A novel nonsense variant in REEP6 is involved in a sporadic rod-cone dystrophy case

Rod-cone dystrophy (RCD), also called retinitis pigmentosa, is the most common form of progressive inherited retinal disorders secondary to photoreceptor degeneration. It is a genetically heterogeneous disease characterized by night blindness, followed by visual field constriction and, in most severe cases, total blindness. The aim of our study was to identify the underlying gene defect leading to severe RCD in a 60-year-old woman. The patient's DNA was investigated by targeted next generation sequencing followed by whole exome sequencing. A novel nonsense variant, c.267G>A p.(Trp89*), was identified at a homozygous state in the proband in REEP6 gene, recently reported mutated in 7 unrelated families with RCD. Further functional studies will help to understand the physiopathology associated with REEP6 mutations that may be linked to a protein trafficking defect.

Abstract P6-18-18: Phase I trial of eribulin and everolimus in patients with metastatic triple negative breast cancer

Background: Alteration of PI3K/Akt/mTOR pathway is the most common genomic abnormality detected in triple negative breast cancer (TNBC). Everolimus acts synergistically with eribulin in inducing apoptosis in TNBC cell lines and xenografts in our preclinical study. This phase I trial was designed to test the safety and tolerability of combining eribulin and everolimus in patients (pts) with metastatic TNBC.

Methods: The overall objective of this study was to describe the safety and toxicities of the combination. The secondary objective was to assess activity based on response rate (RR) and progression free survival (PFS). Eligibility criteria included pts with metastatic TNBC, ECOG 0-2, 0-3 lines of prior chemotherapy in metastatic setting, and prior treatment with anthracycline and/or taxane therapy. The study utilized the toxicity equivalence range (TEQR) design with a target equivalence range for dose-limiting toxicities (DLTs) of 0.20-0.35. The recommended phase 2 dose (RP2D) will be the dose closest to the target of 0.25 below 0.51 based on isotonic regression.Three dosing levels of the combinations were tested: level A1 (everolimus 5mg daily; eribulin 1.4 mg/m2 days 1, 8 every 3 weeks), level A2 (everolimus 7.5mg daily; eribulin 1.4 mg/m2, days 1, 8 every 3 weeks), level B1(everolimus 5mg daily; eribulin 1.1 mg/m2 days 1, 8 every 3 weeks). Nanostring RNA analysis and genomic mutation analysis were conducted in 16 pts with available tumor tissue.

Results: A total of 27 pts were enrolled. Median age was 55 years (range 36-76). Two pts were ineligible due to HER2+ on repeat biopsy and were only included in the toxicity analysis. Dose level B1 (everolimus 5mg daily and eribulin 1.1 mg/m2 days 1, 8 every 3 weeks) was determined to be the RP2D doses. The DLTs were neutropenia, stomatitis and hyperglycemia. Across all cycles, 59% (16/27) had a ≥ Gr3 toxicity attributed to treatment at the possible or above level. 44% (12/27) had Gr3 heme-toxicities. The most common toxicities were ≥ Gr3 neutropenia (10 pts), Gr3 lymphopenia (6 pts) and ≥ Gr3 leukopenia (7 pts). 33% (9/27) had Gr3 non-heme toxicities. The most common were Gr3 stomatitis (3 pts), Gr3 hyperglycemia (3 pts) and Gr3 fatigue (5 pts). The median number of cycles completed was 4 (0-8). 68% (17/25) had a dose modification or hold, 14 of 25 (56%) were for eribulin and 15 of 25 (60%) were for everolimus. Of 25 eligible pts, 8 (32%) achieved a best response as partial response, 11 (44%) had stable disease and 6 (24%) had progression. 80% (20/25) experienced progression by RECIST or showed clinical progression, and the median time to progression was 2.7 mo (95% CI (2.2, 4.6)). At the time of this analysis, 16 participants had died, median OS was 6.3 mo (95% CI (5.3, undefined)). Two pts are still being followed on treatment. PI3K-Akt-mTOR pathway genes and mutations profiles were studied.

Conclusion: Eribulin 1.1 mg/m2 days 1, 8 and everolimus 5mg daily was defined as the RP2D. Genomic analysis is currently underway to understand the molecular mechanisms of resistance.

