Using biomarkers to allocate patients in a response-adaptive clinical trial

In this paper, we discuss a response adaptive randomization method, and why it should be used in clinical trials for rare diseases compared to a randomized controlled trial with equal fixed randomization. The developed method uses a patient's biomarkers to alter the allocation probability to each treatment, in order to emphasize the benefit to the trial population. The method starts with an initial burn-in period of a small number of patients, who with equal probability, are allocated to each treatment. We then use a regression method to predict the best outcome of the next patient, using their biomarkers and the information from the previous patients. This estimated best treatment is assigned to the next patient with high probability. A completed clinical trial for the effect of catumaxomab on the survival of cancer patients is used as an example to demonstrate the use of the method and the differences to a controlled trial with equal allocation. Different regression procedures are investigated and compared to a randomized controlled trial, using efficacy and ethical measures.

How accurately is hospital acquired pneumonia documented for the correct assignment of a hospital acquired complication (HAC)?

BACKGROUND

In 2016, the Australian Commission on Safety and Quality in Healthcare (ACSQHC) released a list of 16 categories of potentially preventable, high impact hospital-acquired complications (HAC) identified by using administrative coded data (ACD). An important category are hospital-acquired infections (HAI). Within this category, hospital-acquired pneumonia (HAP) is among the most frequent complications documented. There are no published studies concerning the current ACSQHC approach to HAI surveillance using ACD and no pneumonia-specific ACD studies reported from Australia. Published work indicates that ACD detection of HAP has low a sensitivity and positive predictive value (PPV). The current study was designed to examine whether coders correctly reflected the documentation of HAP that was present in the medical record and also evaluated the medical documentation that was present.

METHODS

One hundred patients with ACD encoded HAP were selected for review, drawn from admissions to 2 Hunter New England Health hospitals during 2017. Patient records and the eMR were reviewed by two medical officers to assess medical and radiological documentation of pneumonia. The district coding manager reviewed the accuracy of coding of a subset of 23 cases where medical review had not located documented evidence of HAP.

RESULTS

Of the 100 reviewed cases, the median patient age was 75 years (range 0-95 years) with 3% under 16 years of age. Twenty one were intensive care-associated of which 13 were associated with ventilation. In 23 cases the documentation was disputed and a secondary review took place - the coding manager confirmed coding changes in 14 of these 23 cases.

CONCLUSIONS

This study found that administrative coded data of HAP, utilizing the ACSQHC method reliably reflected the available documentation with a PPV of 86% (95% binomial exact confidence interval 77-92%), much higher than documented by previous ACD studies. The actual documentation of pneumonia by medical staff frequently used the non-specific term 'lower respiratory infection (LRTI)' which we recommend to be avoided. Radiological confirmation was absent in one third of cases. We recommend the adoption of a medical note template checklist for HAP to prompt clinicians with the accepted diagnostic criteria. We also recommend documenting a reason as to why any antibiotic has been commenced in a hospitalized patient in accord with the ACSQHC Antimicrobial Stewardship Clinical Care Standard.

Electronic Stability of Carbon Nanotube Transistors Under Long-Term Bias Stress

Thousands of reports have demonstrated the exceptional performance of sensors based on carbon nanotube (CNT) transistors, with promises of transformative impact. Yet, the effect of long-term bias stress on individual CNTs, critical for most sensing applications, has remained uncertain. Here, we report bias ranges under which CNT transistors can operate continuously for months or more without degradation. Using a custom characterization system, the impacts of defect formation and charge traps on the stability of CNT-based sensors under extended bias are determined. In addition to breakdown, which is well-known, we identify three additional operational modes: full stability, slow decay, and fast decay. We identify a current drift behavior that reduces dynamic range by over four orders of magnitude but is avoidable with appropriate sensing modalities. Identification of these stable operation modes and limits for nanotube-based sensors addresses concerns surrounding their development for a myriad of sensing applications.

