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Samanta S, Tan M, Kissack C, Nayak S, Chittick R, Yoxall CW. The value of Bilicheck as a screening tool for neonatal jaundice in term and near-term babies. ACTA PAEDIATRICA (OSLO, NORWAY : 1992) 2005; 93:1486-90. [PMID: 15513577 DOI: 10.1080/08035250410033042] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
Abstract
AIMS To determine the accuracy of Bilicheck in assessing serum bilirubin. To evaluate the effectiveness of Bilicheck as a screening device in a population of jaundiced term and near-term babies. METHODS Prospective evaluation of paired Bilicheck measurements and serum bilirubin in 300 babies. RESULTS There was a strong correlation between Bilicheck and serum bilirubin. The mean difference between Bilicheck and serum bilirubin was -10.7 micromol/l, but the 95% limits of agreement were wide at -80 micromol/l to +60 micromol/l. Bilicheck identified significant jaundice (serum bilirubin above 250 micromol/l) with a sensitivity (95% confidence interval) of 91% (88% to 94%) and specificity of 66% (60% to 71%). The area under the receiver operator characteristic curve was 0.85. There were five false negatives, all of whom had a serum bilirubin below 300 micromol/l. If Bilicheck had been used as a screening device, there would have been a 55% decrease in blood samples taken in these babies. CONCLUSION Bilicheck cannot be used to measure serum bilirubin in term and near-term babies with jaundice, but is an effective screening method, which can be used to safely reduce the number of blood tests in these babies.
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Abstract
Attention deficit hyperactivity disorder (ADHD) is characterised by inattention, impulsivity, and hyperactivity. The DSM-IV diagnosis of ADHD requires the presence of six of nine items or features that must have been present for at least six months, to have had an onset before 7 years of age, and to have resulted in significant distress or impairment.1 In the general population, the prevalence of ADHD is approximately 5%.2 There is a high co-morbidity of epilepsy and attentional and behavioural problems,3,4 including ADHD, and it has been estimated that at least 20% of patients with epilepsy may present with features of ADHD.5.
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Low ECT, Ong MCC, Tan M. Breath carbon monoxide as an indication of smoking habit in the military setting. Singapore Med J 2004; 45:578-82. [PMID: 15568119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
INTRODUCTION The breath carbon monoxide (CO) monitor has been shown to be an effective tool in predicting smoking habits. This study aims to assess whether the breath CO level can be employed to determine a person's smoking habit in the military setting and to analyse various factors that can influence the breath CO levels. METHODS 155 navy personnel were questioned on their smoking habits in phase one of the study. The subjects were explained the objective of the study and instructed to provide two breaths into the CO monitor (EC-50 Smokerlyser, Bedford Instruments, Kent, UK). In a subsequent single blind study, 40 trainees were not told of the purpose of the study and were assessed via a questionnaire and smokerlyser estimation. Descriptive statistics were used to examine the data and assess distribution. Depending on the distribution, a two-sample t test or Mann-Whitney U test were used to test for a significant difference between CO levels among smokers and non-smokers. RESULTS In phase one, the mean breath CO levels were 11.6 (plus or minus 6.2) ppm for smokers and (1.9 plus or minus 0.9) ppm for non-smokers (p-value less than 0.0001). A cut-off level of 5 ppm gave a sensitivity of 96 percent and a specificity of 98 percent. The high CO levels were clustered within five hours of the last cigarette smoked. Therefore, this value may not reliably predict smoking habits if an individual smoked more than five hours before the test. Of the 40 subjects in phase two, five smokers who stated that their last cigarette smoked was 48 hours before the breath test had a mean CO level greater than 5 ppm. (range of 5.5 to 18.0 ppm). On further questioning, all admitted to having smoked on the day of the test. CONCLUSION The breath CO monitor has good potential for use as an adjunct in future smoking control assessments and a reading greater than 5 ppm strongly suggests that the military outpatient is a smoker.
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Costello LC, Feng P, Milon B, Tan M, Franklin RB. Role of zinc in the pathogenesis and treatment of prostate cancer: critical issues to resolve. Prostate Cancer Prostatic Dis 2004; 7:111-7. [PMID: 15175662 PMCID: PMC4464831 DOI: 10.1038/sj.pcan.4500712] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The most consistent and persistent biochemical characteristic of prostate cancer (PCa) is the marked decrease in zinc and citrate levels in the malignant cells. This relationship provides compelling evidence that the lost ability of the malignant cells to accumulate zinc is an important factor in the development and progression of prostate malignancy. In addition, this relationship provides a rational basis for the concept that restoration of high zinc levels in malignant cells could be efficacious in the treatment and prevention of PCa. Epidemiological studies regarding dietary zinc effects on PCa have been conflicting and confusing. The purpose of this presentation is to present a current state of information regarding zinc relationships in the pathogenesis and treatment of PCa. We also hope to bring more attention to the medical and research community of the critical need for concerted clinical and basic research regarding zinc and PCa.
