Additional booster doses in patients with chronic lymphocytic leukemia induce humoral and cellular immune responses to SARS-CoV-2 similar to natural infection regardless ongoing treatments: A study by ERIC, the European Research Initiative on CLL

Profound immune dysregulation and impaired response to the SARS-CoV-2 vaccine put patients with chronic lymphocytic leukemia (CLL) at risk of severe COVID-19. We compared humoral memory and T-cell responses after booster dose vaccination or breakthrough infection. (Green) Quantitative determination of anti-Spike specific antibodies. Booster doses increased seroconversion rate and antibody titers in all patient categories, ultimately generating humoral responses similar to those observed in the postinfection cohort. In detail, humoral response with overscale median antibody titers arose in >80% of patients in watch and wait, off-therapy in remission, or under treatment with venetoclax single-agent. Anti-CD20 antibodies and active treatment with BTK inhibitors (BTKi) represent limiting factors of humoral response, still memory mounted in ~40% of cases following booster doses or infection. (Blue) Evaluation of SARS-CoV-2-specific T-cell responses. Number of T-cell functional activation markers documented in each patient. The vast majority of patients, including those seronegative, developed T-cell responses, qualitatively similar between treatment groups or between vaccination alone and infection cases. These data highlight the efficacy of booster doses in eliciting T-cell immunity independently of treatment status and support the use of additional vaccination boosters to stimulate humoral immunity in patients on active CLL-directed treatments.

P-475 Similar fertilization rates and preimplantation embryo development among testosterone-treated transgender men and cisgender women

Study question

What are the effects of testosterone treatment on fertilization rates and preimplantation embryo development among transgender men who underwent fertility preservation?

Summary answer

Testosterone exposure among transgender men has no adverse impacts on fertilization rates and preimplantation embryo development and quality.

What is known already

Transmen are assigned female sex at birth but identify as men. This mismatch might induce distress that is termed gender dysphoria. Testosterone therapy induces “masculine” physical traits, suppresses “feminine” ones, and relieves gender dysphoria. More transmen present for testosterone therapy, their average age is decreasing, and many express the desire to have biological children. Therefore, understanding the effects of testosterone on fertility is crucial. Previous data suggest that despite testosterone treatment, the ovarian reserve and the in-vitro oocyte maturation are preserved among transmen. However, the fertility potential in terms of fertilization rate and early embryo development was not explored.

Study design, size, duration

This retrospective cohort study included 7 testosterone-treated transgender men and 34 cisgender women between April 2016 and November 2021.

Participants/materials, setting, methods

Testosterone-treated transgender men who cryopreserved embryos were compared to 10 fertile women who cryopreserved embryos and to 24 women who underwent IVF treatment due to unexplained or mechanical infertility. Statistical analyses compared assisted reproductive technology data and outcomes between the transgender men group and the two cisgender women groups. Morphokinetic and morphological parameters were compared between 210 embryos of transgender men and 411 embryos of cisgender women.

Main results and the role of chance

The transgender men (30.2±3.59 years) were significantly younger than the cisgender women who cryopreserved embryos (35.1±1.85 years; P = 0.005) and the cisgender women who underwent fertility treatment (33.8±3.23 years; P = 0.017). Among the transgender men, the mean length of testosterone exposure was 99.7±49.24 months (range 14-156 months) and the mean time of discontinuation of testosterone prior to stimulation was 6.57±2.14 months (range 4-10 months). After adjusting for the patient’s age, the fertilization rate was comparable between the transgender men and both cisgender women groups (P = 0.391 and 0.659). No significant differences in the number of cryopreserved embryos (7.2±5.09 and 3.5±2.66; P = 0.473) and the days on which they were frozen (P = 0.576) were observed between the transgender men and the fertile cisgender women. All morphokinetic parameters that were evaluated using time-lapse imaging, as well as the morphological characteristics, were comparable between transgender men and both groups of cisgender women.

Limitations, reasons for caution

All transgender men in our study discontinued the testosterone treatment before starting ovarian stimulation. Stopping hormonal therapy might cause considerable anguish and gender dysphoria. Therefore, further studies that include subjects who did not stop testosterone before fertility preservation are needed.

Wider implications of the findings

Transgender men have acceptable fertilization rates and normal preimplantation embryo development and quality after long-term testosterone treatment. Embryo cryopreservation is, therefore, a feasible and effective way for them to preserve their fertility for future biological parenting.

Trial registration number

Not applicable

Abstract 3447: Tumor treating fields (TTFields) treatment planning for a patient with astrocytoma in the spinal cord

Objectives: The use of TTFields following resection and chemoradiation has increased survival in patients with Glioblastoma (Stupp, et al. JAMA. 2015;314:2535-2543). Randomized data provide a strong rationale for the treatment of high grade gliomas using TTFields with individualized array placement that maximizes the dose at the tumor in a patient-specific manner: providing higher TTFields intensity (≥1.0 V/cm) and power density (≥1.1 mW/cm3) which are associated with improved overall survival (Ballo, et al. Int J Radiat Oncol Biol Phys. 2019;104:1106-11). Here for the first time, we present a case demonstrating the use of numerical simulations for patient-specific TTFields treatment planning for a spinal tumor.

