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McCurdy M, Pang S, Keey R. Experimental determination of the effect of temperature and humidity on the development of colour in Pinus radiata. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2005. [DOI: 10.1590/s0104-66322005000200003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Kettel LM, Scholl G, Bonaventura L, Pang S, Sacks P, Chantilis S, Mahony M. Evaluation of a pen device for self-administration of recombinant human FSH in clomiphene citrate-resistant anovulatory women undergoing ovulation induction. Reprod Biomed Online 2005; 9:373-80. [PMID: 15511333 DOI: 10.1016/s1472-6483(10)61272-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This open-label multicentre study evaluated ease of use, safety, and efficacy of a pen device for self-administration of recombinant follicle-stimulating hormone (rFSH) in 43 subjects undergoing ovulation induction. Follitropin beta was administered subcutaneously with the Follistim Pen within 3 days of onset of menses. A 75 IU starting dose could be increased by 25 or 50 IU on days 8 and 15 if no ovarian response was observed. Human chorionic gonadotrophin (HCG; 10,000 IU) was administered when one follicle > or =18 mm or two to three follicles > or =15 mm were observed. Subjects received standardized instruction for the pen device and subject comprehension was recorded as subjects practised and prepared injections. Ease of use was also evaluated by questionnaire. Forty-four subjects enrolled; 43 were treated with rFSH and 41 were treated with HCG. The comprehension questionnaire revealed that during the mock injection, 100% of subjects properly loaded the cartridge into the pen device, while 95% selected the correct dose and 100% self-injected the medication prescribed. During the second actual injection, 100% of subjects comprehended these pen-related steps. The ease-of-use questionnaire showed that 100% of the subjects rated the overall experience of self-administering with the pen as 'very good' to 'good'. Mean duration and total amount of follitropin beta were 11.4 +/- 4.2 days and 1070.3 +/- 580.3 IU respectively. Ovulation rate was 95%. Biochemical and ongoing pregnancy rates per attempt were 34.9 and 30.2% respectively. Three subjects experienced serious adverse events [asthma; ovarian hyperstimulation syndrome (OHSS) and pain; OHSS]. In conclusion, the pen device provides an easy, safe, and effective way for women to self-administer follitropin beta during ovarian stimulation.
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Hotamisligil S, Carson R, Ezcurra D, Pang S. Paternal age and outcome in egg donation cycles. Fertil Steril 2004. [DOI: 10.1016/j.fertnstert.2004.07.455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Hotamisligil S, Carson R, Pang S. Serum hCG concentrations in autologous and egg donation IVF cycles. Fertil Steril 2004. [DOI: 10.1016/j.fertnstert.2004.07.512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Zheng JY, Yu D, Foroohar M, Ko E, Chan J, Kim N, Chiu R, Pang S. Regulation of the Expression of the Prostate-specific Antigen by Claudin-7. J Membr Biol 2003; 194:187-97. [PMID: 14502431 DOI: 10.1007/s00232-003-2038-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2003] [Indexed: 11/29/2022]
Abstract
Claudins are a family of proteins involved in forming tight junctions between cells. Here we describe two forms of claudin-7 (CLDN-7), a full-length form of CLDN-7 with 211 amino-acid residues and a C-terminal truncated form with 158 amino-acid residues. These two forms of CLDN-7 are able to regulate the expression of a tissue-specific protein, the prostate-specific antigen (PSA), in the LNCaP prostate cancer cell line. We also found that the expression of CLDN-7 is responsive to androgen stimulation in the LNCaP cell line, suggesting that this protein is involved in the regulatory mechanism of androgen. Both forms of claudin-7 are expressed in human prostate, kidney and lung samples, and in most samples, the full-length form of claudin-7 was predominant. However, in some prostate samples from healthy individuals, the truncated form of claudin-7 is predominantly expressed. Our results demonstrated that unlike other claudins, CLDN-7 has both structural and regulatory functions, and the two forms of CLDN-7 may be related to cell differentiation in organ development.
