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Phillips J, Singh N, Lai H. Electromagnetic fields and DNA damage. PATHOPHYSIOLOGY 2009; 16:79-88. [DOI: 10.1016/j.pathophys.2008.11.005] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Revised: 11/16/2008] [Accepted: 11/16/2008] [Indexed: 12/24/2022] Open
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Lai H, Singh N. Interaction of Microwaves and a Temporally Incoherent Magnetic Field on Single and Double DNA Strand Breaks in Rat Brain Cells. Electromagn Biol Med 2009. [DOI: 10.1081/jbc-200055046] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Chow PK, Poon D, Choo S, Lai H, Goh A, Lim T, Lo R, Tay K, Tan SB, Soo K. Phase I study of SIR-sphere plus sorafenib as first-line treatment in patients with nonresectable hepatocellular carcinoma: The Asia-Pacific Hepatocellular Carcinoma Trials Group protocol 05 (AHCC05). J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.e15538] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e15538 Background: Sorafenib has been shown to significantly prolong survival in patients with nonresectable hepatocellular carcinoma (HCC) without however significant tumour regression. The addition of radio-ablative therapy could confer additional survival benefit. This phase I trial was carried out to ascertain the toxicities and safety of this combination and was designed as a prelude to a phase II trial. Methods: Eligible patients were administered SIR-sphere (max dose 3 GBq) and subsequently given Sorafenib therapy (400mg bd) either 14 days (Cohort 1: first 3 patients) or 11 days (Cohort 2: subsequent patients) later. Assessment was carried out for 30 days after commencement of Sorafenib. Results: 10 patients were recruited into this phase I trial. The second patient became ineligible for sorafenib therapy after SIR-sphere due to pulmonary bleeding not related to radio-therapy and was excluded from assessment. The characteristics of the patients are in the Table. At the end of the study period, there was no adverse events (AE) of grade 3 or 4 for Cohort 1 and 3 for Cohort 2. The only serious adverse event (SAE) recorded was from Cohort 2. Conclusions: Starting sorafenib 14 days after SIR-sphere therapy is associated fewer AEs and SAEs. The phase II trial has commenced withsorafenib starting 14 days after SIR-sphere. [Table: see text] [Table: see text]
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Lai S, Fishman EK, Lai H, Pannu H, Detrick B. Serum IL-6 levels are associated with significant coronary stenosis in cardiovascularly asymptomatic inner-city black adults in the US. Inflamm Res 2009; 58:15-21. [PMID: 19130178 DOI: 10.1007/s00011-008-8150-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
OBJECTIVES AND DESIGN The objective of this study was to explore whether increased levels of inflammatory cytokines are associated with the risk of clinically silent coronary artery disease. SUBJECTS Three-hundred-fifty-six black adults aged 25-54 residing in inner city of Baltimore, Maryland, United States were included in this study. METHODS Sociodemographics were assessed as were lipid profiles, IL-6, tumor necrosis factor-alpha (TNF-alpha), soluble intercellular adhesion molecule-1 (sICAM-1), and high-sensitivity C-reactive protein (hs-CRP) levels. Computed tomography (CT) coronary angiography was performed. RESULTS Coronary calcification was identified in 22.5 % participants and 14 % had significant (>or=50 %) coronary stenosis. Multiple logistic regression analyses suggested that IL-6 levels were independently associated with the presence of coronary calcification and significant coronary stenosis, while TNF-alpha, sICAM-1 and hs-CRP levels were not. CONCLUSIONS This study underscores a critical role for IL-6 in atherosclerosis and suggests that IL-6 may be a marker for significant coronary stenosis in cardiovascularly asymptomatic individuals.
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Durica DS, Kupfer D, Najar F, Lai H, Tang Y, Griffin K, Hopkins PM, Roe B. EST library sequencing of genes expressed during early limb regeneration in the fiddler crab and transcriptional responses to ecdysteroid exposure in limb bud explants. Integr Comp Biol 2006; 46:948-64. [DOI: 10.1093/icb/icl005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Lai H, Lai S, Krongrad A, Trapido E, Page JB, McCoy CB. The effect of marital status on survival in late-stage cancer patients: an analysis based on surveillance, epidemiology, and end results (SEER) data, in the United States. Int J Behav Med 2006; 6:150-76. [PMID: 16250685 DOI: 10.1207/s15327558ijbm0602_4] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Recently findings that marital status is associated with survival in patients with late-stage prostate cancer led to an examination of the generalizability of this association for all cancers. We restricted the investigation to patients with late-stage cancer using population-based data collected from 261,070 patients with late-stage cancer at multiple sites in the United States to determine relations between marital status and survival. After controlling for age, race, and treatment, married patients with cancers of all major primary sites had significantly better survival than single, separated, divorced, or widowed patients. Although single and widowed patients had the poorest prognosis in general, single patients appeared to show the most consistently poor survival across the different types of cancers. Survival differences by marital status were more pronounced in men than in women. This observation raises the possibility that some characteristics associated with being married delay death from cancer. These findings require investigators to ask new questions about the effect of being married and its possible correlates, such as general health status, access to health care, and socioeconomic status. Known correlates of marital status, such as available social support and social isolation also merit attention in relation to these findings.
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Zhang Z, Lai H, Roberg K, Evans M, Gangnon R, Anderson E, Gern J, Lemanske R. Occurrence of wheezing and being overweight in the first three years of life in a birth cohort at high risk for the development of asthma/allergy. J Allergy Clin Immunol 2005. [DOI: 10.1016/j.jaci.2004.12.825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Lewis A, Congdon N, Munoz B, Bowie H, Lai H, Chen P, West SK. Cataract surgery and subtype in a defined, older population: the SEECAT Project. Br J Ophthalmol 2004; 88:1512-7. [PMID: 15548802 PMCID: PMC1772435 DOI: 10.1136/bjo.2004.045484] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2004] [Indexed: 11/04/2022]
Abstract
AIM To describe the distribution of cataract subtypes present before surgery among a defined population of older, bilaterally pseudophakic individuals. METHODS This was a cohort study of bilaterally pseudophakic individuals participating in the Salisbury Eye Evaluation (SEE), and their locally resident siblings. Subjects underwent slit lamp and retroillumination photography and grading using the Wilmer Cataract Grading System. For all individuals determined to be bilaterally pseudophakic, an attempt was made to determine for each eye the type(s) of cataract present before surgery, based on previous SEE photographs (for SEE participants) and/or medical records obtained from the operating ophthalmologist (for both SEE participants and their siblings). RESULTS The mean age of 223 participants providing data in this study was 78.7 (SD 5.2) years, 19.3% of subjects were black and 60.1% female. The most common surgically removed cataract subtype in this population was pure nuclear (43.5%), followed by nuclear combined with posterior subcapsular cataract (PSC) (20.6%), and nuclear combined with cortical (13.9%); less common types were pure cortical (4.9%), pure PSC (4.5%), and PSC combined with cortical (2.7%). Factors such as sex and source of lens data (study photograph versus clinical record) did not significantly affect the distribution of lens opacity types, while PSC was significantly (p = 0.01) more common among younger people and nuclear cataract was significantly (p = 0.001) more common among white compared to black people. CONCLUSION Epidemiological studies have suggested that the different subtypes of cataract are associated with different risk factors. As studies begin to identify new prevention strategies for cataract, it would appear likely that different strategies will be efficacious against different types of cataract. In this setting, it will be helpful to know which cataract types are most frequently associated with surgery. Among this older, majority white population, nuclear cataract showed a clear predominance among individuals having undergone surgery in both eyes. This may be contrasted with both clinic and population based studies of younger people, which have generally found PSC cataract to predominate.