Citation Format: Yuan Y, Yost S, Blanchard S, Yin H, Li M, Robinson K, Tang A, Martinez N, Leong L, Somlo G, Tank Patel N, Waisman J, Portnow J, Hurria A, Luu T-H, Mortimer J. Phase I trial of eribulin and everolimus in patients with metastatic triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-18.

Abstract P5-21-08: Tolerability of the combination of lapatinib and trastuzumab in older patients with HER2 positive metastatic breast cancer

Background: Older adults are less likely to be included in clinical trials leading to the approval of novel cancer treatments. The Institute of Medicine and ASCO have identified therapeutic phase II trials as a key research priority to increase the evidence base for older adults with cancer. While targeted therapies may represent a less toxic option for older patients, few trials have studied their tolerability and efficacy in older adults. Here, we present a phase II study (NCT01273610) of the combination of trastuzumab and lapatinib in older patients with HER2+ metastatic breast cancer (MBC), incorporating geriatric oncology principles in the study design.

Methods: Patients age ≥ 60 years with MBC and any number of prior chemotherapy (CT) lines received trastuzumab (either 4mg/kg loading dose followed by 2mg/kg weekly or 8mg/kg followed by 6mg/kg q/3 weeks) plus lapatinib 1000 mg/m2 daily in 21-day cycles. Patients completed a pre-treatment geriatric assessment including measures of function, comorbidity, cognition, nutrition, and psychosocial status. A toxicity risk score developed for older adults receiving cytotoxic CT was calculated for each patient (Hurria et al. JCO 2011 & 2016). Relationships between tolerability (dose reductions and grade (G) ≥ 3 toxicity attributed to treatment) and risk score analyzed using a log2 transformation were assessed using generalized linear models, Student's t tests, and Fisher's exact test. Response rate (RR) and progression free survival (PFS) were evaluated.

Results: 40 patients (mean age 72 [60-92]) were accrued from 04/11 to 05/15. 25% (n = 10) were ≥ 75 years of age. 65% of patients (n = 26) had HR+ tumors and 35% (n = 14) were receiving ≥ 3rd line treatment. Median number of cycles was 4 (0-28). RR was 23% (n = 9, 95% CI 11-38%; 1 complete, 8 partial). 23% (n = 9) achieved stable disease. PFS was 2.7 months (95% CI 2.5-12). Based on the toxicity risk score, 21% (n = 8), 54% (n = 21), and 26% (n = 10) were at low, intermediate, and high risk. 70% (n = 28) of patients had G ≥ 2 toxicities and 20% (n = 8) G ≥ 3 toxicities. G 2 and 3 diarrhea occurred in 28% (n = 11) and 5% (n = 2) respectively. 5% (n = 2) were hospitalized due to treatment-related toxicity. No G ≥ 3 cardiac toxicities were observed. 23% of patients (n = 9) had treatment delays, and 43% (n = 17) required a lapatinib dose reduction. The mean toxicity risk score was higher in patients who required dose reductions (Student's t: p = 0.02). No statistically significant relationship was found between toxicity risk scores and the presence of G ≥ 3 treatment toxicity (logistic regression: OR = 3.08, 95% CI [0.54, 21.2], p = 0.22).

Conclusions: Among older patients with MBC (79% at intermediate or high risk of G ≥ 3 cytotoxic CT toxicity), trastuzumab and lapatinib were well tolerated, with only 20% experiencing G3 toxicities. The toxicity risk score was not found to be significantly related with treatment toxicity, which may be explained by the very low incidence of G3 events. Patients with a low toxicity risk score were not likely to require a lapatinib dose reduction.

Citation Format: O'Connor T, Soto-Perez-de-Celis E, Blanchard S, Chapman A, Kimmick G, Muss H, Luu T, Waisman JR, Li D, Mortimer J, Yuan Y, Somlo G, Stewart D, Katheria V, Levi A, Hurria A. Tolerability of the combination of lapatinib and trastuzumab in older patients with HER2 positive metastatic breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-08.