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Holden M, Krasatanova S, Xue B, Pang S, Sekiya M, Momol E, Gonsalves D. GENETIC ENGINEERING OF GRAPE FOR RESISTANCE TO CROWN GALL. ACTA ACUST UNITED AC 2003. [DOI: 10.17660/actahortic.2003.603.62] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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57
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Pang S, Kaplan B, Karande V, Westphal L, Scott R, Givens C, Sacks P. Self-administration of Follistim® AQ (in cartridge) in women undergoing controlled ovarian hyperstimulation (COH): ease of use, safety, and efficacy of the Follistim Pen™. Fertil Steril 2003. [DOI: 10.1016/s0015-0282(03)00114-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Pang S, Kaplan B, Karande V, Westphal LM, Scott R, Givens C, Sacks P. Administration of recombinant human FSH (solution in cartridge) with a pen device in women undergoing ovarian stimulation. Reprod Biomed Online 2003; 7:319-26. [PMID: 14653893 DOI: 10.1016/s1472-6483(10)61871-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
This study evaluated the first multiple-use pen device for the self-administration of recombinant FSH. The pen device is used for the subcutaneous injection of a pre-mixed ready-to-use solution of follitropin beta from a multiple-dose cartridge, and has flexible dosing capabilities. In the ease-of-use questionnaire, 90% of subjects rated the overall experience of self-injecting follitropin beta using the pen device as 'very good' (on day 6). The comprehension questionnaire revealed that prior to the first injection and during the second injection, the follitropin beta cartridge was properly loaded into the pen device by 96.7 and 100% of the subjects respectively. The questionnaire also showed that the correct dose was selected and self-administered by 98.3 and 100% of the subjects respectively. Biochemical and ongoing pregnancy rates per attempt were 56.7 and 45.0% respectively. The pen device is safe, effective, and easy to use for self-administering recombinant FSH during ovarian stimulation.
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Spink BC, Pang S, Pentecost BT, Spink DC. Induction of cytochrome P450 1B1 in MDA-MB-231 human breast cancer cells by non-ortho-substituted polychlorinated biphenyls. Toxicol In Vitro 2002; 16:695-704. [PMID: 12423652 DOI: 10.1016/s0887-2333(02)00091-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The effects of 12 non-ortho-substituted polychlorinated biphenyl (PCB) congeners on the induction of human cytochrome P450 1B1 (CYP1B1), an estradiol 4-hydroxylase, were investigated in MDA-MB-231 breast cancer cells. Three independent quantitative assays were used, in which the rates of estrogen metabolism, the levels of the CYP1B1 and CYP1A1 mRNAs, and luciferase activities under the control of the CYP1B1 promoter were measured. Of the congeners investigated, 3,4,4',5-tetrachlorobiphenyl (PCB 81), 3,3',4,4',5-pentachlorobiphenyl (PCB 126), 3,4',5-trichlorobiphenyl (PCB 39) and 3,3',4,5-tetrachlorobiphenyl (PCB 78) were the most potent in each assay, causing four to 10-fold increases in response. Exposure to 3,3',4,4',5,5'-hexachlorobiphenyl (PCB 169) resulted in elevated CYP1B1 mRNA and increased CYP1B1-promoter driven luciferase activity, but caused depressed rather than elevated rates of E(2) metabolism due to inhibition of CYP1B1. The relative magnitudes of CYP1B1 induction by the PCB congeners, as determined by the three assays, were in close agreement, with the exception noted for PCB 169. These results indicate that PCB structure-activity relationships for the induction of human CYP1B1 are similar to those observed for human CYP1A1, but differ somewhat from what has been reported for induction of rat CYP1A1.
