Consideration of factors associated with inequalities in interventions that support health-care professionals' interaction with patients to reduce inappropriate antimicrobial use: a systematic review

BACKGROUND

Tackling the public health challenge of antimicrobial resistance (AMR) requires promotion of appropriate antimicrobial use by health-care professionals. The objective of this review was to identify interventions that facilitate appropriate antimicrobial behaviours when health-care professionals interact with patients and any considerations for factors associated with health inequalities.

METHODS

For this systematic review, we searched electronic databases (MEDLINE, EMBASE, Web of Science and Google Scholar) from Jan 31, 2023, to Feb 8, 2023. We included search terms such as antimicrobial use/prescribing, health-care professionals, and AMR programmes. We included any relevant primary study published from year 2010 and in English. We conducted forward and backward citation searching from included studies on March 27, 2023. We extracted information on the interventions following the Template for Intervention Description and Replication (TIDieR) guideline and examined reports on how the interventions might impact on inequalities. We performed quality assessment using the Mixed Methods Appraisal Tool (MMAT). We conducted descriptive synthesis. The protocol is registered with PROSPERO (CRD42023395642).

FINDINGS

After screening 4979 records, we included 59 studies. Most studies were randomised trials (n=25) and qualitative/mixed methods studies (n=16). Included studies covered 16 countries, particularly the UK (n=16) and the USA (n=13). Most studies (n=34) fulfilled at least 80% of the relevant quality criteria, but 12 studies fulfilled less than 50%. Many interventions were established strategies (eg, TARGET: Treat Antibiotics Responsibly, Guidance, Education and Tools). Patient interaction elements of the interventions often involved using education materials (eg, digital/paper leaflets, and videos) and point-of-care testing. While many studies (n=49) included participants from disadvantaged groups, only three examined how outcomes differ between groups. In those studies, antimicrobial prescription was not associated with age, sex, and level of learning disability. Some other studies reported issues with language barriers and potential digital exclusion, especially for older people.

INTERPRETATION

We might have missed some relevant studies due to publication year and language restrictions. Notwithstanding, this review showed that the potential impact of factors associated with health inequalities are not routinely considered during the implementation and evaluation of interventions to improve health-care professionals' interaction with patients. Future work should routinely consider this to help mitigate potential inequalities.

FUNDING

UK Health Security Agency.

Habit training versus habit training with direct visual biofeedback in adults with chronic constipation: A randomized controlled trial

AIM

The aim was to determine whether specialist-led habit training using Habit Training with Biofeedback (HTBF) is more effective than specialist-led habit training alone (HT) for chronic constipation and whether outcomes of interventions are improved by stratification to HTBF or HT based on diagnosis (functional defaecation disorder vs. no functional defaecation disorder) by radio-physiological investigations (INVEST).

METHOD

This was a parallel three-arm randomized single-blinded controlled trial, permitting two randomized comparisons: HTBF versus HT alone; INVEST- versus no-INVEST-guided intervention. The inclusion criteria were age 18-70 years; attending specialist hospitals in England; self-reported constipation for >6 months; refractory to basic treatment. The main exclusions were secondary constipation and previous experience of the trial interventions. The primary outcome was the mean change in Patient Assessment of Constipation Quality of Life score at 6 months on intention to treat. The secondary outcomes were validated disease-specific and psychological questionnaires and cost-effectiveness (based on EQ-5D-5L).

RESULTS

In all, 182 patients were randomized 3:3:2 (target 384): HT n = 68; HTBF n = 68; INVEST-guided treatment n = 46. All interventions had similar reductions (improvement) in the primary outcome at 6 months (approximately -0.8 points of a 4-point scale) with no statistically significant difference between HT and HTBF (-0.03 points; 95% CI -0.33 to 0.27; P = 0.85) or INVEST versus no-INVEST (0.22; -0.11 to 0.55; P = 0.19). Secondary outcomes showed a benefit for all interventions with no evidence of greater cost-effectiveness of HTBF or INVEST compared with HT.

CONCLUSION

The results of the study at 6 months were inconclusive. However, with the caveat of under-recruitment and further attrition at 6 months, a simple, cheaper approach to intervention may be as clinically effective and more cost-effective than more complex and invasive approaches.

Bacteriophage Therapy of Multidrug-resistant Achromobacter in an 11-Year-old Boy With Cystic Fibrosis Assessed by Metagenome Analysis

BACKGROUND

Cystic fibrosis (CF) is a genetic disease associated with lung disease characterized by chronic pulmonary infection, increasingly caused by multiple drug-resistant pathogens after repeated antibiotic exposure, limiting antibiotic treatment options. Bacteriophages can provide a pathogen-specific bactericidal treatment used with antibiotics to improve microbiologic and clinical outcomes in CF.

METHODS

Achromobacter species isolates from sputum of a chronically infected person with CF, were assessed for susceptibility to bacteriophages: 2 highly active, purified bacteriophages were administered intravenously every 8 hours, in conjunction with a 14-day piperacillin/tazobactam course for CF exacerbation. Sputum and blood were collected for metagenome analysis during treatment, with sputum analysis at 1-month follow-up. Assessments of clinical status, pulmonary status and laboratory evaluation for safety were conducted.

RESULTS

Bacteriophage administration was well-tolerated, with no associated clinical or laboratory adverse events. Metagenome analysis documented an 86% decrease in the relative proportion of Achromobacter DNA sequence reads in sputum and a 92% decrease in blood, compared with other bacterial DNA reads, comparing pretreatment and posttreatment samples. Bacteriophage DNA reads were detected in sputum after intravenous administration during treatment, and at 1-month follow-up. Reversal of antibiotic resistance to multiple antibiotics occurred in some isolates during treatment. Stabilization of lung function was documented at 1-month follow-up.

CONCLUSIONS

Bacteriophage/antibiotic treatment decreased the host pulmonary bacterial burden for Achromobacter assessed by metagenome analysis of sputum and blood, with ongoing bacteriophage replication documented in sputum at 1-month follow-up. Prospective controlled studies are needed to define the dose, route of administration and duration of bacteriophage therapy for both acute and chronic infection in CF.

