The Effect of Body Mass Index on Tumor Treating Fields (TTFields) Intensity Distribution in the Lungs

PURPOSE/OBJECTIVE(S)

Tumor Treating Fields (TTFields) therapy is a locoregional, noninvasive antimitotic cancer treatment modality. TTFields are electric fields that disrupt processes critical for cancer cell viability and tumor progression. They are generated by a portable medical device and delivered noninvasively to the tumor via two pairs of orthogonally placed transducer arrays. TTFields therapy is currently FDA-approved for recurrent and newly diagnosed glioblastoma and pleural mesothelioma, with ongoing studies in other solid tumor types including non-small cell lung cancer (NSCLC). In the phase 3 LUNAR study (NCT02973789), TTFields therapy demonstrated an improvement in overall survival when added to NSCLC standard of care. TTFields effectiveness depends upon several factors, including field intensity; thus, it is relevant to assess the impact of body mass index (BMI) on the distribution of TTFields in the lungs. This study utilized simulation-based approaches to assess the impact of BMI on electric field intensity distribution in the lungs.

MATERIALS/METHODS

Three computerized female phantom models (with BMIs of 22, 26 and 30), were used to simulate electric field intensity. Two different arrays sizes (small [13 disks] and large [20 disks]) were applied to the thoracic region of the models. An electric field intensity distribution map for each model was generated, and electric field intensity values across the entirety of the lungs were analyzed.

RESULTS

Electric field intensities were above 1 V/cm (amplitude), which is typically considered a sufficient level of TTFields dose to achieve a therapeutic effect, in all lobes in the lungs for all BMI models when large arrays were used. Therapeutic intensities were achieved in all lobes with the small arrays in all but one model (BMI 30), where intensities fell slightly below 1 V/cm in the right middle lobe.

CONCLUSION

Results from this simulation-based study demonstrate that delivery of TTFields at therapeutic intensities is feasible even in patients with a high BMI, provided the appropriately sized array is used. These findings support ongoing clinical studies of TTFields therapy in lung cancer, including the recently completed LUNAR study in advanced NSCLC, and could facilitate optimization of therapeutic TTFields delivery to individual patients, based on their BMI.

Patient-Specific Segmentation-Based Treatment Planning vs. NovoTAL for TTFields Therapy in Glioblastoma

PURPOSE/OBJECTIVE(S)

Patients treated with Tumor Treating Fields (TTFields) therapy for glioblastoma (GBM) have array layouts planned by NovoTAL. NovoTAL requires morphometric inputs and maximizes field intensity at the tumor. Patient-specific segmentation-based treatment planning (SBTP) software uses segmentation-based plans to maximize power density at defined regions of interest (ROIs). This technical analysis compared expected local minimum power density (LMiPD; mW/cm3) and local minimum field intensity (LMiFI; V/cm) delivered to ROIs with array layouts planned with SBTP vs NovoTAL. We hypothesized that SBTP has the potential to increase LMiPD and LMiFI to ROIs vs NovoTal.

MATERIALS/METHODS

37 patients from 5 sites who received TTFields therapy for GBM using NovoTAL were included. Treatment plans using the prescribed/treated NovoTAL layouts were created with SBTP. De novo SBTP layouts were also created. Three ROIs representing the original treated GBM (CTV), high risk margin around the GBM (CTV-2), and recurrent GBM (CTV-R) were created. Plans were optimized to CTV. SBTP vs NovoTAL LMiPD and LMiFI volumetrics to ROIs were evaluated. LMiPD and LMiFI were normalized with the delivered current from the treated NovoTAL layout. Layout rankings based on LMiPD and LMiFI, average LMiPD and LMiFI, D95, D5, DVHs, and voxel-by-voxel LMiPD and LMiFI for SBTP derived from NovoTAL layouts were compared to de novo SBTP layouts (paired t-tests).

RESULTS

Average LMiPD (1.551 vs 1.194) and LMiFI (1.115 vs 0.978) to CTV were significantly higher with SBTP vs NovoTAL (P < 0.0001 for each). Average LMiPD (1.445 vs 1.164) and LMiFI (1.197 vs 1.077) to CTV-2 were also higher (P < 0.0001 for each). There was a positive trend to higher average LMiPD (1.203 vs 1.157; P = 0.212) and LMiFI (1.103 vs 1.090; P = 0.311) to CTV-R. Top ranked overall layouts by LMiPD to CTV were SBTP layouts (97%; n = 36). Percent ratio ([SBTP-NovoTAL]/NovoTAL*100) D95 for LMiPD was 34% (to CTV), 24% (to CTV-2), and 5% (to CTV-R) and for LMiFI was 16%, 12%, and 2% respectively. Percent ratio D5 for LMiPD was 31%, 24%, and 3% and for LMiFI was 14%, 9%, and 0%, respectively. For a given percent CTV volume, minimum LMiPD and LMiFI were higher with SBTP (95%, n = 35; DVH curves shifted to right). SBTP yielded higher LMiPD and LMiFI to the majority of voxels within the CTV (95%, n = 35). With SBTP, LMiPD to CTV was significantly higher than to CTV-R (P < 0.001).

CONCLUSION

Overall, these data demonstrate that SBTP compared to NovoTAL yielded higher expected average LMiPD and LMiFI, D95, D5, and percent voxel LMiPD and LMiFI to defined ROIs. Higher LMiPD and LMiFI delivered to CTV vs CTV-R with SBTP suggests a benefit to re-planning if the GBM recurs. Given previous reports showing that higher LMiPD and LMiFI are positively correlated with improved overall and progression free survival, patient-specific SBTP may lead to improved clinical outcomes for GBM patients vs NovoTAL.

Development and internal validation of a diagnostic prediction model for COVID-19 at time of admission to hospital

BACKGROUND

Early coronavirus disease 2019 (COVID-19) diagnosis prior to laboratory testing results is crucial for infection control in hospitals. Models exist predicting COVID-19 diagnosis, but significant concerns exist regarding methodology and generalizability.

AIM

To generate the first COVID-19 diagnosis risk score for use at the time of hospital admission using the TRIPOD (transparent reporting of a multivariable prediction model for individual prognosis or diagnosis) checklist.

DESIGN

A multivariable diagnostic prediction model for COVID-19 using the TRIPOD checklist applied to a large single-centre retrospective observational study of patients with suspected COVID-19.