Abstract OT1-02-05: Phase II clinical trial of neratinib in patients 60 and older with HER2 over-expressed or mutated breast cancer: Trial design considerations for older adults

Background: This study addresses a key knowledge gap identified by the Institute of Medicine report on quality cancer care. Although there has been a growth in the number of targeted agents approved for the treatment of breast cancer, there are limited data regarding the efficacy, toxicity, and management of side effects in older adults. Neratinib is a potent oral small molecule tyrosine kinase inhibitor. Early clinical data have demonstrated the activity of neratinib in patients who have already progressed through HER2 targeted therapies. This study is designed to evaluate the tolerability and toxicity profile of neratinib in older adults with metastatic breast cancer (MBC) incorporating geriatric oncology design considerations.

Trial Design: This is an open label, single arm, phase II study of single agent neratinib in patients with HER2 positive MBC. Neratinib is given at 240mg orally in 28 day cycles. Unique factors of this geriatric oncology trial design include: 1) pre-treatment and on-treatment geriatric assessment; 2) additional nurse toxicity visits; 3) an algorithm for aggressive management of diarrhea; 4) measurements of the pharmacokinetics (PK) of neratinib; 5) inclusion of biomarkers of aging; 6) measurement of patient adherence; and 7) evaluation of quality of life.

Eligibility Criteria: Patients must be age≥60 with histologically-proven HER2 positive MBC or MBC with HER2 receptor activating mutations. There is no limitation on the number of previous lines of therapy, but patients must have adequate organ and bone marrow functions, and a baseline LVEF ≥ 50%. Exclusion Criteria include: prior treatment with neratinib; major surgery within 28 days; uncontrolled cardiac disease; concurrent use of digoxin; or chronic diarrhea.

Specific Aims: The primary objective of this study is to identify the rate of grade 2 or higher toxicities attributed to neratinib in adult age ≥60 with HER2 over-expressing breast cancer. The secondary objectives are to describe the full toxicity profile (including all grades of gastrointestinal toxicities); to estimate the rate of dose reduction, holds and hospitalizations; to describe the PK parameters; to estimate the adherence rate to neratinib; and to estimate the overall response, clinical benefit rate, progression-free and overall survival. Furthermore, we will explore the role of a cancer-specific geriatric assessment and serum biomarkers of aging (IL-6, CRP, and D-dimer) in predicting treatment toxicities and PK parameters.

Statistical Design: We plan to enroll 40 patients age ≥60 (at least 5 patients age 75 years or older, and no more than 15 patients 60-70) in order to assure that our sample is representative of the entire age range of older adults. Given a sample size of 40 subjects, the widest half-width of the 95% confidence limits for the rate of grade 2 or higher toxicities will be less than or equal to 0.16. An interim analysis will be performed after 20 subjects have been on study for at least one cycle.

Accrual goal: 40

Contact information: Yuan Yuan MD PhD, Email: yuyuan@coh.org.

Citation Format: Yuan Y, Blanchard S, Li D, Mortimer J, Waisman J, Somlo G, Yost S, Katheria V, Hurria A. Phase II clinical trial of neratinib in patients 60 and older with HER2 over-expressed or mutated breast cancer: Trial design considerations for older adults [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT1-02-05.

ARL2BP mutations account for 0.1% of autosomal recessive rod-cone dystrophies with the report of a novel splice variant

We report a novel ARL2BP splice site mutation after whole-exome sequencing (WES) applied to a Moroccan family including two sisters affected with autosomal recessive rod-cone dystrophy (arRCD). Subsequent analysis of 844 index cases did not reveal further pathogenic chances in ARL2BP indicating that mutations in ARL2B are a rare cause of arRCD (about 0.1%) in a large cohort of French patients.