Methods: Treatment planning was performed for a 48 year old patient following T10-L1 laminectomy, gross total resection, and postoperative chemoradiation for an anaplastic astrocytoma of the spinal cord. An MRI at 3 weeks following chemoradiation showed tumor recurrence. Based on the post-chemoradiation MRI, a patient-specific model was created. The model was created by modifying a realistic computational phantom of a healthy female. To mimic the laminectomy, the lamina in T10-L1 was removed and the region was assigned an electric conductivity similar to that of muscle. A virtual mass was introduced into the spinal cord. Virtual transducer arrays were placed on the model at multiple positions, and delivery of TTFields simulated. The dose delivered by different transducer array layouts was calculated, and the layouts that yielded maximal dose to the tumor and spine identified.

Results: Combinations of the best layouts targeting the tumor (all above 2.5 mW/cm3) and the best layouts targeting the spinal cord were investigated. Transducer array layouts where the arrays were placed on the back of the patient with one above the tumor and one below yielded the highest doses at the tumor site. Such layouts yielded TTFields doses of over 2.5mW/cm3, which is well above the threshold dose of 1.1 mW/cm3. Three such layouts were presented as possibilities for a recommended treatment plan. As patient usage, or time on treatment, is correlated with improved patient outcomes, an interactive process was followed to adjust the treatment so that it incorporates both increased therapeutic dose to the tumor and increased overall patient usage and comfort.

Conclusions: These data represent the first ever study on utilizing numerical simulations to plan treatment for a spinal tumor in a patient-specific manner. This is an important milestone in the development of a framework for TTFields dosimetry and treatment planning. This framework will have the potential to increase dose delivery to the tumor bed while optimizing placement that may enhance comfort and encourage device usage.

Citation Format: Jennifer De Los Santos, Smadar Arvatz, Oshrit Zeevi, Shay Levi, Noa Urman, Melissa Shackelford, Ariel Naveh, Tal Marciano. Tumor treating fields (TTFields) treatment planning for a patient with astrocytoma in the spinal cord [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3447.

The Impact of Tumor Treating Fields on Glioblastoma Progression Patterns

BACKGROUND

Tumor-treating fields (TTFields) is an antimitotic treatment modality that interferes with glioblastoma cell division and organelle assembly by delivering low-intensity alternating electric fields to the tumor. A previous analysis from the pivotal EF-14 trial demonstrated a clear correlation between TTFields dose-density at the tumor bed and survival in patients treated with TTFields. This study tests the hypothesis that the antimitotic effects of TTFields result in measurable changes in the location and patterns of progression of newly diagnosed glioblastoma (nGBM) patients.

METHODS

MRI images of 428 nGBM patients that participated in the pivotal EF-14 trial were reviewed and the rates at which distant progression occurred in the TTFields treatment and control arm were compared. Realistic head models of 252 TTFields treated patients were created and TTFields intensity distributions were calculated using a Finite Elements Method. TTFields dose was calculated within regions of the tumor bed and normal brain and its relationship with progression determined.

RESULTS

Distant progression was frequently observed in the TTFields-treated arm, and distant lesions in the TTFields-treated arm appeared at larger distances from the primary lesion than in the control arm. Distant progression correlated with improved clinical outcome in the TTFields patients, with no such correlation observed in the controls. Areas of normal brain that remained normal were exposed to higher TTFields doses compared to normal brain that subsequently exhibited neoplastic progression. Additionally, the average dose to areas of enhancing tumor that returned to normal was significantly higher than in the areas of normal brain that progressed to enhancing tumor.

CONCLUSIONS

There was a direct correlation between TTFields dose distribution and tumor response, confirming the therapeutic activity of TTFields and the rationale for optimizing array placement to maximize TTFields dose in areas at highest risk of progression, as well as array layout adaptation after progression.

RBIO-01. DEVELOPING THE FRAMEWORK FOR TUMOR TREATING FIELDS (TTFIELDS) TREATMENT PLANNING FOR A PATIENT WITH ASTROCYTOMA IN THE SPINAL CORD

The use of Tumor Treating Fields (TTFields) following resection and chemoradiation has increased survival in patients with Glioblastoma. Patient-specific planning for TTFields transducer array placement has been demonstrated to maximize TTFields dose at the tumor: providing higher TTFields intensity (≥ 1.0 V/cm) and power density (≥ 1.1 mW/cm3) which are associated with improved overall survival. Treatment planning was performed for a 48 year old patient following T10-L1 laminectomy, gross total resection, and postoperative chemoradiation for an anaplastic astrocytoma of the spinal cord. An MRI at 3 weeks following chemoradiation showed tumor recurrence. Based on the post-chemoradiation MRI, a patient-specific model was created. The model was created by modifying a realistic computational phantom of a healthy female. To mimic the laminectomy, the lamina in T10-L1 was removed, and the region assigned electric conductivity similar to that of muscle. A virtual mass was introduced into the spinal cord. Virtual transducer arrays were placed on the model at multiple positions, and delivery of TTFields simulated. The dose delivered by different transducer array layouts was calculated, and the layouts that yielded maximal dose to the tumor and spine identified. Transducer array layouts, in which the arrays were placed on the back of the patient with one array above the tumor and one array below the tumor, yielded the highest doses at the tumor site. Such layouts yielded TTFields doses of over 3.4mW/cm3 which is well above the threshold dose of 1.1 mW/cm3 reported previously [Ballo et al. Red Jour 2019]. The framework developed for TTFields dosimetry and treatment planning for this spinal tumor will have the potential to increase dose delivery to the tumor bed while optimizing placement that may enhance comfort and encourage device usage.