METHODS

581 individuals were admitted with suspected COVID-19; the majority had laboratory-confirmed COVID-19 (420/581, 72.2%). Retrospective collection was performed of electronic clinical records and pathology data.

RESULTS

The final multivariable model demonstrated AUC 0.8535 (95% confidence interval 0.8121-0.8950). The final model used six clinical variables that are routinely available in most low and high-resource settings. Using a cut-off of 2, the derived risk score has a sensitivity of 78.1% and specificity of 86.8%. At COVID-19 prevalence of 10% the model has a negative predictive value (NPV) of 96.5%.

CONCLUSIONS

Our risk score is intended for diagnosis of COVID-19 in individuals admitted to hospital with suspected COVID-19. The score is the first developed for COVID-19 diagnosis using the TRIPOD checklist. It may be effective as a tool to rule out COVID-19 and function at different pandemic phases of variable COVID-19 prevalence. The simple score could be used by any healthcare worker to support hospital infection control prior to laboratory testing results.

Post-mortem confirmation of fetal brain abnormalities: challenges highlighted by the MERIDIAN cohort study

OBJECTIVES

To assess and analyse the concordance between post-mortem findings and in utero magnetic resonance imaging (iuMRI) in the MERIDIAN (MRI to enhance the diagnosis of fetal developmental brain abnormalities in utero) cohort.

DESIGN

Prospective cohort study.

SETTING

Fetal medicine units in the UK.

POPULATION

Pregnant women with a diagnosis of fetal brain abnormality identified on ultrasound at 18 weeks of gestation or later.

METHODS

All pregnancies from the MERIDIAN study that resulted in a abortion were included and the rate of uptake and success of post-mortem examinations were calculated. In the cases in which diagnostic information about the fetal brain was obtained by post-mortem, the results were compared with the diagnoses from iuMRI.

MAIN OUTCOME MEASURE

Outcome reference diagnosis from post-mortem examination.

RESULTS

A total of 155 from 823 pregnancies (19%) ended in a termination of pregnancy and 71 (46%) had post-mortem brain examinations, 62 of which were diagnostically adequate. Hence, the overall rate of successful post-mortem investigation was 40%, and for those cases there was a concordance rate of 84% between iuMRI and post-mortem examination. Detailed information is provided when the results of the post-mortem examination and the iuMRI study differed.

CONCLUSIONS

We have shown tissue-validation of radiological diagnosis is hampered by a low rate of post-mortem studies in fetuses aborted with brain abnormalities, a situation further compounded by a 12% rate of autopsy being technically unsuccessful. The agreement between iuMRI and post-mortem findings is high, but our analysis of the discrepant cases provides valuable clues for improving how we provide information for parents. TWEETABLE ABSTRACT: iuMRI should be considered a reliable indicator of fetal brain abnormalities when post-mortem is not performed.

Assessment of the reliability and validity of a novel point-of-care fibrinogen (F-Point) device against an industry standard at fibrinogen levels >2 g/L in non-haemorrhage scenarios

INTRODUCTION

A diagnostic accuracy study assessing the reliability and validity of a novel plasma fibrinogen point-of-care (F-Point) device compared with the von Clauss method of assay.

METHODS

Forty-one women presenting for elective caesarean delivery and 43 non-pregnant female patients presenting for elective gynaecological surgery were recruited to assess agreement at normal fibrinogen levels (elective gynaecological cohort) and high fibrinogen levels (elective caesarean section cohort). Validity was assessed by comparing the F-Point results with the gold standard of von Clauss fibrinogen assay performed on the ACL Top 500. Reliability (test-retest) and validity were assessed using the intraclass correlation to control for operator variance (two-way random absolute agreement method), presented as intra class correlation coefficients (ICCs) and 95% confidence interval, and Bland-Altman analysis, presented as mean bias and 95% limits of agreement and coefficient of variation (COV).

RESULTS

The results demonstrated a high test-retest reliability demonstrated in the paired F-Point measurements with an intraclass correlation coefficient (ICC) of 0.95, a bias of 0 (-00.69 to 0.69) and a COV of 9%. Similarly, there was acceptable agreement demonstrated between F-Point and von Clauss assay with an ICC of 0.91, a bias of -0.1 (-0.96 to 0.75) and a COV of 11%.

CONCLUSIONS

Our novel plasma fibrinogen point-of-care device has been shown to be reliable and valid when testing fibrinogen levels as low as 2 g/L. Future studies investigating the correlation at lower fibrinogen levels, for example during haemorrhage and in patients with coagulopathies, are required.

Plasma microRNA levels in male and female children with cystic fibrosis

A gender gap exists in cystic fibrosis (CF). Here we investigate whether plasma microRNA expression profiles differ between the sexes in CF children. MicroRNA expression was quantified in paediatric CF plasma (n = 12; six females; Age range:1-6; Median Age: 3; 9 p.Phe508del homo- or heterozygotes) using TaqMan OpenArray Human miRNA Panels. Principal component analysis indicated differences in male versus female miRNA profiles. The miRNA array analysis revealed two miRNAs which were significantly increased in the female samples (miR-885-5p; fold change (FC):5.07, adjusted p value: 0.026 and miR-193a-5p; FC:2.6, adjusted p value: 0.031), although only miR-885-5p was validated as increased in females using specific qPCR assay (p < 0.0001). Gene ontology analysis of miR-885-5p validated targets identified cell migration, motility and fibrosis as processes potentially affected, with RAC1-mediated signalling featuring significantly. There is a significant increase in miR-885-5p in plasma of females versus males with CF under six years of age.

A Preliminary Analysis of Compassion Fatigue in a Surgeon Population: Are Female Surgeons at Heightened Risk?