Structure and ligand-based design of mTOR and PI3-kinase inhibitors leading to the clinical candidates VS-5584 (SB2343) and SB2602

Phosphoinositide 3-kinases (PI3Ks) and the mammalian target of rapamycin (mTOR) act as critical effectors in a commonly deregulated cell signaling pathway in human cancers. The abnormal activation of the PI3K/mTOR pathway has been shown to play a role in initiation, progression, and metastasis of human tumors. Being one of the most frequently activated pathways in cancer, much effort has been directed toward inhibition of the PI3K/mTOR pathway as a novel oncology therapy. Previous work by a number of groups has revealed several selective PI3K and dual mTOR/PI3K inhibitors. However, there are few reports of therapeutic agents with a pan-PI3K/mTOR inhibitory profile within a narrow concentration range. We therefore initiated a drug discovery project with the aim of discovering dual mTOR/PI3K inhibitors which would equipotently inhibit the 4 isoforms of PI3K, α, β, γ, and δ, and mTOR a compelling profile for powerful blockage of the PI3K/mTOR pathway. A pharmacophore model was generated and used for designing a series of novel compounds, based on a purine scaffold, which potently inhibited mTOR and PI3Ks. These compounds contained a phenol headgroup essential for binding to the target proteins. Early efforts concentrated on finding replacements for the phenol as it was rapidly conjugated resulting in a short half-life in vivo. Compounds with a variety of headgroups were docked into the PI3Kα and mTOR ATP-binding sites, and aminopyrimidine and aminopyrazine were found to make excellent phenol replacements. Further structure guided optimization of side chains in the 8- and 9-positions of the purine resulted in potent inhibitors with good PKDM properties. As the PI3 kinases play a role in insulin signaling, it is believed that targeting mTOR selectively may give the benefit of blocking the AKT-pathway while avoiding the potential side effects associated with PI3K inhibition. As a result we designed a further series of selective mTOR kinase inhibitors. The project was successfully concluded by progressing both a dual mTOR/PI3K inhibitor, SB2343, and a selective mTOR inhibitor, SB2602, into preclinical development. SB2343 has since entered phase 1 clinical development as VS-5584.

2-anilino-4-aryl-8H-purine derivatives as inhibitors of PDK1

A series of 2-anilino substituted 4-aryl-8H-purines were prepared as potent inhibitors of PDK1, a serine-threonine kinase thought to play a role in the PI3K/Akt signaling pathway, a key mediator of cancer cell growth, survival and tumorigenesis. The synthesis, SAR and ADME properties of this series of compounds are discussed culminating in the discovery of compound 6 which possessed sub-micromolar cell proliferation activity and 65% oral bioavailability in mice.

Discovery of kinase spectrum selective macrocycle (16E)-14-methyl-20-oxa-5,7,14,26-tetraazatetracyclo[19.3.1.1(2,6).1(8,12)]heptacosa-1(25),2(26),3,5,8(27),9,11,16,21,23-decaene (SB1317/TG02), a potent inhibitor of cyclin dependent kinases (CDKs), Janus kinase 2 (JAK2), and fms-like tyrosine kinase-3 (FLT3) for the treatment of cancer

Herein, we describe the design, synthesis, and SAR of a series of unique small molecule macrocycles that show spectrum selective kinase inhibition of CDKs, JAK2, and FLT3. The most promising leads were assessed in vitro for their inhibition of cancer cell proliferation, solubility, CYP450 inhibition, and microsomal stability. This screening cascade revealed 26 h as a preferred compound with target IC(50) of 13, 73, and 56 nM for CDK2, JAK2 and FLT3, respectively. Pharmacokinetic (PK) studies of 26 h in preclinical species showed good oral exposures. Oral efficacy was observed in colon (HCT-116) and lymphoma (Ramos) xenograft studies, in line with the observed PK/PD correlation. 26h (SB1317/TG02) was progressed into development in 2010 and is currently undergoing phase 1 clinical trials in advanced leukemias and multiple myeloma.

P5-19-05: Age-Related Changes in the Pharmacokinetics (pK), Response, and Toxicity of Weekly nab-Paclitaxel in Patients with Metastatic Breast Cancer (MBC)

