Decrease in numbers of glandular cell groups in post-LLETZ liquid-based cytology preparations

Objective:  Large loop excision of the transformation zone (LLETZ) has become standard of care in the management of cervical squamous neoplasia and with cone biopsy glandular intraepithelial neoplasia. Controversy remains about the long-term effects of this traumatic procedure. The aim of this study was to count and compare the number of endocervical glandular cell groups in pre- and post-LLETZ cervical preparations using liquid-based cytology to establish a cyto-morphological correlate of destruction of the transformation zone.
Methods:  The cytology/histology correlation audit records of the Cytopathology Department of St Luke's Hospital in 2003 and early 2004 were used to select patients with a cytological diagnosis of high grade dyskaryosis followed by LLETZ. Only those cases with post-LLETZ cytological follow-up were selected. Cases using conventional smears were excluded. One hundred and twenty slides (60 pairs of slides) in total were retrieved. The cases underwent review and all groups of >3 glandular cells in each slide were counted by AM while blinded as to whether smears were pre- or post-LLETZ. Medians were compared using a Mann–Whitney U -test.
Results:  The median number of groups of endocervical glandular cells of the pre-treatment group was 5.5 and of the post-treatment group was 2.0. There were significantly fewer endocervical glandular cell groups in the post-LLETZ population ( P  = 0.03).
Conclusions:  The number of endocervical glandular groups in cervical cytological preparations decreases significantly following LLETZ procedure. This suggests that cytological follow-up may not be as useful in glandular neoplasia cases. Few or absent glandular cell groups in post-LLETZ preparations may have implications for adequacy assessment.     

Directional dispersal between mid-ocean ridges: deep-ocean circulation and gene flow in Ridgeia piscesae

This study examined relationships between bathymetrically induced deep-ocean currents and the dispersal of the hydrothermal vent tubeworm Ridgeia piscesae along the northeast Pacific ridge system. A robust diagnostic model of deep-ocean circulation in this region predicted strong southeasterly currents following contours of the Blanco Transform Fault, a 450-km lateral offset that separates the Gorda and Juan de Fuca ridge systems. Such currents should facilitate the southward dispersal of R. piscesae larvae. Immigration rates for populations north and south of the Blanco Transform Fault were estimated from molecular population genetic data. Mitochondrial DNA evidence revealed population subdivision across the Blanco Transform Fault, and a strong directional bias in gene flow that was consistent with predictions of the circulation model. The distribution of mitochondrial diversity between the northern and southern populations of R. piscesae suggests that the Gorda Ridge tubeworms have maintained larger effective population sizes than the northern populations, a pattern that also exists in co-occurring limpets. Together, these data suggest that the northern vent fields may experience a higher frequency of habitat turnover and consequently more rapid losses of genetic diversity.     

Aberrant T cell activation and heightened apoptotic turnover in end-stage renal failure patients: a comparative evaluation between non-dialysis,haemodialysis, and peritoneal dialysis

Patients in end-stage renal disease (ESRD) have a high incidence of bacterial and viral infections. Fifteen non-dialysed (ND), 15 haemodialysed (HD), 15 patients with peritoneal dialysis (PD), and 15 healthy controls were included. T cell proliferation was measured by [3H]thymidine uptake. Apoptosis and cell phenotype were determined by FACS. sTNF-R1, sCD95, interleukin-1beta-converting enzyme (sICE), and interleukin (IL)-10 were measured by ELISA. PHA and CD3-driven T cell proliferation were significantly decreased in ESRD patients. CD3(+), CD19(+) B cells, and percentage of CD4(+) T cells were significantly reduced. Percent memory T cells (CD45RO(+)) and cells undergoing apoptosis (CD95(+)/Annexin V+) were significantly increased in ESRF. Moreover, sCD95, sTNFRI, and ICE were significantly increased. Serum level of IL-10, a Th2 cytokine, was enhanced. These findings strongly suggest that in ESRD patients Th1 T cells are selectively susceptible to undergo apoptosis. This observation provides an additional pathophysiological concept in the genesis of Th2 dominance.     

A novelin vitro release technique for peptide-containing biodegradable microspheres

The purpose of this study was to develop and evaluate a dialysisin vitro release technique for peptide-containing poly(d, 1-lactide-coglycolide) (PLGA) microspheres (ms) that would correlate within vitro data. Using a luteinizing hormone- releasing hormone analogue (LHRH), Orntide acetate, solubility and stability were determined in 0.1 M phosphate buffer (PB), pH 7.4, and in 0.1 M acetate buffer (AB), pH 4.0, with highperformance liquid chromotography (HPLC), and peptide permeability through a dialysis membrane (molecular weight cut-off 300,000) was determined. Orntide ms were prepared by a dispersion/solvent extraction/evaporation method and characterized for drug content (HPLC), particle size distribution (laser diffraction method), and surface morphology (scanning electron microscopy).In vitro release was studied in PB using a conventional extraction method and with a new dialysis method in AB. Gravimetric analyses of polymer mass loss and matrix hydration, and peptide adsorption to blank PLGA ms (50∶50, M_w 28 022) were carried out in PB and AB upon incubation at 37°C. Serum Orntide and testosterone levels in rats after administration of Orntide ms were determined by radioimmunoassay. Orntide acetate solubility was influenced by pH; approximately 2.3 mg/mL dissolved in PB and >18 mg/mL in AB. Stability was pH- and temperature-dependent. The peptide was very stable at pH 4.0, 4°C, but degraded rapidly at pH 7.4,37°C. Peptide permeability through the dialysis membrane was accelerated by agitation and>95% equilibrium was reached within 48 hours. The overall release rate was higher with the dialysis method. Mass loss of the Orntide ms was faster in AB (50% loss in 3 weeks: 95% in 35 days) than in PB (65% in 35 days). In contrast, hydration after 35 days was 4-fold higher in PB. The nonspecific adsorption to blank ms was greater in PB (128 μ g Orntide/10 mg PLGA) compared with AB (<5 μ g Orntide/10 mg PLGA). Administration of 30-day Orntide PLGA ms to rats resulted in an initial serum Orntide level of 21 ng/mL after 6 hours and a C_max of 87 ng/mL after 6 days. Testesterone levels were suppressed immediately after ms administration (3 mg Orntide/Kg) from 5.2 ng/mL to 0.3 ng/mL (after 24 hours) and remained suppressed for 38 days. Orntide acetate solubility and degradation kinetics were markedly influenced by pH of the buffer systems and mass loss; matrix hydration, as well as the nonspecific adsorption to blank ms, was pH-dependent. Thein vitro release profile obtained with the dialysis method in AB correlated well with thein vivo data, therepy providing a more reliable prediction ofin vivo performance.     