Compassion fatigue (CF), a state of physical/emotional distress caused by repeatedly caring for those experiencing traumatic episodes, is a prevalent issue for today's healthcare provider. We sought to characterize levels of CF within a surgeon population, particularly comparing trauma surgery with other surgical specialties. A survey containing the Professional Quality of Life Scale (ProQOL), a validated tool assessing compassion satisfaction (CS), CF, and burnout (BO) was distributed via electronic newsletter to members of the American College of Surgeons. Demographic data and Professional Quality of Life Scale scores for CS, BO, and CF were collected and compared within specialty and gender subgroups. A total of 178 surgeons completed surveys. Respondents were predominantly male, general surgeons, >55 years old. Trauma surgeons composed the second largest subgroup. Levels of CS were significantly lower in the trauma surgeon subgroup compared to other surgical specialties (trauma: 37.1 ± 5.28, other: 39.5 ± 6.30; P = 0.044). Female surgeons from all specialties exhibited significantly higher levels of BO (female: 26.7 ± 6.10, male: 24.6 ± 6.79; P = 0.035) and CF (female: 24.2 ± 6.29, male: 21.9 ± 6.11; P = 0.021) compared with male surgeons. Subanalyses comparing female trauma surgeons to female surgeons in other specialties found female trauma surgeons exhibited significantly lower levels of CS (trauma: 34.8 ± 4.63, other: 38.8 ± 5.99; P = 0.038) and higher levels of BO (trauma: 29.1 ± 3.14, other: 25.3 ± 6.41; P = 0.049). Trauma surgeons, particularly female trauma surgeons, may be at a heightened risk for developing a poorer overall professional quality of life compared with surgeons of other specialties. In addition, female surgeons may be at greater risk for developing CF compared with male counterparts.

Anatomical subgroup analysis of the MERIDIAN cohort: ventriculomegaly

OBJECTIVE

To assess the contribution of fetal magnetic resonance imaging (MRI) in fetuses of the MERIDIAN cohort diagnosed with ventriculomegaly (VM) as the only abnormal intracranial finding on antenatal ultrasound.

METHODS

This was a subgroup analysis of the MERIDIAN study of fetuses with only VM diagnosed on ultrasound in women who had a subsequent MRI examination within 2 weeks and for whom outcome reference data were available. The diagnostic accuracy of ultrasound and MRI was reported in relation to the severity of VM. The difference in measurements of trigone size on the two imaging methods and the clinical impact of adding MRI to the diagnostic pathway were also studied.

RESULTS

In 306 fetuses with VM, ultrasound failed to detect 31 additional brain abnormalities, having an overall diagnostic accuracy of 89.9% for ultrasound, whilst MRI correctly detected 27 of the additional brain abnormalities, having a diagnostic accuracy of 98.7% (P < 0.0001). There were other brain abnormalities in 14/244 fetuses with mild VM on ultrasound (diagnostic accuracy, 94.3%) and MRI correctly diagnosed 12 of these (diagnostic accuracy, 99.2%; P = 0.0005). There was a close agreement between the size of trigones measured on ultrasound and on MRI, with categorical differences in only 16% of cases, showing that MRI did not systematically overestimate or underestimate trigone size. Complete prognostic data were available in 295/306 fetuses and the prognosis category changed after MRI in 69/295 (23.4%) cases. The overall effect of MRI on clinical management was considered to be 'significant', 'major' or 'decisive' in 76/295 (25.8%) cases.

CONCLUSION

Our data suggest that a woman carrying a fetus with VM as the only intracranial finding on ultrasound should be offered an adjuvant investigation by MRI for further evaluation. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Anatomical subgroup analysis of the MERIDIAN cohort: posterior fossa abnormalities

OBJECTIVE

To assess the diagnostic and clinical contribution of fetal magnetic resonance imaging (MRI) in fetuses of the MERIDIAN cohort diagnosed with abnormalities of the posterior fossa as the only intracranial abnormality recognized on antenatal ultrasound.

METHODS

This was a subgroup analysis of the MERIDIAN study of fetuses with abnormalities of the posterior fossa (with or without ventriculomegaly) diagnosed on antenatal ultrasound in women who had MRI within 2 weeks of ultrasound and for whom outcome reference data were available. The diagnostic accuracy of ultrasound and MRI is reported, as well as indicators of diagnostic confidence and effects on prognosis and clinical management. Appropriate diagnostic confidence was assessed by the score-based weighted average method, which combines diagnostic accuracy with diagnostic confidence data.

RESULTS

Abnormalities confined to the posterior fossa according to ultrasound were found in 81 fetuses (67 with parenchymal and 14 with cerebrospinal fluid-containing lesions). The overall diagnostic accuracy for detecting an isolated posterior fossa abnormality was 65.4% for ultrasound and 87.7% for MRI (difference, 22.3% (95% CI, 14.0-30.5%); P < 0.0001). There was an improvement in 'appropriate' diagnostic confidence, as assessed by the score-based weighted average method (P < 0.0001), and a three-fold reduction in 'high confidence but incorrect diagnosis' was achieved using MRI. Prognostic information given to the women changed after MRI in 44% of cases, and the overall effect of MRI on clinical management was considered to be 'significant', 'major' or 'decisive' in 35% of cases.

CONCLUSIONS

Our data suggest that any woman whose fetus has a posterior fossa abnormality as the only intracranial finding on ultrasound should have MRI for further evaluation. This is on the basis of improved diagnostic accuracy and confidence, which impacts substantially on the prognostic information given to women as well as their clinical management. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Anatomical subgroup analysis of the MERIDIAN cohort: failed commissuration

OBJECTIVE

To assess the contribution of fetal magnetic resonance imaging (MRI) in fetuses of the MERIDIAN cohort diagnosed with either agenesis or hypogenesis of the corpus callosum (referred to collectively as failed commissuration) on antenatal ultrasound.

METHODS

This was a subgroup analysis of the MERIDIAN study of fetuses with failed commissuration (with or without ventriculomegaly) diagnosed on ultrasound in women who had MRI assessment within 2 weeks of ultrasound and for whom outcome reference data were available. The diagnostic accuracy of ultrasound and MRI was studied, as well as indicators of diagnostic confidence and effects on prognosis/clinical management. Appropriate diagnostic confidence was assessed by the score-based weighted average method, which combines diagnostic accuracy with diagnostic confidence data.