Development of an In Vitro Model of Inflammatory Cytokine Influences on Intervertebral Disk Cells in 3D Cell Culture Using Activated Macrophage-Like THP-1 Cells

We developed a new model for evaluation of the influence of proinflammatory cytokines on intervertebral disc cells in a 3D culture based on co-culturing of these cells with activated macrophage-like THP-1 cells. The levels of TNFα, IL-1β, IL-6, IL-8, IL-10, and IL-12p70 production were assessed by flow cytofluorometry using microspheres. Considerable differences in the level of spontaneous cytokine secretion by normal and degenerated intervertebral disc cells were revealed. A significant increase in the level of IL-1β and IL-8 was observed during co-culturing, which confirms consistency of the developed model.

Risk of persistent or recurrent cervical neoplasia in patients with 'pure' adenocarcinoma-in-situ (AIS) or mixed AIS and high-grade cervical squamous neoplasia (cervical intra-epithelial neoplasia grades 2 and 3 (CIN 2/3)): a population-based study

OBJECTIVE

To compare outcomes of patients with pure adenocarcinoma-in-situ (AIS) and mixed AIS/CIN 2/3 lesions including the incidence of AIS persistence, recurrence and progression to adenocarcinoma.

DESIGN

Retrospective cohort study.

SETTING

Statewide population in Western Australia.

POPULATION

Women diagnosed with AIS between 2001 and 2012.

METHODS

We conducted a retrospective, population-based cohort study.

MAIN OUTCOME MEASURES

De-identified linked data were utilised to ascertain the association between patient age at excisional treatment, margin status, lesion type, lesion size, and risk of persistent AIS (defined as the presence of AIS <12 months from treatment), recurrent AIS (≥12 months post-treatment), and adenocarcinoma.

RESULTS

636 patients were eligible for analysis. The mean age was 32.3 years and median follow-up interval was 2.5 years. Within the study cohort, 266 patients (41.8%) had pure AIS and 370 (58.2%) had mixed AIS/CIN 2/3. Overall, 47 patients (7.4%) had AIS persistence/recurrence and 12 (1.9%) had adenocarcinoma. Factors associated with persistence/recurrence were pure AIS (hazard ratio (HR) 2.3; 95%CI 1.28-3.94; P = 0.005), age >30 years (HR 2.1; 95%CI 1.16-3.81; P = 0.015), positive endocervical margins (HR 5.8; 95%CI 3.05-10.92; P = <0.001) and AIS lesions >8 mm (HR 2.5; 95%CI 1.00-6.20; P = 0.049). A histologically positive AIS ectocervical margin was not associated with persistence/recurrence.

CONCLUSION

In this study, pure AIS was associated with greater risk of persistence/recurrence than was mixed AIS/CIN 2/3. AIS lesions >8 mm and positive endocervical margins were significant predictors for persistent or recurrent disease.

TWEETABLE ABSTRACT

Pure cervical adenocarcinoma-in-situ (AIS) may have greater risk of recurrence than AIS co-existing with CIN 2/3.

Review of 31 cases of anterior thoracolumbar fixation with the anterior thoracolumbar locking plate system

Anterior fixation devices for the thoracolumbar spine have gained wide acceptance as viable alternatives to long-segment posterior fixation in cases of thoracolumbar spine trauma. This review was undertaken to evaluate the safety and efficacy of the Synthes anterior thoracolumbar locking plate (ATLP) system. Over a 3-year period, 31 patients with unstable traumatic fractures of the thoracolumbar spine underwent corpectomy, placement of a structural bone graft, and anterior fixation in which the Synthes ATLP system was used. Long-term follow-up data were obtained in 29 patients. Two patients were lost to follow up, one at 4 months and the other at 1 year. In the remaining patients, the average length of follow up was 20 months. In all patients radiographic evidence of solid bone fusion was demonstrated on follow-up plain x-ray films, and there were no signs or symptoms of pseudarthrosis. No patient suffered neurological deterioration as a result of surgery, and there was relatively little morbidity associated with this plating system. To date, none of the patients in this study has developed any delayed complications related to the fixation device. In one patient, who had sustained a severe flexion injury, loosening of the anterior fixation device occurred, and the patient developed progressive kyphosis, which required a posterior stabilization procedure. These results appear slightly better than those obtained in published studies in which other anterior plating systems were used, indicating that this system is safe and effective in the treatment of unstable fractures of the thoracolumbar spine.

Can UK healthcare workers remotely support medical education in the developing world?: Focus group evaluation

Objectives

To evaluate the feasibility of providing regular, live, text-based teaching to medical students and junior doctors in Somaliland using a dedicated case-based medical education website (www.MedicineAfrica.com).