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Chen A, Pang S. Births averted in Singapore during 1966-1975. SINGAPORE STATISTICAL BULLETIN. SINGAPORE. NATIONAL STATISTICAL COMMISSION 2002; 6:57-70. [PMID: 12337018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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Pang S, Fiume MZ. Final report on the safety assessment of Ammonium, Potassium, and Sodium Persulfate. Int J Toxicol 2002; 20 Suppl 3:7-21. [PMID: 11766134 DOI: 10.1080/10915810152630710] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Ammonium, Potassium, and Sodium Persulfate are inorganic salts used as oxidizing agents in hair bleaches and hair-coloring preparations. Persulfates are contained in hair lighteners at concentrations up to 60%, in bleaches and lighteners at up to 22% and 16%, respectively, and in off-the-scalp products used to highlight hair strands at up to 25%. They are used in professional product bleaches and lighteners at similar concentrations. Much of the available safety test data are for Ammonium Persulfate, but these data are considered applicable to the other salts as well. Acute dermal, oral, and inhalation toxicity studies are available, but only the latter are remarkable, with gross lesions observed in the lungs, liver, stomach, and spleen. In short-term and subchronic feeding studies the results were mixed; some studies found no evidence of toxicity and others found local damage to the mucous membrane in the gastrointestinal tract, but no other systemic effects. Short-term inhalation toxicity was observed when rats were exposed to aerosolized Ammonium Persulfate at concentrations of 4 mg/m3 and greater. Ammonium Persulfate (as a moistened powder) was not an irritant to intact rabbit skin, but was sensitizing (in a saline solution) to the guinea pig. It was slightly irritating to rabbit eyes. Ammonium Persulfate was negative in the Ames test and the chromosomal aberration test. No significant evidence of tumor promotion or carcinogenicity was observed in studies of rats receiving topical applications of Ammonium Persulfate. The persulfates were reported to cause both delayed-type and immediate skin reactions, including irritant dermatitis, allergic eczematous dermatitis, localized contact urticaria, generalized urticaria, rhinitis, asthma, and syncope. The most common causes of allergic dermatitis in hairdressers are the active ingredients in hair dyes, and Ammonium Persulfate has been identified as a frequent allergen. A sensitization study that also examined the incidence of urticarial reactions was performed with 17.5% Ammonium, Potassium, and Sodium Persulfate under occlusive patches. At this concentration and exposure conditions, a mixture of these Persulfates was not sensitizing, and application of Ammonium, Potassium, and Sodium Persulfate did not result in an urticarial reaction. In normal use (i.e., not occluded and rinsed off), it was expected that a concentration greater than 17.5% would also be safe. Given the clinical reports of urticarial reactions, however, manufacturers and formulators should be aware of the potential for urticarial reactions at concentrations of Persulfates greater than 17.5%. Based on the available data, the Cosmetic Ingredient Review (CIR) Expert Panel concluded that Ammonium, Potassium, and Sodium Persulfate are safe as used as oxidizing agents in hair colorants and lighteners designed for brief discontinuous use followed by thorough rinsing from the hair and skin.
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Pang S, Kang MK, Kung S, Yu D, Lee A, Poon B, Chen IS, Lindemann B, Park NH. Anticancer effect of a lentiviral vector capable of expressing HIV-1 Vpr. Clin Cancer Res 2001; 7:3567-73. [PMID: 11705878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
A lentiviral vector capable of expressing the HIV-1 vpr gene (Vpr lentiviral vector) was constructed, and its in vivo anticancer effect was determined against cutaneous tumors derived from the AT-84 oral cancer cells in immunocompetent mice. A single intratumoral injection of the Vpr lentiviral vector not only significantly reduced the primary tumor volume but also completely regressed tumors in >40% of animals. More interestingly, the mice of which the primary tumors were completely regressed by the Vpr lentiviral vector were additionally protected from a secondary challenge of AT-84 cells. These data suggest that the Vpr lentiviral vector elicits its anticancer activity in part by the activation of the immune system. The above suggestion is additionally supported by the failure of the lentiviral vector to demonstrate anticancer activity in immunocompromised nude or SCID mice. The Vpr lentiviral vector offers a powerful new strategy for cancer gene therapy and may be useful for the control of solid tumors, such as human oral squamous cell carcinomas.
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Yu G, Pang S, Li G. [The tensor fascia lata racket shape myocutaneous island flap]. ZHONGHUA ZHENG XING WAI KE ZA ZHI = ZHONGHUA ZHENGXING WAIKE ZAZHI = CHINESE JOURNAL OF PLASTIC SURGERY 2001; 17:261-3. [PMID: 11767697] [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 provide a racket shape tensor fascia lata myocutaneous island flap according to the anatomical form and blood supply of the tensor fascia lata. METHODS Four tensor fascia lata racket shape myocutaneous island flaps were used in four patients clinically. All 4 flaps were for repairing abdominal defect. RESULTS Three of the four flaps survived without complication. In one of the four flaps, skin necrosis at the distal tip was noted and needed additional skin graft. CONCLUSIONS The tensor fascia lata racket shape myocutaneous island flap is a convenient island flap. The island flap designed like racket shape has two benefits than the conventional rectangular island flap: 1. The narrow proximal part of the flap is like a extended pedicle, which makes the broad distal part of the flap can easily be transposed to the recipient site. 2. The donor defect of the narrow proximal part can be closed directly, which lessens the size of skin graft for the donor defect. The cause of skin necrosis at the distal tip of one flap is mainly due to that the length of the flap exceeds the distal end of the middle one third of the lateral thigh.
