A rapid method for relative quantification of N-glycans from a therapeutic monoclonal antibody during trastuzumab biosimilar development

Glycosylation is a common post-translational modification and critical quality attribute that can modulate the efficacy of therapeutic proteins. In the production of monoclonal antibodies (mAbs), quantifying the glycoform profile is a vital characterization step. Traditional glycan analysis is time consuming and involves steps at extreme temperature or pH, which may alter glycans. Here, we describe a rapid method for glycan analysis in which glycans are released from mAb samples that are bound to protein A columns. Since host cell proteins, which may also contain glycans, were already removed, this step enables analysis of cell culture products. Glycans released from the mAb samples are then derivatized with InstantPC™ labeling agent and analyzed by HILIC-FLD-MS. To illustrate the method, the glycan profiles of six trastuzumab (Herceptin®) antibody lots and four biosimilar developmental lots were analyzed. The results derived from our novel method, which takes less than 90 min, are compared with those from a typical glycan preparation approach.

Ground and In-Flight Calibration of the OSIRIS-REx Camera Suite

The OSIRIS-REx Camera Suite (OCAMS) onboard the OSIRIS-REx spacecraft is used to study the shape and surface of the mission's target, asteroid (101955) Bennu, in support of the selection of a sampling site. We present calibration methods and results for the three OCAMS cameras-MapCam, PolyCam, and SamCam-using data from pre-flight and in-flight calibration campaigns. Pre-flight calibrations established a baseline for a variety of camera properties, including bias and dark behavior, flat fields, stray light, and radiometric calibration. In-flight activities updated these calibrations where possible, allowing us to confidently measure Bennu's surface. Accurate calibration is critical not only for establishing a global understanding of Bennu, but also for enabling analyses of potential sampling locations and for providing scientific context for the returned sample.

Ground and In-Flight Calibration of the OSIRIS-REx Camera Suite

The OSIRIS-REx Camera Suite (OCAMS) onboard the OSIRIS-REx spacecraft is used to study the shape and surface of the mission's target, asteroid (101955) Bennu, in support of the selection of a sampling site. We present calibration methods and results for the three OCAMS cameras-MapCam, PolyCam, and SamCam-using data from pre-flight and in-flight calibration campaigns. Pre-flight calibrations established a baseline for a variety of camera properties, including bias and dark behavior, flat fields, stray light, and radiometric calibration. In-flight activities updated these calibrations where possible, allowing us to confidently measure Bennu's surface. Accurate calibration is critical not only for establishing a global understanding of Bennu, but also for enabling analyses of potential sampling locations and for providing scientific context for the returned sample.

Rapid global characterization of immunoglobulin G1 following oxidative stress

Although peroxide and leachable metal-induced chemical modifications are among the most important quality attributes in bioprocess development, there is no mainstream characterization method covering all common modifications theoretically possible on therapeutic proteins that also gives consistent results quickly. Here, we describe a method for rapid and consistent global characterization of leachable metals- or peroxide-stressed immunoglobulin (Ig) G1 monoclonal antibodies (mAbs). Using two independent protease digestions, data-independent acquisition and data-dependent acquisition liquid chromatography high-resolution mass spectrometry, we monitored 55 potential chemical modifications on trastuzumab, a humanized IgG1 mAb. Processing templates including all observed peptides were developed on Skyline to consistently monitor all modifications throughout the stress conditions for both enzymatic digestions. The Global Characterization Data Processing Site, a universal automated data processing application, was created to batch process data, plot modification trends for peptides, generate sortable and downloadable modification tables, and produce Jmol code for three-dimensional structural models of the analyzed protein. In total, 53 sites on the mAb were found to be modified. Oxidation rates generally increased with the peroxide concentration, while leachable metals alone resulted in lower rates of modifications but more oxidative degradants. Multiple chemical modifications were found on IgG1 surfaces known to interact with FcɣRIII, complement protein C1q, and FcRn, potentially affecting activity. The combination of Skyline templates and the Global Characterization Data Processing Site results in a universally applicable assay allowing users to batch process numerous modifications. Applying this new method to stability studies will promote a broader and deeper understanding of stress modifications on therapeutic proteins.