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Liu ZL, Han FP, Tan M, Shan XH, Dong YZ, Wang XZ, Fedak G, Hao S, Liu B. Activation of a rice endogenous retrotransposon Tos17 in tissue culture is accompanied by cytosine demethylation and causes heritable alteration in methylation pattern of flanking genomic regions. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2004; 109:200-9. [PMID: 15071728 DOI: 10.1007/s00122-004-1618-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2003] [Accepted: 01/26/2004] [Indexed: 05/22/2023]
Abstract
Tos17 is a copia-like, cryptic retrotransposon of rice, but can be activated by tissue culture. To study possible epigenetic mechanism controlling activity of Tos17, we subjected three rice lines (the parental line cv. Matsumae and two introgression lines, RZ2 and RZ35) that harbor different copies of the element to tissue culture. For each line, we investigated transcription and transposition of Tos17 in seed plants, calli and regenerated plants, cytosine-methylation status at CG and CNG positions within Tos17, effect of 5-azacytidine on methylation status and activity of Tos17, and cytosine-methylation states in genomic regions flanking original and some newly transposed copies of Tos17 in calli and regenerated plants. We found that only in introgression line RZ35 was Tos17 transcriptionally activated and temporarily mobilized by tissue culture, which was followed by repression before or upon plant regeneration. The activity and inactivity of Tos17 in calli and regenerated plants of RZ35 are accompanied by hypo- and hyper-CG methylation and hemi- and full CNG methylation, respectively, within the element, whereas immobilization of the element in the other two lines is concomitant with near-constant, full hypermethylation. Treatment with 5-azacytidine induced both CG and CNG partial hypomethylation of Tos17 in two lines (Matsumae and RZ35), which, however, was not accompanied by activation of Tos17 in any line. Heritable alteration in cytosine-methylation patterns occurred in three of seven genomic regions flanking Tos17 in calli and regenerated plants of RZ35, but in none of the five regions flanking dormant Tos17 in the other two lines.
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Casey RG, Tan M, Salman R, Ryan J, Gillen P. Acute abdomen in pregnancy due to mucinous cystadenoma of the appendix. J OBSTET GYNAECOL 2003; 23:566-7. [PMID: 12963525 DOI: 10.1080/0144361031000156564] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Chan CY, Tan M. Spatial relations of the angular vein, an important landmark in axillary nodal dissection. Br J Surg 2003; 90:948-9. [PMID: 12905546 DOI: 10.1002/bjs.4147] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Helpful anatomy for the breast surgeon
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Goldberg D, Tan M, Dale Sarradet M, Gordon M. Nonablative dermal remodeling with a 585-nm, 350-microsec, flashlamp pulsed dye laser: clinical and ultrastructural analysis. Dermatol Surg 2003; 29:161-3; discussion 163-4. [PMID: 12562346 DOI: 10.1046/j.1524-4725.2003.29040.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND A nonablative 350-microsec, 585-nm, flashlamp pulsed dye laser is currently being used for the treatment of rhytides. OBJECTIVE To analyze both clinical rhytid improvement and electron microscopic evidence of ultrastructural changes after treatment with a nonablative 350-microsec, 585-nm, flashlamp pulsed dye laser. RESULTS At 6 months after two treatments, 40% of the treated subjects noted mild improvement in rhytid appearance. Nontreating physician evaluation revealed some degree of improvement in 50% of the treated subjects. Mild improvement in quality and texture of the skin was also reported by 50% of the subjects. Electron microscopic evaluation showed ultrastructural changes that are consistent with new collagen formation. CONCLUSION Treatment with a nonablative 350-microsec, 585-nm, flashlamp pulsed dye laser can lead to both clinical and electron microscopic evidence of improvement in photo-damaged skin.