Design

Review of MedicineAfrica database for details of teaching sessions held in Somaliland from December 2008-October 2010 and evaluation of user experiences through focus groups.

Setting

King's College Hospital, London, UK and Ahmoud University, Borama, Somaliland.

Participants

Final year medical students, newly graduated interns and second year interns at Ahmoud University, Borama, Somaliland.

Main outcome measures

Qualitative and quantitative user rating of online case-based tutorials in the context of pre-existing educational opportunities available to them.

Results

Regular online teaching sessions are received enthusiastically by students and junior doctors and are reported to improve their clinical practice.

Conclusions

Despite technological limitations in Somaliland, a live text-based teaching service can be delivered effectively and streamlined with local curricula. This represents an alternative to traditional static teaching methodologies currently used in international medical education.

A rapid access diagnostic clinic for prostate cancer: the experience after one year

BACKGROUND

The National Cancer Control Programme is developing standards for access to diagnostics and treatment of prostate cancer. The Rapid Access Prostate Cancer (RAPC) clinic in St. James's Hospital commenced in May 2009 allowing general practitioners (GPs) more streamlined access for patients.

AIMS

To demonstrate that RAPC clinics allow GPs direct access to a designated cancer centre improving the prostate cancer referral process. This ultimately should reduce referral delays.

METHODS

A prospective analysis of all patients referred to the RAPC clinic in St. James's Hospital over a 12-month period beginning from May 2009.

RESULTS

Over the 12-month period 215 patients were referred to the RAPC clinic. The median age was 63 years (range 45-78). The median waiting time between referral and review at the RAPC clinic was 13 days (range 1-37). The median PSA was 7.7 μg/L (range 2.6-150). In total 199 TRUS biopsies were performed, of which 46% were positive for prostate cancer. We found that 70% of all patients had a PSA ≤ 10 μg/L and of these 32% were positive for prostate cancer. For the remaining 30% of patients who had a PSA > 10 μg/L, we found 63% were positive for prostate cancer. Regarding patients diagnosed with prostate cancer 56% have been referred for radiotherapy, 13% for surgery, 13% for hormonal treatment, 10% for active surveillance and 8% watchful waiting.

CONCLUSION

RAPC clinics allow GPs easier access to specialist urological opinion for patients suspected of having prostate cancer.

Proliferation-associated Brn-3b transcription factor can activate cyclin D1 expression in neuroblastoma and breast cancer cells

Brn-3b transcription factor enhances proliferation of neuroblastoma (NB) and breast cancer cell lines in vitro and increases the rate and size of in vivo tumour growth, whereas reducing Brn-3b slows growth, both in vitro and in vivo. Brn-3b is elevated in >65% of breast cancer biopsies, and here we demonstrate that Brn-3b is also elevated in NB tumours. We show a significant correlation between Brn-3b and cyclin D1 (CD1) in breast cancers and NB tumours and cell lines. Brn-3b directly transactivates the CD1 promoter in co-transfection experiments, whereas electrophoretic mobility shift assay and chromatin immunoprecipitation assays demonstrate that Brn-3b protein binds to an octamer sequence located in the proximal CD1 promoter. Site-directed mutagenesis of this sequence resulted in loss of transactivation of the CD1 promoter by Brn-3b. Thus, Brn-3b may act to alter growth properties of breast cancer and NB cells by enhancing CD1 expression in these cells.

PTSD symptoms, substance use, and vipassana meditation among incarcerated individuals

The present study evaluated whether Posttraumatic Stress Disorder (PTSD) symptom severity was associated with participation and treatment outcomes comparing a Vipassana meditation course to treatment as usual in an incarcerated sample. This study utilizes secondary data. The original study demonstrated that Vipassana meditation is associated with reductions in substance use. The present study found that PTSD symptom severity did not differ significantly between those who did and did not volunteer to take the course. Participation in the Vipassana course was associated with significantly greater reductions in substance use than treatment as usual, regardless of PTSD symptom severity levels. These results suggest that Vipassana meditation is worthy of further study for those with comorbid PTSD and substance use problems.