RBIO-06. MECHANISM OF ACTION AND ASSOCIATED EFFECTS OF TUMOR TREATING FIELDS (TTFIELDS) ON LIVING CELLS USING SIMULATIONS

Following FDA approval, TTFields treatment has become a commonly used modality for treating patients with Glioblastoma (GBM) and Mesothelioma. From the early 2000’s, extensive research has been performed in in-vitro systems for studying the effects of TTFields on living cells. These studies have shown that multiple cellular functions are affected by TTFields. However, the physical mechanism by which the fields exert effects on cells are not well understood. We propose an analytical model for predicting the geometric and electrical parameters enabling amplification of the electric field in the living cells. This amplification favors the emergence of local heating, dielectrophoretic (DEP) force, or electrostatic pressure at TTFields frequencies. This model is supported by simulations of cells in different configurations. Computational studies were performed with Comsol Multiphysics software. Cell models were constituted of cytoplasm, membrane and extracellular matrix. A field of 1V/cm was generated at different frequencies between 10kHz and 1GHz. Maximal field amplification of X20 of the applied field (@200 kHz) was observed in a model of confluent cells with 5nm intercellular distance. Such field amplification could create electrostatic pressure on the membrane potentially leading to its deformation and to stress on the cytoskeleton. Analytical calculations show the field gradient could result in DEP forces of ~10pN on the membrane. Such force could potentially disrupt the membrane or junctions. Results show that a 10nm pore in membrane would lead to a 450 times amplification in the pore’s vicinity, potentially resulting in forces of between 0.1pN and 100pN on intracellular structures. Those forces are sufficient for disrupting microtubules. Specific Absorption Rates of up to 106 W/kg were observed in the vicinity of the pore, suggesting that strong thermal effects may also explain the effect of TTFields on cells. Our generic analytical model predicts the conditions for field amplification at TTFields frequencies.

Abstract 1435: The distribution of Tumor Treating Fields is affected by cell confluence and pores in the membrane

Introduction: Better understanding of the interaction between Tumor Treating Fields (TTFields) and living cells would help to elaborate on its mechanism of action. Numerical simulations investigating the electric field distribution within isolated cells have shown that during metaphase a uniform electric field forms within the rounded cells, and during cytokinesis a non-uniform field forms at the furrow, leading to strong dielectrophoretic (DEP) forces that can disrupt cell division. However, preclinical studies have shown that TTFields influence cells during earlier stages of cell division. Hence, field non-uniformity within the cell during cytokinesis cannot provide a full explanation for how TTFields exerts an anti-mitotic effect on cells. We hypothesized that strong DEP forces could arise at the boundaries between cells and in pores on the membrane when applying TTFields to cell culture. We tested this hypothesis by using numerical simulations to investigate how the clustering of cells and pores within the membrane influence TTFields distribution.

Methods: COMSOL was used to numerically simulate delivery of TTFields to clusters of round cells placed in a hexagonal arrangement. The influence of the distance between the cells on field distribution was investigated. The effect of pores in the cell membrane on field distribution was also investigated. A generic analytical model was developed for predicting conditions for field amplification in the TTFields frequencies.

Results: Placing round cells in clusters separated by ~10 nm resulted in regions of highly non-uniform fields within the cells and very strong DEP forces at the intercellular level. Maximum field intensities between cells were observed at 200 kHz. Very strong gradients in the electric field were observed around pores placed in the membrane, and a strong field amplification was observed at 200 kHz regardless of the pore size. For a 10 nm pore, up to 450 V/cm is generated at the pore's vicinity. 100 nm pores generate more than 130 V/cm for an applied external field of 1 V/cm. Electroporation generates enough energy for overcoming the internal KT energy at pores that are ≤30 nm and may allow for dipole alignment.

Conclusions: Cells in close proximity to one another creates gradients in the electric field, and are associated with strong DEP forces that enhance the effects of TTFields on cells. Strong DEP forces in the membrane may provide a physical mechanism by which TTFields enhance membrane permeability. The strong field amplification could cause local heating, particle diffusion, and impact the cytoskeleton in the vicinity of membrane pores. These simulations have validated a generic model that predicts the conditions for strong field amplifications in cells at TTFields frequencies, allowing further elaboration of the mechanism of action. Our model fits well with other analytical models; the furrow model, cells in confluence, or electroporation.

Citation Format: Tal Marciano, Shay Levi, Eduard Fedorov, Zeev Bomzon. The distribution of Tumor Treating Fields is affected by cell confluence and pores in the membrane [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1435.