Residual Protein Contamination of ProSeal™ Laryngeal Mask Airways after Two Washing Protocols

The risk of prion protein cross-infection has focussed attention on the potential hazards of protein contamination of re-usable medical devices. This study determined the frequency of protein contamination of ProSeal™ laryngeal mask airways (PLMA) after two cleaning procedures and tested the hypothesis that the combination of hand- and machine-washing removes protein contamination more effectively than hand-washing alone. After clinical use fifty-four PLMAs were randomly allocated to be washed by hand or by hand then machine. All PLMAs were then autoclaved at 134°C for 4 minutes. After processing, each PLMA was immersed in a 1.2% solution of erythrosin B and examined for uptake of stain. The site (outer surface, bowl and edges of the cuff, airway and drain tube, finger strap) and severity (nil/mild/moderate/severe) of staining was scored by a blinded observer. There were no differences in the site or severity of staining between the two cleaning procedures. Staining was detected on 89% of PLMAs that were hand-washed and 78% of PLMAs that were hand-, then machine-washed (P=0.27). When staining occurred, it was mild in 98%, moderate in 2% and was never severe. Staining was more frequent on the edge than at any other location (all comparisons: P≤0.01). The strap never had any staining. We conclude that residual contamination of PLMAs with protein deposits is common even when machine-washing is used to augment hand-washing before autoclaving. The infection risk associated with these deposits remains to be determined.

Improving the safety and tolerability of local anaesthetic outpatient transperineal prostate biopsies: A pilot study of the CAMbridge PROstate Biopsy (CAMPROBE) method

OBJECTIVES

The aim of this study was to pilot the use of a bespoke device (CAMPROBE, the CAMbridge PROstate Biopsy) to enable routine outpatient free-hand local anaesthetic (LA) transperineal prostate biopsies.

MATERIALS AND METHODS

The CAMPROBE prototype was designed and built in our institution. Men on active surveillance due prostate resampling were invited to have a CAMPROBE biopsy as an alternative to repeat transrectal ultrasound-guided prostate biopsies (TRUSBx) as part of an approved trial (NCT02375035). Biopsies were performed using LA infiltration only, without sedation or additional analgesia. Patient-reported outcomes were recorded at day 0 and 7 using validated questionnaires and visual analogue scales (VAS). Complications were recorded prospectively.

RESULTS

Thirty men underwent biopsies with a median of 11 cores taken per procedure (interquartile range 10-12). There were no infections, sepsis or retention episodes. Haematuria and haematospermia occurred in 67% and 62% of patients, which are similar to rates reported for TRUSBx. Mean VAS for pain (0-10 scale) was less than 3 for every part of the procedure. All 30 men described the procedure as tolerable under LA. In total, 26/30 (86.7%) men expressed a preference for a CAMPROBE procedure over TRUSBx and a further 3 (10.0%) would have either.

CONCLUSIONS

In this small pilot study, the CAMPROBE device and method appears to be a safe, simple and well-tolerated out-patient transperineal replacement for TRUSBx. A major new National Institute for Health Research grant will allow its further development from a prototype to a single use, low-cost disposable device ready for multi-centre testing.

LEVEL OF EVIDENCE

1b: individual cohort study.

Sex differences in the splenic flexure

INTRODUCTION Anecdotally, surgeons claim splenic flexure mobilisation is more difficult in male patients. There have been no scientific studies to confirm or disprove this hypothesis. The implications in colorectal surgery could be profound. The aim of this study was to assess quantitatively whether there is an anatomical difference in the position of the splenic flexure between men and women using computed tomography (CT). METHODS Portal venous phase CT performed for preoperative assessment of colorectal malignancy was analysed using the hospital picture archiving and communication system. The splenic flexure was compared between men and women using two variables: anatomical height corresponding to the adjacent vertebral level (converted to ordinal values between 1 and 17) and distance from the midline. RESULTS In total, 100 CT images were analysed. Sex distribution was even. The mean ages of the male and female patients were 68.1 years and 66.7 years respectively (p=0.630). The mean vertebral level for men was 8.88, equating to the inferior half of the T11 vertebral body (range: 1-17 [superior half of T9 to inferior half of L2]), and 11.36 for women, equating to the inferior half of the T12 vertebral body (range: 4-16 [superior half of T10 to superior half of L2]). This difference was statistically significant (p=0.0001) and is equivalent to one whole vertebra. The mean distance from the midline was 160.8mm (range: 124-203mm) for men and 138.2mm (range: 107-185mm) for women (p<0.0001). CONCLUSIONS The splenic flexure is both higher and further from the midline in men than in women. This provides one theory as to why mobilising the splenic flexure may be more difficult in male patients.