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Choo S, Teo SH, Tan M, Yong MH, Ho LY. Tissue-limited mosaicism in Pallister-Killian syndrome -- a case in point. J Perinatol 2002; 22:420-3. [PMID: 12082482 DOI: 10.1038/sj.jp.7210712] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We report a case of Pallister-Killian syndrome in a term female infant. Antenatal ultrasound showed left diaphragmatic hernia and polyhydramnios. She was ventilated from birth and the diaphragm defect repaired on day 5. She had dysmorphic features, including median cleft palate, patchy frontotemporal alopecia, hypopigmented skin whorls, and bilateral profound sensorineural hearing loss. Fetal and postnatal karyotypes of peripheral lymphocytes were both normal, 46, XX. Subsequently, a skin fibroblast culture showed mosaic tetrasomy of isochromosome 12p both on G-banding and fluorescence in situ hybridization, consistent with Pallister-Killian syndrome. This case illustrates the importance of using the appropriate sample type for karyotype analysis with implications for prenatal and postnatal diagnosis.
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MESH Headings
- Abnormalities, Multiple/diagnosis
- Abnormalities, Multiple/genetics
- Cells, Cultured
- Chromosomes, Human, Pair 12/genetics
- Cleft Palate/surgery
- Developmental Disabilities/genetics
- Female
- Fibroblasts/cytology
- Hernia, Diaphragmatic/surgery
- Hernias, Diaphragmatic, Congenital
- Humans
- In Situ Hybridization, Fluorescence
- Infant, Newborn
- Intellectual Disability/genetics
- Karyotyping
- Mosaicism/diagnosis
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Dagci T, Tan M, Koylu EO, Tan U, Pogun S. The effect of octreotide on kainate-induced wet dog shakes and seizure activity in male and female rats. Int J Neurosci 2002; 112:829-39. [PMID: 12424823 DOI: 10.1080/00207450290025842] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Systemic kainic acid (KA) administration to rats triggers wet dog shakes (WDS) followed by epileptic seizures. Although WDS are often associated with the occurrence of seizures, we have recently shown that following nitric oxide (NO) synthesis inhibition, the number of WDS decreased; subsequently the onset of seizure activity was shortened, and the number of convulsions was increased. Somatostatin (SS), whose release appears to be controlled by NO, inhibits seizure activity. There are sex differences in seizure susceptibility as well as in SS and NO activities in brain. The present study was undertaken to assess the effect of octreotide (OC), a stable SS analogue, on KA-induced WDS and seizures in rats, with emphasis on possible sex differences. WDS and seizures were induced by KA in male and female (proestrus) Sprague Dawley rats; OC or saline was injected 30 min before KA and the behavior was monitored for 120 min after KA. Octreotide increased the number of WDS and decreased the number of convulsions; this effect was more pronounced in males. Onset of KA-induced seizure activity was earlier in females than males; however, there was no effect of OC on seizure latency. Seizure activity started after the termination of WDS. These results show OC has opposite effects on WDS and convulsions, in that it stimulates the former and inhibits the latter. These results support our previous findings that WDS and seizure activity involve separate mechanisms and suggest that WDS may have an inhibitory effect on limbic seizures.
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Casey RG, Tan M, Ryan J, Gillen P. Nonsteroidal anti-inflammatory induced small bowel obstruction. Ir J Med Sci 2002; 171:118. [PMID: 12173887 DOI: 10.1007/bf03168969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Tan M, Tan U. Sex difference in susceptibility to epileptic seizures in rats: importance of estrous cycle. Int J Neurosci 2002; 108:175-91. [PMID: 11699190 DOI: 10.3109/00207450108986513] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Sex difference in seizure susceptibility is one of the unresolved issues of epilepsy. It is known that estrogen is excitatory and progesterone is inhibitory to the central nervous system. Therefore, it is to be expected that seizure susceptibility may be associated with the estrous cycle, which should be tested in epilepsy research. Otherwise, different results in epilepsy studies could be an artifact of the estrous cycle. Reports in the literature are inconsistent about testosterone effects on seizures. In light of these considerations, sex differences in seizure susceptibility were restudied in rats. There was no significant sex difference in mean latencies to picrotoxin-induced seizures; prestrous-females had the shortest latencies to epileptic seizures compared to males and estrousfemales. With testosterone-injected rats, there was either no sex difference in latencies (to akinetic and focal seizures) or females had significantly shorter latencies than males (to status epilepticus, generalized tonic-clonic seizures, and myoclonic seizures). Testosterone-treated male rats had a significantly longer mean latency than controls for status epilepticus only; otherwise, these males showed no significant differences between mean latencies before and after testosterone (to focal, myoclonic, or generalized tonic-clonic seizures). In females, mean latencies to myoclonic seizures and status epilepticus were significantly shorter after testosterone than before. It was concluded that there is a sex difference in susceptibility to epileptic seizures in rats, provided that the estrous cycle is taken into account. Testosterone may increase and decrease seizure susceptibility in females and males, respectively. These effects may be important for understanding the mechanisms of epileptic phenomena and may provide some important clues to epilepsy treatment.