Abstract PO-076: First steps towards a framework for Tumor Treating Fields dosimetry and treatment planning

Introduction: In 2019 a study establishing the connection between Tumor Treating Fields (dose) at the tumor bed and overall survival in newly diagnosed Glioblastoma patients was published [1]. The investigators created realistic computational models of 340 newly diagnosed Glioblastoma patients that received TTFields as part of the EF-14 clinical trial. Computational models of the patients were created, and finite element simulations used to evaluate TTFields dose at the tumor bed comprising the region of enhancing tumor as well as a 3mm boundary zone surrounding the tumor and resection cavity. Their analysis showed a connection between the average field power of the field delivered to this region and patient survival. This study provide rationale for TTFields treatment planning, in which computational models are used in order to determine how best to place TTFields transducer arrays on the body to enhance patient outcome. Here we discuss a workflow we have developed for performing TTFields treatment planning a practical manner. Methods: TTFields treatment planning involves several steps including: (a) importing of patient imaging data into the treatment planning system (b) creation of an accurate patient model (c) defining a target region-the region in which TTFields dose should be optimized (d) optimization phase in which numerical simulations and optimization algorithms are used to optimal placement of the arrays (referred to as a treatment plan) (d) evaluation of the treatment plan and sign off. Here we present a practical framework for this procedure. Results: To framework utilizes a combination of T1c MRI and CT images in order to create a patient model. The images are first fused and the patient model created by semi-automatic segmentation of the images. Electric properties are assigned to each tissue type according to empirical values reported in the literature. The user selects the target region in which to optimize TTFields dose. Standard practice is to define a target region consistent with that used by Ballo et. al. [1]. Model quality is evaluated by the user, and if sufficient, optimization is initiated. During optimization, an iterative algorithm incorporating finite element simulations is used to identify optimal array layouts. The algorithm attempts to identify a layout that maximizes TTFields dose in the target region. Finally, the user is presented with a small set of (up to 5) layouts including the optimal layout. A set of color maps and dose Volume Histograms enable the user to select a treatment plan for the patient. Summary: We have developed a practical framework for TTFields treatment planning that in the future may be integrated into standard clinical practice when treating patients with TTFields.

Citation Format: Zeev Bomzon, Noa Urman, Shay Levi, Ariel Naveh. First steps towards a framework for Tumor Treating Fields dosimetry and treatment planning [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-076.

NIMG-58. THE EFFECT OF CELL CONFLUENCE ON THE DISTRIBUTION OF TUMOR TREATING FIELDS

BACKGROUND

Tumor Treating Fields (TTFields) are known to exert anti-mitotic effects on cells. Numerical simulations investigating the electric field distribution within isolated cells have been reported. These studies have shown that during metaphase a uniform electric field forms within the rounded cells. This field is thought to disrupt spindle formation through alignment of the tubulin dimers with the field. Simulations also show that during cytokinesis, a non-uniform electric field forms at the furrow, leading to strong dielectrophoretic forces that further disrupt cell division. Cells in the tumor are densely packed. We used numerical simulations to investigate how the clustering of cells influences TTFields distribution.

METHODS

COMSOL was used to numerically simulate delivery of TTFields to clusters of round cells placed in a hexagonal arrangement. The influence of the distance between the cells on field distribution was investigated. The effect of pores in the cell membrane on field distribution was also investigated.

RESULTS

Placing round cells in clusters resulted in regions of highly non-uniform fields within the cells. Strong gradients in the electric field were also observed around pores placed in the membrane. Non-uniformity and gradients in the field could result in strong dielectrophoretic forces capable of disrupting key cellular structures such as the cytoskeleton and mitotic spindle, as well as cell membrane integrity.

CONCLUSIONS

The placement of cells in close proximity to one another creates gradients in the electric field, which could be associated with very strong dielectrophoretic forces that enhance the effects of TTFields on cells. Strong dielectrophoretic forces were also observed around the membrane pores. Previous studies have reported that TTFields increases membrane permeability [Chang et al Cell Death Discovery. 2018]. The strong dielectrophoretic forces in the membrane may provide a physical mechanism by which TTFields enhance membrane permeability.

Feasibility of encouraging participation in colorectal cancer screening campaigns by motivating people through the social network, Facebook

AIM

To describe the results of a feasibility phase and the expected results of a new approach to increase the participation rate in a Colorectal Cancer Organized Screening Program (CRCSP) through Facebook awareness messages.

METHOD

This approach targets people aged 50-74 years, who reside in an urban deprived area and regularly connect to Facebook. The feasibility phase ran over 2 months (December 2018 and January 2019) in six municipalities (Seine-Saint-Denis, France). The full provisional campaign will run over a year. The approach consists of sending electronic awareness messages on the importance of screening for colorectal cancer using a specific Facebook module. Subjects who consent to screening complete a test-kit application form. The eligibility of each subject to participate in screening is determined by a doctor before the kit is sent out.