Are energy and protein requirements met in hospital?

BACKGROUND

Malnutrition is a problem within hospitals, which impacts upon clinical outcomes. The present audit assesses whether a hospital menu meets the energy and protein standards recommended by the British Dietetic Association's (BDA) Nutrition and Hydration Digest and determines the contribution of oral nutrition supplements (ONS) and additional snacks.

METHODS

Patients in a UK South West hospital were categorised as 'nutritionally well' or 'nutritionally vulnerable' in accordance with their Malnutrition Universal Screening Tool score. Energy and protein content of food selected from the menu ('menu choice'), menu food consumed ('hospital intake') and total food consumed including snacks ('overall intake') were calculated and compared with the standards.

RESULTS

In total, 93 patients were included. For 'nutritionally well' patients (n = 81), energy and protein standards were met by 11.1% and 33.3% ('menu choice'); 7.4% and 22.2% ('hospital intake'); and 14.8% and 28.4% ('overall intake'). For 'nutritionally vulnerable' patients (n = 12), energy and protein standards were met by 0% and 8.3% ('menu choice'); 0% and 8.3% ('hospital intake'); and 8.3% and 16.7% ('overall intake'). Ten percent of patients consumed ONS. Patients who consumed hospital snacks (34%) were more likely to meet the nutrient standards (P ≤ 0.001).

CONCLUSIONS

The present audit demonstrated that most patients are not meeting the nutrient standards recommended by the BDA Nutrition and Hydration Digest. Recommendations include the provision of energy/protein-dense snacks, as well as menu, offering ONS where clinically indicated, in addition to training for staff. A food services dietitian is ideally placed to lead this, forming a vital link between patients, caterers and clinical teams.

SMAD transcription factors are altered in cell models of HD and regulate HTT expression

Transcriptional dysregulation is observable in multiple animal and cell models of Huntington's disease, as well as in human blood and post-mortem caudate. This contributes to HD pathogenesis, although the exact mechanism by which this occurs is unknown. We therefore utilised a dynamic model in order to determine the differential effect of growth factor stimulation on gene expression, to highlight potential alterations in kinase signalling pathways that may be in part responsible for the transcriptional dysregulation observed in HD, and which may reveal new therapeutic targets. We demonstrate that cells expressing mutant huntingtin have a dysregulated transcriptional response to epidermal growth factor stimulation, and identify the transforming growth factor-beta pathway as a novel signalling pathway of interest that may regulate the expression of the Huntingtin (HTT) gene itself. The dysregulation of HTT expression may contribute to the altered transcriptional phenotype observed in HD.

Anatomical siting of the splenic flexure using computed tomography

INTRODUCTION Often, left-sided colorectal surgery requires splenic flexure mobilisation (SFM) to allow a tension-free anastomosis to be carried out. This step is difficult and not without risk. We investigated a system of anatomical siting of the splenic flexure using computed tomography (CT). METHODS The Shrewsbury Splenic Flexure Siting (SSFS) system involves siting of the splenic flexure using the vertebral level (VL) as a reference point. We asked three surgical registrars (SRs) to analyse 20 CT scans of patients undergoing colonic resection to ascertain the anatomical site of the splenic flexure using the SSFS system. The distance from the centre of the vertebral body to the lateral edge (CVBL) of the splenic flexure was measured, as was the distance from the centre of the vertebral body to the inner abdominal wall (CVBI) along the same line, on axial images. RESULTS VL assessment demonstrated substantial inter-observer agreement with a kappa (κ) value of 0.742 (95% confidence interval (CI), 0.463-0.890). CVBL and CVBI demonstrated very strong inter-observer agreement (CVBL: κ = 0.905 (95% CI, 0.785-0.961); CVBI: 0.951 (0.890-0.979) (p<0.001). Overall, there was strong correlation between assessments by all three SRs across the three variables measured. CONCLUSIONS The SSFS system is an accurate method to site the splenic flexure anatomically using CT. We can use the SSFS system to develop a validated scoring system to help colorectal surgeons assess the difficulty of SFM.