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Lai H, Chen P, Chen W. The effects of fatty liver on hepatocyte apoptosis and liver regeneration after partial hepatectomy. Clin Nutr 2003. [DOI: 10.1016/s0261-5614(03)80204-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Gehlbach P, Demetriades AM, Yamamoto S, Deering T, Duh EJ, Yang HS, Cingolani C, Lai H, Wei L, Campochiaro PA. Periocular injection of an adenoviral vector encoding pigment epithelium-derived factor inhibits choroidal neovascularization. Gene Ther 2003; 10:637-46. [PMID: 12692592 DOI: 10.1038/sj.gt.3301931] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Gene transfer provides an exciting new approach for the treatment of retinal and choroidal diseases. Two areas of concern are the potential for vector-related toxicity and uncertainties associated with prolonged transgene expression. One way to address these concerns for transfer of genes encoding secreted proteins is to transduce cells on the outside of the eye, provided the gene product can gain access to the eye and have the desired effect. In this study, we investigated the feasibility of this approach. Periocular injection of an adenoviral vector encoding beta-galactosidase (AdLacZ.10) resulted in LacZ-stained cells throughout the orbit and around the eye. Compared to periocular injection of 5 x 10(9) particles of control vector, periocular injection of 5 x 10(9) or 1 x 10(9) particles of an adenoviral vector expressing pigment epithelium-derived factor (PEDF) regulated by a CMV promoter (AdPEDF.11) resulted in significantly elevated intraocular levels of PEDF and suppression of choroidal neovascularization. Periocularly injected recombinant PEDF was also found to diffuse through the sclera into the eye. Although similar experiments are needed in an animal with a human-sized eye, these data suggest that periocular gene transfer deserves consideration for the treatment of choroidal diseases.
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Yan Y, Lai H, Gentle C, Smith J. Numerical Analysis of Fluid Flows Inside and Around a Liquid Drop Using an Incorporation of Multi-Block Iteration and Moving Mesh. Chem Eng Res Des 2002. [DOI: 10.1205/026387602753582132] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Abstract
Video-based imaging systems for continuous (nonpulsed) x-ray fluoroscopy use a variety of video formats. Conventional video-camera systems may operate in either interlaced or progressive-scan modes, and CCD systems may operate in interline- or frame-transfer modes. A theoretical model of the image noise power spectrum corresponding to these formats is described. It is shown that with respect to frame-transfer or progressive-readout modes, interline or interlaced cameras operating in a frame-integration mode will result in a spectral shift of 25% of the total image noise power from low spatial frequencies to high. In a field-integration mode, noise power is doubled with most of the increase occurring at high spatial frequencies. The differences are due primarily to the effect of noise aliasing. In interline or interlaced formats, alternate lines are obtained with each video field resulting in a vertical sampling frequency for noise that is one half of the physical sampling frequency. The extent of noise aliasing is modified by differences in the statistical correlations between video fields in the different modes. The theoretical model is validated with experiments using an x-ray image intensifier and CCD-camera system. It is shown that different video modes affect the shape of the noise-power spectrum and therefore the detective quantum efficiency. While the effect on observer performance is not addressed, it is concluded that in order to minimize image noise at the critical mid-to-high spatial frequencies for a specified x-ray exposure, fluoroscopic systems should use only frame-transfer (CCD camera) or progressive-scan (conventional video) formats.
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Singh NP, Lai H. Selective toxicity of dihydroartemisinin and holotransferrin toward human breast cancer cells. Life Sci 2001; 70:49-56. [PMID: 11764006 DOI: 10.1016/s0024-3205(01)01372-8] [Citation(s) in RCA: 221] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Artemisinin becomes cytotoxic in the presence of ferrous iron. Since iron influx is high in cancer cells, artemisinin and its analogs selectively kill cancer cells under conditions that increase intracellular iron concentrations. We report here that after incubation with holotransferrin, which increases the concentration of ferrous iron in cancer cells, dihydroartemisinin, an analog of artemisinin, effectively killed a type of radiation-resistant human breast cancer cell in vitro. The same treatment had considerably less effect on normal human breast cells. Since it is relatively easy to increase the iron content inside cancer cells in vivo, administration of artemisinin-like drugs and intracellular iron-enhancing compounds may be a simple, effective, and economical treatment for cancer.
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Wang D, Ma H, Zhang J, Wang X, Lai H. Effects of peripheral blood mononuclear cells from idiopathic nephrotic children on cultured rat glomerular epithelial and mesangial cells. Chin Med J (Engl) 2001; 114:813-6. [PMID: 11780356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
OBJECTIVE To investigate the effect of immune cell from idiopathic nephrotic children on extracellular matrix (ECM) synthesis by cultured rat glomerular epithelial cell (GEC) and on the proliferation of mesangial cell (GMC). METHODS Twenty-eight children with idiopathic nephrotic syndrome and 15 age-matched healthy children were randomly selected and divided into 4 groups: Group 1, untreated nephrotic children; Group 2, glucocorticoid treated nephrotic children; Group 3, children undergoing glucocorticoid treatment with negative proteinuria; and Group 4, normal control. The peripheral blood mononuclear cells (PBMC) were collected from these children and PBMC conditioned medium (PBMC-CM) were prepared. The PBMC-CM was co-cultured with GEC and GMC respectively. The concentrations of collagen, laminin, collagen III and collagen IV in the GEC and PBMC-CM co-culture medium were investigated. The GMC proliferation was measured by the 3H-thymidin incorporation method. RESULTS The 3H-proline incorporation coefficients of the GEC treated with the PBMC-CM of the 4 groups were 0.93, 1.24, 1.23, and 1.11, respectively. The laminin inhibitory coefficients of the 4 groups were 0.95, 1.02, 1.01, and 1.04, respectively. The inhibitory coefficients of collagen III were 0.97, 1.00, 0.99, and 1.01, respectively, for the 4 groups. All these parameters showed a significant difference between Group 1 and the other 3 groups (P < 0.05). However, there was no significant difference in the inhibitory coefficient of collagen IV between each two of the 4 groups (1.04, 1.05, 1.04, 1.08, P > 0.05). The 3H-thymidine incorporation coefficients of GMC responsive to PBMC-CM were 1.21, 1.53, 1.50, and 1.10, respectively, and no significant difference was found between the 4 groups (P > 0.05). CONCLUSION The results suggested that the circulating immune cells from idiopathic nephrotic children have a direct effect on some ECM component synthesis in cultured rat GEC; the bio-activity of immune cells could be neutralized by administering glucocorticoid; and the circulating immune cells of nephrotic children have no direct effect on GMC proliferation.
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Lai S, Lai H, Page JB, McCoy CB. The association between cigarette smoking and drug abuse in the United States. J Addict Dis 2001; 19:11-24. [PMID: 11110061 DOI: 10.1300/j069v19n04_02] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Cigarette smoking has been identified as an independent risk factor for many human diseases. However, the association between cigarette smoking and illegal drug use has not been thoroughly investigated. We have analyzed the 1994 National Household Survey on Drug Abuse to clarify whether cigarette smoking has any effect on the initiation of illegal drug use. Data from 17,809 respondents completing the 1994 "new" (1994-B) questionnaire were analyzed. Logistic regression analyses were performed with the use of statistical package SUDAAN, taking into consideration the multistage sampling design. The results show that those who had smoked cigarettes were far more likely to use cocaine (OR = 7.5; 95% CI: 5.7-9.9), heroin (OR = 16.0; 95% CI: 6.8-37.9), crack (OR = 13.9; 95% CI: 7.9-24.5) and marijuana (OR = 7.3; 95% CI: 6.2-8.7). The associations are consistent across age-strata and remain after adjusting for race and gender. This study suggests that cigarette smoking may be a gateway drug to illegal drug use.