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Tan M, Sheng L, Qian Y, Ge Y, Wang Y, Zhang H, Jiang M, Zhang G. Changes of serum selenium in pregnant women with gestational diabetes mellitus. Biol Trace Elem Res 2001; 83:231-7. [PMID: 11794515 DOI: 10.1385/bter:83:3:231] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2001] [Accepted: 03/22/2001] [Indexed: 11/11/2022]
Abstract
Gestational diabetes is one of the most common diseases in pregnancy. In the present work, the possible relationship between serum selenium concentration and gestational diabetes was investigated. Blood samples of 234 pregnant women were collected, including 98 subjects with impaired glucose tolerance (IGT), 46 subjects with gestational diabetes mellitus (GDM), and 90 normal pregnant women (NPW). An additional 17 samples of normal women of fertile age (NW) were collected for comparison. The hydride generation atomic fluorescence spectrometry was used for selenium determination. The mean serum selenium levels obtained for each group were 0.0741 +/- 0.0167 mg/L for NPW, 0.0631 +/- 0.0132 mg/L for IGT, 0.0635 +/- 0.0120 mg/L for GDM, and 0.108 +/- 0.0170 mg/L for NW. Serum selenium levels were significantly lower in pregnant woman with IGT (p < 0.001) and GDM (p < 0.001) than in NPW. Furthermore, an inverse correlation between the serum selenium concentration and the gestational period was also observed. Selenium supplementation during gestation for pregnant women, especially with IGT and GDM, should be considered.
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Jiang T, Liu S, Tan M, Huang F, Sun Y, Dong X, Guan W, Huang L, Zhou F. The phase-shift mutation in the glucocorticoid receptor gene: potential etiologic significance of neuroendocrine mechanisms in lupus nephritis. Clin Chim Acta 2001; 313:113-7. [PMID: 11694247 DOI: 10.1016/s0009-8981(01)00661-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Glucocorticoid (GC), a mediator of the hypothalamo-pituitary-adrenal axis, has been found to play an important role in maintaining the stability of immune endo-environment of the body. The pathogenesis of lupus nephritis, an autoimmune disease, is thought to be related to the intrinsic hyposensitivity to GC secreted by adrenal gland, and impairs the regulation of the immuno-neuro-endocrine axis. METHODS To test this hypothesis, we examined the response of 39 clinic patients with lupus nephritis to GC and analyzed the molecular structure and function of the GC receptor (GR) on peripheral blood mononuclear cells. RESULTS There was no difference in the level of ACTH, GC and ligand affinity of GR between the patients and the controls. The GR number on mononuclear cells of lupus patients was lower than that of the controls. There was no difference in GR number between the patients with heterogeneous response, i.e. sensitive, dependent and resistance, to GC. The analysis of exon 9 of the GC receptor with PCR-amplified single strand conformation polymorphism (PCR-SSCP) method showed the polymorphism in exon 9 of GC receptor in 8 of the 39 lupus nephritis patients. DNA sequence analysis revealed an adenine insertion at the 2439 base pair of the GC receptor gene. This phase-shift mutation caused an additional 20 amino acids being translated into protein of GC receptor. CONCLUSION The decreased number of GC receptor and the molecular variation of GR on mononuclear cells could explain the phenomenon of GC resistance, potentially to endogenous GC, which suggested an etiological significance of neuro-endocrine-immune mechanism in lupus nephritis. This may be useful in the design of lupus nephritis therapy.
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Tan M, O'Hanlon DM, Cassidy M, O'Connell PR. Advantages of a posterior fourchette incision in anal sphincter repair. Dis Colon Rectum 2001; 44:1624-9. [PMID: 11711734 DOI: 10.1007/bf02234382] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE Delayed repair of obstetric-related anal sphincter injury remains problematic, and perineal wound breakdown is common. The aim of this study was to assess the outcome after overlap anal sphincter repair and to determine the advantages, if any, of a posterior fourchette incision (n = 18) compared with a conventional perineal incision (n = 32). METHODS Fifty females of mean parity 2.8 (standard deviation, 1.6) underwent repair in a five-year period. The mean follow-up was 23 months. Assessment was by anal vector manometry, endoanal ultrasound, and continence scoring. RESULTS Functional outcomes were similar in the two groups. Repair increased squeeze-pressure increment and improved continence scores in both groups. Postoperative wound complications were fewer when a posterior fourchette incision was used compared with a perineal incision (11 vs. 44 percent, respectively; P < 0.05). CONCLUSIONS Delayed anal sphincter repair improves continence. A posterior fourchette approach is associated with fewer postoperative wound complications without compromising the quality of repair and the functional outcome.