RESULTS

A total of 39 900 people were reached by the feasibility phase campaign, and 9200 were able to watch at least one Facebook message/video. Of those, 4450 people logged to learn more about the CRCSP, 298 applied for a test kit, 160 test kit applicants were eligible to participate and the test completion rate was 41.9%. According to these feasibility results, 366 120 targeted people would connect regularly in the tested area, 141 541 of whom would be interested in a specific promotional message posted on Facebook. Requests could be made for 9770 kits, with 5246 people being eligible to participate in screening. The expected test-completion rate is estimated at 42%-89%. This would represent 5%-11% of the tests carried out in the area during the same period by 'classical' CRCSP.

CONCLUSION

Implementation of the Facebook strategy would significantly improve the rate of participation in the CRCSP by mobilizing people with no previous participation, including younger subjects.

Abstract 44: TTFields dose distribution alters tumor growth patterns: An imaging-based analysis of the randomized phase 3 EF-14 trial

Introduction: The pivotal phase 3 EF-14 trial revealed extended Overall Survival (OS) and Progression Free Survival (PFS) in newly Diagnosed Glioblastoma (ndGBM) patients that received Tumor Treating Fields + chemoradiation vs. patients that received chemoradiation alone. The effect of TTFields is dose-dependent, with improved outcomes for patients who received higher doses of TTFields to the tumor bed [1]. Recent studies have also shown that TTFields influences tumor progression patterns in patients in a dose-dependent manner, with recurrence more likely to occur in regions of the brain in which field intensities are lower. This study also revealed that distal progressions are more common in ndGBM patients treated with TTFields_chemoradiation vs. patients treated with chemoradiation alone [2]. Thus it seems that a major influence of TTFields is to enhance local control of the primary lesion. Here we present an analysis testing this hypothesis by analyzing tumor growth rates in patients who participated in the EF-14 trial.

Methods: Biopsy patients of the EF-14 trial who exhibited radiological progression were included in this study (treatment: N=37/60, control: N=12/29). Volumes of enhancing tumor were segmented on T1-contrast MRIs at baseline and at progression. The tumor Specific Growth Rate (SGR) was calculated as: Specific_Growth_Rate=(ln(v0)-ln(v1))/dt. Here, v0 represents tumor volume at baseline, v1 represents tumor volume at progression, and dt represents the time to progression. This equation models tumor volume as increasing exponentially over time [3]. The distribution of growth rates in the treatment and control arms were compared. The analysis was restricted to biopsy-only patients since the definition of tumor volume is ambiguous in patients that underwent resection, as a large portion of the tumor has been removed.

Results: The median growth rate was lower in the treatment arm than in the control. (control: 0.14±0.12 mL/month, TTFields -0.011±0.11 mL/month, p<0.008 Wilcoxon rank-sum).

Discussion and conclusions: This study suggests that TTFields does indeed enhance local control of the tumor, significantly inhibiting the growth rate of the primary lesion. In this context, is worth noting that standard practice is to plan placement of the transducer arrays used to deliver TTFields in order to maximize dose delivered to the tumor. Thus, the results of this study support the hypothesis that adaptive treatment planning, in which the transducer array layout is periodically changed in order to dynamically target regions in which progression is observed, may help to improve patient outcomes.

References: [1] Ballo, Matthew, et al. IJRBOP (2019) [2] S. Jeyapalan et. al., presented at ASTRO 2019 [3] Stensjøen, Anne Line, et al. Neuro-oncology (2015)

Citation Format: Ze'ev Bomzon, Noa Urman, Shay Levi, Gitit Lavy-Shahaf. TTFields dose distribution alters tumor growth patterns: An imaging-based analysis of the randomized phase 3 EF-14 trial [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 44.

Measurement of Ferritin-Bearing Lymphocytes in Man. Preliminary Studies on the Use of Monoclonal Antibodies Specific for the L and H Subunits of Ferritin

We used the monoclonal antibodies LFO3 (specific for the L subunit of ferritin) and 2A4 (specific for the H subunit) in an indirect immunofluorescence test for enumerating ferritin-bearing lymphocytes (FBL). In 13 normal subjects, the geometric mean value of FBL was 4 % (range 0–13 %) with the monoclonal antibody LFO3, and 3 % (range 0–8 %) with the monoclonal antibody 2A4. Values in 5 subjects with transfusional iron overload and increased plasma L-type ferritin concentration were 5 % (4–7 %) and 3 % (2–4 %), respectively, which is similar to those in normal subjects. Thirteen patients with malignant disease had normal to increased values for plasma ferritin; the circulating protein was largely of L-type with undetectable or very low concentrations of H-type ferritin. In the same patients, the percentage of FBL was greater with the monoclonal antibody 2A4 (geometric mean value 8 %; range 3–12 %) than with the monoclonal antibody LFO3 (geometric mean value 3 %; range, 1–7 %). It is concluded that acidic and basic isoferritins can be differently expressed on the surface of peripheral blood lymphocytes, and that the monoclonal 2A4 could be particularly useful in the measurement of FBL in patients with malignancy.