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Lai H, Lai S, Shor-Posner G, Ma F, Trapido E, Baum MK. Plasma zinc, copper, copper:zinc ratio, and survival in a cohort of HIV-1-infected homosexual men. J Acquir Immune Defic Syndr 2001; 27:56-62. [PMID: 11404521 DOI: 10.1097/00126334-200105010-00010] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A prospective cohort study of 121 HIV-1-positive homosexual men was conducted in Miami, Florida, U.S.A. to evaluate the associations between plasma zinc and copper levels and mortality. Plasma zinc and copper levels were measured at baseline and then at semiannual visits. Zinc inadequacy and copper inadequacy were defined as plasma zinc levels <75 (microg/dl) and plasma copper levels <85 (microg/dl), respectively. HIV-1-related deaths were confirmed by review of death certificates. Cox proportional hazards regression models with time-dependent covariates were used to estimate the relative risks of zinc and copper inadequacy on mortality. Over the average course of the 3.3-year follow-up, 19 participants (16%) died of HIV-1-related causes. After adjustment for potential confounders, including low CD4+ cell counts and antiretroviral therapy, zinc inadequacy and copper:zinc ratio >1 (i.e., plasma copper level greater than plasma zinc level) were associated with increased mortality (relative risks [RRs]; 95% confidence intervals [CIs], 4.98, 1.30-19.00 and 8.28, 1.03-66.58, respectively). A negative association was also observed between plasma zinc levels and mortality (RR 0.94; 95% CI, 0.91-0.98). Plasma levels of copper were not significantly associated with mortality. These results suggest that plasma zinc inadequacy or the plasma copper:zinc ratio may be useful predictors of survival in HIV-1 infection. The latter appears to be a stronger predictor.
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Kim HW, Yang P, Qyang Y, Lai H, Du H, Henkel JS, Kumar K, Bao S, Liu M, Marcus S. Genetic and molecular characterization of Skb15, a highly conserved inhibitor of the fission yeast PAK, Shk1. Mol Cell 2001; 7:1095-101. [PMID: 11389855 DOI: 10.1016/s1097-2765(01)00248-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The p21-activated kinase, Shk1, is essential for viability, establishment and maintenance of cell polarity, and proper mating response in the fission yeast, Schizosaccharomyces pombe. Here we describe the characterization of a highly conserved, WD repeat protein, Skb15, which negatively regulates Shk1 in fission yeast. A null mutation in the skb15 gene is lethal and results in deregulation of actin polymerization and localization, microtubule biogenesis, and the cytokinetic machinery, as well as a substantial uncoupling of these processes from the cell cycle. Loss of Skb15 function is suppressed by partial loss of Shk1, demonstrating that negative regulation of Shk1 by Skb15 is required for proper execution of cytoskeletal remodeling and cytokinetic functions. A mouse homolog of Skb15 can substitute for its counterpart in fission yeast, demonstrating that Skb15 protein function has been substantially conserved through evolution.
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Lai S, Lai H, Lamm S, Obek C, Krongrad A, Roos B. Radiation therapy in non-surgically-treated nonmetastatic prostate cancer: geographic and demographic variation. Urology 2001; 57:510-7. [PMID: 11248630 DOI: 10.1016/s0090-4295(00)01034-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES To examine the geographic variation in the use of radiation to treat nonmetastatic prostate cancer and to identify factors that explain the variation in the United States. METHODS This study was based on data from the nine geographic regions of the Surveillance, Epidemiology, and End Results Program for 1983 through 1996. Patients with localized or regional prostate cancer who did not undergo surgical treatment were included in the analysis. Logistic regression analysis was used to investigate the influence of geographic and demographic factors on the use of radiation. The squared multiple correlation coefficient R(2) was used to measure the proportion of variation in the selection of radiation explained by each factor of interest. RESULTS Compared with San Francisco, the adjusted odds ratios for 6 of the 8 geographic areas had highly significant P values, suggesting the use of radiation therapy varies from region to region. However, geographic location only explained less than 3% of the total variation in the use of radiation. The geographic location explained a much higher proportion of variation in the youngest (younger than 55 years) and the oldest (80 years old or older) groups. Overall, age was the most important factor that influenced the use of radiation. CONCLUSIONS The finding that geographic location explains a significant proportion of the variation in the use of radiation in the youngest and oldest age groups demonstrates the outcome of longstanding controversies in the nonsurgical treatment of prostate cancer. Documenting the impact of the interaction of age and geographic location on the treatment approaches provides for better understanding of the impact of patients and physicians making clinical decisions in the management of nonmetastatic prostate cancer.
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Zhu H, Nowrousian M, Kupfer D, Colot HV, Berrocal-Tito G, Lai H, Bell-Pedersen D, Roe BA, Loros JJ, Dunlap JC. Analysis of expressed sequence tags from two starvation, time-of-day-specific libraries of Neurospora crassa reveals novel clock-controlled genes. Genetics 2001; 157:1057-65. [PMID: 11238394 PMCID: PMC1461561 DOI: 10.1093/genetics/157.3.1057] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In an effort to determine genes that are expressed in mycelial cultures of Neurospora crassa over the course of the circadian day, we have sequenced 13,000 cDNA clones from two time-of-day-specific libraries (morning and evening library) generating approximately 20,000 sequences. Contig analysis allowed the identification of 445 unique expressed sequence tags (ESTs) and 986 ESTs present in multiple cDNA clones. For approximately 50% of the sequences (710 of 1431), significant matches to sequences in the National Center for Biotechnology Information database (of known or unknown function) were detected. About 50% of the ESTs (721 of 1431) showed no similarity to previously identified genes. We hybridized Northern blots with probes derived from 26 clones chosen from contigs identified by multiple cDNA clones and EST sequences. Using these sequences, the representation of genes among the morning and evening sequences, respectively, in most cases does not reflect their expression patterns over the course of the day. Nevertheless, we were able to identify four new clock-controlled genes. On the basis of these data we predict that a significant proportion of the expressed Neurospora genes may be regulated by the circadian clock. The mRNA levels of all four genes peak in the subjective morning as is the case with previously identified ccgs.
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Lai S, Lai H, Krongrad A, Roos BA. Overall and disease-specific survival after radical prostatectomy: geographic uniformity. Urology 2001; 57:504-9. [PMID: 11248629 DOI: 10.1016/s0090-4295(00)01035-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVES To examine whether the survival (both overall and disease-specific) of patients who underwent radical prostatectomy varies from region to region in the United States. Previous reports have documented a geographic variation in the use of radical prostatectomy. METHODS This study was based on the data from nine geographic regions of the Surveillance, Epidemiology, and End Results Program (SEER) for 1983 through 1992. Patients with localized prostate cancer who underwent radical prostatectomy were included in the analysis. A proportional hazards model was used to investigate whether geographic variation is associated with both overall and disease-specific survival. RESULTS From 1983 through 1992, the SEER Program collected information from nine geographic regions on 66,293 patients with localized prostate cancer (mean age 71.8 +/- 8.4 years), who had SEER grade codes of 1, 2, or 3. Of these patients, 11,429 (mean age 65.3 +/- 6.5 years) underwent radical prostatectomy and lymph node dissection. Cox's proportional hazards analyses revealed that the impact of geographic location on both overall and disease-specific survival in patients who underwent radical prostatectomy was not statistically significant. CONCLUSIONS The results of this study indicate that the survival (both overall and disease-specific) of patients with localized prostate cancer who underwent radical prostatectomy is not influenced by geographic location, suggesting that their survival is relatively uniform across the geographic regions in the United States.