The recombinant rat glucagon-like peptide-1 receptor, expressed in an alpha-cell line, is coupled to adenylyl cyclase activation and intracellular calcium release

The glucagon-like peptide-1 (GLP-1) receptor is expressed on alpha-cells, though its functional significance is unknown. The endogenous beta-cell GLP-1 receptor is coupled to adenylyl cyclase, cell depolarization, activation of voltage-dependent Ca2+ channels (VDCC) and extracellular Ca2+ influx (Lu et al., 1993 b). In contrast, the signaling pathways of the GLP-1 receptor in alpha-cells are poorly understood. To determine the signaling mechanisms of the alpha-cell GLP-1 receptor, we established a stable pancreatic islet alpha-cell line expressing the recombinant rat GLP-1 receptor (INR1-SF2), using INRl-G9 cells. These INRl-G9 cells do not express endogenous GLP-1 receptor. In INR1-SF2 cells, GLP-1 bound to the recombinant receptor (Kd = 0.9 nM) and increased cAMP (ED50 = 0.6 nM). GLP-1 increased the free cytosolic Ca2+ ([Ca2+]i) (ED50 = 50 nM) by release from intracellular stores, but did not affect INR1-SF2 cell phosphoinositol turnover. Despite expressing VDCC, the INR1-SF2 cells were not depolarized by GLP-1, even in the presence of glucose. This contrasts with the depolarizing action of GLP-1 in beta-cells in the presence of glucose (Lu et al., 1993 b). This study establishes that a single GLP-1 receptor species can mediate the effects of GLP-1 through multiple signaling pathways, including the adenylyl cyclase system and intracellular Ca2+ release, in an alpha-cell type. Furthermore, since GLP-1 is unable to cause cellular depolarization or activate VDCC in INR1-SF2 cells, these data suggest that glucose-induced membrane depolarization may be crucial for GLP-1 to further activate VDCC and potentiate glucose-stimulated insulin release in beta-cells. Finally this study describes a cell line that can be used as a model system for evaluation of GLP-1 signaling in alpha-cells.

Inhibition of bacterial IF2 binding to fMet-tRNA((fMet)) by aminoglycosides

Screening for inhibitors of bacterial protein synthesis Initiation Factor 2 (IF2) binding to N-formyl-Methionyl-transfer RNA (fMet-tRNA((fMet))) identified a series of aminoglycosides, that included amikacin and kanamycin A1, as inhibitors of this interaction. Subsequent testing revealed that aminoglycosides displayed a wide range of inhibitory activity. However, the failure of these compounds to completely inhibit binding of IF2 to fMet-tRNA((fMet)), the known ability of aminoglycosides to bind RNA, and the ability of the aminoglycosides to displace PicoGreen bound to fMet-tRNA((fMet)) suggest these compounds act by binding fMet-tRNA((fMet)). This hypothesis is further supported by isothermal denaturation experiments that failed to show any interaction between the IF2 protein and the aminoglycosides.

Dehydroepiandrosterone sulfate and beta-cell function: enhanced glucose-induced insulin secretion and altered gene expression in rodent pancreatic beta-cells

Administration of dehydroepiandrosterone (DHEA), or its sulfated form (DHEAS), controls hyperglycemia in diabetic rodents without directly altering insulin sensitivity. We show that DHEAS enhanced glucose-stimulated insulin secretion when administered in vivo to rats or in vitro to beta-cell lines, without changing cellular insulin content. Insulin secretion increased from 3 days of steroid exposure in vitro, suggesting that DHEAS did not directly activate the secretory processes. DHEAS selectively increased the beta-cell mRNA expression of acyl CoA synthetase-2 and peroxisomal acyl CoA oxidase in a time-dependent manner. Although DHEAS is a peroxisomal proliferator, it did not alter the mRNA expression of peroxisomal proliferator-activated receptor (PPAR) alpha or beta, or enhance the activity of transfected PPAR alpha, beta, or gamma in vitro. Thus, DHEAS directly affected the beta-cell to enhance glucose-stimulated insulin secretion and increased the mRNA expression of specific beta-cell mitochondrial and peroxisomal lipid metabolic enzymes. This effect of DHEAS on insulin secretion may contribute to the amelioration of hyperglycemia seen in various rodent models of diabetes.