质粒DNA抗原芯片检测抗双链DNA抗体的初步研究

目的:建立以质粒DNA作为抗原的检测血清中抗双链DNA(dsDNA)抗体的芯片方法,并与酶联免疫吸附实验比较,初步探讨用芯片法检测抗dsDNA抗体的临床价值。方法:将原核表达载体质粒pcDNAⅡ用质粒DNA快速抽提试剂盒提取纯化DNA后按1∶2稀释,用点样仪点在经3-氨丙基三乙氧基硅烷(APES)修饰的玻片上,温孵后用含有1%小牛血清白蛋白和2.5%蔗糖的PBST封闭,以Cy3标记的人IgG为二抗,建立检测dsDNA抗体的芯片方法,并与德国欧蒙公司生产的抗双链DNA检测ELISA试剂盒做比较,对包括58例系统性红斑狼疮(SLE)、25例干燥综合征(SS)、10例皮肌炎(DM)和7例类风湿关节炎(RA)在内的病人和60例健康人对照进行了抗dsDNA的对比检测。结果:对阳性标本的检测,与现用常规检测方法ELISA相比,芯片检测抗dsDNA的灵敏度为91.3%,特异度为90.7%,阳性预测值为89.3%,阴性预测值为92.5%;对健康对照的检测,2种方法均为阴性,符合率为100%。结论:与ELISA相比,用质粒DNA作为抗原建立的芯片方法的灵敏度和特异度较高,为今后建立同时检测多个自身抗体的芯片奠定了基础。     

A New Technique for Localization of Cellulase in situ Using Silver Nitrate

A new staining technique has been developed for the histochemical localization of cellulase in plant tissues by light microscopy. The products of cellulolysis are reducing sugars which can reduce the salts of heavy metals under appropriate conditions. The present technique relies on the deposition of black silver oxide due to reduction of alkaline silver nitrate to detect cellulase in tissues.     

A Pilot Randomized Placebo Controlled Trial of Electroacupuncture for Women with Pure Stress Urinary Incontinence

Background

Acupuncture is a potential conservative therapy for women with stress urinary incontinence (SUI). There is limited evidence to support its effectiveness due to the poor quality of existing studies.

Methods

We performed a pilot randomized, controlled trial to preliminarily assess the efficacy of electroacupuncture (EA) in women with pure SUI. A total of 80 women with pure SUI were randomly assigned to receive EA with deep needling at BL33 and BL35 (n = 40) or sham EA with non-penetrating needling at sham acupoints (n = 40) three sessions per week for 6 weeks. The women were followed for 24 weeks. The primary outcome was the change from baseline in the amount of urine leakage measured by a 1-hour pad test after 6 weeks. The secondary outcomes included the 72-hour incontinence episode frequency (IEF), International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) score, and patient self-evaluation of therapeutic effect. Adverse events (AEs) were monitored throughout the trial.

Results

The median decrease from baseline of urine leakage measured by the 1-hour pad test was 2.5 g [interquartile range (IQR): 1.80–14.6 in the EA group, which was greater than the median decrease of 0.05 g (IQR: -2.80–+0.50) in the sham EA group after 6 weeks (p<0.01). The differences between groups in the decrease from baseline of 72-hour IEF became statistically significant at week 30 with a median decrease of 3.25 g (IQR: 1.25–5.69) in the EA group, and a median decrease of 1.00 g (IQR: -0.69–+2.88) in the sham EA group (p = 0.01). The participants in the EA group showed greater decreases in ICIQ-SF score and higher ratings in the help they received from the treatment than those in the sham EA group at weeks 6,18 and 30 (all p<0.05). No obvious AEs were observed in either group.

Conclusion

EA may effectively and safely relieve urinary incontinence symptoms and improve quality of life in women with pure SUI. EA demonstrated more than a placebo effect. Since this is a pilot study, results should be interpreted with caution.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT02445573","term_id":"NCT02445573"}}NCT02445573.     

