External validation of AF-BLEED for predicting major bleeding and for tailoring NOAC dose in AF patients: A post hoc analysis in the ENGAGE AF-TIMI 48

OBJECTIVE

AF-BLEED, a simple bleeding risk classifier, was found to predict major bleeding (MB) in patients with atrial fibrillation (AF) and identify AF patients at high risk of MB who might potentially benefit from a lower direct oral anticoagulant dose. This post hoc study aimed to externally validate these findings in the ENGAGE AF-TIMI 48 (Effective aNticoaGulation with factor Xa next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction study 48) trial.

METHODS

The ENGAGE AF-TIMI 48 trial randomized AF patients to higher-dose edoxaban regimen (HDER 60/30 mg) versus lower-dose edoxaban regimen (LDER 30/15 mg), with prespecified dose reduction criteria. AF-BLEED was calculated in the modified intention-to-treat cohort (n = 21,026 patients) used for primary outcome analysis. Annualized event rates and hazard ratios (HRs) were obtained for the primary composite outcome (PCO) and its single components (MB, ischemic stroke/systemic embolism and death) to compare LDER 30 mg with HDER 60 mg in both AF-BLEED classes.

RESULTS

AF-BLEED classified 2882 patients (13.7 %) as high-risk, characterized by a two- to three-fold higher MB risk than AF-BLEED classified low-risk patients. AF-BLEED classified high-risk patients randomized to LDER 30 mg demonstrated a 3.3 % reduction in MB at the cost of a 0.5 % increase in ischemic stroke/systemic embolism. LDER 30 mg resulted in a 3.1 % reduction of PCO compared to HDER 60 mg (HR of 0.81; 95%CI 0.65-1.01). Additional to existing dose reduction criteria, another 6 % of patients could potentially benefit of this dose adjustment strategy.

CONCLUSION

AF-BLEED could identify AF patients to be at high risk of major bleeding. Our findings support the hypothesis that LDER 30 mg might provide a reasonable option in AF patients with legitimate bleeding concerns.

Determinants of label non-adherence to non-vitamin K oral anticoagulants in patients with newly diagnosed atrial fibrillation

Aims

To evaluate the extent and determinants of off-label non-vitamin K oral anticoagulant (NOAC) dosing in newly diagnosed Dutch AF patients.

Methods and results

In the DUTCH-AF registry, patients with newly diagnosed AF (<6 months) are prospectively enrolled. Label adherence to NOAC dosing was assessed using the European Medicines Agency labelling. Factors associated with off-label dosing were explored by multivariable logistic regression analyses. From July 2018 to November 2020, 4500 patients were registered. The mean age was 69.6 ± 10.5 years, and 41.5% were female. Of the 3252 patients in which NOAC label adherence could be assessed, underdosing and overdosing were observed in 4.2% and 2.4%, respectively. In 2916 (89.7%) patients with a full-dose NOAC recommendation, 4.6% were underdosed, with a similar distribution between NOACs. Independent determinants (with 95% confidence interval) were higher age [odds ratio (OR): 1.01 per year, 1.01–1.02], lower renal function (OR: 0.96 per ml/min/1.73 m2, 0.92–0.98), lower weight (OR: 0.98 per kg, 0.97–1.00), active malignancy (OR: 2.46, 1.19–5.09), anaemia (OR: 1.73, 1.08–2.76), and concomitant use of antiplatelets (OR: 4.93, 2.57–9.46). In the 336 (10.3%) patients with a reduced dose NOAC recommendation, 22.9% were overdosed, most often with rivaroxaban. Independent determinants were lower age (OR: 0.92 per year, 0.88–0.96) and lower renal function (OR: 0.98 per ml/min/1.73 m2, 0.96–1.00).

Conclusion

In newly diagnosed Dutch AF patients, off-label dosing of NOACs was seen in only 6.6% of patients, most often underdosing. In this study, determinants of off-label dosing were age, renal function, weight, anaemia, active malignancy, and concomitant use of antiplatelets.

Implication of microglia in ketamine-induced long-term cognitive impairment in murine pups

BACKGROUND

Ketamine, a non-competitive N-methyl-D-aspartate receptor (NMDAR) antagonist, is widely applicable to anesthesia, analgesia, and sedation. However, the function and mechanisms of ketamine in the long-term learning and memory function of neonatal mice are unclear.

OBJECTIVE

The present study aims to investigate whether long-term learning and memory function will be affected by multiple ketamine exposures in the early development period.

METHODS

The mRNA and protein levels were measured by RT-qPCR and western blot, respectively. The Morris Water Maze test was performed to assess spatial learning and memory.

RESULTS

We identified that neonatal exposure to ketamine downsized the positive neurons for microtubule-associated protein doublecortin (DCX) and Ki67 in hippocampal dentate gyrus at the juvenile and late adolescence stages. Double-labeling tests demonstrated that the counts of Iba1⁺ cells and Ki67⁺ cells were pronouncedly diminished with exposure to ketamine. Further, qPCR assays to screen the key factors predisposing the populations and maturation of microglia exhibited remarkable decline of CX3CR1 mRNA levels in ketamine group versus the control group. The close relation of microglia to synaptic plasticity was depicted by the significantly downregulated synaptic plasticity-related proteins NR2B and PSD-95 subsequent to multiple exposures to ketamine. Finally, we found that both the protein and mRNA levels of BDNF were markedly decreased in ketamine group versus the control group.

CONCLUSION

We found that multiple exposures to ketamine in neonatal mice lead to spatial learning and memory dysfunction. The alterations of microglial development and function are the possible mechanisms of long-term learning and memory impairment.

Antithrombotic therapy and bleeding complications in patients with atrial fibrillation and active cancer

Background

Little is known about the extent to which an active cancer diagnosis increases bleeding and thromboembolic risks in atrial fibrillation (AF) patients. Data on major bleeding rates per antithrombotic management strategy are lacking in AF patients with active cancer.

Purpose

To examine the incidence rates of major bleeding per antithrombotic treatment in AF patients with active cancer and to examine whether cancer type impacts major bleeding and thromboembolic risks.

Methods

We used Danish population-based health care databases to conduct this cohort study. We included all incident AF (including atrial flutter) patients aged ≥50 years between January 1st 1995 and December 31st 2016, out of whom we identified AF patients who subsequently developed cancer. We used International Classification of Diseases 10th Revision codes to identify data on cancer type and outcomes (i.e. major bleeding, arterial and venous thromboembolism). We used Anatomical Therapeutic Chemical codes to provide information on antithrombotic treatment (e.g. no anticoagulant treatment, platelet inhibitors, vitamin K antagonists, direct oral anticoagulants, or a combination of antithrombotic drugs) which was evaluated as a time-dependent variable. The follow-up started from the incident cancer diagnosis until the occurrence of an outcome, death or the end of the two year follow-up. Incidence rates per 100 patient-years and adjusted hazard ratios were computed.

