Structure, genomic DNA typing, and kinetic characterization of the D allozyme of placental alkaline phosphatase (PLAP/ALPP)

The D allozyme of placental alkaline phosphatase (PLAP) displays enzymatic properties at variance with those of the common PLAP allozymes. We have deduced the amino acid sequence of the PLAP D allele by PCR cloning of its gene, ALPP. Two coding substitutions were found in comparison with the cDNA of the common PLAP F allele, i.e., 692C>G and 1352A>G, which translate into a P209R and E429G substitution. A single nucleotide primer extension (SNuPE) assay was developed using PCR primers that enable the amplification of a 1.9 kb PLAP fragment. Extension primers were then used on this PCR fragment to detect the 692C>G and 1352A>G substitution. The SNuPE assay on these two nucleotide substitutions enabled us to distinguish the PLAP F and D alleles from the PLAP S/I alleles. Functional studies on the D allozyme were made possible by constructing and expressing a PLAP D cDNA, i.e., [Arg209, Gly429]PLAP, into wild-type Chinese hamster ovary cells. We determined the k(cat) and K(m), of the PLAP S, F, and D allozymes using the non-physiological substrate p-nitrophenylphosphate at an optimal pH (9.8) as well as two physiological substrates, i.e., pyridoxal-5-phosphate and inorganic pyrophosphate at physiological pH (7.5). We found that the biochemical properties of the D allozyme of PLAP are significantly different from those of the common PLAP allozymes. These biochemical findings suggest that a suboptimal enzymatic function by the PLAP D allozyme may be the basis for the apparent negative selective pressure of the PLAP D allele. The development of the SNuPE assay will enable us to test the hypothesis that the PLAP D allele is subjected to intrauterine selection by examining genomic DNA from statistically informative population samples.     

Myoblasts fail to stimulate T cells but induce tolerance

Recent interest in myoblast transfer and in the use of myoblastsas vehicles in gene therapy has made it important to understandthe potential immunogenicity of allogeneic or neoantlgen-expresslngmyoblasts. Given the problems of producing a pure populationof myoblasts, In this study we used a tumour-derived musclecell line (TE671), with phenotyplc features of myoblasts, whichwe transfected to express HLA-DR1. However, this cell line wasunable to stimulate either established HLA-DR1-specific alloreactlveT cell clones or a primary alloresponse. Nor could it presenthaemagglutlnln peptide HA 306–324 to DR1-restricted, HA306–324-speciflc T cell clones or lines. Indeed, prelncubatlonwith DR1-expressing TE671 and HA 306–324 rendered suchT cells tolerant as Judged by their subsequent inability toproliferate in response to a DR1⁺ B cell line plus peptide HA306–324. These results imply that myoblasts do not providecostlmulatory signals, and are therefore unlikely to stimulateallospeclfic T cells following myoblasts transplantation orto initiate neoantlgen-speclfic immune responses following Invivo transfection.     

Effects of specific post-menopausal hormone therapies on bone mineral density in post-menopausal women: a meta-analysis

BACKGROUND: Long-term post-menopausal hormone therapy (pHT) was often regarded as first-line therapy to prevent fractures in post-menopausal women, a recommendation under scrutiny given the benefit-risk profile of the Women's Health Initiative results of the estrogen-progestin combination. Apart from controlled clinical studies providing data with fractures as an end point, measures of lumbar and hip bone mineral density (BMD) may be used to assess bone-related effects of pHT. The objective of this study was to conduct a systematic review of 2-year trials, published between 1990 and December 2002, and assessing changes in BMD by any estrogen including ethinyl estradiol, any estrogen plus any progestin, or tibolone. METHODS: We searched MEDLINE, EMBASE and systematic reviews. Thirty-nine randomized, prospective, controlled 2-year trials were analysed in pre-specified groups according to the profile of the compounds. RESULTS: Virtually all pHT regimens at least maintain BMD at the lumbar spine and the hip compared with baseline; there is no apparent difference between the various estrogenic compounds. Tibolone, a synthetic progestin, appears to be as effective as any estrogen. Most trials were conducted in early post-menopausal women, fewer in women with hysterectomy and/or bilateral oophorectomy. CONCLUSIONS: The size of impact on BMD does not appear to differ between tibolone and any estrogen compound studied.     