Disaster nursing skills, knowledge and attitudes required in earthquake relief: Implications for nursing education

BACKGROUND

Globally, nurses becoming more aware of getting better prepared for disaster relief, but in China, disaster nursing knowledge, courses and research are still limited.

INTRODUCTION

China has long been prone to disasters, but disaster nursing education and training is in its infancy.

AIM

This study explored the skills, knowledge and attitudes required by registered nurses from across China who worked in the aftermath of three large earthquakes to try to determine future disaster nursing education requirements.

METHOD

The Questionnaire of Nurses' Disaster Nursing Skills at Earthquake Sites, assessing nursing skills, knowledge and attitudes, was distributed to 139 registered nurses in 38 hospitals in 13 provinces across China who had worked in one or more earthquake disaster zones. Descriptive statistics were used for quantitative data, and content analysis for qualitative data.

RESULTS

Eighty-nine questionnaires were returned, a response rate of 68.3%. No respondent had ever received specific disaster nursing training prior to their post-earthquake nursing. Skills most often used by respondents were haemostasis bandaging, fixation, manual handling, observation and monitoring, debridement and dressing, and mass casualty transportation. Respondents identified that the most important groups of skills required were cardiopulmonary resuscitation; haemostasis, bandaging, fixation, and manual handling; and emergency management. They emphasized the need for psychological care of victims as well as that of fellow health workers.

CONCLUSION

No respondent had ever received disaster nursing training prior to engagement at the earthquake disaster sites. All believed that there were important gaps in their knowledge and skills, and supported disaster nursing courses in the future.

IMPLICATIONS FOR NURSING AND HEALTH POLICY

China urgently needs to develop disaster nursing courses, with the support of nurse leaders, educationalists and government, to implement training using an all hazards approach in accordance with international best practice and trainees' background clinical experience and knowledge.

Nuclear localization of clathrin involves a labile helix outside the trimerization domain

Clathrin is a trimeric protein involved in receptor-mediated-endocytosis, but can function as a non-trimer outside of endocytosis. We have discovered that the subcellular distribution of a clathrin cysteine mutant we previously studied is altered and a proportion is also localized to nuclear spaces. MALS shows C1573A hub is a mixture of trimer-like and detrimerized molecules. The X-ray structure of the trimerization domain reveals that without light chains, a helix harboring cysteine-1573 is reoriented. We propose clathrin has a detrimerization switch, which suggests clathrin topology can be altered naturally for new functions.

Integrating a web-based, patient-administered assessment into primary care for HIV-infected adults

Providers routinely under diagnose at risk behaviors and outcomes, including depression, suicidal ideation, substance abuse, and poor medication adherence. To address this, we developed a web-based, self-administered patient-reported assessment tool and integrated it into routine primary care for HIV-infected adults. Printed results were delivered to providers and social workers immediately prior to patient appointments. The assessment included brief, validated instruments measuring clinically relevant domains including depression, substance use, medication adherence, and HIV transmission risk behaviors. Utilizing the Institute for Healthcare Improvement's Plan-Do-Study-Act (PDSA) approach to quality improvement, we addressed issues with clinic flow, technology, scheduling, and delivery of assessment results with the support of all levels of clinic staff. We found web-based patient-reported assessments to be a feasible tool that can be integrated into a busy multi-provider HIV primary care clinic. These assessments may improve provider recognition of key patient behaviors and outcomes. Critical factors for successful integration of such assessments into clinical care include: strong top-level /ort from clinic management, provider understanding of patient-reported assessments as a valuable clinical tool, tailoring the assessment to meet provider needs, communication among clinic staff to address flow issues, timeliness of delivery, and sound technological resources.

A matched study of primary scleral buckle placement during repair of posterior segment open globe injuries

AIMS

To compare the visual and anatomical outcomes of patients who underwent primary scleral buckle (SB) placement during posterior segment open globe repair with matched control patients who did not undergo primary SB placement.

METHODS

Patients who underwent open globe repair alone or with SB placement at Duke University Eye Center (November 1994-September 1997) and the Massachusetts Eye and Ear Infirmary (July 1993-July 1997) were identified. 19 open globe patients who received primary SB placement were matched with control patients who did not receive a primary SB based on three important prognostic factors: (1) visual grade; (2) zone of injury; and (3) mechanism of injury. The outcomes of interest were: (1) visual outcome; (2) anatomical outcome; (3) subsequent retinal detachment (RD); and (4) number of subsequent surgeries.