Results

22,996 AF patients with a subsequent incident cancer diagnosis were included in the study. These patients had higher major bleeding and thromboembolic risk compared to those without cancer, with adjusted HRs of 2.11 (1.99–2.23) and 1.36 (1.27–1.44), respectively (Figure 1). Highest bleeding risk was observed for intracranial and respiratory cancer, while haematological and respiratory cancer were associated with highest thromboembolic risk. Bleeding risk increased with increasing number of antithrombotic drugs and was higher in AF patients with active cancer compared to those without, across all exposure categories (Figure 2).

Conclusions

Patients with AF and active cancer are at increased risk of major bleeding and thromboembolisms than those without cancer. Treatment with dual or triple antithrombotic therapy in AF patients with active cancer showed very high bleeding rates.

Funding Acknowledgement

Type of funding sources: None.

Atrial fibrillation in patients with a history of cancer and risk of bleeding complications associated with antithrombotic therapy

Background

Up to one in four patients with atrial fibrillation (AF) has a cancer diagnosis. It is largely unknown to which extent a prior cancer diagnosis affects major bleeding and thromboembolic risk in AF patients. Moreover, data on major bleeding rates per antithrombotic treatment type are lacking in these patients.

Purpose

To examine the incidence rates of major bleeding per antithrombotic treatment in AF patients with prior cancer and to examine whether cancer type and the time-interval between AF and cancer influence major bleeding and thromboembolic risks.

Methods

This nationwide population-based cohort study included incident Danish AF patients aged ≥50 years between 01–01–1995 and 31–12–2016. Data on prior cancer, major bleeding and thromboembolisms (i.e. arterial and venous) were obtained from Danish health registries via International Classification of Diseases 10th Revision codes. We stratified according to prior cancer and by time between the AF and cancer diagnosis (i.e. <1 year, 1–3 years, >3 years), and cancer type. Data on antithrombotic exposure (e.g. no anticoagulant treatment, platelet inhibitors, vitamin K antagonists, direct oral anticoagulants, or combination of antithrombotic drugs) were evaluated as a time-dependent variable. We computed incidence rates per 100 patient-years and adjusted hazard ratios in a Cox regression model.

Results

We identified 39,178 AF patients with a prior cancer diagnosis. Bleeding risk increased with increasing number of antithrombotic drugs and was higher in AF patients with a history of cancer compared to those without, across all exposure categories (Figure 1). The increased bleeding risk was similar across different time intervals between cancer and AF diagnosis. The increased thromboembolic risk steeply declined with increasing time intervals between AF and cancer diagnosis (Figure 2). Prior gastrointestinal, intracranial, haematological, respiratory and urogenital cancers were associated with an increased bleeding risk. The two latter cancer types were also associated with increased thromboembolic risks.

Conclusion

We showed that patients with atrial fibrillation and a prior history of cancer experience higher rates of bleeding than those without cancer. Both respiratory and urogenital cancers had the highest rates of bleeding and thromboembolisms.

Funding Acknowledgement

Type of funding sources: None.

Improved robot-assisted laparoscopic telesurgery: feasibility of network converged communication

The converged transmission-assisted network communication architecture used in this study could meet the requirements of telesurgery, and effectively guarantee the security and immediacy of communication. With the security, flexibility, and universality of the network converged transmission, the clinical practical application of telesurgery and telemedicine would step up to a higher level.

Implementation of a cloud-based electronic patient-reported outcome (ePRO) platform in patients with advanced cancer

Background

Patient reported outcomes (PROs) have been associated with improved symptom management and quality of life in patients with cancer. However, the implementation of PROs in an academic clinical practice has not been thoroughly described. Here we report on the execution, feasibility and healthcare utilization outcomes of an electronic PRO (ePRO) application for cancer patients at an academic medical center.

Methods

We conducted a randomized trial comparing an experimental ePRO arm to standard of care in patients with advanced cancer in the thoracic, gastrointestinal, and genitourinary oncology groups at Stanford Cancer Center from March 2018 to November 2019. We describe the pre-implementation, implementation, and post-implementation phases of the ePRO arm, technological barriers, electronic health record (EHR) integration, clinician burden, and patient data privacy and security. Feasibility was pre-specified to be at least 70% completion of all questionnaires. Acceptability was based on patient and clinician feedback. Ambulatory healthcare utilization was assessed by reviewing numbers of phone messages, electronic portal messages, and referrals for supportive care.

Results

Of 617 ePRO questionnaires sent to 72 patients, 445 (72%) were completed. Most clinicians (87.5%) and patients (93%) felt neutral or positive about the ePRO tool’s ease of use. Exposure to ePRO did not cause a measurable change in ambulatory healthcare utilization, with a median of less than two phone messages and supportive care referrals, and 5–6 portal messages.

Conclusions

Web-based ePRO tools for patients with advanced cancer are feasible and acceptable without increasing clinical burden. Key lessons include the importance of pilot testing, engagement of stakeholders at all levels, and the need for customization by disease group. Future directions for this work include completion of EHR integration, expansion to other centers, and development of integrated workflows for routine clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41687-021-00358-2.

Ablation Index-guided 50W ablation for left atrial posterior wall isolation compared with lower powers: feasibility and lesion level analysis

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Groupe de Rythmologie de la Société Française de Rythmologie

Background 

Posterior Wall Isolation (PWI) is increasingly performed for Atrial Fibrillation (AF). The use of Ablation Index (AI)-guided 50W ablation for PWI has not been described, nor the interplay between ablation parameters at this power when compared to lower powers. 

Methods 

40 consecutive AF patients (26 males, 65.5 ± 10.0 years. 95% non-paroxysmal AF) underwent PWI following pulmonary vein isolation. A roof line and floor line were created with point-by-point ablation, targeting a contact force (CF) of 10-30g, AI 550-600 on the roof and 400-450 on the floor, and inter-tag distance of <6mm. 35-40W powers were used for the first 20 patients, and 50W used for the next 20. Generator impedance was monitored in real time for each lesion. Ablation inside the box was delivered in case of failure of first pass isolation (FPI). All VisiTags (n = 959) were analyzed retrospectively. 