Imported Malaria in United Arab Emirates: Evaluation of a New DNA Extraction Technique Using Nested PCR

Local malaria transmission in the United Arab Emirates (UAE) came to an end in 1997. Nevertheless, UAE has been subjected to substantial importation of malaria cases from abroad, concerning both UAE nationals and immigrants from malarious countries with a total number of 2,119 cases in 2007. To evaluate a new DNA extraction technique using nested PCR, blood samples were collected from 132 individuals who presented to Infectious Diseases Department in Rashid Hospital, Dubai, and Central Department of Malaria Control with fever and persistent headache. Giemsa-stained blood films and ELISA test for malaria antibodies were carried out for detection of Plasmodium infection. Plasmodium infections were identified with the genus-specific primer set and species differentiation using nested PCR. A rapid procedure for diagnosis of malaria infections directly from dried blood spots using for the first time DNA extract from FTA Elute cards was evaluated in contrast to extraction techniques using FTA classic cards and rapid boiling technique. Our new simple technique for DNA extraction using FTA Elute cards was very sensitive giving a sensitivity of 100% compared to 94% using FTA classic cards and 62% in the rapid boiling technique. No complex preparation of blood samples was required prior to the amplification. The production cost of DNA isolation in our PCR assay was much less in comparable to that of other DNA extraction protocols. The nested PCR detected plasmodial infection and could differentiate P. falciparum from P. vivax, and also detected the mixed infection.     

硝酸甘油复合艾司洛尔应用对推管减压术控制性降压的临床观察

目的:比较椎管减压椎弓根钉内固定手术中硝酸甘油(NTG)-艾司洛尔控制性降压与单纯NTG控制性降压对血流动力学的影响。方法:40例在持续异丙酚 瑞芬太尼、异氟醚静吸复合麻醉下实施椎管减压椎弓根钉内固定手术患者,随机分为两组,Ⅰ组采用NTG艾司洛尔,Ⅱ组单纯采用NTG控制性降压至平均压65-70mmHg,持续30min。监测降压前后及降压期间血氧饱和度及心率、血压、动脉氧分压变化。结果:在静吸复合麻醉下Ⅱ组患者的降压消耗时间和复压所需时间均高于Ⅰ组患者,同时维持剂量也大于Ⅰ组患者,且Ⅰ组的血压、心率在降压前后各个时期较Ⅱ组稳定。但两种控制性降压方案时手术病人的血气变化影响情况是基本一致的。结论:NTG-艾司洛尔用于异丙酚 瑞芬太尼、异氟醚复合麻醉在椎管减压椎弓根钉内固定术中的控制性降压比单纯NTG降压对心率、血压的影响小,且更迅速,更平稳,用量少,可控性好。艾司洛尔50μg·kg-1·min-1,可减慢心率,防止硝酸甘油NTG停药后反跳性高血压。所以联合使用NTG、艾司洛尔,优于单纯使用NTG。     

Urinary Volatile Compounds as Biomarkers for Lung Cancer: A Proof of Principle Study Using Odor Signatures in Mouse Models of Lung Cancer

A potential strategy for diagnosing lung cancer, the leading cause of cancer-related death, is to identify metabolic signatures (biomarkers) of the disease. Although data supports the hypothesis that volatile compounds can be detected in the breath of lung cancer patients by the sense of smell or through bioanalytical techniques, analysis of breath samples is cumbersome and technically challenging, thus limiting its applicability. The hypothesis explored here is that variations in small molecular weight volatile organic compounds (“odorants”) in urine could be used as biomarkers for lung cancer. To demonstrate the presence and chemical structures of volatile biomarkers, we studied mouse olfactory-guided behavior and metabolomics of volatile constituents of urine. Sensor mice could be trained to discriminate between odors of mice with and without experimental tumors demonstrating that volatile odorants are sufficient to identify tumor-bearing mice. Consistent with this result, chemical analyses of urinary volatiles demonstrated that the amounts of several compounds were dramatically different between tumor and control mice. Using principal component analysis and supervised machine-learning, we accurately discriminated between tumor and control groups, a result that was cross validated with novel test groups. Although there were shared differences between experimental and control animals in the two tumor models, we also found chemical differences between these models, demonstrating tumor-based specificity. The success of these studies provides a novel proof-of-principle demonstration of lung tumor diagnosis through urinary volatile odorants. This work should provide an impetus for similar searches for volatile diagnostic biomarkers in the urine of human lung cancer patients.     