Development of a Decision Guide — Optimal Discriminators for Meningitis as Determined by Statistical Analysis

Recently physician extenders (pediatric nurse practitioners, corpsmen) have been assuming increased clinical responsibilities in primary health care delivery. To assure that certain medical standards are being met, decision guides (clinical algorithms) offer one acceptable mechanism. In developing a decision guide for meningitis in children, 193 cases were reviewed and statistically analyzed to determine optimal clinical discriminators for this disease. A statistical technique was used to assign numerical weights to various signs and symptoms so that the sum of the weights for present symptoms produces a discriminant equation for the diagnosis of meningitis. Optimal clinical discriminators as determined through the statistical techniques reveal a close association with presently known signs and symptoms indicative of meningitis in children. The optimal clinical discriminators were : nuchal rigidity, bulging fontanel, altered sensorium, seizure, and fever plus Kernig/Brudzinski sign. It is reasoned that this statistical technique has applicability for developing optimal clinical discriminators for diseases and that this technique will also lead to the development of more reliable decision guides.

Stimulation of aerobic degradation of bentazone, mecoprop and dichlorprop by oxygen addition to aquifer sediment

In order to investigate aerobic degradation potential for the herbicides bentazone, mecoprop and dichlorprop, anaerobic groundwater samples from two monitoring and three drinking water wells near a drinking water abstraction field in Nybølle, Denmark, were screened for their degradation potential for the herbicides. In the presence of oxygen (14)C-labelled bentazone and mecoprop were removed significantly from the two monitoring wells' groundwater samples. Oxygen was added to microcosms in order to investigate whether different oxygen concentrations stimulate the biodegradation of the three herbicides in microcosms using groundwater and sandy aquifer materials. To maintain a certain oxygen concentration this level was measured from the outside of the bottles with a fibre oxygen meter using oxygen-sensitive luminescent sensor foil mounted inside the microcosm, to which supplementary oxygen was added. The highest oxygen concentrations (corresponding to 4-11 mg L(-1)) stimulated degradation (a 14-27% increase for mecoprop, 3-9% for dichlorprop and 15-20% for bentazone) over an experimental period of 200 days. Oxygen was required to biodegrade the herbicides, since no degradation was observed under anaerobic conditions. This is the first time bentazone degradation has been observed in aquifer material at low oxygen concentrations (2 mg L(-1)). The sediment had substantial oxygen consumption (0.92-1.45O2 g(-1)dw over 200 days) and oxygen was depleted rapidly in most incubations soon after its addition, which might be due to the oxidation of organic matter and other reduced species such as Fe(2+), S(2-) and Mn in sediment before the biodegradation of herbicides takes place. This study suggests that oxygen enhancement around a drinking water abstraction field could stimulate the bioremediation of diffuse source contamination.

Association between the oxytocin receptor (OXTR) gene and autism: relationship to Vineland Adaptive Behavior Scales and cognition

Evidence both from animal and human studies suggests that common polymorphisms in the oxytocin receptor (OXTR) gene are likely candidates to confer risk for autism spectrum disorders (ASD). In lower mammals, oxytocin is important in a wide range of social behaviors, and recent human studies have shown that administration of oxytocin modulates behavior in both clinical and non-clinical groups. Additionally, two linkage studies and two recent association investigations also underscore a possible role for the OXTR gene in predisposing to ASD. We undertook a comprehensive study of all 18 tagged SNPs across the entire OXTR gene region identified using HapMap data and the Haploview algorithm. Altogether 152 subjects diagnosed with ASDs (that is, DSM IV autistic disorder or pervasive developmental disorder--NOS) from 133 families were genotyped (parents and affected siblings). Both individual SNPs and haplotypes were tested for association using family-based association tests as provided in the UNPHASED set of programs. Significant association with single SNPs and haplotypes (global P-values <0.05, following permutation test adjustment) were observed with ASD. Association was also observed with IQ and the Vineland Adaptive Behavior Scales (VABS). In particular, a five-locus haplotype block (rs237897-rs13316193-rs237889-rs2254298-rs2268494) was significantly associated with ASD (nominal global P=0.000019; adjusted global P=0.009) and a single haplotype (carried by 7% of the population) within that block showed highly significant association (P=0.00005). This is the third association study, in a third ethnic group, showing that SNPs and haplotypes in the OXTR gene confer risk for ASD. The current investigation also shows association with IQ and total VABS scores (as well as the communication, daily living skills and socialization subdomains), suggesting that this gene shapes both cognition and daily living skills that may cross diagnostic boundaries.

