2000.

BACKGROUND AND PURPOSE: A nationwide survey was performed in 2000 to determine the prevalence and severity of myopia among schoolchildren in Taiwan and to compare these findings with the results of the last survey performed in 1995. METHODS: We first divided the whole island into regions according to developmental grade scores and then sampled with the probability proportional to the size of the population within each stratum. A total of 10,889 students were enrolled, including 5,664 boys and 5,225 girls, with ages ranging from 7 to 18 years. The refractive status and corneal radius of each student were measured with an autorefractometer under cycloplegia and checked with retinoscopy. Axial length was measured using biometric ultrasound. RESULTS: The myopia rate increased from 20% at 7 years, to 61% at 12 years, and 81% at 15 years. A myopic rate of 84% was found for schoolchildren aged 16 years through 18 years. The mean refractive index reached myopic status at the age of 8, and increased to -4.12 D in girls and -3.15 D in boys at the age of 18 years. The prevalence of high myopia (> -6.0 D) at the age of 18 years was 24% in girls and 18% in boys. The increase in axial length corresponded with the progression of myopia. The anterior chamber depth was slightly deeper from 7 years to 13 years and then remained stable. The lens thickness decreased from 7 years to 11 years. After age 15, further thickening of the lens was correlated with both age and severity of myopia. However, the corneal curvature was not related to age or severity of myopia. Girls had a higher prevalence and more severe degree of myopia than boys. Children in urban areas had a higher prevalence and more severe degree of myopia than children in rural areas. CONCLUSION: The prevalence and severity of myopia in schoolchildren in Taiwan in 2000 increased compared to 1995, with the most severe increases occurring in younger age groups. Thus, preventing schoolchildren developing myopia at a young age may slow down the increase in severity of myopia in Taiwan.

Adolescent↗
PubMed2000

Induction of ribosomal genes and hepatocyte hypertrophy by adenovirus-mediated expression of c-Myc in vivo.

Overexpression of c-Myc in immortalized cells increases cell proliferation, inhibits cell differentiation, and promotes cell transformation. Recent evidence suggests that these effects, however, do not necessarily occur when c-Myc is overexpressed in primary mammalian cells. We sought to determine the immediate effects of transient overexpression of c-Myc in primary cells in vivo by using recombinant adenovirus to overexpress human MYC in mouse liver. Mice were intravenously injected with adenoviruses encoding MYC (Ad/Myc), E2F-1 (Ad/E2F-1), or beta-galactosidase (Ad/LacZ). Transgene expression was detectable 4 days after injection. Expression of ectopic c-Myc was immediately accompanied by enlarged and dysmorphic hepatocytes in the absence of significant cell proliferation or apoptosis. These findings were not present in the livers of mice injected with Ad/E2F-1 or Ad/LacZ. Prominent hepatocyte nuclei and nucleoli were associated with the up-regulation of large- and small-subunit ribosomal and nucleolar genes, suggesting that c-Myc may induce their expression to increase cell mass. Our studies support a role for c-Myc in the in vivo control of vertebrate cell size and metabolism independent of cell proliferation.

Adenoviridae↗