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Míguez-Burbano MJ, Angarita I, Shultz JM, Shor-Posner G, Klaskala W, Duque JL, Lai H, Londoño B, Baum MK. HIV-related high risk sexual behaviors and practices among women in Bogotá, Colombia. Women Health 2001; 30:109-19. [PMID: 10983613 DOI: 10.1300/j013v30n04_08] [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: 11/18/2022]
Abstract
Determinants associated with high-risk sexual behaviors were investigated in 1,133 sexually active women in Bogotá, Colombia. A self-administered questionnaire was completed by two groups of women: 721 representing the general population (GP), and 412 commercial sex workers (CSWs). High-risk sexual behaviors for HIV/AIDS were evident in both groups. Nevertheless, consistent condom use was reported by only 6% of the GP group, as compared to 67% of the CSWs. Failure to recognize high-risk routes for HIV infection was indicated in 69% of the GP women for anal sex, and by the majority of both groups for intercourse during menses (56% GP women and 54% CSWs). Multivariate analysis revealed that education level, actual age, and age of first sex experience were significant predictors of high-risk sexual practices. The necessity for educational programs regarding high-risk sexual practices and risk of HIV/ AIDS is evident for HIV/AIDS prevention.
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Lu JZ, Zhang JG, Lai H. [The relationship between ECochG and glycerol test in vertigo patients (report of 112 cases)]. LIN CHUANG ER BI YAN HOU KE ZA ZHI = JOURNAL OF CLINICAL OTORHINOLARYNGOLOGY 2000; 14:510-1. [PMID: 12563946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
OBJECTIVE For further investigating the diagnostic value of the ECochG in Meniere's disease. METHOD 112 vertigo patients including Meniere's disease, sudden deafness, cervical vertigo and other vertigo disease, had been done ECochG, glycerol test, audiometry and caloric test. The results were compared with those of normal group. RESULT In Meniere's disease, the positive rate of abnormal-SP/AP in ECochG was 54.69% and the positive rate of glycerol test was 53.12%. There are no statistics difference (P > 0.05) between this two tests with X analysis. CONCLUSION We think that the glycerol test and other relative examination are necessary for the diagnosis of Meniere's disease while the-SP/AP > 0.4 ms in the examination of ECochG.
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Siniscalco M, Robledo R, Orru S, Contu L, Yadav P, Ren Q, Lai H, Roe B. A plea to search for deletion polymorphism through genome scans in populations. Trends Genet 2000; 16:435-7. [PMID: 11203137 DOI: 10.1016/s0168-9525(00)02101-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Qiu SR, Lai H, Yarmoff JA. Self-limiting growth of metal fluoride thin films by oxidation reactions employing molecular precursors. PHYSICAL REVIEW LETTERS 2000; 85:1492-1495. [PMID: 10970537 DOI: 10.1103/physrevlett.85.1492] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2000] [Indexed: 05/23/2023]
Abstract
FeF (2) films are grown by the reaction of XeF (2) and SeF (6) with iron foil. The growth initially follows the Mott-Cabrera parabolic rate law, indicating that the process is diffusion limited. At a certain film thickness, however, the growth abruptly stops, with the thickness using XeF (2) being nearly double that with SeF (6). It is suggested that the shutdown is due to the inability of the molecules to dissociate when too far from the substrate and that SeF (6) must approach more closely than XeF (2). This work suggests the use of molecular precursors to grow thin films via a self-limiting chemical process.
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Lai H, Tsumori T, Shiroyama T, Yokota S, Nakano K, Yasui Y. Morphological evidence for a vestibulo-thalamo-striatal pathway via the parafascicular nucleus in the rat. Brain Res 2000; 872:208-14. [PMID: 10924695 DOI: 10.1016/s0006-8993(00)02457-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We observed by anterograde and retrograde tracing techniques that projection fibers originating from the medial vestibular nucleus (MVe) of the rat terminated in the dorsal two-thirds of the lateral part of the parafascicular thalamic nucleus (PF), where neurons sending their axons to the dorsolateral part of the striatum existed. It was further revealed that the vestibular fibers made asymmetrical synaptic contacts mainly with dendrites and additionally with soma of the striatum-projecting PF neurons. These data suggest that output signals from the MVe may be transmitted disynaptically to the striatal neurons via the PF neurons.
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Lai S, Chen J, Celentano D, Page JB, Lai H, Yang J, Liu W, McCoy CB, Yu XF. Adoption of injection practices in heroin users in Guangxi Province, China. J Psychoactive Drugs 2000; 32:285-92. [PMID: 11061679 DOI: 10.1080/02791072.2000.10400451] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
This preliminary study collected data from 326 heroin users in Guangxi Province, China, in 1997. Logistic regression analysis was performed to identify the risk factors for injection. Survival analysis identified factors independently associated with time from initiation of heroin use to adoption of injection. Four factors were independently associated with injection: number of friends who used heroin in the last year, duration of heroin use, dose of heroin consumed, and total number of times detoxified in drug treatment and rehabilitation centers. Only gender and duration of heroin use were independently associated with time to first injection. Median time to first injection was 11 months for males and 22 months for females. Median time to first injection varied by age. Median time to injection for those who used heroin for more than one year was 8.1 months; it was 19.1 months for on to five years of use, and 40.5 months for more than five years of use. This study's preliminary findings suggest that younger, more recent heroin users, and males are at increased risk of becoming injectors, a major risk behavior for HIV acquisition.
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Lai S, Lai H, Krongrad A, Lamm S, Schwade J, Roos BA. Radical prostatectomy: geographic and demographic variation. Urology 2000; 56:108-15. [PMID: 10869637 DOI: 10.1016/s0090-4295(00)00557-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Previous reports have documented a geographic variation in the use of radical prostatectomy. We examined whether this phenomenon can be explained by factors other than geography alone. METHODS This study was based on the data from nine geographic regions of the Surveillance, Epidemiology, and End Results (SEER) program for the years 1983 through 1994. Patients with localized or regional prostate cancer were included in the analysis. Logistic regression analysis was used to investigate the influence of geographic and demographic factors on the use of radical prostatectomy. The squared multiple correlation coefficient R(2) was used to measure the proportion of variation in the selection of radical prostatectomy explained by each factor of interest. RESULTS As previously reported, the use of radical prostatectomy was significantly associated with geographic location; the degree of geographic variation varied as a function of age and was most dramatic in the youngest (younger than 45 years) and the oldest (75 years or older) groups. Overall, however, geography explained less than 2% of the total variation in the use of radical prostatectomy. Age was the most important factor that influenced the use of radical prostatectomy. CONCLUSIONS Geography explains only a small proportion of the variation in the use of radical prostatectomy. In fact, of the factors examined, only age appeared to meaningfully explain the variation in the use of radical prostatectomy. Overall, our ability to explain the variation in the use of radical prostatectomy remains meager, and new factors must be identified if we are to better understand how patients and physicians make clinical decisions.