Results 

PWI was successful in 19(95%) of the 35-40W group and in all 20 patients in the 50W group, with FPI seen in 8(40%) and 10(50%) respectively, p = 0.53. The mean CF and number of RF applications on the roof. floor and inside the box were similar between the two groups. Ablation time per lesion (10.4 [8.8-12.5]sec) and total ablation time per patient (3.84[3.34-4.66] min) were shorter in the 50W group as compared to 35-40W (13.0 [11.6-16.2] sec and 5.86 [4.23-7.73] min respectively), p < 0.005. The mean AI and Impedance Drop were larger in the 50W group (Table). There was no steam pop observed in any of the 959 radiofrequency applications. 

Conclusion 

Ablation Index guided 50W ablation has a very high success rate for posterior wall isolation with shorter ablation times and higher impedance drop compared to conventional powers. Steam pops may be avoidable by targeting CF < 30g, and by monitoring impedance in real-time. 50W Group(N = 458) 35-40W Group(N = 501) p-value Number of lesions (s, IQR)Roof lineFloor lineAdditional ablation inside box 21.5 [19.5-26.3]7.0 [5.8-9.0]13.0 [10.8-14.3]6.0 [6.0-6.8] 24.0 [20.8-29.5]8.0 [6.0-10.0]12.5 [10.8-14.0]5.5 [2.8-9.0] 0.330.180.850.59 Ablation Time per lesion (s, IQR)Roof lineFloor lineAdditional ablation inside box 10.4 [8.8-12.5]13.0 [10.9-16.0]9.9 [8.7-11.4]8.1 [6.9-9.0] 13.0 [11.6-16.2]14.5 [12.4-19.0]12.7 [11.4-15.9]11.8 [10.6-14.0] <0.005<0.005<0.005<0.005 Total RF Time (min, IQR)Roof lineFloor lineAdditional ablation inside box 3.84 [3.34-4.66]1.54 [1.15-1.90]2.06 [1.68-2.54]0.79 [0.65-1.07] 5.86 [4.23-7.73]1.98 [1.62-2.59]2.78 [2.28-3.25]1.07 [0.59-1.42] < 0.0050.0190.0090.50 Impedance Drop (ohms, IQR)Roof lineFloor lineAdditional ablation inside box 7.4 [5.2-10.3]8.7 [6.1-11.3]6.9 [5.0-10.1]7.1 [5.4-9.8] 6.9 [4.8-9.7]7.5 [5.1-10.0]6.0 [4.2-8.3]8.3 [5.8-10.9] 0.0070.04< 0.0050.17 Contact Force (g, IQR)Roof lineFloor lineAdditional ablation inside box 21.1 [14.5-30.3]23.9 [17.8-32.7]19.2 [13.2-25.3]25.5 [18.5-36.9] 21.2 [14.9-28.1]24.3 [17.2-30.3]19.0 [14.1-25.0]23.1 [16.9-31.7] 0.560.450.870.21 Ablation Index (IQR)Roof lineFloor lineAdditional ablation inside box 471 [441-519]560 [509-571]453 [436-475]461 [430-488] 461 [434-493]502 [466-541]446 [426-464]455 [434-478] < 0.005< 0.005< 0.0050.59 Lesion level analysis for Posterior Wall Isolation

[Research Progress and Prospect of Facial Reconstruction in Forensic Science]

Abstract

Facial reconstruction is a way to recover facial morphology by restoring soft tissues based on unidentified skulls using the knowledge of anatomy, anthropology, aesthetics, and computer science. It is applied in forensic science, oral plastic surgery and archeology, and especially plays an important role in the identification of the origin of the unknown corpses in forensic science. Facial reconstruction is the supplementary means of identification when other approaches （such as DNA comparison, imaging matching, dental records comparison, etc.） cannot identify individual identity. Facial soft tissue thickness （FSTT） is the basis of facial reconstruction and with the development of imaging and computer science, the techniques for measuring FSTT are improving rapidly and many related researches have appeared. This paper summarizes the application of facial reconstruction in forensic science, the accuracy of different methods and the research progress of this field to provide reference to this field.

Point-of-Care Analysis of Blood Ammonia with a Gas-Phase Sensor

Elevated blood ammonia (hyperammonemia) may cause delirium, brain damage, and even death. Effective treatments exist, but preventing permanent neurological sequelae requires rapid, accurate, and serial measurements of blood ammonia. Standard methods require volumes of 1 to 3 mL, centrifugation to isolate plasma, and a turn-around time of 2 h. Collection, handling, and processing requirements mean that community clinics, particularly those in low resource settings, cannot provide reliable measurements. We describe a method to measure ammonia from small-volume whole blood samples in 2 min. The method alkalizes blood to release gas-phase ammonia for detection by a fuel cell. When an inexpensive first-generation instrument designed for 100 μL of blood was tested on adults and children in a clinical study, the method showed a strong correlation (R² = 0.97) with an academic clinical laboratory for plasma ammonia concentrations up to 500 μM (16 times higher than the upper limit of normal). A second-generation hand-held instrument designed for 10-20 μL of blood showed a near-perfect correlation (R² = 0.99) with healthy donor blood samples containing known amounts of added ammonium chloride up to 1000 μM. Our method can enable rapid and inexpensive measurement of blood ammonia, transforming diagnosis and management of hyperammonemia.

Economics of alternative dosing strategies for pembrolizumab and nivolumab at a single academic cancer center

Background

The FDA initially approved pembrolizumab and nivolumab for doses based on patient weight, but subsequently amended approval to fixed doses. We estimated savings from novel dosing strategies based on real‐world patient data from a single cancer center.

Methods

We analyzed all outpatient doses of pembrolizumab and nivolumab administered at three infusion centers affiliated with our academic hospital between July 1, 2018 and Oct 31, 2018. We estimated savings from several dosing strategies with and without vial sharing between patients.

Results

A total of 1029 doses of pembrolizumab or nivolumab were administered for multiple cancer types. For 77% of doses, the weight‐based dose was less than the fixed dose. “Dose‐minimization” (DM), defined as the lesser of weight‐based and fixed dose decreased nivolumab spending by 9% without affecting pembrolizumab spending. DM plus vial sharing decreased pembrolizumab spending by 19% without affecting nivolumab. The differences in savings were due to availability of multiple vial sizes for nivolumab but not pembrolizumab. DM plus vial sharing for both drugs would have saved $1.5 million USD over the 4‐month study period.

Conclusion

New dosing strategies for pembrolizumab and nivolumab can generate large savings without anticipated decrease in efficacy. Barriers include FDA dosing labels, hospital policies against vial sharing, and inaccessibility of smaller vial sizes, which are currently available in other worldwide markets.