RESULTS

Baseline characteristics between the groups were similar. Patients who received primary SB placement had a better final visual grade (p = 0.02), logMAR vision (p = 0.007), and anatomical grade (p = 0.01) compared with control patients. Primary SB patients had an average final vision of 20/270, whereas control patients had an average final vision of hand movement. Primary SB placement also resulted in fewer subsequent RDs (26% versus 53%), but this difference did not reach statistical significance (p = 0.10). There were no complications associated with primary SB placement.

CONCLUSION

Primary SB placement during posterior segment open globe repair may decrease the risk of subsequent RD and improve final visual and anatomical outcome.

A comparative study of bovine pericardium (periguard) and homologous sclera as lower eyelid spacer graft analogs in New Zealand white rabbits

PURPOSE

To compare bovine pericardium (Periguard; Bio-Vascular, Inc., St. Paul, MN, U.S.A.) and homologous sclera as spacer graft analogs in a rabbit model.

METHODS

A nonrandomized experimental animal study was conducted. Elliptical subconjunctival implants were placed in one lower eyelid each of 10 rabbits. Five rabbits received homologous sclera implants, and five received bovine pericardium implants. The rabbits were killed 7 weeks later, and the lower eyelids were examined clinically and histopathologically.

RESULTS

Rabbit eyelids implanted with Periguard had a more marked inflammatory reaction and more significant collagen lamellar disruption than eyelids implanted with homologous sclera, although clinically they appeared quite similar.

CONCLUSIONS

Although bovine pericardium elicited a more intense inflammatory response at the histopathologic level, both implants were similarly tolerated at the clinical level. These findings are consistent with animal and human investigations of bovine pericardium in other parts of the body, and warrant further studies into its potential use in the human eyelid.

Prevention of muscimol-induced long-term depression by brain-derived neurotrophic factor

1. The authors have recently reported a new protocol for inducing long-term depression through activation of GABAA receptors in the hippocampal slices. This long-term depression is reversed by bicuculline and potentiated by neurosteroids such as alphaxalone. It was also shown that glutamate receptor activity is not involved in the induction of this novel type of long-term depression. Brain derived neurotrophic factor is a member of the neurotrophins family widely expressed in the central nervous system. There is increasing evidence that indicate an important role for brain-derived neurotrophic factor in synaptic plasticity. It has been reported that brain-derived neurotrophic factor level is downregulated by GABA system. The present study investigated a possible relation between muscimol-induced long-term depression and brain-derived neurotrophic factor level. 2. Extracellular recordings were made in the CA1 pyramidal cell layer of rat hippocampal slices following orthodromic stimulation of Schaffer collateral fibers in stratum radiatum. 3. It was observed that brain-derived neurotrophic factor at concentration that did not have any effect itself on the population spike, prevents the induction of long-term depression by muscimol. In addition to this, K-252a an inhibitor of Trk type kinase blocked the prevention of muscimol-induced LTD by brain-derived neurotrophic factor. 4. The results suggest that there is an interaction between muscimol-induced long-term depression and brain-derived neurotrophic factor and may explain the post receptor mechanism of muscimol-induced long-term depression through a bilateral relation between GABAA activity and brain-derived neurotrophic factor.

Bovine pericardium versus homologous sclera as wrapping materials for hydroxyapatite ocular implants: an animal study

PURPOSE

We compared bovine pericardium and homologous sclera as wrapping materials for hydroxyapatite (HA) ocular implants in enucleated New Zealand white rabbits.

METHODS

Eighteen rabbits were unilaterally enucleated and the sockets implanted with 10-mm HA spherical implants. Six implants were wrapped with homologous sclera, 6 with bovine pericardium, and 6 were not wrapped. The rabbits were killed 7 weeks later and the sockets were examined clinically for inflammation and implant exposure. Exenterated specimens were assessed histopathologically for inflammation and vascularization.

RESULTS

No clinical evidence of implant exposure or extrusion was detected in rabbits receiving sclera or bovine pericardium wrapped implants. Histopathologically, the bovine pericardium displayed more inflammation in its outer portion, as well as more disruption of its lamellar arrangement than did the sclera. Fibrovascular in-growth was complete in all wrapped implants.