RESULTS

In the MERIDIAN cohort, 79 fetuses were diagnosed with failed commissuration on ultrasound (55 with agenesis and 24 with hypogenesis of the corpus callosum). The diagnostic accuracy for detecting failed commissuration was 34.2% for ultrasound and 94.9% for MRI (difference, 60.7% (95% CI, 47.6-73.9%), P < 0.0001). The diagnostic accuracy for detecting hypogenesis of the corpus callosum as a discrete entity was 8.3% for ultrasound and 87.5% for MRI, and for detecting agenesis of the corpus callosum as a distinct entity was 40.0% for ultrasound and 92.7% for MRI. There was a statistically significant improvement in 'appropriate' diagnostic confidence when using MRI as assessed by the score-based weighted average method (P < 0.0001). Prognostic information given to the women changed in 36/79 (45.6%) cases after MRI and its overall effect on clinical management was 'significant', 'major' or 'decisive' in 35/79 cases (44.3%).

CONCLUSIONS

Our data suggest that any woman whose fetus has failed commissuration as the only intracranial finding detected on ultrasound should have MRI examination for further evaluation. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Coagulation indices in very preterm infants from cord blood and postnatal samples

BACKGROUND

Very premature infants are at high risk of bleeding complications; however, few data exist on ranges for standard coagulation tests.

OBJECTIVES

The primary objective of this study was to measure standard plasma coagulation tests and thrombin generation in very premature infants compared with term infants. The secondary objective was to evaluate whether an association existed between coagulation indices and intraventricular hemorrhage (IVH).

PATIENTS/METHODS

Cord and peripheral blood of neonates < 30 weeks gestational age (GA) was drawn at birth, on days 1 and 3 and fortnightly until 30 weeks corrected gestational age. Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen and coagulation factor levels were measured and tissue factor-stimulated thrombin generation was characterized. Control plasma was obtained from cord blood of term neonates.

RESULTS

One hundred and sixteen infants were recruited. Median (range) GA was 27.7 (23.7-29.9) weeks and mean (SD) birth weight was 1020 (255) g. Median (5th-95th percentile) day 1 PT, APTT and fibrinogen were 17.5 (12.7-26.6) s, 78.7 (48.7-134.3) s and 1.4 (0.72-3.8) g L(-1) , respectively. No difference in endogenous thrombin potential between preterm and term plasma was observed, where samples were available. Levels of coagulation factors II, VII, IX and X, protein C, protein S and antithrombin were reduced in preterm compared with term plasma. Day 1 APTT and PT were not associated with IVH.

CONCLUSION

In the largest cross-sectional study to date of very preterm infants, typical ranges for standard coagulation tests were determined. Despite long clotting times, thrombin generation was observed to be similar in very preterm and term infants.

Predicting Outcome in dogs with Primary Immune-Mediated Hemolytic Anemia: Results of a Multicenter Case Registry

Background

Outcome prediction in dogs with immune‐mediated hemolytic anemia (IMHA) is challenging and few prognostic indicators have been consistently identified.

Objectives

An online case registry was initiated to: prospectively survey canine IMHA presentation and management in the British Isles; evaluate 2 previously reported illness severity scores, Canine Hemolytic Anemia Score (CHAOS) and Tokyo and to identify independent prognostic markers.

Animals

Data from 276 dogs with primary IMHA across 10 referral centers were collected between 2008 and 2012.

Methods

Outcome prediction by previously reported illness‐severity scores was tested using univariate logistic regression. Independent predictors of death in hospital or by 30‐days after admission were identified using multivariable logistic regression.

Results

Purebreds represented 89.1% dogs (n = 246). Immunosuppressive medications were administered to 88.4% dogs (n = 244), 76.1% (n = 210) received antithrombotics and 74.3% (n = 205) received packed red blood cells. Seventy‐four per cent of dogs (n = 205) were discharged from hospital and 67.7% (n = 187) were alive 30‐days after admission. Two dogs were lost to follow‐up at 30‐days. In univariate analyses CHAOS was associated with death in hospital and death within 30‐days. Tokyo score was not associated with either outcome measure. A model containing SIRS‐classification, ASA classification, ALT, bilirubin, urea and creatinine predicting outcome at discharge was accurate in 82% of cases. ASA classification, bilirubin, urea and creatinine were independently associated with death in hospital or by 30‐days.

Conclusions and clinical importance

Markers of kidney function, bilirubin concentration and ASA classification are independently associated with outcome in dogs with IMHA. Validation of this score in an unrelated population is now warranted.

De-repression of myelin-regulating gene expression after status epilepticus in mice lacking the C/EBP homologous protein CHOP

The C/EBP homologous protein CHOP is normally present at low levels in cells but increases rapidly after insults such as DNA damage or endoplasmatic reticulum stress where it contributes to cellular homeostasis and apoptosis. By forming heterodimers with other transcription factors, CHOP can either act as a dominant-negative regulator of gene expression or to induce the expression of target genes. Recent work demonstrated that seizure-induced hippocampal damage is significantly worse in mice lacking CHOP and these animals go on to develop an aggravated epileptic phenotype. To identify novel CHOP-controlled target genes which potentially influence the epileptic phenotype, we performed a bioinformatics analysis of tissue microarrays from chop-deficient mice after prolonged seizures. GO analysis revealed genes associated with biological membranes were prominent among those in the chop-deficient array dataset and we identified myelin-associated genes to be particularly de-repressed. These data suggest CHOP might act as an inhibitor of myelin-associated processes in the brain and could be targeted to influence axonal regeneration or reorganisation.

CX3CL1 is up-regulated in the rat hippocampus during memory-associated synaptic plasticity

Several cytokines and chemokines are now known to play normal physiological roles in the brain where they act as key regulators of communication between neurons, glia, and microglia. In particular, cytokines and chemokines can affect cardinal cellular and molecular processes of hippocampal-dependent long-term memory consolidation including synaptic plasticity, synaptic scaling and neurogenesis. The chemokine, CX₃CL1 (fractalkine), has been shown to modulate synaptic transmission and long-term potentiation (LTP) in the CA1 pyramidal cell layer of the hippocampus. Here, we confirm widespread expression of CX₃CL1 on mature neurons in the adult rat hippocampus. We report an up-regulation in CX₃CL1 protein expression in the CA1, CA3 and dentate gyrus (DG) of the rat hippocampus 2 h after spatial learning in the water maze task. Moreover, the same temporal increase in CX₃CL1 was evident following LTP-inducing theta-burst stimulation in the DG. At physiologically relevant concentrations, CX₃CL1 inhibited LTP maintenance in the DG. This attenuation in dentate LTP was lost in the presence of GABA_A receptor/chloride channel antagonism. CX₃CL1 also had opposing actions on glutamate-mediated rise in intracellular calcium in hippocampal organotypic slice cultures in the presence and absence of GABA_A receptor/chloride channel blockade. Using primary dissociated hippocampal cultures, we established that CX₃CL1 reduces glutamate-mediated intracellular calcium rises in both neurons and glia in a dose dependent manner. In conclusion, CX₃CL1 is up-regulated in the hippocampus during a brief temporal window following spatial learning the purpose of which may be to regulate glutamate-mediated neurotransmission tone. Our data supports a possible role for this chemokine in the protective plasticity process of synaptic scaling.