Research Progress of Age Estimation Based on the Demirjian's Method

Abstract

In recent years, individual age estimation has gained increasing attention in forensic practice. Common age estimation methods mainly use developments of teeth and bones. Compared with bones, teeth are stronger and are highly resistant to external factors, therefore plays an important role in age estimation. Demirjian's method is one of the most commonly used methods to evaluate dental age and has been widely used in many countries. In this paper, the accuracy of its application in different populations is reviewed. It is found that compared with the chronological ages, most of the estimated ages are overestimated. By combining research results of many scholars and by analyzing, it can be assumed that this situation may be related with race, region, sex, etc.

Feasibility and design of a cloud-based digital platform in patients with advanced cancer

211

Background: Patient reported outcomes (PROs) allow for systematic and more continuous capture of the patient experience. PROs have been associated with improved symptom management and quality of life in patients with advanced cancer; however how to do this in a real world setting is not thoroughly described. We sought to provide a description of the implementation and feasibility of a digital PRO application in patients with advanced cancer at one academic center. Methods: This is an ongoing randomized trial, comparing digital PRO intervention vs standard of care, in advanced cancer patients from three oncology groups (thoracic, gastrointestinal, genitourinary). Prior to trial initiation, a lead in period to test workflows was conducted, as well as key stakeholder interviews to optimize engagement with the platform. Clinical team members (e.g. nurses, advanced practice providers) were critical to the workflows developed, thus operational leadership buy-in was required. We were unable to integrate our PRO platform with our digital EHR. Regular sponsor meetings addressed technical concerns and patient/provider feedback. Processes were tailored for each disease group to handle varying degrees of symptoms (mild, moderate and severe). Patient and clinician satisfaction and qualitative feedback was collected. We defined feasibility as > 70% questionnaire completion on the platform. Results: There are 64 patients on the intervention arm and 64 on the control arm. Of eligible patients, 93% (128/138) enrolled in the study. During the study period, 447 digital symptom questionnaires were sent by the platform, of which 333 were completed (74%). The majority of clinicians (82%, n = 18) and patients (85%, n = 64) felt neutral or positive when asked if the tool was easy to use. Approximately half of clinicians (45%, n = 10) and patients (46%, n = 36) would probably or definitely recommend the platform. Conclusions: Web-based PRO reporting for patients with advanced cancer is feasible. Clinicians and patients found the platform both acceptable and easy to use. Future directions include integration with our EHR, expansion across disease groups and other centers, and creation of workflows that are integrated into routine clinical practice.

Construction of Age Estimation Model of 18-Year-Olds in the Northern Chinese Population Based on the Development of Mandibular Second and Third Molars

Abstract

Objective To establish a linear relationship between age and the development process of the mandibular second, third molars in a northern Chinese population and test its accuracy in inferring whether the subject is over 18 years old. Methods The orthopantograms （OPGs） of 960 northern Chinese people aged between 10.00 to 25.99 years were selected. The gender, birth date, and date of the orthopantograms of each sample were recorded. The development stages of left mandibular second and third molars were divided with Demirjian method. The experimental group （760 individuals） constructed a Logistic regression equation to infer whether the subject is over 18 years old. The validation group （200 individuals） tested the accuracy of the equation. Results When only using third molar, the formula obtained for inferring whether the subject's age is over 18 years is： logit P₁=-18.276+0.494 x₁+2.953 x₃. When combining the second and the third molars, the formula is： logit P₂=-21.045+3.177 x₁+0.619 x₂+2.088 x₃. （x₁ stands for gender, male is marked as 1 and female is marked as 2; x₂ and x₃ stand for the development stage of second molar and third molar, respectively）. The accuracy rates of this equation in estimating whether ages of subjects from the validation group were over 18 years old for males and females were 88.0%-92.0% and 85.0%-88.0%, respectively. Conclusion The age estimation formulas based on the development of mandibular second and third molars have important value in judging whether the individual is over 18 years old. Meanwhile, the accuracy of age estimation can be improved by combining the development of second and third molars together.

Hyperammonemia after capecitabine associated with occult impairment of the urea cycle

Background

Cancer patients receiving chemotherapy often complain of “chemobrain” or cognitive impairment, but mechanisms remain elusive.

Methods

A patient with gastric cancer developed delirium and hyperammonemia after chemotherapy with the 5‐fluorouracil pro‐drug capecitabine. Exome sequencing facilitated a search for mutations among 43 genes associated with hyperammonemia and affecting the urea cycle directly or indirectly.

Results

The patient's urea cycle was impaired by capecitabine‐induced liver steatosis, and portosystemic shunting of gut ammonia into the systemic circulation. The patient was also heterozygous for amino acid substitution mutations previously reported to create dysfunctional proteins in 2 genes, ORNT2 (ornithine transporter‐2 for the urea cycle), and ETFA (electron transport flavoprotein alpha for fatty acid oxidation). The mutations explained the patient's abnormal plasma amino acid profile and exaggerated response to allopurinol challenge. Global population variations among the 43 hyperammonemia genes were assessed for inactivating mutations, and for amino acid substitutions predicted to be deleterious by complementary algorithms, SIFT and PolyPhen‐2. One or 2 deleterious mutations occur among the 43 genes in 13.9% and 1% of individuals, respectively.

Conclusions

Capecitabine and 5‐fluorouracil inhibit pyrimidine biosynthesis, decreasing ammonia utilization. These drugs can induce hyperammonemia in susceptible individuals. The risk factors of hyperammonemia, gene mutations and liver dysfunction, are not rare. Diagnosis will trigger appropriate treatment and ameliorate brain toxicity.

The applied anatomy and clinical significance of the proximal, V1 segment of vertebral artery

BACKGROUND

The aim of the study was to probe the morphological features of the proximal segment (V1) of vertebral artery (VA) in a sample of Chinese cadavers.

MATERIALS AND METHODS

The origin, course and outer diameter at origin of the pre-vertebral part of the VAs were evaluated in 119 adult cadavers.

RESULTS

It was found that 94.12% of the VAs originated from the subclavian arteries, bilaterally. The variant origins were present in 5.88% of the cadavers and all originated directly from the arch of the aorta. All the variations were observed on the left side of male cadavers. The average outer diameters at origin of the normal and variation groups were 4.35 ± 1.00 mm and 4.82 ± ± 1.42 mm, respectively, p = 0.035. In the normal group, but not in the variation group, the average diameter in the males was significantly larger than that in the females (4.50 ± 0.99 mm, 3.92 ± 0.92 mm, respectively, p = 0.000). In addition, only 5 cadavers in the normal group had hypoplastic VAs (4.20%, 4 males, 3 right-sided). Vertebral artery dominance (VAD) was present in 91 (69 males) out of 112 cadavers and more common on the left (n = 48). In addition, 3 cadavers satisfied conditions for coexistence of VAD and vertebral artery hypoplasia. All 7 cadavers in the variation group exhibited VAD, which was more common on the right side (n = 5).