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Lai H, Carino M. Intracerebroventricular injection of mu- and delta-opiate receptor antagonists block 60 Hz magnetic field-induced decreases in cholinergic activity in the frontal cortex and hippocampus of the rat. Bioelectromagnetics 2000; 19:432-7. [PMID: 9771587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
In previous research, we have found that acute exposure to a 60 Hz magnetic field decreased cholinergic activity in the frontal cortex and hippocampus of the rat as measured by sodium-dependent high-affinity choline uptake activity. We concluded that the effect was mediated by endogenous opioids inside the brain because it could be blocked by pretreatment of rats before magnetic field exposure with the opiate antagonist naltrexone, but not by the peripheral antagonist naloxone methiodide. In the present study, the involvement of opiate receptor subtypes was investigated. Rats were pretreated by intracerebroventricular injection of the mu-opiate receptor antagonist, beta-funaltrexamine, or the delta-opiate receptor antagonist, naltrindole, before exposure to a 60 Hz magnetic field (2 mT, 1 hour). It was found that the effects of magnetic field on high-affinity choline uptake in the frontal cortex and hippocampus were blocked by the drug treatments. These data indicate that both mu- and delta-opiate receptors in the brain are involved in the magnetic field-induced decreases in cholinergic activity in the frontal cortex and hippocampus of the rat.
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79
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Lai H, Singh NP. Acute exposure to a 60 Hz magnetic field increases DNA strand breaks in rat brain cells. Bioelectromagnetics 2000; 18:156-65. [PMID: 9084866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Acute (2 h) exposure of rats to a 60 Hz magnetic field (flux densities 0.1, 0.25, and 0.5 mT) caused a dose-dependent increase in DNA strand breaks in brain cells of the animals (assayed by a microgel electrophoresis method at 4 h postexposure). An increase in single-strand DNA breaks was observed after exposure to magnetic fields of 0.1, 0.25, and 0.5 mT, whereas an increase in double-strand DNA breaks was observed at 0.25 and 0.5 mT. Because DNA strand breaks may affect cellular functions, lead to carcinogenesis and cell death, and be related to onset of neurodegenerative diseases, our data may have important implications for the possible health effects of exposure to 60 Hz magnetic fields.
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Lai H, Singh NP. Melatonin and a spin-trap compound block radiofrequency electromagnetic radiation-induced DNA strand breaks in rat brain cells. Bioelectromagnetics 2000; 18:446-54. [PMID: 9261542 DOI: 10.1002/(sici)1521-186x(1997)18:6<446::aid-bem7>3.0.co;2-2] [Citation(s) in RCA: 146] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Effects of in vivo microwave exposure on DNA strand breaks, a form of DNA damage, were investigated in rat brain cells. In previous research, we have found that acute (2 hours) exposure to pulsed (2 microseconds pulses, 500 pps) 2450-MHz radiofrequency electromagnetic radiation (RFR) (power density 2 mW/cm2, average whole body specific absorption rate 1.2 W/kg) caused an increase in DNA single- and double-strand breaks in brain cells of the rat when assayed 4 hours post exposure using a microgel electrophoresis assay. In the present study, we found that treatment of rats immediately before and after RFR exposure with either melatonin (1 mg/kg/injection, SC) or the spin-trap compound N-tert-butyl-alpha-phenylnitrone (PBN) (100 mg/kg/injection, i.p.) blocks this effects of RFR. Since both melatonin and PBN are efficient free radical scavengers it is hypothesized that free radicals are involved in RFR-induced DNA damage in the brain cells of rats. Since cumulated DNA strand breaks in brain cells can lead to neurodegenerative diseases and cancer and an excess of free radicals in cells has been suggested to be the cause of various human diseases, data from this study could have important implications for the health effects of RFR exposure.
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Lai H, Carino MA, Ushijima I. Acute exposure to a 60 Hz magnetic field affects rats' water-maze performance. Bioelectromagnetics 2000; 19:117-22. [PMID: 9492169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Rats were trained in six sessions to locate a submerged platform in a circular water-maze. They were exposed to a 1 mT, 60 Hz magnetic field for one hour in a Helmholtz coil system immediately before each training session. In addition, one hour after the last training session, they were tested in a probe trial during which the platform was removed and the time spent in the quadrant of the maze in which the platform was located during the training sessions was scored. Control animals were sham-exposed using the exposure system operating with the coils activated in an anti-parallel direction to cancel the fields. A group of "non-exposed" control animals was also included in the study. There was no significant difference between the magnetic field-exposed and control animals in learning to locate the platform. However, swim speed of the magnetic field-exposed rats was significantly slower than that of the controls. During the probe trial, magnetic field-exposed animals spent significantly less time in the quadrant that contained the platform, and their swim patterns were different from those of the controls. These results indicate that magnetic field exposure causes a deficit in spatial "reference" memory in the rat. Rats subjected to magnetic field exposure probably used a different behavioral strategy in learning the maze.
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Lai H, Carino M. 60 Hz magnetic fields and central cholinergic activity: effects of exposure intensity and duration. Bioelectromagnetics 2000; 20:284-9. [PMID: 10407513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
In previous research, we have found that acute exposure to a 60 Hz magnetic field caused a decrease in cholinergic activity in the frontal cortex and hippocampus of the rat. In the present study, the effects of exposure to different intensities of the magnetic field and durations of exposure were investigated. Rats were exposed to a 60 Hz magnetic field for 60 min at a flux density of either 0.5, 1.0, 1.5, or 2.0 mT. A significant decrease in cholinergic activity was observed in the frontal cortex and hippocampus immediately after exposure to the 2.0 mT field. No significant effect was observed at lower intensities. In another experiment, effect of exposure to a 1.0 mT magnetic field for 30, 45, 60, and 90 min was investigated. A decrease in cholinergic activity was found in both brain areas after 90 min of exposure. No significant effect was observed after shorter durations of exposure. In a further experiment, the exposure duration was extended to 3 h at flux densities of 0.5, 0.1, and 0.05 mT. A significant decrease in cholinergic activity was observed in the frontal cortex and hippocampus of the rat immediately after exposure to all the intensities. It is concluded that the intensity and duration of exposure interact. By increasing the duration of exposure, effects can be observed at lower intensities.
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Abstract
Medium-chain triacylglycerols (MCTs) have been shown to provide better nutritional support than long-chain triacylglycerols (LCTs). This study compares the efficacy of MCT combined with LCT with LCT alone in pediatric patients with surgical stress. Two groups of patients (n = 19 in each) received equivalent amounts of glucose (12 g. kg. d) and amino acids (2 g. kg. d), but one group received 10% Lipofundin MCT/LCT and the other received 10% LCT (1.5 g. kg. d) in a randomized study. Total parenteral nutrition (TPN) was given for 14 d. Blood and urine samples were collected before and after TPN administration for determination of various biochemical parameters. Indirect calorimetry was also performed to determine respiratory quotients and fuel utilization. After 14 d of TPN in the MCT/LCT group, there was a significantly higher blood lymphocyte percentage, a decreasing tendency of serum asparate aminotransferase and of total and direct bilirubin (P < 0.05). These changes were not observed in the LCT group. A significantly better nitrogen balance and a higher ketogenesis from day 3 were observed in the MCT/LCT group. The MCT/LCT group showed a more marked increased utilization of fat than the LCT group, whereas carbohydrate oxidation was less in the MCT/LCT group than in the LCT group (P < 0.05). In children after surgery, MCT/LCT is more protein sparing and induces a better immune response when compared with LCT-containing lipid emulsion. A TPN regimen containing MCT/LCT is likely to result in rapid oxidation of fats for energy without compromising the respiratory system.