Phase II trial of sorafenib (bay 43–9006) in patients with advanced anaplastic carcinoma of the thyroid (ATC)

6058

Background: Sorafenib (bay 43–9006) is an oral, small molecule tyrosine kinase inhibitor of the raf-1 protein kinase receptor, VEGFR2 and PDGFR-β with antiangiogenic properties. We are conducting an open label, phase II study of sorafenib in patients with biopsy-proven ATC to evaluate if its objective response rate is >20% and to further characterize its safety profile. Methods: Patients with progressive ATC, after cytotoxic chemotherapy with or without radiation were given sorafenib, on a fixed dosing schedule of 400 mg PO bid on 28-day cycles. Treatment was continued until disease progression, unacceptable toxicity or patient refusal. Response was evaluated every 8 weeks with body scans using RECIST criteria. We employed a 2-stage study design: if none of the first 18 patients respond the study is terminated, otherwise accrual is continued to a total of 36 patients at which point if ≤3 of the patients respond, the treatment option is rejected. Results: To date 16 patients (10 male) have enrolled in the study. Median age is 55 years; with (range 28–79). Median time on study is 2 months. Median number of cycles given is 2 (range 1–27). Two of 15 evaluable patients (13%) have partial response (PR) and 4 patients (27%) have stable disease (SD). Median duration of PR/SD is 5.1 months (range 1–24.7months). Median time to progression is 1.5 months. Median duration of survival is 3.5 months (range 1–26 months). All patients at time of reporting are deceased. Most common toxicities are lymphopenia (81%) and fatigue (62%). Grade 3 toxicities include lymphopenia (25%), rash with desquamation, weight loss, and chest pain (all 12%). Grade 4 toxicities include dyspnea (6%) and lymphopenia (6%). There has been no significant cardiovascular toxicity. One patient died on study with rapidly progressive disease. Conclusions: Sorafenib demonstrates objective tumor response in the first 15 evaluable and pretreated patients with advanced ATC. This trial is ongoing and supported in part by NIH grant nos. CA62502.

[Table: see text]

The quest for Factor VIIa exosite inhibitors

Coagulation proteases are involved in a highly orchestrated proteolytic cascade which is essential for haemostasis and blood clotting. In particular, the initiator of the coagulation cascade, Factor VIIa, binds to its cofactor, tissue factor, and its substrate, Factor X, via exosite interactions to form a ternary catalytic complex named extrinsic Xase. These exosite interactions have also been shown to allosterically induce the active conformation of the catalytic site of Factor VIIa. We have developed a direct continuous fluorescence polarization-based extrinsic Xase assay, which has been used to screen in excess of 1 million structurally diverse low-molecular-mass compounds as a potential starting point for the development of anticoagulants. The primary screen hits were categorized with deconvolution assays into either active-site or exosite inhibitors. The latter category of hits displayed both competitive and uncompetitive modalities of inhibition with respect to Factor X activation. An uncompetitive mechanism of action is of particular interest as it offers a hypothetical inhibitory advantage in the context of inhibiting a proteolytic cascade such as the blood coagulation pathway.

A micro case study of the legal and administrative arrangements for river health in the Kangaroo River (NSW)

Kangaroo Valley is a drinking water supply catchment for Kangaroo Valley village, parts of the Southern Highlands and Sydney. It is also a popular recreation area both for swimming and canoeing. Land use has traditionally been dominated by dairy farming but there has been significant and continuing development of land for hobby farms and rural residential subdivision. Dairy industry restructuring has affected the viability of some farms in the Valley and created additional pressure for subdivision. River health is a function of flows, water quality, riparian vegetation, geomorphology and aquatic habitat and riverine biota. River flows in the Kangaroo River are affected by water extraction and storage for urban water supply and extraction by commercial irrigators and riparian land holders which have a significant impact at low flows. Current water quality often does not meet ANZECC Guidelines for primary contact and recreation and the river is a poor source of raw drinking water. Key sources of contaminants are wastewater runoff from agriculture, and poorly performing on-site sewage management systems. Riparian vegetation, which is critical to the maintenance of in-stream ecosystems suffers from uncontrolled stock access and weed infestation. The management of land use and resulting diffuse pollution sources is critical to the long term health of the river. The Healthy Rivers Commission of New South Wales Independent Inquiry into the Shoalhaven River System Final Report July, 1999 found that the longer term protection of the health of the Kangaroo River is contingent upon achievement of patterns of land use that have regard to land capability and also to the capability of the river to withstand the impacts of inappropriate or poorly managed land uses. This micro case study of Kangaroo Valley examines the complex legal and administrative arrangements with particular reference to the management of diffuse pollution for river health. In the past, diffuse pollution has fallen through the gaps in legislation and its administration. Although water pollution legislation is broad enough to embrace diffuse pollution, in practice the Environment Protection Authority has focused on regulating point sources. Water legislation has traditionally been concerned with issues of water quantity rather than water quality. Legislation which allows agency intervention in relation to land degradation has grown from soil conservation roots, neglecting the flow-on effects upon water quality. Under the land use planning system existing land uses are protected from new regulatory requirements. A number of recent developments in NSW law and its administration have set the scene for addressing this past neglect. Water planning provisions in the Water Management Act 2000 have the potential to enable community based Water Management Committees to move away from a narrow focus on water quantity to the broader issues of river health, including water quality. Improved management of on-site sewage management systems is expected as a result of the Local Government (Approvals) Amendment (Sewage Management Regulation) 1998. A draft Regional Environmental Plan prepared for the Sydney Catchment Authority aims to improve the assessment of new development in terms of its impact on drinking water quality. It also moves away from an exclusive concern with controlling new development towards grappling with existing uses. Proposed amendments to the Environmental Planning and Assessment Act, 1979 as detailed in the White Paper, Plan First (2001) include the integration of imperatives derived from catchment strategies and water management plans into local land use plans.