CONCLUSIONS

The morphologic variations and frequencies described above have implications for the early prevention, abnormal anatomy detection, accurate diagnosis, safe surgery and endovascular treatment of cardiovascular and neurological disease.

[Research Progress of Age Estimation Based on Age-related Changes of Dentin-pulp Complex]

Age estimation is a hot and difficult issue in forensic practice. Teeth are the most solid organs in human body and can be kept in vitro for a long time. With age, the secondary dentin gradually generates and the volume of pulp cavity constantly decreases. Therefore, forensic dentists proposed that age-related changes of dentin-pulp complex could be used to estimate age, which has been widely applied in forensic practice over the years. Due to the development of imaging technology, a variety of methods have been advocated by forensic dentists to detect the age-related changes of dentin-pulp complex for age estimation. However, different methods have their own advantages and limitations, forensic scientists should combine the use of different methods for improving the accuracy of age estimation according to the actual situation. This paper reviews current research of age estimation based on dentin-pulp complex, so as to provide reference for related research.

Cardiac magnetic resonance imaging-indeterminate/negative cardiac sarcoidosis revealed by 18F-fluorodeoxyglucose-positron emission tomography: two case reports and a review of the literature

Background

Sarcoidosis is an inflammatory disorder of immune dysregulation characterized by non-caseating granulomas that can affect any organ. Cardiac sarcoidosis is an under-recognized entity that has a heterogeneous presentation and may occur independently or with any severity of systemic disease. Diagnosing cardiac sarcoidosis remains problematic with endomyocardial biopsies associated with a high risk of complications. Several diagnostic algorithms are currently available that rely on histopathology or clinical and radiological measures. The dominant mode of diagnostic imaging to date for cardiac sarcoidosis has been cardiac magnetic resonance imaging with gadolinium enhancement.

Case presentations

We report the cases of two adult patients: case 1, a 50-year-old white man who presented with severe congestive cardiac failure; and case 2, a 37-year-old white woman who presented with complete heart block. Both patients had a background of untreated pulmonary sarcoidosis. Cardiac magnetic resonance imaging did not show evidence of sarcoidosis in either patient and both proceeded to ¹⁸F-fluorodeoxyglucose-positron emission tomography scans that were highly suggestive of cardiac sarcoidosis. Both patients were systemically immunosuppressed with orally administered prednisone and methotrexate and had subsequent improvement by clinical and nuclear medicine imaging measures.

Conclusions

Current consensus guidelines recommend all patients with sarcoidosis undergo screening for occult cardiac disease, with thorough history and examination, electrocardiogram, and transthoracic echocardiogram. If any abnormalities are detected, advanced cardiac imaging should follow. While cardiac magnetic resonance imaging identifies the majority of cardiac sarcoidosis, early disease may not be detected. These cases demonstrate ¹⁸F-fluorodeoxyglucose-positron emission tomography is warranted following an indeterminate or normal cardiac magnetic resonance imaging if clinical suspicion remains high. Unidentified and untreated cardiac sarcoidosis risks significant morbidity and mortality, but early detection can facilitate disease-modifying immunosuppression and cardiac-specific interventions.

Dengue fever with compartment syndrome of the right arm

A 44-year-old woman was admitted to our hospital with dengue fever. She developed a haematoma in the right arm at the site of a previous arterial line insertion. Due to coexisting thrombocytopenia, the bleeding was severe enough to cause compartment syndrome. An emergency fasciotomy was performed and her limb salvaged. The case illustrates one important potential complication of this common infectious disease.

Protein diffusion through charged nanopores with different radii at low ionic strength

The diffusion of two similar molecular weight proteins, bovine serum albumin (BSA) and bovine haemoglobin (BHb), through nanoporous charged membranes with a wide range of pore radii is studied at low ionic strength. The effects of the solution pH and the membrane pore diameter on the pore permeability allow quantifying the electrostatic interaction between the charged pore and the protein. Because of the large screening Debye length, both surface and bulk diffusion occur simultaneously. By increasing the pore diameter, the permeability tends to the bulk self-diffusion coefficient for each protein. By decreasing the pore diameter, the charges on the pore surface electrostatically hinder the transport even at the isoelectric point of the protein. Surprisingly, even at pore sizes 100 times larger than the protein, the electrostatic hindrance still plays a major role in the transport. The experimental data are qualitatively explained using a two-region model for the membrane pore and approximated equations for the pH dependence of the protein and pore charges. The experimental and theoretical results should be useful for designing protein separation processes based on nanoporous charged membranes.

Heightened clinical suspicion of pulmonary embolism and disregard of the D-dimer assay: a contemporary trend in an era of increased access to computed tomography pulmonary angiogram?

BACKGROUND

Prospective studies have shown that utilising qualitative D-dimers in those with a low Wells pre-test probability (PTP) of pulmonary embolism (PE) have significantly reduced the number of computed tomography pulmonary angiograms (CTPA) being performed. These studies have been based on a PE prevalence of approximately 6% in the low PTP group.

AIM

This study compares the diagnostic approach to PE in the study institution to well-established guidelines. The study also re-examines the cost-benefit analyses of qualitative d-dimers and CTPA in the low PTP group.

METHODS

A retrospective study of 169 consecutive CTPA requested in the emergency department of a major teaching hospital during a 12-month period.

RESULTS

The prevalence of PE was 0% (0/65), 11.7% (9/77) and 0% (0/2) in the low, moderate and high Wells PTP groups respectively, and 6.3% (9/144) overall. PTP was documented in 10 (6.9%) cases, and the qualitative Clearview Simplify D-dimer was only ordered in 33.8% (22/65) of low PTP subjects. The false positive D-dimer rate was 90.2% (37/41). Cost-benefit analysis and assay performance defines a narrow range of low PTP PE prevalence between 1% and 5% for the utilisation of the qualitative D-dimer assay.

CONCLUSIONS

The overall prevalence of PE in subjects undergoing CTPA was significantly lower compared with data in the literature. The authors recommend warranted clinical suspicion of PE should be confirmed by a senior physician prior to placing a patient in the PE work-up pathway. In such patients, the qualitative D-dimer assay should be utilised if PTP is low, and the exclusionary efficiency of the D-dimer will be improved in the setting of higher PE prevalence in this subgroup. Hospitals should audit local PE prevalence, as cost-benefit analyses raises questions about the effectiveness of D-dimers when PE prevalence is very low in the low PTP subgroup.