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Campbell Dwyer EJ, Lai H, MacDonald RC, Salvato MS, Borden KL. The lymphocytic choriomeningitis virus RING protein Z associates with eukaryotic initiation factor 4E and selectively represses translation in a RING-dependent manner. J Virol 2000; 74:3293-300. [PMID: 10708446 PMCID: PMC111830 DOI: 10.1128/jvi.74.7.3293-3300.2000] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Only a few host cell proteins that associate with arenaviruses have been identified. To date, the arenavirus Z protein associates with the promyelocytic leukemia protein PML and the ribosomal P proteins. The majority of PML is present in nuclear bodies which are translocated to the cytoplasm by infection with the arenavirus, lymphocytic choriomeningitis virus (LCMV). The Z protein is a small zinc-binding RING protein with an unknown function which is required for the viral life cycle. Here, we demonstrate an association between Z and the host cell translation factor, eukaryotic initiation factor 4E (eIF-4E) in infected and transfected cells. Z's association with both ribosomal proteins and this translation factor led us to investigate whether Z could modulate host cell translation. In cell culture, Z selectively represses protein production in an eIF-4E-dependent manner. Specifically, we see reduction in cyclin D1 protein production with no effect on glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in cells transfected with Z. Previous reports indicate that cyclin D1 is sensitive to eIF-4E levels, whereas GAPDH is not. Consistent with this, we observe preferential downregulation of cyclin D1 during infection and no effect on GAPDH. Further, no changes in RNA levels were observed for cyclin D1 or GAPDH transcripts. The interaction between eIF-4E and Z may provide a mechanism for slower growth observed in infected cells and a viral strategy for establishing chronic infection.
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Tsumori T, Yokota S, Lai H, Yasui Y. Monosynaptic and disynaptic projections from the substantia nigra pars reticulata to the parafascicular thalamic nucleus in the rat. Brain Res 2000; 858:429-35. [PMID: 10708697 DOI: 10.1016/s0006-8993(99)02368-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We examined a direct pathway and an indirect pathway via the reticular thalamic nucleus (RT) from the substantia nigra pars reticulata (SNr) to the parafascicular thalamic nucleus (PF) by using anterograde and retrograde tract tracing methods. After biotinylated dextranamine (BDA) injection into the dorsolateral part of the SNr, many labeled fibers and axon terminals were distributed in the ventral part of the RT, as well as in the ventrolateral part of the PF, bilaterally with an ipsilateral dominance. After BDA injection into the ventral part of the RT, a plexus of labeled axons was found bilaterally with an ipsilateral dominance in the ventrolateral part of the PF. After combined injections of BDA into the dorsolateral part of the SNr and cholera toxin B subunit (CTb) into the ventrolateral part of the PF on the same side, overlapping distribution of BDA-labeled fibers and CTb-labeled neurons was observed in the ventral part of the RT ipsilateral to the injection sites, where the BDA-labeled axon terminals made symmetrical synaptic contacts with soma and dendrites of the CTb-labeled neurons.
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Leung TF, Chik KW, Li CK, Lai H, Shing MM, Chan PK, Lee V, Yuen PM. Incidence, risk factors and outcome of varicella-zoster virus infection in children after haematopoietic stem cell transplantation. Bone Marrow Transplant 2000; 25:167-72. [PMID: 10673675 DOI: 10.1038/sj.bmt.1702119] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We report a retrospective analysis of VZV infection after haematopoietic stem cell transplantation (HSCT) in children. Thirty-three (30%) of the total 109 children who were transplanted during a 7 year period developed post-transplant VZV infection. Twenty-four of these 33 (73%) children had VZV infection within 1 year following HSCT. The cumulative incidences of post-transplant VZV infection at 1 and 5 years were 26% and 45%, respectively. The positive and negative predictive values of pretransplant VZV serology in recipients on the development of HZ following HSCT were 39% and 88%, respectively. Pretransplant VZV seropositivity in recipients was the only risk factor for post-transplant herpes zoster (HZ) infection on multivariate analysis. All patients responded to acyclovir. The median duration of VZV infection was 5 days. Three (11%) and one (3%) children with HZ developed visceral dissemination and post-herpetic neuralgia, respectively. No mortality was directly attributed to VZV infection. VZV infection remains a major cause of morbidity in children after HSCT. Further studies are warranted to evaluate the potential use of VZV vaccine in these children. Bone Marrow Transplantation (2000) 25, 167-172.
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Fletcher M, Miguez-Burbano MJ, Shor-Posner G, Lopez V, Lai H, Baum MK. Diagnosis of human immunodeficiency virus infection using an immunoglobulin E-based assay. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2000; 7:55-7. [PMID: 10618277 PMCID: PMC95822 DOI: 10.1128/cdli.7.1.55-57.2000] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/1999] [Accepted: 09/29/1999] [Indexed: 11/20/2022]
Abstract
Immunoglobulin assays that are sensitive and specific for detecting human immunodeficiency virus type 1 (HIV-1) infection are especially important in developing countries where PCR and viral culture may not be readily available. Immunoglobulin E (IgE), which is elevated in HIV-1 infection, is the only antibody that does not cross the placenta, making it potentially valuable for viral detection in both children and adults. This study developed an assay for detection of HIV specific IgE antibodies in adults. A total of 170 serum samples from 170 adults (116 HIV positive and 54 HIV negative) were analyzed. Serum or plasma samples were treated by using the protein G affinity method. The HIV status was determined by using two IgG enzyme-linked immunosorbent assays (ELISAs) and one Western blot evaluation. The IgE enzyme immunoassay test for HIV-1 correctly identified the HIV status in 98.8% of the samples (168 of 170). One false-positive and one false-negative test occurred with the IgE ELISA, as well as with the IgG ELISA test but were correctly identified by the IgE test. Analysis of the data demonstrated a high specificity (99%) and sensitivity (99%) of the IgE test, with 95% confidence intervals. The IgE assay appears to be sensitive and specific, suggesting that IgE-specific antibodies offer an effective method to detect HIV-1 infection in adults.
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88
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Wang B, Lai H. Acute exposure to pulsed 2450-MHz microwaves affects water-maze performance of rats. Bioelectromagnetics 2000; 21:52-6. [PMID: 10615092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Rats were trained in six sessions to locate a submerged platform in a circular water maze. They were exposed to pulsed 2450-MHz microwaves (pulse width 2 micros, 500 128;pulses/s, average power density 2 mW/cm(2), average whole body specific absorption rate 1.2 W/kg) for 1 h in a circular waveguide system immediately before each training session. One hour after the last training session, they were tested in a probe trial during which the platform was removed and the time spent in the quadrant of the maze in which the platform had been located during the 1-min trial was scored. Three groups of animals, microwave-exposed, sham-exposed, and cage control, were studied. Microwave-exposed rats were slower than sham-exposed and cage control rats in learning to locate the platform. However, there was no significant difference in swim speed among the three groups of animals, indicating that the difference in learning was not due to a change in motor functions or motivation. During the probe trial, microwave-exposed animals spent significantly less time in the quadrant that had contained the platform, and their swim patterns were different from those of the sham-exposed and cage control animals. The latter observation indicates that microwave-exposed rats used a different strategy in learning the location of the platform. These results show that acute exposure to pulsed microwaves caused a deficit in spatial "reference" memory in the rat.