Analysis of retted and non retted flax fibres by chemical and enzymatic means

Flax fibres (Linum usitatissimum L.) were subjected to chemical and enzymatic analysis in order to determine the compositional changes brought about by the retting process and also to determine the accessibility of the fibre polymers to enzymatic treatment. Chemical analysis involved subjecting both retted and non retted fibres to a series of sequential chemical extractions with 1% ammonium oxalate, 0.05 M KOH, 1 M KOH and 4 M KOH. Retting was shown to cause minimal weight loss from the fibres but caused significant changes to the pectic polymers present. Retted fibres were shown to have significantly lower amounts of rhamnogalacturonan as well as arabinan and xylan. In addition the average molecular mass of the pectic extracts was considerably lowered. Enzyme treatment of the 1 M KOH extracts with two different enzymes demonstrated that the non retted extract contained a relatively high molecular weight xylan not found in the retted extract. Treatment of the 1 M KOH extracts and the fibres with Endoglucanase V from Trichoderma viride demonstrated that while this enzyme solubilised cellulose as well as xylan and xyloglucan oligomers from the extract, it had limited access to these polymers on the fibre. MALDI-TOF MS analysis of the material solubilised from the extract suggested that the xylan was randomly substituted with 4-O-methyl glucuronic acid moieties. The xyloglucan was shown to be of the XXXG type and was substituted with galactose and fucose units. The enzyme treatments of the fibres demonstrated that the xylan and xyloglucan polymers in the fibres were not accessible to the enzyme but that material which was entrapped by the cellulose could be released by the hydrolysis of this cellulose.

Physician referral rates: style without much substance?

BACKGROUND

Primary care physicians (PCPs) exhibit widely varying referral rates, resulting in dramatic differences in the exposure of their patients to specialists. The relationships between this physician behavior and costs and patient outcomes are unknown.

OBJECTIVES

To examine the relationships between PCP referral rates and costs, risk of avoidable hospitalization, health status, and satisfaction.

DESIGN

Cross-sectional analyses of claims and patient survey data.

SETTING AND SUBJECTS

Independent practice association (IPA)-style managed care organization in the Rochester, NY, metropolitan area. The 1995 claims data included 457 PCPs in the IPA and 217,606 adult patients assigned to their panels. Approximately 50 consecutive patients of each of a random sample of 100 PCPs completed a patient survey in 1997-1998.

MEASURES

From the claims data, total expenditures per panel member, the risk of avoidable hospitalization, and physician referral rate were measured. Measures derived from the survey included SF-12 scores, satisfaction, and physician referral rate.

RESULTS

The relationship between physician referral rate and per-panel-member costs was not statistically significant after case-mix adjustment of the referral rate. There was no relationship between the case-mix-adjusted referral rate and risk of avoidable hospitalization. In the survey data, there was no adjusted relationship between the physicians' referral rate and their patients' self-rated physical or mental health. There was a modest direct relationship between patient satisfaction and survey-derived referral rate.

CONCLUSIONS

Despite stable, wide variations in PCP referral rates, there are few discemible relationships between this physician behavior and costs and patient outcomes. Efforts to constrain PCP referrals to specialists may be misguided.

Is travel distance a barrier to veterans' use of VA hospitals for medical surgical care?

Lengthy travel distances may explain why relatively few veterans in the United States use VA hospitals for inpatient medical/surgical care. We used two approaches to distinguish the effect of distance on VA use from other factors such as access to alternatives and veterans' characteristics. The first approach describes how disparities in travel distance to the VA are related to other characteristics of geographic areas. The second approach involved a multivariate analysis of VA use in postal zip code areas (ZCAs). We used several sources of data to estimate the number of veterans who had priority access to the VA so that use rates could be estimated. Access to hospitals was characterized by estimated travel distance to inpatient providers that typically serve each ZCA. The results demonstrate that travel distance to the VA is variable, with veterans in rural areas traveling much farther for VA care than veterans in areas of high population density. However, Medicare recipients also travel farther in areas of low population density. In some areas veterans must travel lengthy distances for VA care because VA hospitals which were built over the past few decades are not located close to areas in which veterans reside in the 1990s. The disparities in travel distance suggest inequitable access to the VA. Use of the VA decreases with increases in travel distance only up to about 15 miles, after which use is relatively insensitive to further increases in distance. The multivariate analyses indicate that those over 65 are less sensitive to distance than younger veterans, even though those over 65 are Medicare eligible and therefore have inexpensive access to alternatives. The results suggest that proximity to a VA hospital is only one of many factors determining VA use. Further research is indicated to develop an appropriate response to the needs of the small but apparently dedicated group of VA users who are traveling very long distances to obtain VA care.

Do physicians who diagnose more mental health disorders generate lower health care costs?

BACKGROUND

Underrecognition and undertreatment of mental health disorders in primary care have been associated with poor health outcomes and increased health care costs, but little is known about the impact of the diagnoses of mental health disorders on health care expenditures or outcomes. Our goal was to examine the relationships between the proportion of mental health diagnoses by primary care physicians and both health care expenditures and the risk of avoidable hospitalizations.

METHODS

We used cross-sectional analyses of claims data from an independent practice association-style (IPA) managed care organization in Rochester, New York, in 1995. The sample was made up of the 457 primary care physicians in the IPA and the 243,000 adult patients assigned to their panels. We looked at total expenditures per panel member per year generated by each primary care physician and avoidable hospitalizations among their patients.

RESULTS

After adjustment for case mix, physicians who recorded a greater proportion of mental health diagnoses generated significantly lower per panel member expenditures. For physicians in the highest quartile of recording mental health diagnoses, expenditures were 9% lower than those of physicians in the lowest quartile (95% confidence interval, 5% - 13%). There was a trend (P = .051) for patients of physicians in the highest quartile of recording mental health diagnoses to be at lower risk for an avoidable hospitalization than those of physicians in the lowest quartile.

CONCLUSIONS

Primary care physicians with higher proportions of recorded mental health diagnoses generate significantly lower panel member costs, and their patients may be less likely to be admitted for avoidable hospitalization conditions.

Why do physicians vary so widely in their referral rates?