Stepped-wedge randomized controlled trial of laparoscopic ventral mesh rectopexy in adults with chronic constipation

Background

The effectiveness of laparoscopic ventral mesh rectopexy (LVMR) in patients with defecatory disorders secondary to internal rectal prolapse is poorly evidenced. A UK-based multicenter randomized controlled trial was designed to determine the clinical efficacy of LVMR compared to controls at medium-term follow-up.

Methods

The randomized controlled trial was conducted from March 1, 2015 TO January 31, 2019. A stepped-wedge RCT design permitted observer-masked data comparisons between patients awaiting LVMR (controls) with those who had undergone surgery. Adult participants with radiologically confirmed IRP refractory to conservative treatment were randomized to three arms with different delays before surgery. Efficacy outcome data were collected at equally stepped time points (12, 24, 36, 48, 60, and 72 weeks). Clinical efficacy of LVMR compared to controls was defined as ≥ 1.0-point reduction in Patient Assessment of Constipation-Quality of Life and/or Symptoms (PAC-QOL and/or PAC-SYM) scores at 24 weeks. Secondary outcome measures included 14-day diary data, the Generalized Anxiety Disorder scale (GAD-7), the Patient Health Questionnaire-9 (PHQ-9), St Marks incontinence score, the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12), the chronic constipation Behavioral Response to Illness Questionnaire (CC-BRQ), and the Brief Illness Perception Questionnaire (BIPQ).

Results

Of a calculated sample size of 114, only 28 patients (100% female) were randomized from 6 institutions (due mainly to national pause on mesh-related surgery). Nine were assigned to the T0 arm, 10 to T12, and 9 to T24. There were no substantial differences in baseline characteristics between the three arms. Compared to baseline, significant reduction (improvement) in PAC-QOL and PAC-SYM scores were observed at 24 weeks post-surgery (– 1.09 [95% CI – 1.76, – 0.41], p = 0.0019, and – 0.92 [– 1.52, – 0.32], p = 0.0029, respectively) in the 19 patients available for analysis (9 were excluded for dropout [n = 2] or missing primary outcome [n = 7]). There was a clinically significant long-term reduction in PAC-QOL scores (− 1.38 [− 2.94, 0.19], p = 0.0840 at 72 weeks). Statistically significant improvements in PAC-SYM scores persisted to 72 weeks (− 1.51 [− 2.87, − 0.16], p = 0.0289). Compared to baseline, no differences were found in secondary outcomes, except for significant improvements at 24 and 48 weeks on CC-BRQ avoidance behavior (− 14.3 [95% CI − 23.3, − 5.4], and − 0.92 [− 1.52, − 0.32], respectively), CC-BRQ safety behavior (− 13.7 [95% CI − 20.5, − 7.0], and − 13.0 [− 19.8, − 6.1], respectively), and BIPQ negative perceptions (− 16.3 [95% CI − 23.5, − 9.0], and − 10.5 [− 17.9, − 3.2], respectively).

Conclusions

With the caveat of under-powering due to poor recruitment, the study presents the first randomized trial evidence of short-term benefit of LVMR for internal rectal prolapse.

Trial registration

ISRCTN Registry (ISRCTN11747152).

Supplementary Information

The online version contains supplementary material available at 10.1007/s10151-022-02633-w.

Non-drug therapies for the management of chronic constipation in adults: the CapaCiTY research programme including three RCTs

Background

Chronic constipation affects 1–2% of adults and significantly affects quality of life. Beyond the use of laxatives and other basic measures, there is uncertainty about management, including the value of specialist investigations, equipment-intensive therapies using biofeedback, transanal irrigation and surgery.

Objectives

(1) To determine whether or not standardised specialist-led habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback is more clinically effective than standardised specialist-led habit training alone, and whether or not outcomes of such specialist-led interventions are improved by stratification to habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback or habit training alone based on prior knowledge of anorectal and colonic pathophysiology using standardised radiophysiological investigations; (2) to compare the impact of transanal irrigation initiated with low-volume and high-volume systems on patient disease-specific quality of life; and (3) to determine the clinical efficacy of laparoscopic ventral mesh rectopexy compared with controls at short-term follow-up.

Design

The Chronic Constipation Treatment Pathway (CapaCiTY) research programme was a programme of national recruitment with a standardised methodological framework (i.e. eligibility, baseline phenotyping and standardised outcomes) for three randomised trials: a parallel three-group trial, permitting two randomised comparisons (CapaCiTY trial 1), a parallel two-group trial (CapaCiTY trial 2) and a stepped-wedge (individual-level) three-group trial (CapaCiTY trial 3).

Setting

Specialist hospital centres across England, with a mix of urban and rural referral bases.

Participants

The main inclusion criteria were as follows: age 18–70 years, participant self-reported problematic constipation, symptom onset > 6 months before recruitment, symptoms meeting the American College of Gastroenterology’s constipation definition and constipation that failed treatment to a minimum basic standard. The main exclusion criteria were secondary constipation and previous experience of study interventions.

Interventions

CapaCiTY trial 1: group 1 – standardised specialist-led habit training alone (n = 68); group 2 – standardised specialist-led habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback (n = 68); and group 3 – standardised radiophysiological investigations-guided treatment (n = 46) (allocation ratio 3 : 3 : 2, respectively). CapaCiTY trial 2: transanal irrigation initiated with low-volume (group 1, n = 30) or high-volume (group 2, n = 35) systems (allocation ratio 1 : 1). CapaCiTY trial 3: laparoscopic ventral mesh rectopexy performed immediately (n = 9) and after 12 weeks’ (n = 10) and after 24 weeks’ (n = 9) waiting time (allocation ratio 1 : 1 : 1, respectively).

Main outcome measures

The main outcome measures were standardised outcomes for all three trials. The primary clinical outcome was mean change in Patient Assessment of Constipation Quality of Life score at the 6-month, 3-month or 24-week follow-up. The secondary clinical outcomes were a range of validated disease-specific and psychological scoring instrument scores. For cost-effectiveness, quality-adjusted life-year estimates were determined from individual participant-level cost data and EuroQol-5 Dimensions, five-level version, data. Participant experience was investigated through interviews and qualitative analysis.