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Skapek SX, Lin SC, Jablonski MM, McKeller RN, Tan M, Hu N, Lee EY. Persistent expression of cyclin D1 disrupts normal photoreceptor differentiation and retina development. Oncogene 2001; 20:6742-51. [PMID: 11709709 DOI: 10.1038/sj.onc.1204876] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2001] [Revised: 07/31/2001] [Accepted: 08/01/2001] [Indexed: 11/09/2022]
Abstract
The differentiation of neuronal cells in the developing mammalian retina is closely coupled to cell cycle arrest and proceeds in a highly organized manner. Cyclin D1, which regulates cell proliferation in many cells, also drives the proliferation of photoreceptor progenitors. In the mouse retina, cyclin D1 protein normally decreases as photoreceptors mature. To study the importance of the down-regulation of cyclin D1 during photoreceptor development, we generated a transgenic mouse in which cyclin D1 was persistently expressed in developing photoreceptor cells. We observed numerous abnormalities in both photoreceptors and other nonphotoreceptor cells in the retina of these transgenic mice. In particular, we observed delayed opsin expression in developing photoreceptors and alterations in their number and morphology in the mature retina. These alterations were accompanied by disorganization of the inner nuclear and plexiform layers. The expression of cyclin D1 caused excess photoreceptor cell proliferation and apoptosis. Loss of the p53 tumor suppressor gene decreased cyclin D1-induced apoptosis and led to microscopic hyperplasia in the retina. These findings are distinct from other mouse models in which the retinoblastoma gene pathway is disrupted and suggest that the IRBP-cyclin D1 mouse model may recapitulate an early step in the development of retinoblastoma.
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Qing K, Hansen J, Weigel-Kelley KA, Tan M, Zhou S, Srivastava A. Adeno-associated virus type 2-mediated gene transfer: role of cellular FKBP52 protein in transgene expression. J Virol 2001; 75:8968-76. [PMID: 11533160 PMCID: PMC114465 DOI: 10.1128/jvi.75.19.8968-8976.2001] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although adeno-associated virus type 2 (AAV) has gained attention as a potentially useful vector for human gene therapy, the transduction efficiencies of AAV vectors vary greatly in different cells and tissues in vitro and in vivo. We have documented that a cellular tyrosine phosphoprotein, designated the single-stranded D-sequence-binding protein (ssD-BP), plays a crucial role in AAV-mediated transgene expression (K. Y. Qing, X.-S. Wang, D. M. Kube, S. Ponnazhagan, A. Bajpai, and A. Srivastava, Proc. Natl. Acad. Sci. USA 94:10879-10884, 1997). We have documented a strong correlation between the phosphorylation state of ssD-BP and AAV transduction efficiency in vitro as well as in vivo (K. Y. Qing, B. Khuntrirat, C. Mah, D. M. Kube, X.-S. Wang, S. Ponnazhagan, S. Z. Zhou, V. J. Dwarki, M. C. Yoder, and A. Srivastava, J. Virol. 72:1593-1599, 1998). We have also established that the ssD-BP is phosphorylated by epidermal growth factor receptor protein tyrosine kinase and that the tyrosine-phosphorylated form, but not the dephosphorylated form, of ssD-BP prevents AAV second-strand DNA synthesis and, consequently, results in a significant inhibition of AAV-mediated transgene expression (C. Mah, K. Y. Qing, B. Khuntrirat, S. Ponnazhagan, X.-S. Wang, D. M. Kube, M. C. Yoder, and A. Srivastava, J. Virol. 72:9835-9841, 1998). Here, we report that a partial amino acid sequence of ssD-BP purified from HeLa cells is identical to a portion of a cellular protein that binds the immunosuppressant drug FK506, termed the FK506-binding protein 52 (FKBP52). FKBP52 was purified by using a prokaryotic expression plasmid containing the human cDNA. The purified protein could be phosphorylated at both tyrosine and serine or threonine residues, and only the phosphorylated forms of FKBP52 were shown to interact with the AAV single-stranded D-sequence probe. Furthermore, in in vitro DNA replication assays, tyrosine-phosphorylated FKBP52 inhibited AAV second-strand DNA synthesis by greater than 90%. Serine- or threonine-phosphorylated FKBP52 caused approximately 40% inhibition, whereas dephosphorylated FKBP52 had no effect on AAV second-strand DNA synthesis. Deliberate overexpression of FKBP52 effectively reduced the extent of tyrosine phosphorylation of the protein, resulting in a significant increase in AAV-mediated transgene expression in human and murine cell lines. These studies corroborate the idea that the phosphorylation status of the cellular FKBP52 protein correlates strongly with AAV transduction efficiency, which may have important implications for the optimal use of AAV vectors in human gene therapy.