Behavioral treatment parameters with primary dysmenorrhea

Fourteen women with primary dysmenorrhea were administered four sessions of systematic desensitization (SD) by either a male or a female therapist. The following measures were taken during the flow periods before and after treatment and at a 6-month follow-up: menstrual symptom checklist, medication usage, invalid hours, and menstrual attitudes. At pretreatment, menstrually distressed women had significantly higher scores on all measures compared to a normative group and an explicitly nondistressed group. At posttreatment, treated women's scores on the dependent variables were significantly reduced. All indices were reduced to a nondistressed level at posttreatment and at 6-month follow-up. Type of dysmenorrhea (congestive vs. spasmodic), trait anxiety level, and therapist sex did not predict differential responsiveness to SD. SD did not affect frontalis EMG, peripheral blood flow, or pain threshold. A Retrospective Symptom Scale of menstrual distress was found to be highly reliable, valid, and sensitive.     

HSV-TK/GCV自杀基因系统治疗宫颈癌的研究

目的探讨HSV-TK/GCV自杀基因系统对人宫颈癌细胞系Hela体外及体内杀伤作用及其产生的旁观者效应.方法采用脂质体转染法将GINaTK载体转入包装细胞PA317.取病毒上清液感染人宫颈癌细胞Hela,得到带有HSV-TK基因的Hela/TK细胞,并将其分别用于体外和体内实验.结果载体HSV-TK导入了PA317细胞.体外实验结果显示,当Hela/TK细胞数占混合细胞10%时,低浓度(10μg/ml)的GCV就可将50%左右的肿瘤细胞杀死.体内实验结果显示GCV可明显抑制Hela/TK细胞在BALB/C小鼠体内的肿瘤形成.经GCV治疗后,肿瘤体积分别较对照组肿瘤体积缩小约11.1%、30.6%和47.2%(均P＜0.001);RT-PCR检测HSV-TK基因在肿瘤组织中有表达;实验组肿瘤组织与对照组相比存在明显的病理学改变.结论逆转录病毒可介导HSV-TK基因转入人宫颈癌细胞Hela并获稳定表达,HSV-TK/GCV自杀基因系统在体内外对宫颈癌细胞均有杀伤作用,且存在明显的旁观者效应.     

Invasive electrophysiological evaluation of patients with sleep apnoea-associated ventricular asystole—methods and preliminary results

SUMMARY  Twelve patients (aged 48 ± 12 y) with ventricular asystole of >3s due to complete atrioventricular (AV) block ( n = 8), sinoatrial (SA) block or sinus node arrest ( n = 3) or both ( n = 1) associated with obstructive sleep apnoea underwent invasive electrophysiological evaluation of sinus node function and AV conduction properties before and after administration of atropine (0.02 mg kg^-1). Ventricular asystole lasted for 5.9 ± 2.8 s (range 3.1–13 s). Sinus node function was assessed by measurement of sinus node recovery time, sinoatrial conduction time, and the response of sinus rate to atropine. Parameters of AV-conduction assessment included AH- and HV-intervals, AV- and VA-Wenckebach periods, and effective refractory period of the AV node before and after atropine. Sinus node function was normal in 11 of the 12 study patients and moderately abnormal in 1 patient. AV-nodal function was normal in 8 patients and moderately abnormal in 4 patients. A slightly prolonged HV-interval (59–63 ms) was present in 6 patients. Intra- or infra His block was not observed in any patient. In conclusion, normal or only moderately abnormal electrophysiological findings in patients with sleep apnoea-associated ventricular asystole suggest that a neurally mediated cardioinhibitory reflex may cause ventricular asystole in these patients. This sleep apnoea-triggered 'vasovagal' reflex may unmask pre-existing mild to moderate structural abnormalities of the AV conduction system.     