Results

A total of 275 participants were recruited. Baseline phenotyping demonstrated high levels of symptom burden and psychological morbidity. CapaCiTY trial 1: all interventions (standardised specialist-led habit training alone, standardised specialist-led habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback and standardised radiophysiological investigations-guided habit training alone or habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback) led to similar reductions in the Patient Assessment of Constipation Quality of Life score (approximately –0.8 points), with no statistically significant difference between habit training alone and habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback (–0.03 points, 95% confidence interval –0.33 to 0.27 points; p = 0.8445) or between standardised radiophysiological investigations and no standardised radiophysiological investigations (0.22 points, 95% confidence interval –0.11 to 0.55 points; p = 0.1871). Secondary outcomes reflected similar levels of benefit for all interventions. There was no evidence of greater cost-effectiveness of habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback or stratification by standardised radiophysiological investigations compared with habit training alone (with the probability that habit training alone is cost-effective at a willingness-to-pay threshold of £30,000 per quality-adjusted life-year gain; p = 0.83). Participants reported mixed experiences and similar satisfaction in all groups in the qualitative interviews. CapaCiTY trial 2: at 3 months, there was a modest reduction in the Patient Assessment of Constipation Quality of Life score, from a mean of 2.4 to 2.2 points (i.e. a reduction of 0.2 points), in the low-volume transanal irrigation group compared with a larger mean reduction of 0.6 points in the high-volume transanal irrigation group (difference –0.37 points, 95% confidence interval –0.89 to 0.15 points). The majority of participants preferred high-volume transanal irrigation, with substantial crossover to high-volume transanal irrigation during follow-up. Compared with low-volume transanal irrigation, high-volume transanal irrigation had similar costs (median difference –£8, 95% confidence interval –£240 to £221) and resulted in significantly higher quality of life (0.093 quality-adjusted life-years, 95% confidence interval 0.016 to 0.175 quality-adjusted life-years). CapaCiTY trial 3: laparoscopic ventral mesh rectopexy resulted in a substantial short-term mean reduction in the Patient Assessment of Constipation Quality of Life score (–1.09 points, 95% confidence interval –1.76 to –0.41 points) and beneficial changes in all other outcomes; however, significant increases in cost (£5012, 95% confidence interval £4446 to £5322) resulted in only modest increases in quality of life (0.043 quality-adjusted life-years, 95% confidence interval –0.005 to 0.093 quality-adjusted life-years), with an incremental cost-effectiveness ratio of £115,512 per quality-adjusted life-year.

Conclusions

Excluding poor recruitment and underpowering of clinical effectiveness analyses, several themes emerge: (1) all interventions studied have beneficial effects on symptoms and disease-specific quality of life in the short term; (2) a simpler, cheaper approach to nurse-led behavioural interventions appears to be at least as clinically effective as and more cost-effective than more complex and invasive approaches (including prior investigation); (3) high-volume transanal irrigation is preferred by participants and has better clinical effectiveness than low-volume transanal irrigation systems; and (4) laparoscopic ventral mesh rectopexy in highly selected participants confers a very significant short-term reduction in symptoms, with low levels of harm but little effect on general quality of life.

Limitations

All three trials significantly under-recruited [CapaCiTY trial 1, n = 182 (target 394); CapaCiTY trial 2, n = 65 (target 300); and CapaCiTY trial 3, n = 28 (target 114)]. The numbers analysed were further limited by loss before primary outcome.

Trial registration

Current Controlled Trials ISRCTN11791740, ISRCTN11093872 and ISRCTN11747152.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 9, No. 14. See the NIHR Journals Library website for further project information.

Testing strategies for Lynch syndrome in people with endometrial cancer: systematic reviews and economic evaluation

BACKGROUND

Lynch syndrome is an inherited genetic condition that is associated with an increased risk of certain cancers. The National Institute for Health and Care Excellence has recommended that people with colorectal cancer are tested for Lynch syndrome. Routine testing for Lynch syndrome among people with endometrial cancer is not currently conducted.

OBJECTIVES

To systematically review the evidence on the test accuracy of immunohistochemistry- and microsatellite instability-based strategies to detect Lynch syndrome among people who have endometrial cancer, and the clinical effectiveness and the cost-effectiveness of testing for Lynch syndrome among people who have been diagnosed with endometrial cancer.

DATA SOURCES

Searches were conducted in the following databases, from inception to August 2019 - MEDLINE ALL, EMBASE (both via Ovid), Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials (both via Wiley Online Library), Database of Abstracts of Reviews of Effects, Health Technology Assessment Database (both via the Centre for Reviews and Dissemination), Science Citation Index, Conference Proceedings Citation Index - Science (both via Web of Science), PROSPERO international prospective register of systematic reviews (via the Centre for Reviews and Dissemination), NHS Economic Evaluation Database, Cost-Effectiveness Analysis Registry, EconPapers (Research Papers in Economics) and School of Health and Related Research Health Utilities Database. The references of included studies and relevant systematic reviews were also checked and experts on the team were consulted.

REVIEW METHODS

Eligible studies included people with endometrial cancer who were tested for Lynch syndrome using immunohistochemistry- and/or microsatellite instability-based testing [with or without mutL homologue 1 (MLH1) promoter hypermethylation testing], with Lynch syndrome diagnosis being established though germline testing of normal (non-tumour) tissue for constitutional mutations in mismatch repair. The risk of bias in studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool, the Consolidated Health Economic Reporting Standards and the Philips' checklist. Two reviewers independently conducted each stage of the review. A meta-analysis of test accuracy was not possible because of the number and heterogeneity of studies. A narrative summary of test accuracy results was provided, reporting test accuracy estimates and presenting forest plots. The economic model constituted a decision tree followed by Markov models for the impact of colorectal and endometrial surveillance, and aspirin prophylaxis with a lifetime time horizon.