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Tan M, Liang A, Brünen-Nieweler C, Heckmann K. Programmed translational frameshifting is likely required for expressions of genes encoding putative nuclear protein kinases of the ciliate Euplotes octocarinatus. J Eukaryot Microbiol 2001; 48:575-82. [PMID: 11596922 DOI: 10.1111/j.1550-7408.2001.tb00193.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Three macronuclear genes encoding putative nuclear protein kinases of the ciliate Euplotes octocarinatus syngen 1 were isolated and sequenced. All three deduced gene products share significant properties with a group of recently identified nuclear serine/threonine protein kinases named Ndr. The three predicted proteins contain the twelve conserved catalytic subdomains of protein kinases and 22 near universally-conserved amino acids residues that are characteristic of serine/threonine protein kinases. In addition, there is an approximately 30 amino acid-peptide insertion between subdomains VII and VIII that contains a potential nuclear localization signal. Sequence analysis suggests that expression of the Eondr2 gene requires a + 1 programmed translational frameshift for its translation. Comparison of the deduced EoNdr2 with other known Ndr protein kinases implies that a + 1 ribosomal frameshift occurs at the motif AAATAA.
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Sun Y, Tan M, Duan H, Swaroop M. SAG/ROC/Rbx/Hrt, a zinc RING finger gene family: molecular cloning, biochemical properties, and biological functions. Antioxid Redox Signal 2001; 3:635-50. [PMID: 11554450 DOI: 10.1089/15230860152542989] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The RING (really interesting new gene) finger proteins containing a characteristic C3HC4 or C3H2C3 motif appear to act as E3 ubiquitin ligase and play important roles in many processes, including cell-cycle progression, oncogenesis, signal transduction, and development. This review is focused on SAG/ROC/Rbx/Hrt (sensitive to apoptosis gene/regulator of cullins/RING box protein), an evolutionarily conserved RING finger family of proteins that were cloned recently by several independent laboratories through differential display, yeast two-hybrid screening, or biochemical purification. SAG/ROC2/Rbx2/Hrt2 is expressed in multiple mouse adult tissues, as well as early embryos. In humans, both SAG and ROC1 are ubiquitously expressed at a very high level in heart, skeletal muscle, and testis. Expression of both SAG and ROC1 is induced by mitogenic stimulation. SAG is also induced by a redox agent in cultured cells, as well as in in vivo mouse brain upon ischemia/reperfusion. Structurally, SAG consists of four exons and three introns with at least one splicing variant and two pseudogenes. The SAG gene promoter is enriched with multiple transcription factor binding sites. Biochemically, SAG binds to RNA, has metal-ion binding/free radical scavenging activity, and is redox-sensitive. Most importantly, like ROC1, SAG/ROC2 binds to cullins and acts as an essential component of E3 ubiquitin ligase. Biologically, SAG is a growth-essential gene in yeast. In mammalian cells, SAG protects apoptosis mainly through inhibition of cytochrome c release/caspase activation, and promotes growth under serum deprivation at least in part by inhibiting p27 accumulation. Blocking SAG expression via antisense transfection inhibits tumor cell growth. Thus, SAG appears to be a valid drug target for anticancer therapy.
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Tan M, Okada M, Wu Z. [Application of laparoscopic technique in splenectomy]. ZHONGHUA WAI KE ZA ZHI [CHINESE JOURNAL OF SURGERY] 2001; 39:599-601. [PMID: 11758196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To investigate the application and effect of laparoscopic splenectomy (LS) in the treatment of spleen diseases. METHODS Under CO2 pneumoperitoneum, laparoscopic splenectomy was performed on 43 patients. General conditions before and after operation, platelet counting, complications and recovery of patients were studied. RESULTS Laparoscopic splenectomy was performed without complications in all the patients. In the patients with ITP, the effective rate of LS was 89.3%. The difficulty of operation was identified when the diameter of the spleen was over 15 cm assessed by ultrasonic examination, and the operative time was usually prolonged. CONCLUSIONS LS is one of the best choices when proper indications exist and good techniques under laparoscopy are provided.