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Yu D, Chen D, Chiu C, Razmazma B, Chow YH, Pang S. Prostate-specific targeting using PSA promoter-based lentiviral vectors. Cancer Gene Ther 2001; 8:628-35. [PMID: 11593331 DOI: 10.1038/sj.cgt.7700344] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2001] [Indexed: 11/09/2022]
Abstract
The prostate-specific antigen (PSA) promoter is known to be highly tissue specific. Although its tissue specificity has been confirmed, its efficiency of gene transcription is significantly lower compared to known nonspecific viral promoters. These lower levels of promoter activity therefore pose a problem when developing an efficacious gene vector for prostate cancer gene therapy. Thus, selecting an appropriate therapeutic gene and vector system to carry the gene driven by the PSA promoter (PSAP) is important. In the studies described here, a human immunodeficiency virus (HIV)-1-based lentiviral vector carrying either the enhanced green fluorescent protein (EGFP) reporter or the diphtheria toxin A (DTA) gene was constructed. The results demonstrate that the PSA promoter in a lentiviral vector drives genes in prostate cells with satisfactory efficacy and specificity. The tissue-specific expression of the DTA protein efficiently eradicates LNCaP prostate cells in culture. We also infected prostate cancer cells and control cells carried by nude mice with the EGFP lentiviral vector. Significant numbers of EGFP-positive LNCaP cells were detected in all the mice bearing these tumors, but no EGFP-positive control cells were detected in any other mouse tissue. The high levels of expression in prostate cells, compared with the low levels of background expression in other cells, show that the PSAP-lentiviral vector could be a potential useful tool for gene therapy of metastatic prostate cancer.
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Pang S, Chubb AJ, Schwager SL, Ehlers MR, Sturrock ED, Hooper NM. Roles of the juxtamembrane and extracellular domains of angiotensin-converting enzyme in ectodomain shedding. Biochem J 2001; 358:185-92. [PMID: 11485566 PMCID: PMC1222046 DOI: 10.1042/0264-6021:3580185] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Angiotensin-converting enzyme (ACE) is one of a growing number of integral membrane proteins that is shed from the cell surface through proteolytic cleavage by a secretase. To investigate the requirements for ectodomain shedding, we replaced the glycosylphosphatidylinositol addition sequence in membrane dipeptidase (MDP) - a membrane protein that is not shed - with the juxtamembrane stalk, transmembrane (TM) and cytosolic domains of ACE. The resulting construct, MDP-STM(ACE), was targeted to the cell surface in a glycosylated and enzymically active form, and was shed into the medium. The site of cleavage in MDP-STM(ACE) was identified by MS as the Arg(374)-Ser(375) bond, corresponding to the Arg(1203)-Ser(1204) secretase cleavage site in somatic ACE. The release of MDP-STM(ACE) and ACE from the cells was inhibited in an identical manner by batimastat and two other hydroxamic acid-based zinc metallosecretase inhibitors. In contrast, a construct lacking the juxtamembrane stalk, MDP-TM(ACE), although expressed at the cell surface in an enzymically active form, was not shed, implying that the juxtamembrane stalk is the critical determinant of shedding. However, an additional construct, ACEDeltaC, in which the N-terminal domain of somatic ACE was fused to the stalk, TM and cytosolic domains, was also not shed, despite the presence of a cleavable stalk, implying that in contrast with the C-terminal domain, the N-terminal domain lacks a signal required for shedding. These data are discussed in the context of two classes of secretases that differ in their requirements for recognition of substrate proteins.