Cancer risk after use of recombinant bone morphogenetic protein-2 for spinal arthrodesis

BACKGROUND

Recombinant human bone morphogenetic protein-2 (rhBMP-2) is a growth factor known to have in vitro effects on the growth and invasiveness of cancer. It has been approved by the U.S. Food and Drug Administration in limited doses for single-level anterior spinal arthrodesis, but it is commonly used off-label and at high doses. The effect of rhBMP-2 on the risk of cancer has been a concern. We sought to evaluate the risk of new cancers in patients receiving high-dose rhBMP-2.

METHODS

We used publicly available data from a pivotal, multicenter, randomized controlled trial of patients with degenerative lumbar spine conditions who underwent a single-level instrumented posterolateral arthrodesis with either high-dose rhBMP-2 in a compression-resistant matrix (CRM) (rhBMP-2/CRM; n = 239) or autogenous bone graft (control group; n = 224). We compared the risks of new cancers in the rhBMP-2/CRM and control groups at two and five years after surgery.

RESULTS

At two years, with 86% follow-up, there were fifteen new cancer events in eleven patients in the rhBMP-2/CRM group compared with two new cancer events in two patients in the control group treated with autogenous bone graft. The incidence rate of new cancer events per 100 person-years was 3.37 (95% confidence interval [CI], 1.89 to 5.56) in the rhBMP-2/CRM group at two years compared with 0.50 (95% CI, 0.06 to 1.80) in the control group. The incidence rate ratio was 6.75 (95% CI, 1.57 to 60.83; p = 0.0026) at two years. Calculated in terms of the number of patients with one or more cancer events two years after the surgery, the incidence rate per 100 person-years was 2.54 (95% CI, 1.27 to 4.54) in the rhBMP-2/CRM group compared with 0.50 (95% CI, 0.06 to 1.82) in the control group at two years; the incidence rate ratio was 5.04 (95% CI, 1.10 to 46.82; p = 0.0194). At five years, there was a 37% loss of follow-up, but a significantly greater incidence of cancer events was still observed in the rhBMP-2/CRM group.

CONCLUSIONS

A high dose of 40 mg of rhBMP-2/CRM in lumbar spinal arthrodesis was associated with an increased risk of new cancer.

Role of p300 in regulating neuronal nitric oxide synthase gene expression through nuclear factor-κB-mediated way in neuronal cells

Nuclear factor (NF)-κB acetylation has been shown to participate in a number of neurological processes by regulating the expression of certain genes. We have previously demonstrated the neuronal nitric oxide synthase (nNOS) expression and nitric oxide (NO) production may be regulated by NF-κB acetylation via an NF-κB responsive element within the nNOS promoter in neuronal cells. p300 is a ubiquitous transcription coactivator with intrinsic histone acetyltransferase (HAT) activity, which is important in the nervous system. In the present study, we aimed at probing if p300 participated in regulating the nNOS expression through the NF-κB-mediated way. As a result, we found p300 enhanced the nNOS protein and mRNA levels in human neuroblastoma SK-N-SH cells by enhancing the binding of NF-κB to the nNOS promoter and NF-κB-mediated nNOS transcription. Meanwhile, p300 was shown to directly acetylate NF-κB p65 and p50 subunits, interact with NF-κB and bind to the NF-κB responsive element region within the nNOS promoter. Taken together, our results indicate p300 acts as both an HAT and a coactivator in regulating NF-κB-mediated nNOS expression, which provide some correlations between p300 and nNOS in neuronal cell, and suggest that some p300-related neurological disorders may be partially based on its effect on the nNOS expression.

Cooperative assembly of a protein-DNA filament for nonhomologous end joining

Nonhomologous end joining repairs DNA double-strand breaks created by ionizing radiation and V(D)J recombination. Ku, XRCC4/Ligase IV (XL), and XLF have a remarkable mismatched end (MEnd) ligase activity, particularly for ends with mismatched 3' overhangs, but the mechanism has remained obscure. Here, we showed XL required Ku to bind DNA, whereas XLF required both Ku and XL to bind DNA. We detected cooperative assembly of one or two Ku molecules and up to five molecules each of XL and XLF into a Ku-XL-XLF-DNA (MEnd ligase-DNA) complex. XLF mutations that disrupted its interactions with XRCC4 or DNA also disrupted complex assembly and end joining. Together with published co-crystal structures of truncated XRCC4 and XLF proteins, our data with full-length Ku, XL, and XLF bound to DNA indicate assembly of a filament containing Ku plus alternating XL and XLF molecules. By contrast, in the absence of XLF, we detected cooperative assembly of up to six molecules each of Ku and XL into a Ku-XL-DNA complex, consistent with a filament containing alternating Ku and XL molecules. Despite a lower molecular mass, MEnd ligase-DNA had a lower electrophoretic mobility than Ku-XL-DNA. The anomalous difference in mobility and difference in XL to Ku molar ratio suggests that MEnd ligase-DNA has a distinct structure that successfully aligns mismatched DNA ends for ligation.

Early Diagnosis of Acute Myocardial Infarction by Bedside Multimarker Test at an Emergency Department in Hong Kong

Introduction

Cardiac biomarker measurement can aid diagnosis of acute myocardial infarction. The present study evaluates the efficacy and efficiency of point-of-care multimarkers measurement of myoglobin, creatine kinase (CK-MB) and troponin in identifying patients with acute myocardial infarction.

Method

We prospectively enrolled consecutive patients (N=105) in the emergency department who were being evaluated for possible acute myocardial infarction. Point-of-care testing (POCT) of myoglobin, CK-MB and troponin I (TnI) was performed in all patients. Central laboratory measurement of troponin I was also performed simultaneously. The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio and receiver operating characteristic (ROC) curve were evaluated.

Result

The specificity and positive likelihood ratio of TnI (POCT) and TnI (laboratory) were 98%, 13.0 and 98%, 21.8 respectively. The areas under curve of the ROC curve of TnI (POCT) and TnI (laboratory) were 0.692 and 0.725 respectively.

Conclusion

A high positive likelihood ratio for acute myocardial infarction through point-of-care testing can help timely diagnosis and just-in-time appropriate management for patients presenting with chest pain.

Local false discovery rate facilitates comparison of different microarray experiments

The local false discovery rate (LFDR) estimates the probability of falsely identifying specific genes with changes in expression. In computer simulations, LFDR <10% successfully identified genes with changes in expression, while LFDR >90% identified genes without changes. We used LFDR to compare different microarray experiments quantitatively: (i) Venn diagrams of genes with and without changes in expression, (ii) scatter plots of the genes, (iii) correlation coefficients in the scatter plots and (iv) distributions of gene function. To illustrate, we compared three methods for pre-processing microarray data. Correlations between methods were high (r = 0.84-0.92). However, responses were often different in magnitude, and sometimes discordant, even though the methods used the same raw data. LFDR complements functional assessments like gene set enrichment analysis. To illustrate, we compared responses to ultraviolet radiation (UV), ionizing radiation (IR) and tobacco smoke. Compared to unresponsive genes, genes responsive to both UV and IR were enriched for cell cycle, mitosis, and DNA repair functions. Genes responsive to UV but not IR were depleted for cell adhesion functions. Genes responsive to tobacco smoke were enriched for detoxification functions. Thus, LFDR reveals differences and similarities among experiments.