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Tan M, Di Carlo A, Stein LA, Cantarovich M, Tchervenkov JI, Metrakos P. Pseudoaneurysm of the superior mesenteric artery after pancreas transplantation treated by endovascular stenting. Transplantation 2001; 72:336-8. [PMID: 11477363 DOI: 10.1097/00007890-200107270-00030] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Pseudoaneurysm after pancreas transplantation can have serious consequences, including rupture, hemorrhage, and graft loss. We describe a 38-year-old patient who presented with a pseudoaneurysm of the donor superior mesenteric artery 1 month after pancreas transplantation. Selective arteriography was performed and the lesion was repaired with endovascular placement of a 28-mm covered stent. Laparotomy was avoided. The pancreatic graft was continuing to function well 9 months later. As far as we know, this minimally invasive approach was not previously reported. According to published series, pseudoaneurysms often occur secondary to infection and require operative intervention necessitating graft pancreatectomy. Patients can present with serious symptoms including hypotension and shock. Therefore, it is important to detect pseudoaneurysm in a timely manner. Computed tomography and Doppler ultrasound are important diagnostic tools in this regard. We demonstrated the utility of endovascular stenting in the treatment of pseudoaneurysm after pancreas transplantation. When used in a timely manner in well selected patients, endovascular stenting can abrogate the need for operative intervention and its attendant morbidity.
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Ho YH, Seow-Choen F, Tan M. Colonic J-pouch function at six months versus straight coloanal anastomosis at two years: randomized controlled trial. World J Surg 2001; 25:876-81. [PMID: 11572027 DOI: 10.1007/s00268-001-0044-1] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The colonic J-pouch (pouch group) functions better than the straight coloanal anastomosis (straight group) immediately after ultra-low anterior resection, but there are few studies with long-term follow-up. This randomized controlled study compared functional outcome, anal manometry, and rectal barostat assessment of these two groups over a 2-year period. Forty-two consecutive patients were recruited, of which 19 of the straight group [17 men with a mean age of 62.1 +/- 2.3 (SEM) year] and 16 of the pouch group (11 men with a mean age of 61.3 +/- 3.2 year) completed the study. Four died from metastases and two emigrated; there was no surgical morbidity or local recurrence. At 6 months the Pouch patients had significantly less frequent stools (32.9 +/- 2.8 vs. 49 +/- 1.4/week; p < 0.05) and less soiling at passing flatus (38% vs. 73.7%; p < 0.05). At 2 years both groups had improved with no longer any differences in stool frequency (7.3 +/- 0.4 vs. 8 +/- 0.2/week) and soiling at passing flatus (38% vs. 53%). Defecation problems remained minimal in both groups. Anal squeeze pressures were significantly impaired in both groups up to 2 years (p < 0.05). The rectal maximum tolerable volume and compliance were not different between groups. Rectal sensory testing on the barostat phasic program showed impairment at 6 months and recovery at 2 years, suggesting that postoperative recovery of residual afferent sympathetic nerves may play a role in functional recovery. In conclusion, stool frequency and incontinence were less in the Pouch patients at 6 months; but after adaptation at 2 years the straight group patients yielded similar results. Nonetheless, this functional advantage can be given to patients with minimal added effort or complications by using the colonic J-pouch.
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Tan M, Di Carlo A, Robinson P, Tchervenkov JI, Barkun JS, Metrakos P. Successful outcome after transplantation of a donor liver with focal nodular hyperplasia. Liver Transpl 2001; 7:652-5. [PMID: 11460236 DOI: 10.1053/jlts.2001.23910] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Because of the increasing gap in the number of patients awaiting organ transplantation and the supply of organ donors, reevaluation of donor criteria is an important issue in clinical transplantation. It has become necessary to make maximal use of the currently available donor pool. We describe a case of successful orthotopic liver transplantation in a 57-year-old man with Laënnec's cirrhosis using a liver containing an 8-cm focal nodular hyperplasia (FNH) lesion involving segments II and III and the caudate lobe. The donor liver was procured from a 46-year-old woman declared brain dead after a subarachnoid hemorrhage. Definitive pathological diagnosis was made at laparotomy by obtaining a Tru-cut (Allegiance Health Care Inc, Toronto, Ontario, Canada) core biopsy specimen. The recipient operation was performed uneventfully except for bleeding from the biopsy site. The patient did well postoperatively and was discharged on tacrolimus, mofetil mycophenolate, and prednisone therapy. He continues to thrive 2(1/2) years posttransplantation with no change in the size of the lesion. In well-selected donors, FNH should not be a contraindication for use in transplantation. However, FNH must be differentiated from hepatocellular adenoma. Although FNH has a benign course with little propensity for bleeding and almost no malignant potential, hepatic adenoma is reported to have a 15% to 33% chance of bleeding and rupture with a well-documented potential for neoplastic degeneration, making the liver unsuitable for donation.