OBJECTIVE

To determine which physician practice and psychological factors contribute to observed variation in primary care physicians' referral rates.

DESIGN

Cross-sectional questionnaire-based survey and analysis of claims database.

SETTING

A large managed care organization in the Rochester, NY, metropolitan area.

PARTICIPANTS

Internists and family physicians.

MEASUREMENTS AND MAIN RESULTS

Patient referral status (referred or not) was derived from the 1995 claims database of the managed care organization. The claims data were also used to generate a predicted risk of referral based on patient age, gender, and case mix. A physician survey completed by a sample of 182 of the physicians (66% of those eligible) included items on their practice and validated psychological scales on anxiety from uncertainty, risk aversiveness, fear of malpractice, satisfaction with practice, autonomous and controlled motivation for referrals and test ordering, and psycho-social beliefs. The relation between the risk of referral and the physician practice and psychological factors was examined using logistic regression. After adjustment for predicted risk of referral (case mix), patients were more likely to be referred if their physician was female, had more years in practice, was an internist, and used a narrower range of diagnoses (a higher Herfindahl index, also derived from the claims data). Of the psychological factors, only greater psychosocial orientation and malpractice fear was associated with greater likelihood of referral. When the physician practice factors were excluded from the analysis, risk aversion was positively associated with referral likelihood.

CONCLUSIONS

Most of the explainable variation in referral likelihood was accounted for by patient and physician practice factors like case mix, physician gender, years in practice, specialty, and the Herfindahl index. Relatively little variation was explained by any of the examined physician psychological factors.

Variations in primary care physician referral rates

OBJECTIVE

To examine primary care physician referral rate variations, including their extent and their stability over time and across diagnostic categories.

DATA SOURCES

1995/1996 claims data for adult patients from a large Independent Practitioner Association (IPA) model managed care organization (MCO) in the Rochester, NY metropolitan area. The IPA includes over 95 percent of area primary care physicians (PCPs), and the MCO includes over 50 percent area residents.

STUDY DESIGN

Referral rates (patients referred to and seen by specialists one or more times/patients seen by PCP/year) were developed for the PCPs (457 general practitioners, family physicians, and internists) in the MCO, including observed referral rates, expected referral rates based on case-mix adjustment across the whole sample, physician-specific case mix-adjusted referral rates (empirical Bayes estimates), and diagnostic category-specific case mix-adjusted referral rates.

PRINCIPAL FINDINGS

Wide variations in observed referral rates (0.01-0.69 patients referred/patients seen/year) were attenuated relatively little by case-mix adjustment and persisted in case mix-adjusted empirical Bayes estimates (0.02-0.65). The year-to-year case mix-adjusted referral rate correlation was .90. Correlations of case mix adjusted-referral rates across diagnostic categories were moderate (r=.46-.67).

CONCLUSIONS

PCP referral rates exhibit wide variations that are independent of case mix, remain stable over time, and are generalizable across diagnostic categories. Understanding this physician practice variation and its relationship to costs and outcomes is critical to evaluating the effect of current efforts to reduce PCP referral rates.

5,5-trans lactone-containing inhibitors of serine proteases: identification of a novel, acylating thrombin inhibitor

Synthesis of a variety of 5,5-trans fused lactones, related to compounds found in extracts of Lantana camara, has provided a series of novel acylating inhibitors of human thrombin, trypsin, chymotrypsin and human leucocyte elastase. The most effective thrombin inhibitor is 7 with an IC50 of 130 nM and a Kobs/[1] of 4,000 M-1 s-1.

The cost-effectiveness of magnetic resonance imaging for patients with equivocal neurological symptoms

OBJECTIVE

To determine the incremental cost-effectiveness of magnetic resonance imaging (MRI) and computed tomography (CT) in young adults presenting with equivocal neurological signs and symptoms.

DESIGNS AND METHODS

A decision analysis of long-term survival using accuracy data from a diagnostic technology assessment of MRI and CT in patients with suspected multiple sclerosis, information from the medical literature, and clinical assumptions.

MAIN RESULTS

In the baseline analysis, at 30% likelihood of an underlying neurologic disease, MRI use has an incremental cost of $101,670 for each additional quality-adjusted life-year saved compared with $20,290 for CT use. As the probability of disease increases, further MRI use becomes a cost-effective alternative costing $30,000 for each quality-adjusted life-year saved. If a negative MRI result provides reassurance, the incremental costs of immediate MRI use decreases and falls below $25,000 for each quality-adjusted life-year saved no matter the likelihood of disease.

CONCLUSIONS

For most individuals with neurological symptoms or signs, CT imaging is cost-effective while MR imaging is not. The cost-effectiveness of MRI use, however, improves as the likelihood of an underlying neurological disease increases. For selected patients who highly value diagnostic information, MRI is a reasonable and cost-effective use of medical resources when even the likelihood of disease is quite low (5%).

The prostate: decreasing cost-effectiveness of biopsy with advancing age

RATIONALE AND OBJECTIVES

The purpose of this study was to determine the cost-effectiveness of prostate biopsy at different excess prostate-specific antigen (PSA) levels as a function of age.

METHODS

Medical decision analysis was performed with standard software (SMLTREE) to determine marginal effectiveness in quality adjusted life years (QALYs) and marginal cost-effectiveness in dollars per QALY of immediate prostate biopsy at different excess PSA levels between 0 ng/mL and 20 ng/mL. The probability of clinically significant cancer with a positive biopsy (pD+Bx+) was assumed to decrease with age from 1.0 at age 50 to 0.2 at age 70. Costs were based on charges at our hospital and were considered over a 2-year time frame.

RESULTS

With our base case assumptions there was a decrease in QALYs and an increase in costs doing an immediate prostate biopsy at all excess PSA levels between 0 ng/mL and 20 ng/mL, compared with not biopsying the prostate at > or = 70 years. Doubling pD+Bx+ from 0.2 to 0.4 in the 70-and-older age group resulted in a small increase in QALYs in biopsying the prostate at excess PSA levels between 0 ng/mL and 20 ng/mL. However, the marginal cost-effectiveness of prostate biopsy was very high, ranging from $275,000/QALY biopsying at an excess PSA level of 0 ng/mL to $68,000/QALY biopsying at an excess PSA level of 20 ng/mL. This compared with it being more effective and less costly to biopsy at all excess PSA levels > or = 0 ng/mL in 50-year old patients.