Novel Application of MRI Technique Combined with Flow-Through Cell Dissolution Apparatus as Supportive Discriminatory Test for Evaluation of Controlled Release Formulations

Dissolution studies cannot distinguish phenomena occurring inside the dosage forms when studying formulation with similar dissolution profiles—such formulations can behave differently when considering their physical changes. The application of flow-through dissolution apparatus integrated with magnetic resonance imaging (MRI) system for discriminative evaluation of controlled release dosage forms with similar dissolution profiles was presented. Hydrodynamically balanced systems (HBS) containing l-dopa and various grades hydroxypropyl methylcelluloses were prepared. The dissolution studies of l-dopa were performed at high field (4.7 T) MR system with MR-compatible flow-through cell. MRI was done with 0.14 × 0.14 × 1-mm spatial resolution and temporal resolution of 10 min to record changes of HBS parameters during dissolution in 0.1 M HCl. Structural and geometrical changes were evaluated using the following parameters: total area of HBS cross-section, its Feret’s diameter, perimeter and circularity, area of hydrogel layer, and “dry core” area. While the dissolution profiles of l-dopa were similar, the image analysis revealed differences in the structural and geometrical changes of the HBS. The mechanism of drug release from polymeric matrices is a result of synergy of several different phenomena occurring during dissolution and may differ between formulations, yet giving similar dissolution profiles. A multivariate analysis was performed to create a model taking into account dissolution data, data from MRI, information about chemical structure, and polymer viscosity. It provided a single model for all the formulations which was confirmed to be competent. The presented method has merit as a potential Process Analytical Technology tool.     

Efficacy of a New Educational Tool to Improve Handrubbing Technique amongst Healthcare Workers: A Controlled,Before-After Study

Introduction

Hand hygiene is a key component of infection control in healthcare. WHO recommends that healthcare workers perform six specific poses during each hand hygiene action. SureWash (Glanta Ltd, Dublin, Ireland) is a novel device that uses video-measurement technology and immediate feedback to teach this technique. We assessed the impact of self-directed SureWash use on healthcare worker hand hygiene technique and evaluated the device''s diagnostic capacity.

Methods

A controlled before-after study: subjects in Group A were exposed to the SureWash for four weeks followed by Group B for 12 weeks. Each subject''s hand hygiene technique was assessed by blinded observers at baseline (T₀) and following intervention periods (T₁ and T₂). Primary outcome was performance of a complete hand hygiene action, requiring all six poses during an action lasting ≥20 seconds. The number of poses per hand hygiene action (maximum 6) was assessed in a post-hoc analysis. SureWash''s diagnostic capacity compared to human observers was assessed using ROC curve analysis.

Results

Thirty-four and 29 healthcare workers were recruited to groups A and B, respectively. No participants performed a complete action at baseline. At T₁, one Group A participant and no Group B participants performed a complete action. At baseline, the median number of poses performed per action was 2.0 and 1.0 in Groups A and B, respectively (p = 0.12). At T₁, the number of poses per action was greater in Group A (post-intervention) than Group B (control): median 3.8 and 2.0, respectively (p<0.001). In Group A, the number of poses performed twelve weeks post-intervention (median 3.0) remained higher than baseline (p<0.001). The area under the ROC curves for the 6 poses ranged from 0.59 to 0.88.

Discussion

While no impact on complete actions was demonstrated, SureWash significantly increased the number of poses per hand hygiene action and demonstrated good diagnostic capacity.     

重组人血管内皮抑素联合化疗治疗骨肉瘤的前瞻性对照非随机临床研究

目的:探讨重组人血管内皮抑素(恩度)联合新辅助化疗治疗II期经典型骨肉瘤的疗效。方法:2013年1月至2014年7月我院骨肿瘤科治疗72例II期经典型骨肉瘤患者,根据病人意愿将病人分为新辅助化疗联合恩度组和单纯化疗组。单纯化疗组化疗方案为:阿霉素30 mg/m2静滴,d1-d3,顺铂120 mg/m2静滴,d4;甲氨蝶呤10-12 g/m2静滴,d1;异环磷酰胺3 g/m2静滴,d1-d5。新辅助化疗联合恩度组在化疗基础上加用恩度,初期8个病例恩度15 mg/d,d1-d5,配合化疗每周期4次,术前术后各一个周期,总剂量40支;后期14个病例,恩度15 mg/d,d1-d10,配合化疗每周期4次,术前术后各一个周期,总剂量80支。化疗后根据化疗结果进行手术治疗,术后对手术标本进行组织学评估和免疫组化染色,测量化疗前后联合组和对照组肿瘤坏死率、血管内皮生长因子(vascular endothelial growth factor,VEGF)及微血管密度(microvessel density,MVD)。结果:72例患者入组,剔除资料不全5例,共纳入评价67例,其中联合组22例,对照组45例。术后进行随访,随访时间3-19个月,平均随访时间11.5个月。两组在肿瘤坏死率无明显差异,但术前术后比较,VEGF染色和MVD联合组较对照组有明显下降。结论:本研究显示恩度联合新辅助化疗并不能提高肿瘤坏死率,但恩度能有效抑制肿瘤新生血管生成。     