RESULTS

The clinical effectiveness search identified 3308 studies; 38 studies of test accuracy were included. (No studies of clinical effectiveness of endometrial cancer surveillance met the inclusion criteria.) Four test accuracy studies compared microsatellite instability with immunohistochemistry. No clear difference in accuracy between immunohistochemistry and microsatellite instability was observed. There was some evidence that specificity of immunohistochemistry could be improved with the addition of methylation testing. There was high concordance between immunohistochemistry and microsatellite instability. The economic model indicated that all testing strategies, compared with no testing, were cost-effective at a willingness-to-pay threshold of £20,000 per quality-adjusted life-year. Immunohistochemistry with MLH1 promoter hypermethylation testing was the most cost-effective strategy, with an incremental cost-effectiveness ratio of £9420 per quality-adjusted life-year. The second most cost-effective strategy was immunohistochemistry testing alone, but incremental analysis produced an incremental cost-effectiveness ratio exceeding £130,000. Results were robust across all scenario analyses. Incremental cost-effectiveness ratios ranged from £5690 to £20,740; only removing the benefits of colorectal cancer surveillance produced an incremental cost-effectiveness ratio in excess of the £20,000 willingness-to-pay threshold. A sensitivity analysis identified the main cost drivers of the incremental cost-effectiveness ratio as percentage of relatives accepting counselling and prevalence of Lynch syndrome in the population. A probabilistic sensitivity analysis showed, at a willingness-to-pay threshold of £20,000 per quality-adjusted life-year, a 0.93 probability that immunohistochemistry with MLH1 promoter hypermethylation testing is cost-effective, compared with no testing.

LIMITATIONS

The systematic review excluded grey literature, studies written in non-English languages and studies for which the reference standard could not be established. Studies were included when Lynch syndrome was diagnosed by genetic confirmation of constitutional variants in the four mismatch repair genes (i.e. MLH1, mutS homologue 2, mutS homologue 6 and postmeiotic segregation increased 2). Variants of uncertain significance were reported as per the studies. There were limitations in the economic model around uncertainty in the model parameters and a lack of modelling of the potential harms of gynaecological surveillance and specific pathway modelling of genetic testing for somatic mismatch repair mutations.

CONCLUSION

The economic model suggests that testing women with endometrial cancer for Lynch syndrome is cost-effective, but that results should be treated with caution because of uncertain model inputs.

FUTURE WORK

Randomised controlled trials could provide evidence on the effect of earlier intervention on outcomes and the balance of benefits and harms of gynaecological cancer surveillance. Follow-up of negative cases through disease registers could be used to determine false negative cases.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42019147185.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Evidence Synthesis programme and will be published in full in Health Technology Assessment; Vol. 25, No. 42. See the NIHR Journals Library website for further project information.

A systematic review of economic evaluations for donor human milk versus standard feeding in infants

Reviews on the cost/outcome of donor human milk (DHM) for infants requiring care in the neonatal intensive care unit (NICU) setting have been undertaken. However, the cost-effectiveness evidence is unclear. Therefore, we conducted a systematic review of published full economic evaluations of DHM versus standard feeding in infants in neonatal care with the aim of undertaking a narrative synthesis of the cost-effectiveness evidence and critical appraisal of the methods used. MEDLINE, EMBASE, Web of Science, Cochrane Library, Centre for Reviews and Dissemination (CRD) and PROSPERO databases were searched. Studies were included if they were full economic evaluations (model-based or trial-based), the participants were infants in neonatal units requiring nutritional support, the intervention was DHM and the comparator was any standard feeding option. There were no restrictions on outcome measures. Two authors independently assessed eligibility, extracted data, assessed quality and cross-checked results, with disagreements resolved by consensus. Information extracted focused on study context, and economic evaluation methods and results. Of 2861 studies, seven were included. Six (86%) studies originated from high-income countries. Four (57%) of the studies were model-based. Although we could not directly compare the different studies, due to the heterogenous nature of health and economic parameters used in the studies, all DHM interventions indicated cost-effective or cost saving results. This review suggests that economic evaluation of DHM interventions is an expanding area of research. Although these interventions show promise, future economic evaluations of DHM interventions need to explicitly provide more details on long-term costs and consequences.

Next Generation Sequencing of Renal Medullary Carcinoma Diagnosed Concurrently with Sickle Cell Trait: A Case Report and Literature Review

Casestudy

We present a 33-year-old African American male with 4 months of intermittent right flank pain and gross hematuria with hypermetabolic retroperitoneal lymphadenopathy, persistent right-sided hydronephrosis, perinephric fat stranding and a 5.5-cm hypermetabolic right lower pole mass demonstrated on imaging.

Results

Core needle biopsies of the mass contained atypical glands composed of epithelioid cells with pleomorphic nuclei, prominent nucleoli, eosinophilic cytoplasm and abundant mitoses infiltrating through desmoplastic stroma.

Immunohistochemical staining demonstrated CK7 and PAX8 reactivity of the tumor cells, and negative staining for CK20, WT1, PSA, PLAP and CD10. The patient underwent a radical right nephrectomy; microscopic examination illustrated invasion of the renal sinus, perirenal fat, and lymphovascular space by the neoplastic glands and sickling erythrocytes in the vasculature. Further IHC staining revealed intact mismatch repair proteins (MLH1, PMS2, MSH2, and MSH6) and a loss in expression of INI1 (SMARCB1), leading to the concurrent diagnoses of renal medullary carcinoma and sickle cell trait (confirmed with hemoglobin fractionation). Next generation sequencing of 144 clinically significant genes detected no mutations.

Conclusion

Renal medullary carcinoma is a rare, aggressive neoplasm that accounts for less than 0.5% of all renal cell carcinomas and presents at an advanced stage. Patients are usually young males who are of African or Mediterranean descent with comorbid sickling disease. Although loss of SMARCB1/INI-1 gene expression is associated with this neoplasm, no effective therapeutic targets have yet been established. Renal medullary carcinomas are usually resistant to chemotherapy and radiotherapy, making the identification of an immunotherapy target paramount. With a median survival of four months from diagnosis, additional genetic studies of these malignancies may identify an effective treatment option for renal medullary carcinoma.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Evaluating FIDO: Developing and pilot testing the Field Instantaneous Dog Observation tool

Field assessments of the health and welfare of kenneled dogs (Canis lupus familiaris) must be both accurate and rapid. In order to facilitate such evaluations, especially by individuals with limited training in canine behavior and welfare, a non-invasive tool was developed and pilot-tested utilizing dogs housed in commercial breeding facilities. Behavioral responses to approach were organized into three categories: red, indicating a fearful response to approach, green, indicating an affiliative or neutral response to approach, and yellow, indicating an ambivalent response to approach. The inter-rater reliability (IRR) of the tool when used by both behavioral experts and novice raters was evaluated with and without the presence of the dog’s familiar caretaker. Utilizing Cohen’s kappa, the experts had almost perfect levels of agreement (kappa=0.87). The novice raters had substantial levels of agreement (kappa=0.74). Overall, the dogs assessed by the novice raters had high proportions of green responses to approach and there was no statistically significant effect of caretaker presence on the proportion of green responses to approach. The assessment tool evaluated herein appears to have a high degree of IRR whether used by experts in canine behavior or by novice raters and may be a useful screening tool to determine the need for more in-depth welfare assessments.         