Crystal structure of human XLF: a twist in nonhomologous DNA end-joining

DNA double-strand breaks represent one of the most severe forms of DNA damage in mammalian cells. One pathway for repairing these breaks occurs via nonhomologous end-joining (NHEJ) and depends on XRCC4, LigaseIV, and Cernunnos, also called XLF. Although XLF stimulates XRCC4/LigaseIV to ligate mismatched and noncohesive DNA ends, the mechanistic basis for this function remains unclear. Here we report the structure of a partially functional 224 residue N-terminal fragment of human XLF. Despite only weak sequence similarity, XLF(1-170) shares structural homology with XRCC4(1-159). However, unlike the highly extended 130 A helical domain observed in XRCC4, XLF adopts a more compact, folded helical C-terminal region involving two turns and a twist, wrapping back to the structurally conserved N terminus. Mutational analysis of XLF and XRCC4 reveals a potential interaction interface, suggesting a mechanism for how XLF stimulates the ligation of mismatched ends.

Cernunnos/XLF promotes the ligation of mismatched and noncohesive DNA ends

Nonhomologous end-joining (NHEJ) repairs DNA double-strand breaks created by ionizing radiation or V(D)J recombination of the immunoglobulin genes. The breaks often leave mismatched or nonligatable ends, and NHEJ must repair the breaks with high efficiency and minimal nucleotide loss. Here, the NHEJ proteins Ku, DNA-dependent protein kinase catalytic subunit, XRCC4/Ligase IV, and Cernunnos/XRCC4-like factor joined mismatched and noncohesive DNA ends in the absence of processing factors. Depending on the mismatch, Cernunnos stimulated joining 8- to 150-fold. For substrates with a blunt end and a 3' overhanging end, Ku, XRCC4/Ligase IV, and Cernunnos ligated the 3' overhanging hydroxyl group to the 5' phosphate of the blunt end, leaving the other strand unjoined. This activity provides a mechanism for retaining 3' overhang sequences, as observed during V(D)J recombination in vivo. Thus, Cernunnos/XRCC4-like factor promotes a mismatched end (MEnd) DNA ligase activity to facilitate joining and to preserve DNA sequence. Furthermore, MEnd ligase activity may have applications in recombinant DNA technology.

Processing of DNA for Nonhomologous End-joining Is Controlled by Kinase Activity and XRCC4/Ligase IV

Nonhomologous end-joining (NHEJ) repairs DNA double-strand breaks created by ionizing radiation and V(D)J recombination. To repair the broken ends, NHEJ processes noncompatible ends into a ligatable form but suppresses processing of compatible ends. It is not known how NHEJ controls polymerase and nuclease activities to act exclusively on noncompatible ends. Here, we analyzed processing independently of ligation by using a two-stage assay with extracts that recapitulated the properties of NHEJ in vivo. Processing of noncompatible ends required wortmannin-sensitive kinase activity. Since DNA-dependent protein kinase catalytic subunit (DNA-PKcs) brings the ends together before undergoing activation of its kinase, this suggests that processing occurred after synapsis of the ends. Surprisingly, all polymerase and most nuclease activity required XRCC4/Ligase IV. This suggests a mechanism for how NHEJ suppresses processing to optimize the preservation of DNA sequence.

Recent insights into the role of host innate and acquired immunity responses

Viral myocarditis can present as dramatic heart failure in the young, and chronic indolent cardiomyopathy in the older adult. The outcome of the disease is still poor, associated with high mortality during long-term follow-up. Enteroviral myocarditis serves as an excellent model to understand virus and host interactions. The virus enters the target cells via collaborating receptors, and this process triggers an inflammatory response in the host. The immune reaction is a two-edged sword, with appropriate activation of the immune system capable of clearing the virus, but excessive activation leads to a chronic inflammatory process that triggers the remodeling of the heart and consequent clinical heart failure. Through genetic dissection strategies, we have identified that the acquired immune system is activated through the T cell receptor and signaling amplification systems, such as the tyrosine kinase p56lck, phosphatase CD45 and downstream ERK1/2, and the family of cytokines. This signaling system not only promotes inflammatory cell clonal expansion but paradoxically also promotes viral proliferation. The innate immune system is now recognized as playing an ever-expanding role in coordinating the host immune response through the Toll-like receptors, triggering downstream signaling adaptors such as MyD88, IRAK, and TRIF/IRFs. These lead to activation of cytokines or interferons, depending on the balance of the signal contributions. The ongoing research in this area should help us to understand the immune response of the heart to viral infection, while identifying potential targets for therapy.

Electrophoretic mobility shift assays to study protein binding to damaged DNA

The electrophoretic mobility shift assay (EMSA) can be used to identify proteins that bind specifically to damaged DNA. EMSAs detect the presence of key DNA repair proteins, such as ultraviolet (UV)-damaged DNA binding protein, which is involved in nucleotide excision repair, and Ku and DNA-PKcs, which are involved in double-strand break repair. This chapter describes EMSA protocols for detecting proteins that bind to UV-damaged DNA, cisplatin-damaged DNA, and DNA ends. The chapter also describes variations of the EMSA that can be used to obtain additional information about these important proteins. The variations include the reverse EMSA, which can detect binding of 35S-labeled protein to damaged DNA, and the antibody supershift assay, which can define the composition of protein-DNA complexes.

Assays for Nonhomologous End Joining in Extracts

In mammalian cells, nonhomologous end-joining (NHEJ) repairs DNA double strand breaks created by ionizing radiation and V(D)J recombination. Using human whole cell extracts prepared by the method of Baumann and West (1998), we have described a cell-free system for NHEJ that joins both compatible and noncompatible DNA ends (Budman and Chu, 2005). To measure joining efficiency and assess the processing of DNA ends, we developed a quantitative polymerase chain reaction assay for the joining of two specific DNA ends. The in vitro NHEJ reaction recapitulates key features of NHEJ observed in vivo: end joining is dependent on DNA-PK and XRCC4/Ligase4, and noncompatible ends are processed by polymerase and nuclease activities that often stabilize the alignment of opposing ends by base pairing. This chapter describes methods for preparing whole cell extracts and for studying the NHEJ reaction in vitro.