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Achermann JC, Ito M, Silverman BL, Habiby RL, Pang S, Rosler A, Jameson JL. Missense mutations cluster within the carboxyl-terminal region of DAX-1 and impair transcriptional repression. J Clin Endocrinol Metab 2001; 86:3171-5. [PMID: 11443184 DOI: 10.1210/jcem.86.7.7660] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
DAX-1 is an orphan nuclear receptor that plays a key role in the development and function of the adrenal gland and hypothalamic-pituitary gonadal axis. Mutations in the gene encoding DAX-1 result in X-linked adrenal hypoplasia congenita (AHC). Affected boys typically present with primary adrenal failure in infancy or childhood and hypogonadotropic hypogonadism at the time of puberty. The majority of DAX1 mutations described to date are nonsense or frameshift mutations that result in premature truncation of the DAX-1 protein and loss of DAX-1 repressor function. Relatively few missense mutations in DAX1 have been reported. Here, we describe missense mutations in three additional families with X-linked AHC. When combined with previous reports, the DAX1 missense mutations appear to cluster within restricted regions of the putative ligand-binding domain of DAX-1 and affect amino acids that are evolutionarily conserved, suggesting that these regions correspond to critical functional domains. Transcription assays, using a variety of artificial and native target genes, were performed to assess the effects of these mutations on the function of DAX-1. All DAX-1 missense mutant constructs showed marked loss of repressor function, with the exception of I439S, a mutation previously shown to be associated with delayed-onset adrenal failure and incomplete hypogonadotropic hypogonadism. These data indicate that most DAX1 missense mutations associated with classic AHC exhibit marked loss of function. The locations of these mutations thereby identify important functional domains in the carboxyl-terminus of the protein.
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Pang S, Zheng N, Felix CA, Scavuzzo J, Boston R, Blair IA. Simultaneous determination of etoposide and its catechol metabolite in the plasma of pediatric patients by liquid chromatography/tandem mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2001; 36:771-781. [PMID: 11473400 DOI: 10.1002/jms.173] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The anticancer drug etoposide is associated with leukemias with MLL gene translocations and other translocations as a treatment complication. The genotype of cytochrome P450 3A4 (CYP3A4), which converts etoposide to its catechol metabolite, influences the risk. In order to perform pharmacokinetic studies aimed at further elucidation of the translocation mechanism, we have developed and validated a liquid chromatography/electrospray/tandem mass spectrometry assay for the simultaneous analysis of etoposide and its catechol metabolite in human plasma. The etoposide analog teniposide was used as the internal standard. Liquid chromatography was performed on a YMC ODS-AQ column. Simultaneous determination of etoposide and its catechol metabolite was achieved using a small volume of plasma, so that the method is suitable for pediatric patients. The limits of detection were 200 ng ml(-1) etoposide and 10 ng ml(-1) catechol metabolite in human plasma and 25 ng ml(-1) etoposide and 2.5 ng ml(-1) catechol metabolite in protein-free plasma, respectively. Acceptable precision and accuracy were obtained for concentrations in the calibration curve ranges 0.2--100 microg ml(-1) etoposide and 10--5000 ng ml(-1) catechol metabolite in human plasma. Acceptable precision and accuracy for protein-free human plasma in the range 25--15 000 ng ml(-1) etoposide and 2.5--1500 ng ml(-1) etoposide catechol were also achieved. This method was selective and sensitive enough for the simultaneous quantitation of etoposide and its catechol as a total and protein-free fraction in small plasma volumes from pediatric cancer patients receiving etoposide chemotherapy. A pharmacokinetic model has been developed for future studies in large populations.
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Pang S, Tsuchiya S, Horie S, Uchida M, Murayama T, Watanabe K. Enhancement of phenylephrine-induced contraction in the isolated rat aorta with endothelium by H2O-extract from an Oriental medicinal plant Leonuri herba. JAPANESE JOURNAL OF PHARMACOLOGY 2001; 86:215-22. [PMID: 11459124 DOI: 10.1254/jjp.86.215] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Leonuri herba (I-mu-ts'ao, the Chinese motherwort) is an ancient Chinese traditional herb. Although the pharmacological effects of extracts of Leonuri herba have been shown in platelets and uteri, the effect on the vascular system has not been determined. In the present study, we investigated the effects of extracts of Leonuri herba on the contraction of the isolated rat aorta. Although the H20-extract (0.3-3 mg/ml) by itself showed a limited effect, the extract enhanced phenylephrine-induced contraction of the aorta with endothelium, but not without endothelium. The H20-extract, like N(G)-nitro-L-arginine methyl ester (L-NAME, an inhibitor of nitric oxide synthase), significantly inhibited the relaxation induced by acetylcholine in the aorta with endothelium. The inhibitory effect of H20-extract on the relaxation decreased by co-addition with 1 mM L-arginine. The vasoconstrictive effect of H20-extract was not due to leonurine, which is a constituent in Leonuri herba and shows uterotonic activity. Intravenous injection of the H20-extract (1.5 mg/kg) to rats caused an increase in blood pressure for 5 min, like L-NAME (1.35 mg/kg). These findings suggest that there is a component(s) in Leonuri herba, which shows a vasoconstrictive activity in rat aorta in vitro and in vivo and has similar pharmacological profile to that of L-NAME.