Association between the arginine vasopressin 1a receptor (AVPR1a) gene and autism in a family-based study: mediation by socialization skills

We examined three microsatellites in the arginine vasopressin 1a receptor gene (AVPR1a), two in the promoter region (RS1 and RS3) and an intronic microsatellite (AVR), for association with autism as well as scores on the Vineland Adaptive Behavior Scale (VABS), the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Scale-Generic (ADOS-G), measures that are widely used to diagnose autism spectrum disorders. We tested for association between the AVPR1a microsatellites and autism in 116 families (128 probands diagnosed with the ADI-R and ADOS-G using a family-based association test (UNPHASED)). Testing each individual microsatellite showed significant transmission disequilibrium in these families with the AVR intronic microsatellite (UNPHASED: LRS=11.46, global P-value=0.009, df=3). Haplotype analysis of three microsatellites also showed significant association (LRS=144.94, df=103, global P=0.004). Additionally, significant association is observed between these three microsatellite haplotypes and the VABS scores (P=0.009), with the ADI-R (P=0.009) and the ADOS-G (P=0.0000765) diagnoses of autistic disorder versus pervasive developmental disorder-not otherwise specified (PDD-NOS) that were available for 47 of these probands. This is the third consecutive report of an association between the AVPR1a gene and autism spectrum disorders and in the current study a third microsatellite is shown to be associated with autism spectrum disorders as well as haplotypes consisting of all three markers. Importantly, the association appears to be mainly mediated by the role of the AVPR1a gene in shaping socialization skills, similar to its role in lower vertebrates.Molecular Psychiatry (2006) 11, 488-494. doi:10.1038/sj.mp.4001812; published online 7 March 2006.

Flow cytometry evaluation of erythroid dysplasia in patients with myelodysplastic syndrome

Erythroid dysplasia is the pathologic hallmark of myelodysplastic syndromes (MDS). To develop a quantitative flow-cytometry approach to its evaluation, we analyzed the expression of CD71, CD105, cytosolic H-ferritin (HF), cytosolic L-ferritin (LF) and mitochondrial ferritin (MtF) in erythroblasts from 104 MDS patients, 69 pathologic control patients and 19 healthy subjects. Six-parameter, 4-color flow cytometry was employed, and data were expressed as mean fluorescence intensity. Compared with pathologic and healthy controls, MDS patients had higher expression of HF (P < 0.001) and CD105 (P < 0.001), and lower expression of CD71 (P < 0.001). MtF was specifically detected in MDS with ringed sideroblasts, and there was a close relationship between its expression and Prussian blue staining (r = 0.89, P < 0.001). In vitro cultures of myelodysplastic hematopoietic progenitors showed that both HF and MtF were expressed at a very early stage of erythroid differentiation, and that MtF expression is specifically related to mitochondrial iron loading. A classification function based on expression levels of HF, CD71 and CD105 allowed us to correctly classify > 95% of MDS patients. This flow-cytometry approach provides an accurate quantitative evaluation of erythroid dysplasia and allows a reliable diagnosis of sideroblastic anemia, and may therefore be a useful tool in the work-up of patients with MDS.

Monolayer-functionalized microfluidics devices for optical sensing of acidity

This paper describes the integration of opto-chemosensors in microfluidics networks. Our technique exploits the internal surface of the network as a platform to build a sensing system by coating the surface with a self-assembled monolayer and subsequently binding a fluorescent sensing molecule to the monolayer. Fluorescent molecules were used that can switch between a fluorescent and a non-fluorescent state, depending on the acidity of the surrounding solution. Two systems were investigated. The first employs surface confinement of a Rhodamine B dye in a glass micro channel that serves as a molecular switch in organic solutions. Upon rinsing the micro channels with acidic or basic solutions it was possible to switch between the fluorescent and non-fluorescent forms reversibly. Moreover, this system could be used to monitor the mixing of two solutions of different acidity along the micro channel. To widen the scope of optical sensing in micro channels an Oregon Green dye derivative was immobilized, which functions as a sensing molecule for pH differences in aqueous solutions. In this case, a hybrid system was used consisting of a glass slide and PDMS channels. The fluorescence intensity was found to be directly correlated to the pH of the solution in contact, indicating the possibility of using such a system as a pH sensor. These systems allow real-time measurements and can be easily implemented in micro- and nanofluidics systems thus enabling analysis of extremely small sample volumes in a fast and reproducible manner.

The Role of Autumn Infections in the Progression of Fire Blight Symptoms in Perennial Pear Branches

The role of autumn infections in the progression of fire blight (caused by Erwinia amylovora) symptoms in perennial pear branches was studied in orchard-grown trees in Israel. The extent of symptom progression and the final length of fire blight cankers in perennial branches were variably affected by the vigor of the trees and the season of infection. Following spring infections, when all trees supported active shoot growth, fire blight symptoms progressed more rapidly and to longer distances in trees that exhibited high vigor (i.e., with numerous annual shoots on most terminal branches) than in low-vigor trees (i.e., few or no annual shoots on terminal branches). Irrespective of the vigor of the trees, the progression of fire blight symptoms in perennial branches ceased between mid-May and mid-July, and only a small proportion (0 to 14.2%) of the infections had invaded main limbs or trunks of trees. Progression of fire blight symptoms following autumn infections was related to the preceding summer (August to No-vember) shoot regrowth: in trees in which the shoots did not restore their growth in the summer, the rate of symptom progression in perennial branches was higher in trees with a low vigor than in those with a high vigor, whereas for those with summer regrowth the relationship between rates of symptom expression was reversed. Irrespective of the vigor group and of whether there was summer regrowth, symptoms in perennial branches continued to progress through the winter until the following spring. Most of the autumn infections (50 to 78.5%) that developed in susceptible trees had invaded main limbs or trunks of trees. The results of this study indicate that factors related to host phenology and physiology, rather than factors related to environmental influences (such as temperature), govern the extent, rate, and duration of fire blight progression in perennial pear branches. Furthermore, it turned out that autumn infections play a substantial role in fire blight epidemiology in Israel.