CONCLUSION

Bovine pericardium behaves similar clinically to homologous sclera as a wrapping material for spherical HA ocular implants in a rabbit model, and may represent a reasonable alternative to sclera in such procedures in humans.

Interindividual heterogeneity in the hypoxic regulation of VEGF: significance for the development of the coronary artery collateral circulation

BACKGROUND

The coronary artery collateral circulation may be beneficial in protecting against myocardial ischemia and necrosis. However, there is a tremendous interindividual variability in the degree of new collateral formation in patients with coronary artery disease. The basis for this interindividual heterogeneity is not understood. In this study we test the hypothesis that failure to generate collateral vessels is associated with a failure to appropriately induce with hypoxia or ischemia the angiogenic factor, vascular endothelial growth factor (VEGF).

METHODS AND RESULTS

We correlated the VEGF response to hypoxia in the monocytes harvested from patients with coronary artery disease with the presence of collaterals visualized during routine angiography. We found that there was a highly significant difference in the hypoxic induction of VEGF in patients with no collaterals compared with patients with some collaterals (mean fold induction 1.9+/-0.2 versus 3.2+/-0.3, P<0.0001). After subjecting the data to ANCOVA, using as covariates a number of factors that might influence the amount of collateral formation (ie, age, sex, diabetes, smoking, hypercholesterolemia), patients with no collaterals still have a significantly lower hypoxic induction of VEGF than patients with collaterals.

CONCLUSIONS

This study provides evidence in support of the hypothesis that the ability to respond to progressive coronary artery stenosis is strongly associated with the ability to induce VEGF in response to hypoxia. The observed interindividual heterogeneity in this response may be due to environmental, epigenetic, or genetic causes. This interindividual heterogeneity may also help to explain the variable angiogenic responses seen in other conditions such as diabetic retinopathy and solid tumors.

Impact of research on pediatric pain assessment and outcomes

PURPOSE

Pediatric nurses from varied practice and educational backgrounds learned about research by doing a ward-based study. The aim of the study was to determine if regular assessment of children's pain would improve their pain management and postoperative progress.

METHOD

Children, ages 5 to 17 years (n = 36), measured their pain every 4 hours postoperatively using the Wong-Baker Faces Pain Rating Scale. Outcomes regarding amount of analgesic given, subjective pain reports, time and progress of ambulation, and length of hospital stay were compared with data from a retrospective chart-review of a control group (n = 50).

FINDINGS

No statistically significant differences in these variables were found. An important clinical finding was that despite all children having prescribed PRN analgesic orders, one quarter of the children received no pain relief intervention. Also, one quarter of the children stated that their pain control was only partially effective.

CONCLUSIONS

Study results reinforce findings reported in the literature regarding ineffective pain management in children, and highlight a need for improved nursing practice. Clinical significance was achieved in terms of staff learning of the research process, increased awareness of pediatric pain management practices, improved ward morale, and inter-agency sharing of resources.

Ro 15-4513 alteration of pentobarbital dependence

This study investigated the ability of the benzodiazepine inverse agonist, Ro 15-4513, to alter the expression of physical dependence on pentobarbital. Male Sprague-Dawley rats were made physically dependent on pentobarbital by continuous. IP, infusion of escalating doses of pentobarbital for 12 days. In Experiment 1, pentobarbital dependent rats received either vehicle or Ro 15-4513, in doses of 5, 10, or 15 mg/kg, IP, periodically during the pentobarbital abstinence period. As expected, Ro 15-4513 produced a significant, dose-dependent, exacerbation of withdrawal signs in the pentobarbital dependent rats. In Experiment 2, either vehicle or Ro 15-4513, at a dose of 15 mg/ kg, was administered, IP, once daily during the 12 days of continuous pentobarbital infusion. During the subsequent pentobarbital abstinence period it was noted that the withdrawal signs were significantly reduced in the rats receiving the daily administration of Ro 15-4513. It is hypothesized that the benzodiazepine inverse agonist, Ro 15-4513, may inhibit the development of physical dependence on pentobarbital through an opposing action on the GABA-A receptor.