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Ye Z, Pang S, He W, Shi X, Guo Z, Zhu L. Copper(II) ion induced monolayer formation of p-tert-butylthiacalix[4]arene at the air-water interface. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2001; 57:1443-1447. [PMID: 11446699 DOI: 10.1016/s1386-1425(00)00485-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The monolayer properties of p-tert-butylthiacalix[4]arene (TCA) at the air-water interface was investigated by the measurements of surface pressure-area isotherms. However, TCA only exists as a trimmer aggregate on the subphase of deionized water. Copper(II) ion in the subphase can induce the monolayer formation of TCA. The UV-Vis spectra and FTIR spectra of the transferred films suggested that the monolayer forrmation was fulfilled through the coordination of copper(II) ion to TCA at the air-water surface.
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Pang S. Monolayers of novel amphiphile with schiff base moiety as headgroup and its complex of copper(II). Colloids Surf A Physicochem Eng Asp 2001. [DOI: 10.1016/s0927-7757(00)00659-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Pang S, Liang Y. Studies on charge transfer properties from mixture of Schiff base and zinc complex in Langmuir-Blodgett film by UV-vis absorption and Fourier transform infrared spectroscopy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2001; 57:435-439. [PMID: 11300554 DOI: 10.1016/s1386-1425(00)00369-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A novel mixed Langmuir Blodgett (LB) film based on a 1:1 (molar ratio) mixture of a non-amphiphile complex (Et4N)2[Zn(dmit)2] (H2dmit = 4,5-dimercapto-1,3-dithiole-2-thione) and Schiff base amphiphile 2,4-dihydroxy-N-octadecylbenzylideneamine (SBC18) was constructed and characterized by Fourier transform infrared (FTIR) spectra and UV-vis electronic absorption spectra. After iodine was doped in situ, magnitude of charge transfer increases, which was demonstrated by FTIR and UV-vis absorption spectral analysis.
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Pang S. Congenital adrenal hyperplasia owing to 3 beta-hydroxysteroid dehydrogenase deficiency. Endocrinol Metab Clin North Am 2001; 30:81-99, vi-vii. [PMID: 11344940 DOI: 10.1016/s0889-8529(08)70020-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recent advances in the genetics of the family of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) enzymes have helped in the understanding of the molecular basis and hormonal phenotype of bona fide 3 beta-HSD deficiency congenital adrenal hyperplasia (CAH). This article revisits the clinical spectra of 3 beta-HSD deficiency disorders, pathophysiology of 3 beta-HSD deficiency CAH, and updates genotype findings and diagnostic hormonal criteria for bona fide classic and nonclassic 3 beta-HSD deficiency CAH. The delta-5 steroid abnormality for the nonclassic 3 beta-HSD deficiency CAH, proven by genotype study, is substantially greater than the hormonal criteria for the disorder published before the advent of molecular information on the gene encoding adrenals and gonads in humans. In hyperandrogenic children and women, the pathogenic mechanism of a subtle abnormality in adrenal 3 beta-HSD activity, determined by modestly elevated ACTH stimulated delta-5 steroid levels, which led to the diagnosis of mild nonclassic 3 beta-HSD deficiency in the past, is outside of the type II 3 beta-HSD gene which encodes adrenals and gonads in humans and remains to be further explored.