Early Clinical Predictors of 5-Year Outcome After Concussive Blast Traumatic Brain Injury

Importance

The long-term clinical effects of wartime traumatic brain injuries (TBIs), most of which are mild, remain incompletely described. Current medical disability cost estimates from world conflicts continually surpass projections. Additional information regarding long-term functional trajectory is needed to reduce this extensive public health burden.

Objectives

To examine 5-year clinical outcomes leveraging existing clinical data collected at 1 year after injury in the same patients and to identify early risk factors for long-term disability.

Design, Setting, and Participants

This prospective, longitudinal study enrolled active-duty US military after concussive blast injury (n = 50) in the acute to subacute stage and combat-deployed control individuals (n = 44) in Afghanistan or after medical evacuation to Germany from November 1, 2008, through July 1, 2013. One- and 5-year clinical evaluations were completed in the United States. All concussive blast injuries met the Department of Defense definition of mild, uncomplicated TBI. In-person clinical evaluations included standardized evaluations for neurobehavior, neuropsychological performance, and mental health burden that were essentially identical to the evaluations completed at 1-year follow-up. Data were analyzed from October 1 through November 30, 2016.

Main Outcomes and Measures

Changes in the in-person standardized evaluations for neurobehavior, neuropsychological performance, and mental health burden from the 1- to 5-year follow-up. Predictive modeling was used to identify early risk factors for long-term disability.

Results

Among the 94 participants (87 men [93%] and 7 women [7%]; mean [SD] age, 34 [8] years), global disability, satisfaction with life, neurobehavioral symptom severity, psychiatric symptom severity, and sleep impairment were significantly worse in patients with concussive blast TBI compared with combat-deployed controls, whereas performance on cognitive measures was no different between groups at the 5-year evaluation. Logistic regression on the dichotomized Extended Glasgow Outcome Scale (GOS-E) at 5 years as a measure of overall disability identified brain injury diagnosis, preinjury intelligence, motor strength, verbal fluency, and neurobehavioral symptom severity at 1 year as risk factors for a poor outcome at 5 years, with an area under the curve of 0.92 indicating excellent prediction strength. Thirty-six of 50 patients with concussive blast TBI (72%) had a decline in the GOS-E from the 1- to 5-year evaluations, in contrast with only 5 of 44 combat-deployed controls (11%). Worsening of symptoms in concussive blast TBI was also observed on measures of posttraumatic stress disorder and depression. Service members with concussive blast TBI experienced evolution, not resolution, of symptoms from the 1- to 5-year outcomes.

Conclusions and Relevance

Considerable decline was observed in military service members with concussive blast TBI when comparing 1- and 5-year clinical outcomes. These results advocate for new treatment strategies to combat the long-term and extremely costly effect of these wartime injuries.

INTERCOMPARISON OF EYE LENS DOSEMETERS

An intercomparison of eye lens dosemeters has been conducted in terms of the quantity Hp(3). For the first time, besides photon radiation also beta radiation qualities were included. Three dosemeter types designed for the quantity Hp(3) and ten for Hp(0.07) took part in the intercomparison. As shown in a previous intercomparison for photon radiation only, the dosemeters designed for Hp(0.07) and calibrated in terms of Hp(3) performed well in photon radiation fields. But for beta radiation, it turned out that Hp(0.07) dosemeters over-responded up to a factor of 5 000 (with respect to the true Hp(3) dose) in the medium beta energy range (85Kr with a beta endpoint energy of 0.69 MeV), while some Hp(3) dosemeters performed quite well. For medium (57 keV) and high (662 keV) energy photon radiation, all dosemeter types showed response values well within the trumpet curve according to the current draft of ISO 14146.

[Proximal corrective osteotomy : Correction of hallux valgus deformity]

Severe symptomatic hallux valgus deformities are usually not treatable with conservative methods in the long-term. Surgical treatment currently aims for mechanical restitution of the first ray with preserved mobility of the first metatarsophalangeal (MTP 1) joint and with low risk of recurrence after surgery. Keeping these aims in mind the surgical methods consist of osteotomy at the proximal part of the first metatarsal bone with a high potential for correction of the deformity. Surgical interventions at the midshaft level of the first metatarsal are only useful if the anatomical shape of the metatarsal shows a wide shaft, which allows a large shift in the osteotomy. In all other cases of severe hallux valgus deformity two different surgical principles are currently used and recommended: 1. proximal or basal osteotomy of the first metatarsal bone in all cases with a preserved MTP 1 and tarsometatarsal (TMT-1) joint without signs of instability. 2. Arthrodesis of the TMT-1 joint in all cases of instability or degenerative changes with an intact MTP 1 joint, the so-called Lapidus arthrodesis. This article gives an overview over the most important and widely used surgical techniques for correction of severe hallux valgus deformities. Emphasis is placed on the different osteosynthesis techniques and the recommended postoperative regimens. The advantages and disadvantages of the most frequently employed osteotomy techniques are discussed based on the current literature and the authors own experience.

[Arthroscopic treatment of chondral lesions of the ankle joint. Evidence-based therapy]

Ankle sprains are the most relevant injuries of the lower extremities and can lead to damage to ligaments and osteochondral lesions. Up to 50 % of patients with a sprained ankle later develop a lesion of the cartilage in the ankle joint or an osteochondral lesion of the talus. This can lead to osteoarthritis of the injured ankle joint. Spontaneous healing is possible in all age groups in cases of a bone bruise in the subchondral bone but in isolated chondral injuries is only useful in pediatric patients. In many cases chondral and osteochondral injuries lead to increasing demarcation of the affected area and can result in progressive degeneration of the joint if not recognized in time. There also exist a certain number of osteochondral changes of the articular surface of the talus without any history of relevant trauma, which are collectively grouped under the term osteochondrosis dissecans. Perfusion disorders are discussed as one of many possible causes of these alterations. Nowadays, chondral and osteochondral defects can be treated earlier due to detection using very sensitive magnetic resonance imaging (MRI) and computed tomography (CT) techniques. The use of conservative treatment only has a chance of healing in pediatric patients. Conservative measures for adults should only be considered as adjuvant treatment to surgery.Based on a comprehensive analysis of the current literature, this article gives an overview and critical analysis of the current concepts for treatment of chondral and osteochondral injuries and lesions of the talus. With arthroscopic therapy curettage and microfracture of talar lesions are the predominant approaches or retrograde drilling of the defect is another option when the chondral coating is retained. Implantation of autologous chondral cells or homologous juvenile cartilage tissue is also possible with arthroscopic techniques. Osteochondral fractures (flake fracture) are usually performed as a mini-open procedure supported by arthroscopy. The use of the osteochondral autograft transfer system (OATS), implantation of membranes with or without autologous bone marrow transfer and possibly with growth factors or implantation of stem cells are carried out in combination with arthroscopic mini-open procedures. The results from the literature are discussed and compared with own results after arthroscopic treatment of chondral lesions of the talus.