Hybridization of horseradish peroxidase-labeled probes and detection by enhanced chemiluminescence

This article describes the use of probes directly labeled with horseradish peroxidase in conjunction with enhanced chemiluminescence, which allows a flexible approach to hybridizations and detections. This system may be used with the following applications: Southern blots, Northern blots, colony and plaque screening for positive clones, YAC clone screening, and PCR products detection. The major steps required for the use of directly labeled HRP probes are hybridization, stringent washes, and detection.

Preparation of horseradish peroxidase-labeled probes

The direct labeling of nucleic acid probes with horseradish peroxidase (HRP) may be used in many membrane hybridization applications, including Southern blots, Northern blots, colony and plaque screening, PCR products detection/identification. This article describes the preparation method, which involves the labeling of a single-stranded nucleic acid probe with a positively charged HRP-parabenzoquinone-polyethyleneimine complex (labeling reagent). The associated hybridization and posthybridization protocols are relatively simple, which makes probes labeled directly with HRP particularly suitable for large scale screening, where tens or hundreds of blots are processed weekly.

Deceiving others/deceiving oneself: four cases of factitious rape

Although patients with factitious disorders typically seek the "patient" role through illness portrayals, some instead portray themselves falsely as "victims." We discuss the cases of four women who claimed to have been victims of rape; the allegations ultimately were disproved. Factitious rape may be prompted by a search for nurturance; by dissociation, leading individuals to believe that trauma earlier in life is ongoing; by a need to be rescued from real, current abuse; and by projection of anger onto specific male targets. Although dramatic, factitious rape is rare, we advocate thorough investigation of rape claims even when patients have known histories of deceptive behavior.

Enhanced chemiluminescence for the detection of membrane-bound nucleic acid sequences: advantages of the Amersham system

A range of nonradioactive nucleic acid labeling and detection systems have been developed that enable the user to label probes directly with enzyme molecules or indirectly with hapten-derivatized nucleotides. Horseradish peroxidase is used for the direct labeling procedures due to the ease of chemical modification and the relative thermal and chemical stability of this enzyme. Horseradish peroxidase has also been conjugated to a high-specificity antifluorescein antibody for detection of hapten (fluorescein)-labeled hybrids. Enhanced chemiluminescence is a light-emitting process optimized for the detection of low levels of horseradish peroxidase on membrane supports. Results are obtained as hard copy images on x-ray film.

Hybrid diffractive-refractive lenses and achromats

Hybrid elements containing optical power with both diffractive (holographic) and refractive components are shown to be useful for obtaining arbitrary or, in special cases, achromatic dispersive characteristics. In one configuration a volume holographic element is coated on the surface of a crown glass lens, and by varying the power distributions among the refractive and holographic components while maintaining constant overall optical power the effective Abbe V numbers of the resultant hybrid element are shown to span all real numbers excepting a narrow interval around zero. In the achromat case (V number = infinity), both refractive and diffractive components are of the same sign resulting in much smaller glass curvatures than in all-refractive achromat doublets or apochromat triplets. The large separation between holographic partial dispersions and available glass partial dispersions is shown to lead to hybrid three-color achromats with greatly reduced glass curvatures. Applications are expected to include broadband achromatic objectives and chromatic aberration corrector plates in high performance optical systems. Such corrector plates may have any net power (including zero) while exhibiting effective V numbers that are positive or negative and that span a wide range, e.g., +/-1 or +/-1000. Further advantages include reducing the need for choosing high dispersion glasses, which may be costly and difficult to grind or polish. High diffraction efficiency and broad spectral bandwidths (in excess of 3000 A) are obtained in the holographic optical elements using single-element central-stop and cascaded element designs.

Standardized endosonographic evaluation of prostate cancer: receiver-operator-characteristic analysis

A standardized endosonographic numeric method has been developed for the detection of prostate cancer. Eighty-six men were examined with a 5-MHz, 96-element linear-array probe. Mean gray-scale amplitudes were produced by a semiautomatic method for periprostatic fat and regions of interest within the external portion of the prostate gland that were visually suspicious for prostate cancer. Mean gray-scale amplitude ratios of visually abnormal areas of prostate to periprostatic fat (Ap/Af) were calculated. Pathologic confirmation of disease was obtained in all patients. Three different numeric Ap/Af ratios were compared with digital palpation and subjective visual interpretation of sonograms. The numeric method resulted in a consistently higher specificity, accuracy, and positive predictive value when compared with palpation and subjective interpretation. The initial results suggest that this technique may also detect atypical hyperplasia.