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Yang P, Pimental R, Lai H, Marcus S. Direct activation of the fission yeast PAK Shk1 by the novel SH3 domain protein, Skb5. J Biol Chem 1999; 274:36052-7. [PMID: 10593886 DOI: 10.1074/jbc.274.51.36052] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The p21-activated kinase (PAK) homolog Shk1 is essential for cell viability in the fission yeast Schizosaccharomyces pombe. Roles have been established for Shk1 in the regulation of cell morphology, sexual differentiation, and mitosis in S. pombe. In this report, we describe the genetic and molecular characterization of a novel SH3 domain protein, Skb5, identified as a result of a two-hybrid screen for Shk1 interacting proteins. S. pombe cells carrying a deletion of the skb5 gene exhibit no discernible phenotypic defects under normal growth conditions, but when subjected to hypertonic stress, become spheroidal in shape and growth impaired. Both of these defects can be suppressed by overexpression of the Shk1 modulator, Skb1. The growth inhibition that results from overexpression of Shk1 in S. pombe cells is markedly suppressed by a null mutation in the skb5 gene, suggesting that Skb5 contributes positively to the function of Shk1 in vivo. Consistent with this notion, we show that Skb5 stimulates Shk1 catalytic function in S. pombe cells. Furthermore, and perhaps most significantly, we show that bacterially expressed recombinant Skb5 protein directly stimulates the catalytic activity of recombinant Shk1 kinase in vitro. These and additional data described herein demonstrate that Skb5 is a direct activator of Shk1 in fission yeast.
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Chang E, Bartholomeusz G, Pimental R, Chen J, Lai H, Wang LH, Yang P, Marcus S. Direct binding and In vivo regulation of the fission yeast p21-activated kinase shk1 by the SH3 domain protein scd2. Mol Cell Biol 1999; 19:8066-74. [PMID: 10567532 PMCID: PMC84891 DOI: 10.1128/mcb.19.12.8066] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Ste20/p21-activated kinase homolog Shk1 is essential for viability and required for normal morphology, mating, and cell cycle control in the fission yeast Schizosaccharomyces pombe. Shk1 is regulated by the p21 G protein Cdc42, which has been shown to form a complex with the SH3 domain protein Scd2 (also called Ral3). In this study, we investigated whether Scd2 plays a role in regulating Shk1 function. We found that recombinant Scd2 and Shk1 interact directly in vitro and that they interact in vivo, as determined by the two-hybrid assay and genetic analyses in fission yeast. The second of two N-terminal SH3 domains of Scd2 is both necessary and sufficient for interaction with Shk1. While full-length Scd2 interacted with only the R1 N-terminal regulatory subdomain of Shk1, a C-terminal deletion mutant of Scd2 interacted with both the R1 and R3 subdomains of Shk1, suggesting that the non-SH3 C-terminal domain of Scd2 may be involved in defining specificity in SH3 binding domain recognition. Overexpression of Scd2 stimulated the autophosphorylation activity of wild-type Shk1 in fission yeast but, consistent with results of genetic analyses, did not stimulate the activity of a Shk1 protein lacking the R1 subdomain. Results of additional two-hybrid experiments suggest that Scd2 may stimulate Shk1 catalytic function, at least in part, by positively modulating protein-protein interaction between Cdc42 and Shk1. We propose that Scd2 functions as an organizing center, or scaffold, for the Cdc42 complex in fission yeast and that it acts in concert with Cdc42 to positively regulate Shk1 function.
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Abstract
In this paper, we describe a method for the visualization of double-strand breaks in a single electrostretched Escherichia coli DNA molecule. We also provide evidence that electrostretched or migrated DNA under neutral microgel electrophoresis conditions is made up of individual chromosomes. Using the neutral microgel electrophoresis technique, DNA migration (stretching) was measured and the number of DNA double-strand breaks were counted following exposure of E. coli cells to 0, 12.5, 25, 50, or 100 rad of X-rays. The use of an intense fluorescent dye, YOYO and custom-made slides have helped us in visualizing individual bacterial DNA molecules. Bacterial DNA appears similar in structure compared to electrostretched DNA from human lymphocytes. We were able to detect changes in DNA migration (stretching) induced by an X-ray dose as low as 12.5 rad and an increase in the number of DNA breaks induced by a dose as low as 25 rad. The extent of DNA migration and number of breaks were directly correlated to X-ray dosage.
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Míguez-Burbano MJ, Jaramillo CA, Palmer CJ, Shor-Posner G, Velásquez LS, Lai H, Baum MK. Total immunoglobulin E levels and dengue infection on San Andrés Island, Colombia. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1999; 6:624-6. [PMID: 10391876 PMCID: PMC95741 DOI: 10.1128/cdli.6.4.624-626.1999] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/1999] [Accepted: 04/26/1999] [Indexed: 11/20/2022]
Abstract
An evaluation of total immunoglobulin E (IgE) and dengue serostatus in 168 subjects from San Andrés Island, Colombia, revealed altered levels of IgE in 89% of the population. IgE levels were higher in patients with a history of dengue or with a current secondary or current primary infection than in subjects with no exposure (P = 0. 01). Dengue infection accounted for 23% of the variation in IgE levels.
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93
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Campa A, Shor-Posner G, Indacochea F, Zhang G, Lai H, Asthana D, Scott GB, Baum MK. Mortality risk in selenium-deficient HIV-positive children. JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES AND HUMAN RETROVIROLOGY : OFFICIAL PUBLICATION OF THE INTERNATIONAL RETROVIROLOGY ASSOCIATION 1999; 20:508-13. [PMID: 10225235 DOI: 10.1097/00042560-199904150-00015] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To determine the independent contribution of specific nutritional factors on disease progression and survival in HIV-1-infected children. POPULATION HIV-infected children (N = 24), who were perinatally exposed to the virus and symptomatic, were recruited between October and December of 1990 from the Jackson Memorial Pediatric Immunology Clinic, Miami, Florida, and observed for 5 years. METHODS Immune status was measured by CD4 cell count; nutritional status was determined using serum albumin and plasma trace elements including iron, zinc, and selenium. Cox proportional hazards regression models were used to evaluate the relationship of these parameters to survival. Use of antiretroviral treatment was considered in the statistical model, and age at death was considered a parameter of disease progression. RESULTS Over the course of the study, 12 children died of HIV-related causes. The final Cox multivariate analysis indicated that, of the variables evaluated, only CD4 cell count below 200 (risk ratio [RR] = 7.05; 95% confidence interval [CI], 1.87-26.5); p = .004], and low levels of plasma selenium (RR = 5.96; 95% CI, 1.32-26.81; p = .02) were significantly and independently related to mortality. Among the children who died, those with low selenium levels (< or =85 microg/L), died at a younger age, suggesting more rapid disease progression. CONCLUSIONS In pediatric HIV-infection, low plasma level of selenium is an independent predictor of mortality, and appears to be associated with faster disease progression.
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Zhou Y, Yu C, Lai H. [Determination of active components in caoyiguang wettable powder by reversed-phase high performance liquid chromatography]. Se Pu 1999; 17:211-2. [PMID: 12549173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Abstract
The Caoyiguang wettable powder is composed of two active components, synergists and other additives. The active components, bensulfuron methyl (Londax) and metolachlor (Dual), in 15.5% Caoyiguang wettable powder were determined by reversed phase high performance liquid chromatographic method simultaneously. The ZORBAX SB-C18 column (4.6 mm i.d. x 250 mm, 5 microns) and acidic mixture of methanol and water as mobile phase were used. The results showed that the recoveries were 98.1%-102.6%, and the coefficients of variation were 0.4%-0.8%. The method has been used to determine samples with satisfactory results.