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Lovett BD, Strumberg D, Blair IA, Pang S, Burden DA, Megonigal MD, Rappaport EF, Rebbeck TR, Osheroff N, Pommier YG, Felix CA. Etoposide metabolites enhance DNA topoisomerase II cleavage near leukemia-associated MLL translocation breakpoints. Biochemistry 2001; 40:1159-70. [PMID: 11170441 DOI: 10.1021/bi002361x] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chromosomal breakage resulting from stabilization of DNA topoisomerase II covalent complexes by epipodophyllotoxins may play a role in the genesis of leukemia-associated MLL gene translocations. We investigated whether etoposide catechol and quinone metabolites can damage the MLL breakpoint cluster region in a DNA topoisomerase II-dependent manner like the parent drug and the nature of the damage. Cleavage of two DNA substrates containing the normal homologues of five MLL intron 6 translocation breakpoints was examined in vitro upon incubation with human DNA topoisomerase IIalpha, ATP, and either etoposide, etoposide catechol, or etoposide quinone. Many of the same cleavage sites were induced by etoposide and by its metabolites, but several unique sites were induced by the metabolites. There was a preference for G(-1) among the unique sites, which differs from the parent drug. Cleavage at most sites was greater and more heat-stable in the presence of the metabolites compared to etoposide. The MLL translocation breakpoints contained within the substrates were near strong and/or stable cleavage sites. The metabolites induced more cleavage than etoposide at the same sites within a 40 bp double-stranded oligonucleotide containing two of the translocation breakpoints, confirming the results at a subset of the sites. Cleavage assays using the same oligonucleotide substrate in which guanines at several positions were replaced with N7-deaza guanines indicated that the N7 position of guanine is important in metabolite-induced cleavage, possibly suggesting N7-guanine alkylation by etoposide quinone. Not only etoposide, but also its metabolites, enhance DNA topoisomerase II cleavage near MLL translocation breakpoints in in vitro assays. It is possible that etoposide metabolites may be relevant to translocations.
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Arthur D, Pang S, Wong T. The effect of technology on the caring attributes of an international sample of nurses. Int J Nurs Stud 2001; 38:37-43. [PMID: 11137721 DOI: 10.1016/s0020-7489(00)00049-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
This paper commences by refining the psychometric characteristics of a quantitative instrument, which was developed to examine the caring attributes of an international sample of 1957 nurses working in 11 countries. Using factor analysis to support the construct validity, and removing weak items, the original 60 caring items were reduced to a 31 item global caring scale which revealed the sub-scales: 'caring communication'; 'caring involvement'; 'caring advocacy'; and 'learning to care'. The sub-scales were internally consistent and revealed generally high correlation coefficients. The subjects also responded to a scale, which was designed to measure degree of technological influence and provide a score for each respondent to reflect how highly they were influenced by technology in the work units of their hospital. The sample was then divided into three equal groups to reflect high, medium and low technological influence. The caring attribute scores then became the dependent variable by which the degree of technology was compared. The group with the lowest technological influence recorded the lowest mean score for caring while the group with the highest technological influence recorded the highest mean score for caring. A significant difference between the group with lowest and highest technological influence (F=6.84, p<0.001) was noted. This also applied to the 'caring communication' and 'caring involvement' sub-scales. For 'caring advocacy' the lowest technology group recorded the highest caring mean which was found to be significantly different to both mean scores for medium and highest technology groups (F=7.15, p<0.001). These results are discussed in the light of the international sample and suggestions for future research are raised.
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Pang S, Yu D, An DS, Baldwin GC, Xie Y, Poon B, Chow YH, Park NH, Chen IS. Human immunodeficiency virus Env-independent infection of human CD4(-) cells. J Virol 2000; 74:10994-1000. [PMID: 11069994 PMCID: PMC113179 DOI: 10.1128/jvi.74.23.10994-11000.2000] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CD4(-) epithelial cells covering mucosal surfaces serve as the primary barrier to prevent human immunodeficiency virus type 1 (HIV-1) infection. We used HIV-1 vectors carrying the enhanced green fluorescent protein gene as a reporter gene to demonstrate that HIV-1 can infect some CD4(-) human epithelial cell lines with low but significant efficiencies. Importantly, HIV-1 infection of these cell lines is independent of HIV-1 envelope proteins. The Env-independent infection of CD4(-) cells by HIV-1 suggests an alternative pathway for HIV-1 transmission. Even on virions bearing Env, a neutralizing antibody directed against gp120 is incapable of neutralizing the infection of these cells, thus raising potential implications for HIV-1 vaccine development.
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