Cyclooxygenase-2 expression: a potential prognostic and predictive marker for high-grade ductal carcinoma in situ of the breast

AIMS: To study cyclooxygenase-2 (COX-2) expression in ductal carcinoma in situ (DCIS) of the breast and its association with histological features. COX-2, an inducible prostaglandin synthase, has been shown to be important in mammary carcinogenesis, being associated with increased tumour size and unfavourable outcome in breast cancer. Animal studies indicate that COX-2 inhibition is effective in the prevention and treatment of mammary cancers. METHODS AND RESULTS: Fifty-one cases of DCIS diagnosed during 1990-2000 were reviewed. Immunohistochemistry for COX-2 was performed and the COX-2 staining scores were correlated with histological features. The majority of cases [41 of 51 (80%)] had positive COX-2 staining, of which 13 cases (25%) had strong staining. High nuclear grade DCIS was significantly associated with increased COX-2 staining (P = 0.04). CONCLUSIONS: High-grade lesions are known to be associated with a higher recurrence rate following excision and are often oestrogen receptor negative, and as such, may be less responsive to adjuvant tamoxifen therapy. There is a need to examine further the role of COX-2 expression in DCIS, as both a prognostic and predictive factor.     

The ARIA/EAACI criteria for antihistamines: an assessment of the efficacy, safety and pharmacology of desloratadine

Background:  The definition of allergic rhinitis and the classification of its severity and treatment have advanced in recent years following the publication of the Allergic Rhinitis and its Impact of Asthma (ARIA) document. The ARIA and the European Academy of Allergology and Clinical Immunology (ARIA/EAACI) have published a set of recommendations that outline the pharmacological and clinical criteria to be met by medications commonly used in the treatment of allergic rhinitis.
Methods:  An international group of experts met to assess the profile of the antihistamine, desloratadine, under the ARIA/EAACI criteria. Data on desloratadine were collected from peer-reviewed clinical studies and review articles, which were corroborated and augmented by comprehensive public access documents from the European Medicines Evaluation Agency (EMEA).
Results and conclusion:  Based on this systematic review, it was concluded that the efficacy, safety and pharmacology of desloratadine broadly meet the ARIA/EAACI criteria for antihistamines.     

帕罗西汀合并认知疗法治疗酒依赖伴发抑郁及对戒酒的影响

目的评价帕罗西汀合并认知疗法治疗酒依赖伴发抑郁的疗效及对戒酒的影响。方法将98例酒依赖伴发抑郁的患者随机分为研究组和对照组,分别用认知疗法合并帕罗西汀、单用帕罗西汀治疗4个月。用汉密顿抑郁量表(HAMD)评定疗效;用复饮率评定戒酒效果。结果治疗1个月后,研究组HAMD评分16.79±6.50与对照组相近17.88±6.59(P>0.05)。治疗4个月后HAMD评分10.76±5.32、明显低于对照组14.54±5.12(P<0.01);临床疗效(痊愈率44.44%、显效率22.22%、有效率33.34%)明显高于对照组(21.74%、21.74%、56.52%)(P<0.05);复饮率(24.44%)低于对照对照组(45.56%)(P<0.05)。结论认知疗法合并帕罗西汀治疗酒依赖伴发抑郁疗效较好,戒酒效果较好。     

地震救援中现场截肢的探讨

目的探讨地震救援中现场截肢手术适应证、手术方法及伦理问题。方法映秀镇地震救援中现场截肢2例共3个肢体，采用局部麻醉，截肢平面靠近压迫物。术后补充等张盐水，补液速度1．5L／h，静脉滴注5％碳酸氢钠溶液150mL。口服头孢克肟胶囊，400mg顿服。结果截肢后2例患者均未出现严重并发症，次日送后方医院行二次截肢。结论灾难救援中现场截肢必须综合考虑，严格掌握适应证，必要的截肢可以挽救伤员生命。