Successful Human Infection with P. falciparum Using Three Aseptic Anopheles stephensi Mosquitoes: A New Model for Controlled Human Malaria Infection

Controlled human malaria infection (CHMI) is a powerful method for assessing the efficacy of anti-malaria vaccines and drugs targeting pre-erythrocytic and erythrocytic stages of the parasite. CHMI has heretofore required the bites of 5 Plasmodium falciparum (Pf) sporozoite (SPZ)-infected mosquitoes to reliably induce Pf malaria. We reported that CHMI using the bites of 3 PfSPZ-infected mosquitoes reared aseptically in compliance with current good manufacturing practices (cGMP) was successful in 6 participants. Here, we report results from a subsequent CHMI study using 3 PfSPZ-infected mosquitoes reared aseptically to validate the initial clinical trial. We also compare results of safety, tolerability, and transmission dynamics in participants undergoing CHMI using 3 PfSPZ-infected mosquitoes reared aseptically to published studies of CHMI using 5 mosquitoes. Nineteen adults aged 18–40 years were bitten by 3 Anopheles stephensi mosquitoes infected with the chloroquine-sensitive NF54 strain of Pf. All 19 participants developed malaria (100%); 12 of 19 (63%) on Day 11. The mean pre-patent period was 258.3 hours (range 210.5–333.8). The geometric mean parasitemia at first diagnosis by microscopy was 9.5 parasites/µL (range 2–44). Quantitative polymerase chain reaction (qPCR) detected parasites an average of 79.8 hours (range 43.8–116.7) before microscopy. The mosquitoes had a geometric mean of 37,894 PfSPZ/mosquito (range 3,500–152,200). Exposure to the bites of 3 aseptically-raised, PfSPZ-infected mosquitoes is a safe, effective procedure for CHMI in malaria-naïve adults. The aseptic model should be considered as a new standard for CHMI trials in non-endemic areas. Microscopy is the gold standard used for the diagnosis of Pf malaria after CHMI, but qPCR identifies parasites earlier. If qPCR continues to be shown to be highly specific, and can be made to be practical, rapid, and standardized, it should be considered as an alternative for diagnosis.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00744133","term_id":"NCT00744133"}}NCT00744133 {"type":"clinical-trial","attrs":{"text":"NCT00744133","term_id":"NCT00744133"}}NCT00744133     

A Combined Immunofluorescence-DNA-Fluorescence Staining Technique for Enumeration of Thiobacillus ferrooxidans in a Population of Acidophilic Bacteria

An antiserum raised against whole cells of Thiobacillus ferrooxidans was allowed to react with a variety of acidophilic and nonacidophilic bacteria in an enzyme-linked immunosorbent assay and an indirect immunofluorescence assay. Both experiments demonstrated that the antiserum was specific at the species level. This preparation was used to evaluate the role of T. ferrooxidans in the microbial desulfurization process. Leaching experiments were performed, and the numbers of T. ferrooxidans cells and other bacteria were estimated by using a combined immunofluorescence-DNA-fluorescence staining technique that was adapted for this purpose. Nonsterile coal samples inoculated with T. ferrooxidans yielded high concentrations of soluble iron after 16 days. After this period, however, T. ferrooxidans cells could no longer be detected by the immunofluorescence assay, whereas the DNA-fluorescence staining procedure demonstrated a large number of microorganisms on the coal particles. These results indicate that T. ferrooxidans is removed by competition with different acidophilic microorganisms that were originally present on the coal.     