Case report: A rare case of eosinophilic cholecystitis presenting after talc pleurodesis for recurrent pneumothorax

Eosinophilic cholecystitis (EC) is a rare inflammatory condition of the gallbladder, confirmed by a cellular infiltrate comprised of more than 90% eosinophils in the gallbladder wall on histological examination. Although the etiology of EC is largely unknown, local autoimmune reactions within the gallbladder wall to inflammatory mediators from distal sites of inflammation have been hypothesized. Talc pleurodesis (TP) is a common clinical procedure used within respiratory medicine. However, it is associated with activation of systemic acute inflammatory responses including an increase in serum interleukin-8 (IL-8), which is a potent mediator of eosinophil chemotaxis. We report a case of EC following a TP procedure for persistent, secondary pneumothorax.

The influence of using antibiotic-coated peripherally inserted central catheters on decreasing the risk of central line-associated bloodstream infections

The use of peripherally inserted central catheters (PICCs) has increased over the past few years due to their less serious insertion complications. The purpose of the present study was to determine whether patients receiving PICCs impregnated with minocycline and rifampin had a lower rate of CLABSI compared with a concurrent control group of patients receiving uncoated PICCs.

A clinical practical approach to the surveillance definition of central line-associated bloodstream infection in cancer patients with mucosal barrier injury

BACKGROUND

The Centers for Disease Control and Prevention recently introduced the concept of mucosal barrier injury (MBI) in an attempt to recognize the possibility of a gastrointestinal source for certain bloodstream infections. This could underestimate the central venous catheter (CVC) as the source of central line-associated bloodstream infection (CLABSI) in cancer. The definition of catheter-related bloodstream infection (CRBSI) by the Infectious Diseases Society of America is a more specific and stringent definition that identifies the CVC as the source of infection. In our study, we compared the 2 definitions in cancer patients.

METHODS

We retrospectively reviewed 149 CLABSI cases that occurred at our center between January 2013 and March 2014 who had 2 simultaneously positive blood cultures drawn from the CVC and peripheral site or concurrent paired tip and blood cultures.

RESULTS

Of the 149 patients with CLABSI, only 70 (47%) had definite CRBSI. CRBSI was identified more commonly in non-MBI CLABSI cases than MBI CLABSI (69% vs 18%, P < .0001).

CONCLUSIONS

The CRBSI definition may be more accurate in identifying the catheter as the source of bloodstream infection in patients with MBI. Because CRBSI continues to occur in patients with MBI, we caution against excluding all MBI patients from CLABSI surveillance.

Accuracy of paediatric echocardiographic transmission via telemedicine

We evaluated the accuracy of realtime echocardiography studies conducted via telemedicine (at 384 kbit/s) and prerecorded video studies, by comparing the results with subsequent in-person echocardiography examination performed at follow-up. Between January 2002 and December 2004, there were 769 paediatric echo studies of patients aged one day to 19 years by telemedicine. There were three cases (0.4%) in which the study could not be successfully transmitted in realtime due to ISDN line or equipment failure. These were recorded, then transmitted and reviewed within 24 h. A normal heart was demonstrated in 272 studies (35%). A non-urgent congenital heart defect (CHD) was detected in 311 studies (41%). A critical cardiac abnormality was identified in 25 studies (3% of the total). Sixty-seven studies were repeated in person at the tertiary centre. All but one of the follow-up echocardiograms confirmed our initial telemedicine diagnosis (99% sensitivity). There were 655 videorecorded studies delivered to the tertiary centre between February 2002 and November 2003. Thirty-two patients had a repeated echocardiogram performed there. There were either discrepancies or lack of diagnostic clarity in 12 studies (38%) compared with on-site echo evaluations. This suggests that echocardiography evaluation using videorecordings may be less accurate than via realtime telemedicine.

Mycobacterium arupense in Cancer Patients: An Emerging Infection or a Commensal Organism

Mycobacterium arupense is a slow-growing, nonchromogenic, acid-fast bacillus. Its clinical spectrum, epidemiology, and frequency of colonization versus true infection remain unknown. We evaluated the clinical significance of M arupense and positive cultures from cancer patients.We retrospectively reviewed records of all cancer patients treated at our institution between 2007 and 2014 to identify those who had positive cultures for M arupense. Mycobacterium arupense was identified by sequencing the 16S rRNA and hsp65 genes. A total of 53 patients had positive cultures, 100% of which were isolated from respiratory specimens. Of these, 7 patients met the American Thoracic Society/Infectious Diseases Society of America criteria for a definitive diagnosis of M arupense infection, 14 cases were considered to be probable infections, and 29 cases were considered to be possible infections. Of the included patients, 13 received therapy for M arupense infection and 40 did not.The outcomes of treated and untreated patients did not differ significantly. No relapses of M arupense infection. In addition, there were no M arupense-related deaths in either group.In cancer patients, M arupense appears to be mostly a commensal organism rather than a pathogen. Patients who did or did not receive treatment had similar outcomes. Validation of these findings in a larger prospective trial is warranted.