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95
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Li K, Wong A, Li CK, Shing MM, Chik KW, Tsang KS, Lai H, Leung TF, Yuen PM. Granulocyte colony-stimulating factor-mobilized peripheral blood stem cells in beta-thalassemia patients: kinetics of mobilization and composition of apheresis product. Exp Hematol 1999; 27:526-32. [PMID: 10089916 DOI: 10.1016/s0301-472x(98)00045-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
beta-Thalassemias are often associated with bone marrow expansion and immunomodulation in terms of lymphocyte subsets and cytokine levels in the peripheral blood. The mobilization of peripheral blood stem cells (PBSC) by cytokines in such a background has not been reported. If achieved, the apheresis product could be used as a stem cell back-up for beta-thalassemia patients prior to bone marrow transplant. PBSC collection may also become a means for providing stem and progenitor cells for gene manipulation and therapy of this disorder. The aim of the study was to assess the administration of G-CSF in mobilizing stem and progenitor cells in these patients and to compare the kinetics of CD34+ cells and lymphocyte subsets with those of healthy PBSC donors. Results showed that the CD34+ cells were effectively mobilized by G-CSF (10-16 micrograms/day per kg) in 20 thalassemia patients and 11 healthy donors. Although no significant difference was observed in levels of daily stem cell counts between the two groups of subjects, a 1 day delay in achieving peak levels of CD34+ cells was observed in the majority of thalassemia patients. The peak increase of CD34+ cells was 21.5 +/- 6.1-fold and 30.8 +/- 7.6-fold of the basal steady-state levels in thalassemia patients and healthy donors, respectively. Similar to the situation of healthy donors, G-CSF stimulated essentially the CD34+ cells and the myeloid lineage (granulocytes, monocytes) in thalassemia patients and had a slight effect on lymphocyte subsets (T-helper, T-suppressor, NK, and B cells) and activation (CD25, HLA-DR, and CD45RO). Compositions of the apheresis products, including CD34+CD38-, CD34+CD33+ and CD34+HLA-DR- cells, were similar in the two groups of subjects. Correlation studies showed that the level of CD34+ cells in the PB is a good indicator of that in the apheresis product (r = 0.88, p < 0.001). The study has demonstrated that under close monitoring of CD34+ cell levels in PB, the mobilization by G-CSF and collection of PBSC in beta-thalassemia patients are feasible.
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96
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Lai H, Zhang F, Zhang B, Yang C, Xue M. Influence of percentage of osseointegration on stress distribution around dental implants. THE CHINESE JOURNAL OF DENTAL RESEARCH : THE OFFICIAL JOURNAL OF THE SCIENTIFIC SECTION OF THE CHINESE STOMATOLOGICAL ASSOCIATION (CSA) 1998; 1:7-11. [PMID: 10557165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
OBJECTIVE Stress around implants may lead to bone resorption and loss of the implant. The present study examined the influence of percentage of osseointegration at the implant-bone interface on the transmission of occlusal forces for endosseous dental implants. METHODS The three-dimensional finite element method used in the study was built from data obtained from slices of dental computed tomography scans. The study modeled a 3.75 x 10-mm cylindric implant placed in an edentulous mandible. Varying the elastic parameters assigned to the implant-bone interface, a load of 35 N was applied at the occlusal surface of the restoration at the vertical axis of the implant. Maximum principal stress, minimum principal stress and Von Mises stress were calculated. RESULTS AND CONCLUSIONS The most extreme stresses in the bone were always located around the neck of the implant. Those stresses in the implant-tissue interface decreased in inverse proportion to the increase in percentage of osseointegration. These results indicate the value of osseointegration in the aspect of mechanics.
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97
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Abstract
PURPOSE Quality of life research in prostate cancer involves the use of many questionnaires and specific items that may be partly redundant. We examine dimensions of quality of life in prostate cancer in the hope of somewhat simplifying communication of basic information. MATERIALS AND METHODS We analyzed cross-sectional survey data on quality of life in patients with prostate cancer belonging to a Southern California HMO. Quality of life was assessed with the University of California, Los Angeles prostate cancer index. Scree plot and parallel analysis were used to identify factors for extraction and orthogonal (varimax) rotation to examine scale loadings. RESULTS Four extracted factors explained a cumulative variance of 86%. The 8 physical and emotional scales loaded on 1 general factor explained 41% of the cumulative variance. Urinary function and bother, sexual function and bother, and bowel function and bother scales loaded on factors explained 16, 15 and 14% of the cumulative variance, respectively. CONCLUSIONS The observation of only 1 general quality of life factor diverges from consistent previous observations of distinct physical and emotional factors in other types of patients, and the tight interaction of emotional and physical scales supports the vulnerability hypothesis, "with age the increasing interactions across dimensions of health leave a patient vulnerable in all when any is affected." The tight interaction of physical and emotional scales in these but not other patients opens the door theoretically to better evaluation of and targeting of health services for patients with prostate cancer.
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98
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Zhang X, Liu S, Lai H, Chen P. One-step two-dimensional rainbow-holographic technique with a nonlaser light source: errata. OPTICS LETTERS 1998; 23:1408. [PMID: 18091801 DOI: 10.1364/ol.23.001408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
On p. 1055 of Ref. 1, just above Eq. (1), the wavelength of the argon-ion laser should be 458 nm, not 4.58 nm. On p. 1056, in the third-to-last paragraph, the spectrum of the InGa lamp should be 320450 nm, not 3.24.5 nm.
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99
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Zhang X, Liu S, Lai H, Chen P. One-step two-dimensional rainbow-holographic technique with a nonlaser light source. OPTICS LETTERS 1998; 23:1055-1056. [PMID: 18087427 DOI: 10.1364/ol.23.001055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A technique for recording two-dimensional rainbow holograms by use of a nonlaser light source is described. Multicolor holograms are recorded in one step. The optical setup is lensless. The recording light source is an InGa lamp that provides a spectrum from UV to blue. The slit effect is generated by replication from the slit master plates.
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100
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Peng B, Zhang M, Sun R, Lin YC, Chong SY, Lai H, Stein D, Raveche ES. The correlation of telomerase and IL-10 with leukemia transformation in a mouse model of chronic lymphocytic leukemia (CLL). Leuk Res 1998; 22:509-16. [PMID: 9678717 DOI: 10.1016/s0145-2126(98)00021-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Telomerase activity is upregulated in activated and malignant lymphocytes. We studied the correlation of telomerase and IL-10 to leukemia transformation in the NZB mouse model of human chronic lymphocytic leukemia (CLL). Telomerase levels increased from early to late leukemic stages, likewise IL-10 gene expression levels increased with the leukemic progression. The inverse relationship of telomerase and IL-10 levels to the survival of NZB mice was also established. Our data suggested that telomerase and IL-10 were involved in transformation in the murine model of CLL and the detection of telomerase activities might be of value in the prediction of CLL progression.
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MESH Headings
- Age Factors
- Animals
- B-Lymphocytes/enzymology
- B-Lymphocytes/immunology
- B-Lymphocytes/metabolism
- CD5 Antigens/analysis
- Cell Transformation, Neoplastic/metabolism
- Disease Models, Animal
- Interleukin-10/biosynthesis
- Interleukin-10/genetics
- Leukemia, Lymphocytic, Chronic, B-Cell/enzymology
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Mice
- Mice, Inbred NZB
- Neoplasm Staging
- Nuclear Proteins/analysis
- RNA, Messenger/analysis
- Telomerase/biosynthesis
- Tumor Cells, Cultured
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