A Regional Ecological Risk Assessment of the Kaipara Harbour,New Zealand,Using a Relative Risk Model

A regional ecological risk assessment was conducted for the Kaipara Harbour catchment in New Zealand. The Relative Risk Model was used to prioritize management of the sources of stress and habitats of concern in the basin. Semi-structured interviews with 25 representative stakeholders were conducted to obtain the resource-users’ perspectives and to identify the regional stressor sources and receptor habitat data for the model. For this risk analysis we divided the catchment into nine ecological districts. Mixed-methodological approaches including content analysis, geospatial analysis, and source documentation were used to categorize source and habitat rankings, based on the relative abundance of each in the nine ecological districts. Risk characterization revealed that fishing pressure and tidal energy pose the largest sources of perceived risk to the catchment; shellfish and Maui dolphin habitats are the receptors estimated to be at greatest risk; and the Kaipara and Rodney ecological districts are the sub-regions estimated with the greatest combined risk. A Monte Carlo analysis confirmed the source inputs and revealed greater uncertainty than the estimated habitat input results. The results of this assessment can be used by policy-makers, conservation groups, and municipalities to inform the future management efforts in the harbor and catchment.     

Development of a Composite Measure of Product Adherence,Protocol Compliance,and Semen Exposure Using DNA and Protein Biomarkers for Topical HIV Prevention Studies

Background

Poor and inconsistent use of study products has hindered clinical HIV prevention studies. It is important to be able to monitor product adherence and protocol compliance in order to determine microbicide efficacy and safety more accurately. Current methods for monitoring adherence are subjective, non-specific, or invasive. Herein, we present a composite, objective measure of product adherence and protocol compliance to assess vaginal insertion, semen exposure and drug expulsion utilizing DNA, protein, and drug isolated directly from returned, vaginally used gel applicators.

Methods

DNA, vaginal cells, and residual tenofovir were isolated from vaginally inserted applicators. Vaginal and semen biomarkers were amplified using a multiplex PCR to determine vaginal insertion. Vaginal cells were fixed followed by cytokeratin 4 immunocytochemistry to confirm DNA assessment of vaginal insertion. Tenofovir was extracted and quantitated through LC-MS/MS.

Results

DNA isolated from vaginally inserted applicators were positive for vaginal bacteria DNA and the control eukaryotic gene, amelogenin, while manually handled, “sham”, applicators were negative for both. Semen exposure was independently determined by simultaneous amplification of one or both Y-chromosomal genes, SRY and TSPY4. Vaginal insertion determination by DNA analysis was further confirmed by positive cytokeratin 4 (CK4) immunocytochemistry of vaginal cells remaining on the gel applicators. On the contrary, sham applicators provided very few cells when swabbed, and they were all negative for CK4. CK4 was not found in epidermal cells from the hand. Drug expulsion was detected through quantitation of residual gel present on the surface of returned applicators. Sham applicators had no detectable tenofovir.

Conclusion

Utilizing a composite, triple marker based panel of DNA, protein, and drug present on the surface of returned vaginal gel applicators, it is possible to determine, objectively and non-invasively, product adherence, protocol compliance, and semen exposure in microbicide trials.     

一种联合检测乙型肝炎病毒前S1抗原与核心抗原方法的建立及其与病毒核酸检测结果的一致性

本研究以与血清中HBV DNA含量高度相关的两种HBV抗原(前S1抗原与核心抗原)为靶标,建立了联合检测这两种HBV核酸相关抗原(NRAg)的双抗体夹心法ELISA试剂.对系列稀释血清的检测表明,该试剂的平均分析灵敏度为103.2基因组拷贝/mL(95%可信限102.2-4.2基因组拷贝/mL),显著高于前S1抗原或核心抗原的单独检测.对994份HBsAg阴性血清的检测结果表明NRAg ELISA的特异性为99.7%(95%可信限:99.1%～99.9%).对271份临床慢性肝炎血清进行检测,结果NRAg ELISA与HBV DNA结果的总符合率达96.3%(95%可信限:93.3%～98.2%),NRAg ELISA的读值/临界值比(S/CO)与HBV基因组拷贝数呈正相关.利用NRAg试剂,发现了1例HBsAg"a"抗原表位突变的变异株.这些结果显示HBV NRAg ELISA与HBV DNA具有高度相关性,并能够检测出HBsAg抗原变异株,有望成为HBsAg变异株筛选的有力工具,并为广大基层医疗单位提供一种便捷的替代HBV DNA定性检测的手段.     