Role of Procalcitonin and Interleukin-6 in Predicting Cancer, and Its Progression Independent of Infection

Procalcitonin (PCT) and Interleukin-6 (IL-6) have emerged as biomarkers for different inflammatory conditions. The purpose of the study was to evaluate the role of PCT and IL-6 as biomarkers of cancer and its progression in a large cohort of patients. This cross-sectional study included residual plasma samples collected from cancer patients, and control subjects without cancer. Levels of PCT and IL-6 were determined by Kryptor compact bioanalyzer. We identified 575 febrile cancer patients, 410 non-febrile cancer patients, and 79 non-cancer individuals. The median PCT level was lower in control subjects (0.029 ng/ml) compared to cancer patients with stage I-III disease (0.127 ng/ml) (p<0.0001) and stage IV disease (0.190 ng/ml) (p<0.0001). It was also higher in febrile cancer patients (0.310 ng/ml) compared to non-febrile cancer patients (0.1 ng/ml) (p<0.0001). Median IL-6 level was significantly lower in the control group (0 pg/ml) than in non-febrile cancer patients with stages I-III (7.376 pg/ml) or stage IV (9.635 pg/ml) (p<0.0001). Our results suggest a potential role for PCT and IL-6 in predicting cancer in non-febrile patients. In addition, PCT is useful in detecting progression of cancer and predicting bacteremia or sepsis in febrile cancer patients.

User-centered design and usability testing of an innovative health-related quality of life module

OBJECTIVES

Various computerized health risk appraisals (HRAs) are available, but few of them assess health-related quality of life (HRQoL) in a goal-directed framework. This study describes the user-centered development and usability testing of an innovative HRQoL module that extends a validated HRA tool in primary care settings.

METHODS

Systematic user-centered design, usability testing, and qualitative methods were used to develop the HRQoL module in primary care practices. Twenty two patients and 5 clinicians participated in two rounds of interactive technology think-out-loud sessions (TOLs) and semi-structured interviews (SSIs) to iteratively develop a four-step, computerized process that collects information on patient goals for meaningful life activities and current level of disability and presents a personalized and prioritized list of preventive recommendations linked to online resources.

RESULTS

Analysis of TOLs and SSIs generated 5 categories and 11 sub-categories related to facilitators and barriers to usability and human-technology interaction. The categories included: Understanding the Purpose, Usability, Perceived Value, Literacy, and Participant Motivation. Some categories were inter-connected. The technology was continually and iteratively improved between sessions until saturation of positive feedback was achieved in 4 categories (addressing motivation will require more research). Usability of all screen units of the module was improved substantially. Clinician feedback emphasized the importance of the module's ability to translate the patient-centered HRQoL Report into actionable items for clinicians to facilitate shared decision-making. Complete integration of the HRQoL module into the existing HRA will require further development and testing.

CONCLUSIONS

Systematic application of user-centered design and human factors principles in technology development and testing may significantly improve the usability and clinical value of health information systems. This more sophisticated approach helped us translate complex clinical concepts, goal-setting steps, and decision-support processes into an accepted and value-added technology.

Albedo neutron dosimetry in Germany: regulations and performance

Personal neutron dosimetry has been performed in Germany using albedo dosemeters for >20 y. This paper describes the main principles, the national standards, regulations and recommendations, the quality management and the overall performance, giving some examples.

Efficacy and safety of fibrin glue and tranexamic acid to prevent postoperative blood loss in total knee arthroplasty: a randomized controlled clinical trial

BACKGROUND

Postoperative blood loss in patients after total knee arthroplasty may cause local and systemic complications and influence clinical outcome. The aim of this study was to assess whether fibrin glue or tranexamic acid reduced blood loss compared with routine hemostasis in patients undergoing total knee arthroplasty.

METHODS

A randomized, single-center, parallel, open clinical trial was performed in adult patients undergoing primary total knee arthroplasty. Patients were divided into four groups. Group 1 received fibrin glue manufactured by the Blood and Tissue Bank of Catalonia, Group 2 received Tissucol (fibrinogen and thrombin), Group 3 received intravenous tranexamic acid, and Group 4 (control) had no treatment other than routine hemostasis. The primary outcome was total blood loss collected in drains after surgery. Secondary outcomes were the calculated hidden blood loss, transfusion rate, preoperative and postoperative hemoglobin, number of blood units transfused, adverse events, and mortality.

RESULTS

One hundred and seventy-two patients were included. The mean total blood loss (and standard deviation) collected in drains was 553.9 ± 321.5 mL for Group 1, 567.8 ± 299.3 mL for Group 2, 244.1 ± 223.4 mL for Group 3, and 563.5 ± 269.7 mL for Group 4. In comparison with the control group, Group 3 had significantly lower total blood loss (p < 0.001), but it was not significantly lower in Groups 1 and 2. The overall rate of patients who had a blood transfusion was 21.1% (thirty-five of 166 patients analyzed per protocol). Two patients required transfusion in Group 3 compared with twelve patients in Group 4 (p = 0.015). No significant difference was observed between the two fibrin glue groups and the control group with regard to the need for transfusion. There was no difference between groups with regard to the percentage of adverse events.

CONCLUSIONS

Neither type of fibrin glue was more effective than routine hemostasis in reducing postoperative bleeding and transfusion requirements, and we no longer use them. However, this trial supports findings from previous studies showing that intravenous tranexamic acid can decrease postoperative blood loss.

Calcium phosphate transfection optimization for serum-free suspension culture

Aim of this study was to identify optimal conditions for suspension transfection in the absence of serum. Transfection parameters for suspension culture can be very different to ones in adherent cells. Most transfection protocols have been developed and optimizedfor adherent culture. Using green fluorescent protein (GFP) as reporter, FCS was eliminated from the transfection process by altering critical parameters and by substituting serum with albumin. Using standard phosphate and calcium concentrations for transfection in the absence of serum resulted in titers of only 1% of those observed in the presence of serum. A reduction of the calcium concentration from 250 mM to 100 mM, yielded a 25-fold increase in the expression of the recombinant protein compared to the serum-free standard conditions. Altering the phosphate concentration, 1.4 mM in the transfection buffer, did not improve the protein expression. Interestingly, reduction of DNA quantity by half to a concentration of 0.5 μg per milliliter of culture volume resulted in a two-fold increase of protein production. Addition of albumin to serum-free medium protected the cells against the toxicity of the calcium phosphate transfection particles (CaPi) yielding higher protein expression. All the experiments were executed in a shaken multi-well system, allowing high multiplicity parameter screening to speed up optimizations. The culture system is inexpensive, simple and efficient, minimizing costs for labor and consumables.