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Yang GY, Pang L, Ge HL, Tan M, Ye W, Liu XH, Huang FP, Wu DC, Che XM, Song Y, Wen R, Sun Y. Attenuation of ischemia-induced mouse brain injury by SAG, a redox-inducible antioxidant protein. J Cereb Blood Flow Metab 2001; 21:722-33. [PMID: 11488541 DOI: 10.1097/00004647-200106000-00010] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Cerebral ischemia resulting from a disruption of blood flow to the brain initiates a cascade of events that causes neuron death and leads to neurologic dysfunction. Reactive oxygen species are thought, at least in part, to mediate this disease process. The authors recently cloned and characterized an antioxidant protein, SAG (sensitive to apoptosis gene), that is redox inducible and protects cells from apoptosis induced by redox agents in a number of in vitro cell model systems. This study reports a neuroprotective role of SAG in ischemia/reperfusion-induced brain injury in an in vivo mouse model. SAG was expressed at a low level in brain tissue and was inducible after middle cerebral artery occlusion with peak expression at 6 to 12 hours. At the cellular level, SAG was mainly expressed in the cytoplasm of neurons and astrocytes, revealed by double immunofluorescence. An injection of recombinant adenoviral vector carrying human SAG into mouse brain produced an overexpression of SAG protein in the injected areas. Transduction of AdCMVSAG (wild-type), but not AdCMVmSAG (mutant), nor the AdCMVlacZ control, protected brain cells from ischemic brain injury, as evidenced by significant reduction of the infarct areas where SAG was highly expressed. The result suggests a rather specific protective role of SAG in the current in vivo model. Mechanistically, SAG overexpression decreased reactive oxygen species production and reduced the number of apoptotic cells in the ischemic areas. Thus, antioxidant SAG appears to protect against reactive oxygen species-induced brain damage in mice. Identification of SAG as a neuroprotective molecule could lead to potential stroke therapies.
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Rodriguez-Galindo C, Poquette CA, Daw NC, Tan M, Meyer WH, Cleveland JL. Circulating concentrations of IGF-I and IGFBP-3 are not predictive of incidence or clinical behavior of pediatric osteosarcoma. MEDICAL AND PEDIATRIC ONCOLOGY 2001; 36:605-11. [PMID: 11344491 DOI: 10.1002/mpo.1137] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Preclinical studies suggest a role of insulin-like growth factor-1 (IGF-1) in the proliferation of osteosarcoma cells in vivo. The purpose of this study is to address the relationship between serum levels of IGF-1 and its binding protein (IGFBP-3), and the clinical behavior and outcome of osteosarcoma in children, and to compare those levels present in osteosarcoma patients with a normal population. PROCEDURE Serum IGF-1 and IGFBP-3 levels were determined by ELISA in 37 patients with osteosarcoma treated on the same treatment regimen (OS-91 protocol), and who had available serum samples from diagnosis. IGF-1 and IGFBP-3 levels were compared with those previously established in the normal population, matched for age and gender, and were correlated with the presence of metastatic disease, histologic response to preoperative chemotherapy, and event-free survival. RESULTS In osteosarcoma patients the median IGF-1 level was 275 ng/ml (range, 105-613) and the median IGFBP-3 level was 3.4 mg/L (range, 2.3-5.1). IGF-1 levels differed from those in the normal population (P = 0.029); although we anticipated higher IGF-1 levels than normal children, 68% of observed standardized scores were less than 0. Furthermore, IGF-1 or IGFBP-3 levels failed to correlate with the presence of metastatic disease (P = 0.12 and P = 0.12, respectively), histologic response (Rosen-Huvos grades 3/4 vs. grades 1/2) (P = 0.95 and P = 0.71, respectively), or event-free survival (P = 0.52 and P = 0.41, respectively). There was a strong association observed between IGF-1 and IGFBP-3 levels (P < 0.001). CONCLUSIONS In this retrospective study of 37 patients, we found that circulating levels of IGF-1 and IGFBP-3 are not predictive of the development or clinical characteristics of pediatric osteosarcoma. However, further studies on a larger patient population should be performed in order to investigate this relationship.
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