The Study of Possible A and B Conformations of Alternating DNA Using a New Program for Conformational Analysis of Duplexes (CONAN)

Abstract

A new program, CONAN has been designed for CONformational ANalysis of oligonucleotide duplexes with natural and modified bases. It allows to model both regular DNA fragments with different types of symmetry and irregular ones including bends, junctions, mismatched pairs and base lesions. Computations and minimization of the energy are performed in a space of internal structural variables chosen to build start structure easier and conveniently analyze the results obtained. These internal structural variables determine mutual base-base and base-sugar arrangement and sugar puckering. The analytical closure procedure is applied both to sugar rings and to backbone fragments between adjacent sugars. For more effective energy minimization, analytical gradient is calculated. The CONAN was applied to the search for low-energy conformations of poly(dA-dT)·poly(dA-dT) and poly(dG-dC)·poly(dG-dC) duplexes. Extended regions of low-energy A and B conformations are revealed and characterized. These regions contain structures with different relative values of helical twist, τ, for pur-pyr and pyr-pur steps, namely, conformations with τ(pur-pyr)>τ(pyr-pur) and with τ(pur-pyr)<τ(pyr-pur). Two types of sugar puckering were found for B-form low-energy conformations, the first type with all C2′-endo sugar residues and the second one—;with C2′-endo purines and O1′-endo pyrimidines. The calculated conformations are compared with X-ray diffraction data for crystals and fibers and NMR data for solution.     

Ranibizumab Monotherapy or Combined with Laser versus Laser Monotherapy for Diabetic Macular Edema: A Meta-Analysis of Randomized Controlled Trials

Objective

To evaluate the relative efficacy of ranibizumab (RBZ) monotherapy or combined with laser (RBZ + Laser) versus laser monotherapy for the treatment of diabetic macular edema (DME).

Methods

A comprehensive literature search using PUBMED, ClinicalTrials.gov, and the Cochrane Library to identify randomized controlled trials (RCTs) comparing RBZ or RBZ + Laser to laser monotherapy in patients with DME. Efficacy estimates were determined by comparing weighted mean differences (WMD) in the change of best corrected visual acuity (BCVA) and central macular thickness (CMT) from baseline, and the risk ratios (RR) for the proportions of patients with at least 15 letters change from baseline. Safety analysis estimated the RR of cardiac disorders at 6 to 12 months in RBZ therapy vs. laser monotherapy. Statistical analysis was performed using the RevMan 5.1 software.

Results

Seven RCTs were selected for this meta-analysis, including 1749 patients (394 patients in the RBZ group, 642 patients in the RBZ + Laser group, and 713 patients in the laser group). RBZ and RBZ + Laser were superior to laser monotherapy in the mean change of BCVA and CMT from baseline (WMD = 5.65, 95% confidence interval (CI), 4.44–6.87, P<0.00001; WMD  = 5.02, 95% CI, 3.83–6.20, P<0.00001, and WMD  = −57.91, 95% CI, −77.62 to −38.20, P<0.00001; WMD  = −56.63, 95% CI, −104.81 to −8.44, P = 0.02, respectively). The pooled RR comparing the proportions of patients with at least 15 letters improvement or deterioration were also in favor of RBZ and RBZ + Laser (RR = 2.94, 95% CI, 1.82–4.77, P<0.00001; RR = 2.04, 95% CI, 1.50–2.78, P<0.00001, and RR = 0.21, 95% CI, 0.06–0.71, P = 0.01; RR = 0.52, 95% CI, 0.29–0.95, P = 0.03, respectively). There were no significant differences between RBZ and RBZ + Laser for any of the parameters. There were no difference in the safety profile between RBZ and laser.

Conclusion

RBZ and RBZ + Laser had better visual and anatomic outcomes than laser monotherapy in the treatment of DME. RBZ + Laser seemed to be equivalent to RBZ.     

Development of a Rapid Detection Procedure for Ctyptosporidium, Using In Vitro Cell Culture Combined with PCR

A detection, viability, and infectivity assay was developed for Cryptosporidiurn parvum. Oocysts or excysted sporozoites were inoculated onto monolayers of CaCo-2 cells grown on chamber slides. C. parvum infection was monitored by three methods: a) application of a fluorescein-labeled anti-sporozoite antibody; b) PCR of a heat-shock protein gene fragment; and c) detection of mRNA from the heat-shock protein gene by RT-PCR.     

A New Apparatus for the Measurement of Sap Flux in Small Shoots with the Magnetohydrodynamic Technique

Apparatus is described which applies the magnetohydrodynamictechnique of fluid flow measurement to the measurement of sapflux in plants. This technique permits instantaneous readingsto be taken. Measurements were made on a range of whole plantsand cut shoots in potometers to facilitate calibration and providean illustration of the linearity of the instrument.