Simulation Of A Large Steam-CO Co-Injection Experiment

Abstract

A high-pressure steam-CO2 co-injection experiment, carried out in a 1.5 m diameter physical simulator packed with Athabasca oil sand, is described. The experimental run lasted/or 113 hours and consisted of two injection-drawdown cycles. During the run, 1454 kg of steam and 75.3 kg of carbon dioxide were injected (equivalent to 2.1 mole % CO2 in the mixture). This resulted in the recovery of 12.5% o/the initial bitumen in the oil sand.

The experimental data obtained was compared to the results of a numerical modelling study. Good agreement was obtained. Differences between the numerical simulation and experiment are discussed.

Results from steam-only predictions are used to discuss the merits of the steam-CO2 injection process relative to steam injection alone.

Introduction

Many experiments have been carried out at Alberta Research Council (ARC) in the last five years to test the effectiveness of additives on recovery of Athabasca bitumen. An adequate numerical simulation capability is useful in analyzing these runs. This capability also serves as a design aid for further experiments as well as serving a need for idealized studies.

The experiment that was simulated for this report (hereafter denoted "Run 15006") was the first run in the 150 cm pressure vessel in which stearn and CO2 were simultaneously injected into an oil sand pack of this physical size. The primary objective was to study recovery benefits from addition of CO2 to the injection stream. Other objectives were to study the rate of advance of temperature profiles in the bed during the run and to provide data to test a numerical simulation of the steam-C02 process. A three component model developed at ARC was used to simulate the above process. The model is a fully implicit thermal numerical simulator with the capability of handling a single additive. Objectives of the numerical simulation were principally to test the numerical model, and hence all its property data for a CO2/water/bitumen system.

Description of Experiment

The 150cm diameter simulator system (Fig. 1) consists of a large pressure vessel (150 cm ID by 270 cm high) designed to allow steam and gas to be injected simultaneously into the test bed under controlled flow rates. Oil sand is packed into this vessel and maintained at field overburden conditions by introducing a nitrogen blanket at the top of the cell. Feed streams were injected to the centre of the test bed via an injection well.

The three main systems are schematically illustrated in Figure 1. These are the injection system, test cell and production system. The steam portion of the injection system consists of a high pressure steam generator followed by a superheater. Flow turbines measure flow rate after the superheater and are marked "F" in Figure 1. Thermocouples and pressure, gauges are also in place, marked "T" and "P" in Figure 1. The steam generator operates at a constant flow rate. Pressure to the system is regulated by a control valve upstream of the superheater.

Retroperitoneal fibrosis with normal intravenous urogram

A 58 year old male presented with a two week history of low back pain and malaise. The intravenous urogram (IVU) at presentation was normal but within three months he had developed renal failure with bilateral ureteric obstruction on repeat IVU. Primary retroperitoneal fibrosis was confirmed at operation. This case demonstrates that retroperitoneal fibrosis may progress rapidly to renal failure within a few months of the first symptoms. In addition, the IVU may be normal in the early stages of the illness.

Endemic goitre, nutrition, and landholding in Bangladesh

Endemic goitre in adult females, cretinism, and anthropometry in children were examined in a goitrous area of Bangladesh. An area survey showed total goitre varying from 62.0 to 93.0%, visible goitre from 9.0 to 54.8% between areas. A village study examining thyroid size in 538 adult females and anthropometry in 116 children showed goitre prevalences varying significantly (p less than 0.001) but unpredictably with household landholding size; underweight and wasting varied inversely and significantly (p less than 0.01 and 0.05 respectively) with the same socioeconomic indicator. By household, there was no relationship between anthropometry in children and thyroid enlargement in the mother. Hormone analyses showed depressed serum T4, but no raised TSH. Only one deaf-mute cretin was found in the area. It is speculated that variation in goitre prevalence in this moderately severe endemic primarily reflects qualitative and quantitative changes in diet, as a function of the socioeconomic status of the household.

Bandwidth of holographic optical elements

The diffraction efficiency, bandpass, and spurious beam rejection are studied for the holographic cascade lens that consists of a diffraction grating in contact with an off-axis zone plate. An analysis is presented for the bandpass of the volume diffraction grating, including the effects of grain polarizability.