Functional Characteristics of TauA Binding Protein from TauABC <Emphasis Type="Italic">Escherichia coli</Emphasis> System

Although TauA shares few common characteristics with other known periplasmic binding protein, TauA is a putative periplasmic binding protein, part of tauABCD gene cluster involved in sulfonate transport in sulphate starvation condition. This protein was expressed in E. coli BL 21 and purified before to assess its binding functionalities. Measurement of K _d value (mean 11.3 nM) by binding/dialysis studies revealed high affinity and specificity with taurine and also indicated that TauA possessed a unique binding site for its ligand. Comparisons with other periplasmic binding proteins suggests TauA plays a major role in ABC transport system and could be ideal candidate to serve as taurine catcher in biological fluids.     

Maintaining the ionic permeability of a cellulose ester membrane

This paper reports the results of a series of experiments designed to test conditions that would permit NaCl to diffuse through 100 Da molecular weight cut-off (MWCO) and 1,000 Da MWCO membranes. For the 100 Da MWCO membrane, the membrane becomes completely impermeable to NaCl when dialyzed against distilled water (DW), but inclusion of one of a variety of different salts in the dialyzing solution maintains membrane permeability to NaCl. A titration experiment revealed that a minimum concentration of 0.1 mM of a salt such as KH2PO4 is required to sustain membrane permeability. In contrast, diffusion through the 1,000 Da MWCO membrane was slightly higher when DW was used as the dialysate. We conclude that the 100 Da MWCO membrane works well for a variety of dialysis applications provided that a maintenance salt is included in all dialyzing solutions.     

一种从琼脂糖凝胶中回收DNA片段的简单电洗脱装置

我们设计了一种简单电洗脱装置,从琼脂糖胶中回收ＤＮＡ。该装置由两个带旋盖的小管、两块透析膜和一个凝胶屏障组成。在电场作用下,ＤＮＡ从凝胶中迁移出来,通过凝胶屏障进入由凝胶屏障和透析膜组成的回收小仓。用微量吸样器收集ＤＮＡ,乙醇沉淀和清洗。该法ＤＮＡ的回收率约８５％;回收的ＤＮＡ可用于基因工程常规实验。     

Challenges in the estimation of extinction from molecular phylogenies: A response to Beaulieu and O'Meara

Time‐calibrated phylogenies that contain only living species have been widely used to study the dynamics of speciation and extinction. Concerns about the reliability of phylogenetic extinction estimates were raised by Rabosky (2010), where I suggested that unaccommodated heterogeneity in speciation rate could lead to positively biased extinction estimates. In a recent article, Beaulieu and O'Meara (2015a) correctly point out several technical errors in the execution of my 2010 study and concluded that phylogenetic extinction estimates are robust to speciation rate heterogeneity under a range of model parameters. I demonstrate that Beaulieu and O'Meara underestimated the magnitude of speciation rate variation in real phylogenies and consequently did not incorporate biologically meaningful levels of rate heterogeneity into their simulations. Using parameter values drawn from the recent literature, I find that modest levels of heterogeneity in speciation rate result in a consistent, positive bias in extinction estimates that are exacerbated by phylogenetic tree size. This bias, combined with the inherent lack of information about extinction in molecular phylogenies, suggests that extinction rate estimates from phylogenies of extant taxa only should be treated with caution.     

维持性血液透析患者营养状况及营养不良的影响因素分析

目的:探讨维持性血液透析(MHD)患者营养状况以及营养不良的影响因素,为临床工作提供指导。方法:选择2010年-2014年在我院进行MHD治疗的120例患者作为研究对象,采用改良定量主观整体评估表(MQSGA)并结合相关生化指标测定等手段综合评估透析患者营养状况,分析MHD患者发生营养不良的危险因素。结果:MQSGA评估显示,营养正常组50例(41.67%),轻中度营养不良组61例(50.83%),重度营养不良组9例(7.50%)。不同营养状况组患者间Alb、PA、Cr比较差异有统计学意义(P0.05)。Logistic回归模型显示,Kt/V1.20、年龄≥60岁、透析龄≥3年及hs-CRP≥3 mg/L是MHD患者发生营养不良的危险因素。结论:MHD患者中发生营养不良的比例较大,Kt/V1.20、年龄≥60岁、透析龄≥3年及hs-CRP≥3 mg/L是其危险因素,可作为评价生营养不良的可靠指标。