New Considerations for Pruning in Management of Fire Blight in Pears

The efficacy of pruning infected pear tissues to combat fire blight (caused by Erwinia amylovora) was evaluated in two sets of experiments conducted during 1999 to 2001 in Israel. In the first set of two experiments, diseased tissues were removed soon after the observation of blossom infections. Pruning was effective in 0 to 50% of the treated trees, and resulted in complete eradication of E. amylovora. In the remaining trees, pruning not only did not result in eradication of the bacteria from the tree tissues, it made the situation worse, as the disease had invaded the main branches and limbs of a significantly larger proportion of pruned trees than of non-pruned ones, because of alteration of the physiological status of the host plant by pruning. In the five experiments of the second set, the efficacy of pruning fire blight infections on main branches and limbs was studied; the time of pruning varied among the experiments. Effectiveness of cutting and removing infected branches and limbs was linearly related to time of treatment: the efficacy of pruning improved significantly with lateness of the treatment. The best results were obtained when pruning was carried out while the trees were dormant, in December: none of these trees had a severely infected canopy the following spring. Based on the results obtained in this study, it was concluded that factors related to all three components of the disease triangle (i.e., pathogen, host, and environment), rather than only the actual presence of diseased tissues, should be taken into account in considering the need for cutting and removing fire blight-diseased tissues. Accordingly, recommendations for Israeli growers were revised and updated.

Short-term outcome of isolated and associated congenital heart defects in relation to antenatal ultrasound screening

OBJECTIVE

To investigate the outcome of fetuses affected by congenital heart defects (CHD), either detected or undetected at ultrasound screening, according to their complexity and severity.

DESIGN

The study group comprised 3633 malformed fetuses entered into the Eurofetus database of which 798 had CHD. We compared the short-term outcome in cases where a CHD was detected by ultrasound screening with that in cases where a CHD was not detected. Isolated and associated CHD (ICHD and ACHD) and the degree of severity of defects were considered separately. Outcome data included termination of pregnancy (TOP), intrauterine fetal death, neonatal death (< 6 days after birth), gestational age at diagnosis and at delivery, mode of delivery and birth weight.

RESULTS

Of the 798 fetuses with CHD, 595 had ICHD and 203 had ACHD. The diagnosis of an anomaly was made significantly earlier in ACHD cases. TOP was chosen in 28% of cases with a prenatal diagnosis of CHD, 20% for ICHD and 37% for ACHD (P < 0.001). The survival rate of antenatally diagnosed fetuses was lower in those with ACHD than in those with ICHD (P < 0.001) and lower for fetuses with antenatal diagnosis than with postnatal diagnosis (P < 0.001); this was due to significant differences in the complexity and severity of the defect. Premature delivery (< 32 weeks) was more frequent in fetuses in which an antenatal diagnosis of CHD had been made. Severe CHD were diagnosed earlier and were associated with a higher rate of TOP and spontaneous loss.

CONCLUSIONS

The severity of CHD has a positive influence on the sensitivity of screening but a negative influence on the outcome. CHD that are not diagnosed antenatally include a high proportion of benign malformations. This explains the apparent paradox of a poorer outcome in fetuses in which a CHD was detected prenatally compared to those fetuses in which the defect was undetected prenatally. However, prenatal diagnosis provides parents with the option of TOP or of preventive care in specialized centers.

Sensitivity of ultrasound screening for congenital anomalies in unselected pregnancies

OBJECTIVE

To assess the influence of heart defect frequency and severity on screening sensitivity of the entire spectrum of congenital anomalies (CA) and on detection rate of congenital heart defect (CHD) when performing routine ultrasound screening in unselected pregnant women.

STUDY DESIGN

Secondary analysis was performed on data from Eurofetus, a large international collaborative study of ultrasound screening for CA in unselected populations. The present study addressed the relations (i) between the frequency of CHD in the screened population and the global sensitivity of ultrasound in detecting CA; (ii) between frequency of ventricular septum defect (VSD) and detection rate of CA and CHD; and (iii) between seriousness of CHD and CHD sensitivity.

RESULTS

A negative correlation (p<0.001) between CHD frequency and CA sensitivity was observed in this study. Likewise, a negative correlation was also found between frequency of VSD and sensitivity for CA or CHD detection (p<0.001). In addition, a positive significant relationship (p<0.001) was observed between sensitivity and severity of CHD.

CONCLUSION

A low CHD frequency introduces bias in CA and CHD sensitivity evaluation. Incomplete assessment of fetal and neonatal malformations brings on systematic error, leading to the pre-eminence of severe defects in the studied population sample and artificially improving sensitivity figures. On the other hand, from a clinician's viewpoint, the higher sensitivity for severe defect is welcomed, since their detection is most crucial for appropriate management.