UV-induced ubiquitylation of XPC protein mediated by UV-DDB-ubiquitin ligase complex

The xeroderma pigmentosum group C (XPC) protein complex plays a key role in recognizing DNA damage throughout the genome for mammalian nucleotide excision repair (NER). Ultraviolet light (UV)-damaged DNA binding protein (UV-DDB) is another complex that appears to be involved in the recognition of NER-inducing damage, although the precise role it plays and its relationship to XPC remain to be elucidated. Here we show that XPC undergoes reversible ubiquitylation upon UV irradiation of cells and that this depends on the presence of functional UV-DDB activity. XPC and UV-DDB were demonstrated to interact physically, and both are polyubiquitylated by the recombinant UV-DDB-ubiquitin ligase complex. The polyubiquitylation altered the DNA binding properties of XPC and UV-DDB and appeared to be required for cell-free NER of UV-induced (6-4) photoproducts specifically when UV-DDB was bound to the lesion. Our results strongly suggest that ubiquitylation plays a critical role in the transfer of the UV-induced lesion from UV-DDB to XPC.

Processing of DNA for nonhomologous end-joining by cell-free extract

In mammalian cells, nonhomologous end-joining (NHEJ) repairs DNA double-strand breaks created by ionizing radiation and V(D)J recombination. We have developed a cell-free system capable of processing and joining noncompatible DNA ends. The system had key features of NHEJ in vivo, including dependence on Ku, DNA-PKcs, and XRCC4/Ligase4. The NHEJ reaction had striking properties. Processing of noncompatible ends involved polymerase and nuclease activities that often stabilized the alignment of opposing ends by base pairing. To achieve this, polymerase activity efficiently synthesized DNA across discontinuities in the template strand, and nuclease activity removed a limited number of nucleotides back to regions of microhomology. Processing was suppressed for DNA ends that could be ligated directly, biasing the reaction to preserve DNA sequence and maintain genomic integrity. DNA sequence internal to the ends influenced the spectrum of processing events for noncompatible ends. Furthermore, internal DNA sequence strongly influenced joining efficiency, even in the absence of processing. These results support a model in which DNA-PKcs plays a central role in regulating the processing of ends for NHEJ.

Portrait of transcriptional responses to ultraviolet and ionizing radiation in human cells

To understand the human response to DNA damage, we used microarrays to measure transcriptional responses of 10 000 genes to ionizing radiation (IR) and ultraviolet radiation (UV). To identify bona fide responses, we used cell lines from 15 individuals and a rigorous statistical method, Significance Analysis of Microarrays (SAM). By exploring how sample number affects SAM, we rendered a portrait of the human damage response with a degree of accuracy unmatched by previous studies. By showing how SAM can be used to estimate the total number of responsive genes, we discovered that 24% of all genes respond to IR and 32% respond to UV, although most responses were less than 2-fold. Many genes were involved in known damage-response pathways for cell cycling and proliferation, apoptosis, DNA repair or the stress response. However, the majority of genes were involved in unexpected pathways, with functions in signal transduction, RNA binding and editing, protein synthesis and degradation, energy metabolism, metabolism of macromolecular precursors, cell structure and adhesion, vesicle transport, or lysosomal metabolism. Although these functions were not previously associated with the damage response in mammals, many were conserved in yeast. These insights reveal new directions for studying the human response to DNA damage.

Toxicity from radiation therapy associated with abnormal transcriptional responses to DNA damage

Toxicity from radiation therapy is a grave problem for cancer patients. We hypothesized that some cases of toxicity are associated with abnormal transcriptional responses to radiation. We used microarrays to measure responses to ionizing and UV radiation in lymphoblastoid cells derived from 14 patients with acute radiation toxicity. The analysis used heterogeneity-associated transformation of the data to account for a clinical outcome arising from more than one underlying cause. To compute the risk of toxicity for each patient, we applied nearest shrunken centroids, a method that identifies and cross-validates predictive genes. Transcriptional responses in 24 genes predicted radiation toxicity in 9 of 14 patients with no false positives among 43 controls (P = 2.2 x 10(-7)). The responses of these nine patients displayed significant heterogeneity. Of the five patients with toxicity and normal responses, two were treated with protocols that proved to be highly toxic. These results may enable physicians to predict toxicity and tailor treatment for individual patients.

Embryonic stem-cell research and the moral status of embryos

Stem-cell research has the potential to significantly advance our knowledge of cell differentiation with the promise of exciting and innovative therapeutic applications for otherwise incurable genetic and degenerative disorders. The issue has been the subject of debate in federal and state parliament as research of embryonic stem cells and their application have come under intense scrutiny. Scientists and medical practitioners are highly skilled in the technical aspects of biomedicine but are decidedly less comfortable with ethics. The place of novel and controversial biomedical technology is commonly left to an ad hoc and complex process whereby social acceptability eventually becomes the final arbiter. Utilitarianism is a popular ethical approach that attempts to weigh all the known and anticipated merits and pitfalls. The scientific background of biomedical professionals, the vast explosion of information, and specialization and subspecialization, have all contributed to a reductionistic view of life and ethics. The 'sanctity of life' doctrine is altogether quite different, as secular and religious advocates appear inflexible and unyielding to the logical propositions of utilitarianism and reductionism or to the consensus of democracy. These four major ethical approaches are discussed with reference to the embryonic stem-cell research debate.

Contributions of ATM mutations to familial breast and ovarian cancer

This study addresses the prevalence of ATM mutations and the association with breast cancer in Austrian families selected for a history of breast or ovarian cancer or both [hereditary breast and ovarian cancer (HBOC)]. In 270 HBOC families previously screened for BRCA1 and BRCA2 mutations, 137 different sequence alterations of ATM were identified. Seven of these were mutations presumed to cause ataxia telangiectasia based on their effect on the ATM protein, including five that caused a protein truncation and two missense mutations in the catalytic kinase domain of the highly conserved COOH terminus of the protein. The seven mutations were found in 10 families (3.7%). In addition, one missense variant, L1420F, was observed in 13 HBOC families (4.8%) but was not observed in any of the 122 healthy volunteers with no history of breast cancer. In addition, the variant segregated with breast cancer in some of the families, suggesting that it may be pathogenic for breast cancer. Sixty-two additional variants of potential significance were observed in 65 HBOC families, but not in healthy controls. These variants included 24 sequence alterations with possible effects on splicing or protein-protein interactions. This study indicates that there is a significant prevalence of ATM mutations in breast and ovarian cancer families and adds to a growing body of evidence that ATM mutations confer increased susceptibility to breast cancer.