CONCLUSION

Immediate prostate biopsy is not cost-effective and can be detrimental in patients > or = 70 years of age at all excess PSA levels between 0 ng/mL and 20 ng/mL.

Clinical diagnosis of multiple sclerosis. The impact of magnetic resonance imaging and ancillary testing. Rochester-Toronto Magnetic Resonance Study Group

OBJECTIVE

Magnetic resonance imaging, computed tomography, cerebrospinal fluid analysis, and evoked potential testing are used to assist in the diagnosis of patients suspected to have multiple sclerosis (MS). The impact of these tests on a clinician's diagnosis of patients suspected to have MS has not been studied systematically.

DESIGN

Clinicians made a diagnosis of each patient following clinical evaluation, again after reviewing the results of magnetic resonance imaging, and finally after reviewing information from other laboratory testing. These diagnoses were compared with the criterion standard of a masked "gold standard" panel reviewing all information after a mean follow-up of 0.9 year.

SETTING

The General Neurology Clinic and Multiple Sclerosis Clinic of the University of Rochester (NY).

PATIENTS

A consecutive sample of 62 patients diagnosed as having either possible or probable MS following clinical evaluation.

MAIN OUTCOME MEASURE

Changes in diagnostic certainty of clinicians following incremental presentation of new laboratory data and the accuracy of such diagnoses.

RESULTS

Clinicians used magnetic resonance imaging findings to diagnose definite MS or to eliminate MS from diagnostic consideration in 44% of cases. In these cases, further laboratory testing did not alter clinicians' decisions. In the remaining 56% of cases, in which magnetic resonance imaging did not lead to a diagnosis of definite MS or eliminate MS from diagnostic consideration, further laboratory testing led to such diagnoses in an additional 13% of cases. Gold standard diagnoses were in agreement with the clinician's assessments.

CONCLUSIONS

Magnetic resonance imaging aids in the evaluation of patients suspected to have MS; other subsequent studies (computed tomography, cerebrospinal fluid analysis, and evoked potential testing) have less impact. After all studies are performed, about half of such patients still have a tentative diagnosis.

The value of diagnostic information to patients with suspected multiple sclerosis. Rochester-Toronto MRI Study Group

OBJECTIVE

To determine the value of diagnostic information to patients with suspected multiple sclerosis (MS). Because treatment choices would be only minimally affected by earlier diagnosis for most patients with this clinical problem, this study assessed the "nondecisional" value of diagnosis.

DESIGN

Prospective survey of patients before and after diagnostic workup, including imaging with magnetic resonance scanning. We assessed the effect of diagnostic information on patients' sense of well-being, as well as direct measures of the utility of information (using time trade-off and willingness-to-pay techniques).

SETTING

Patients referred from primary care practices for diagnostic workup for suspected MS to neurology clinics and practices.

PATIENTS

Sixty-eight individuals, mean age 37.5 years, 53 female and 15 male. Thirty-one patients were classified as having "probable MS," and 37 were classified as having "possible MS" by the examining neurologist before workup.

MEASUREMENTS

Present and future health perception, uncertainty about diagnosis-prognosis, and level of anxiety. Willingness to pay for diagnostic information, quality of life as measured by the time trade-off technique, and psychological state of the patient before and after diagnosis.

RESULTS

Diagnostic uncertainty fell significantly as a result of the diagnostic workup. Most patients (59/62) said that they were better off having received diagnostic information. Although anxiety seemed to be reduced by testing, overall anxiety levels did not decrease as much as anticipated. Patients also became less optimistic about their future health after testing. On average, patients were willing to forgo 4.5 quality-adjusted life days to receive an earlier diagnosis and their quality of life after diagnosis improved slightly. Subgroups of patients differed in their response to diagnostic information. Those in whom no definitive diagnosis emerged tend to be more anxious rather than being reassured by the "negative" workup. Individuals with "positive" workups became less anxious and expressed favorable feelings about the diagnostic workup even though they often faced a chronic disease.

CONCLUSIONS

Overall, the diagnostic workup seemed to benefit patients and improve their sense of well-being. However, whether the effects were beneficial or not depended on the results of the diagnostic workup itself. In clinical practice the decision to undergo testing in situations in which definitive treatment is unavailable should be individualized. The potential for negative as well as positive consequences should be recognized.

The accuracy of magnetic resonance imaging in patients with suspected multiple sclerosis. The Rochester-Toronto Magnetic Resonance Imaging Study Group

OBJECTIVE

To design and implement a methodologically rigorous study to examine the accuracy of magnetic resonance imaging (MRI) in a patient population clinically suspected of having multiple sclerosis (MS).

DESIGN AND SETTING

Three hundred three patients, who were referred to two university medical centers because of the suspicion of MS, underwent MRI of the head and double-dose, contrast-enhanced computed tomography (CT) of the head. The images were read by two observers individually and without knowledge of the clinical course or final diagnosis. Patients were followed up for at least 6 months and reevaluated clinically with subsequent neurological examination. Final diagnosis (MS or not MS) was made by a panel of neurologists on the basis of the clinical findings at presentation, those that developed during follow-up, and other diagnostic tests. The results of the imaging procedures were excluded to avoid incorporation bias. Diagnostic accuracy was assessed using receiver-operating characteristic analysis and likelihood ratios.

RESULTS

Magnetic resonance imaging of the head was considerably more accurate than CT in diagnosing MS. The area under the receiver-operating characteristic curve for MS was 0.82 (compared with 0.52 for CT) indicating that MRI was a good but not definitively accurate test for MS. A "definite MS" reading on an MRI of the head was specific for MS (likelihood ratio, 24.9) and essentially established the diagnosis, especially in patients clinically designated as "probable MS" before testing. However, MRI of the head was negative for MS in 25% and equivocal in 40% of the patients considered to have MS by the diagnostic review committee (sensitivity, 58%).

CONCLUSIONS

Magnetic resonance imaging of the head provided assistance in the diagnosis of MS when lesions were visualized. Its ability far exceeded imaging with double-contrast CT. The sensitivity and, therefore, the predictive value of a negative MRI result for MS were, however, not sufficiently high for a normal MRI to be used to conclusively exclude the diagnosis of MS.