Interactions between animal cells and gas bubbles: The influence of serum and pluronic F68 on the physical properties of the bubble surface

We describe a method by which the degree of bubble saturation can be determined by measuring the velocity of single bubbles at different heights from the bubble source in pure water containing increasing concentrations of surfactants. The highest rising velocities were measured in pure water. Addition of surfactants caused a concentration-dependent and height-dependent decrease in bubble velocity; thus, bubbles are covered with surfactants as they rise, and the distance traveled until saturation is reached decreases with increased concentration of surfactant. Pluronic F68 is a potent effector of bubble saturation, 500 times more active than serum. At Pluronic F68 concentrations of 0.1% (w/v), bubbles are saturated essentially at their source. The effect of bubble saturation on the interactions between animal cells and gas bubbles was investigated by using light microscopy and a micromanipulator. In the absence of surfactants, bubbles had a killing effect on cells; hybridoma cells and Chinese hamster ovary (CHO) cells were ruptured when coming into contact with a bubble. Bubbles only partially covered by surfactants adsorbed the cells. The adsorbed cells were not damaged and they also could survive subsequent detachment. Saturated bubbles, on the other hand, did not show any interactions with cells. It is concluded that the protective effect of serum and Pluronic F68 in sparged cultivation systems is based on covering the medium-bubble interface with surfaceactive components and that cell death occurs either after contact of cells with an uncovered bubble or by adsorption of cells through partially saturated bubbles and subsequent transport of cells into the foam region. (c) 1994 John Wiley & Sons, Inc.

Extraction of plasmid DNA using reactor scale alkaline lysis and selective precipitation for scalable transient transfection

DNA extracted and purified for vaccination, gene therapy or transfection of cultured cells has to meet different criteria. We describe herein, a scalable process for the primary extraction of plasmid DNA suitable for transient expression of recombinant protein. We focus on the scale up of alkaline lysis for the extraction of plasmid DNA from Escherichia coli, and use a simple stirred tank reactor system to achieve this. By adding a series of three precipitations (including a selective precipitation step with ammonium acetate) we enrich very quickly the plasmid DNA content in the extract. The process has been thus far used to extract up to 100 mg of plasmid from 1.5 l of clarified lysate, corresponding to an E.coli bioreactor fermentation of 3 l.

Calcium-phosphate mediated DNA transfer into HEK-293 cells in suspension: control of physicochemical parameters allows transfection in stirred media. Transfection and protein expression in mammalian cells

This is the first report of transient transfection of suspended cells with purified plasmid DNA in bioreactors or spinner flasks. DNA/calcium phosphate complexes were pumped or injected directly into stirred cultures of the immortalized human embryo kidney cell line 293 (HEK-293) which had been adapted to growth in suspension. We identified culture conditions suitable for this approach and modified the protocol for the generation of precipitate complexes, based on our earlier work. In order to stabilize the 'DNA-vehicle'-complex in the culture medium, we identified pH ranges and ion-concentrations which prevent dissolution or aggregation of the precipitate particles. Such conditions maintained suspended fine particles in spinners or bioreactors for up to 6 hr. During that period, cells and precipitate complexes interacted sufficiently to allow DNA transfer and subsequent expression of recombinant protein. In a simple 5 day batch process, with a starting density of 0.3 × 10(6) cells mL(-1), about 0.5 mg L(-1) of a recombinant tissue plasminogen activator variant was observed.

Photonic wire bonding: a novel concept for chip-scale interconnects

Photonic integration requires a versatile packaging technology that enables low-loss interconnects between photonic chips in three-dimensional configurations. In this paper we introduce the concept of photonic wire bonding, where polymer waveguides with three-dimensional freeform geometries are used to bridge the gap between nanophotonic circuits located on different chips. In a proof-of-principle experiment, we demonstrate the fabrication of single-mode photonic wire bonds (PWB) by direct-write two-photon lithography. First-generation prototypes allow for efficient broadband coupling with average insertion losses of only 1.6 dB in the C-band and can carry wavelength-division multiplexing signals with multi-Tbit/s data rates. Photonic wire bonding is well suited for automated mass production, and we expect the technology to enable optical multi-chip systems with enhanced performance and flexibility.

Hp(0.07) photon dosemeters for eye lens dosimetry: calibration on a rod vs. a slab phantom

In recent years, several papers dealing with eye lens dosimetry have been published as epidemiological studies are implying that the induction of cataracts occurs even at eye lens doses of less than 500 mGy. For that reason, the necessity to monitor the eye lens may become more important than it was before. However, only few dosemeters for the appropriate quantity H(p)(3) are available. Partial-body dosemeters are usually designed to measure the quantity H(p)(0.07) calibrated on a rod phantom representing a finger while a slab phantom much better represents the head. Therefore, in this work it was investigated whether dosemeters designed for the quantity H(p)(0.07) calibrated on a rod phantom can also be worn on the head (close to the eyes) and still deliver correct results (H(p)(0.07) on a head). For that purpose, different types of partial-body dosemeters from routine use were irradiated at different photon energies on both a rod and a slab phantom. It turned out that their response values are within ±5% independent of the phantom if the quantity value for the respective phantom is used. Thus, partial-body dosemeters designed for the quantity H(p)(0.07) calibrated on a rod phantom may be worn on the head and used to monitor the eye lens dose due to photon radiation via the measurement of H(p)(0.07) on the head.

Cell-cell adhesion and aggregation: Influence on the growth behavior of CHO cells

The influence of cell-cell adhesion on the growth behavior of Chinese hamster ovary (CHO) cells in suspension culture was investigated. CHO cells form aggregates under suboptimal growth conditions. Clusters are formed around decaying and dead cells. The deoxyribonucleic acid (DNA) released from these cells was found to mediate the cells was found to mediate the cell-cell adhesion. Cluster formation dramatically influenced the growth behavior of the cells. First, cells within aggregates showed a strongly reduced specific proliferation rate, and second, shear forces exerted on large aggregates caused a considerable higher specific death rate than those exerted on single cells. These factors led to a reduction of the specific growth rate up to 50%. This decrease could be avoided by addition of DNase 1 to the medium. It is shown that the separate determination of the specific proliferation and death rates is not feasible with state-of-the-art methods. To achieve a more profound and precise description of the growth pattern of animal cells, we propose an extended Monod model and describe the relevant methods.