Background: Although cancer is a disease of aging, few studies have evaluated the association between patient age and the pK or pharmacodynamics (pD) of cancer therapeutics. The goals of this study were 1) to evaluate the age-related changes in the pK and pD of weekly nab-paclitaxel in patients with MBC; 2) to determine response rate; and 3) to explore the relationship of age with pK and pD parameters (i.e., dose reductions, dose delays and grade ≥ 3 toxicities). Patients and Methods: Forty patients with MBC, receiving 1st or 2nd line chemotherapy, entered an IRB approved protocol to evaluate the age-related changes in the pK of weekly nab-paclitaxel administered at 100 mg/m2 IV for 3 weeks followed by a 1-week break. Patients were accrued from 4 age strata <50, 50–60, 60–70, and >70 years of age. Blood samples were collected for pK analysis with the first dose of nab-paclitaxel. Response was assessed every 2 cycles. Toxicity was graded using the NCI Common Toxicity Criteria for Adverse Events (v 3.0) and was adjudicated as attributable to nab-paclitaxel if it was possibly, probably, or definitely related. Linear regression analysis was used to examine the strength of the relationship between patient age and natural logarithm of 24 hour area under the curve (AUC). Two-sided two-sample t-tests were used to assess if there was a difference in mean age based on the presence of pD variables (i.e., dose reductions, dose delays and grade ≥ 3 toxicities). The significance level was set to 0.05.

Results: Of the 40 patients who entered the study, 39 (98%) were evaluable with a mean age of 60 (SD=13.4; min=30; max=81). Patients were accrued in the following age cohorts: <50 (n= 10; 26%), 50–60 (n= 5; 13%), 60–70 (n= 15; 38%), and >70 (n= 9; 23%) years of age. The median number of courses completed was 4 (min=1, max=21). The response rate was: 0% (n=0) CR, 31% (n=12) PR, 38% (n=15) SD. Grade 3 toxicity was experienced by 26% (n=10). We observed 8% (n=3) grade 3 hematological toxicities [neutrophils (n=1; 3%), leukocytes (n=2; 5%)] and 18% (n=7) grade 3 non-hematological toxicities [nausea and hypophosphatemia (n=1; 3%), diarrhea and infection without neutropenia (n=1; 3%), fatigue (n=2; 5%), hyponatremia (n=1; 3%), and infections without neutropenia (n=2; 5%)]. There were no cases of grade 4 or 5 toxicity. Grade 2 sensory neuropathy was experienced by 8% (n=3; no cases in the 70+ age cohort). Dose reductions or course delays were experienced by 62% (n=24) and 21% (n=8), respectively. There was a borderline significant positive association between age and natural logarithm of total nab-paclitaxel 24 hour AUC (coef=.01; se=.006; p=0.055; n=36). There were no differences in the mean ages based on the presence of grade 3 or higher toxicity (p =0.75), need for dose reductions (p=0.48), or need for dose delays (p=0.61).

Discussion: There is a borderline statistically significant relationship between age and 24 hour AUC but no differences in mean age based on pD variables (i.e., dose reductions, dose delays and grade ≥ 3 toxicities) were identified. The treatment is well-tolerated across all age groups.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-19-05.

Structure-based design of PDK1 inhibitors

A macrocyclic 2-anilino-4-phenyl-pyrimidine CDK/Flt3/JAK2 inhibitor was found to have moderate PDK1 activity. After docking into a PDK1 X-ray structure it was suggested that the pyrimidine ring could be substituted for a purine thereby increasing the number of hydrophobic contacts with the protein and forming an additional hydrogen bond to the kinase hinge. Deletion of the macrocyclic linker allowed a more rapid optimisation of the aromatic substituents as well as the introduction of an amino-amide solubility tag. This improved both binding to the enzyme and physiochemical properties without compromising ligand efficiency.

Discovery of the macrocycle 11-(2-pyrrolidin-1-yl-ethoxy)-14,19-dioxa-5,7,26-triaza-tetracyclo[19.3.1.1(2,6).1(8,12)]heptacosa-1(25),2(26),3,5,8,10,12(27),16,21,23-decaene (SB1518), a potent Janus kinase 2/fms-like tyrosine kinase-3 (JAK2/FLT3) inhibitor for the treatment of myelofibrosis and lymphoma

Discovery of the activating mutation V617F in Janus Kinase 2 (JAK2(V617F)), a tyrosine kinase critically involved in receptor signaling, recently ignited interest in JAK2 inhibitor therapy as a treatment for myelofibrosis (MF). Herein, we describe the design and synthesis of a series of small molecule 4-aryl-2-aminopyrimidine macrocycles and their biological evaluation against the JAK family of kinase enzymes and FLT3. The most promising leads were assessed for their in vitro ADME properties culminating in the discovery of 21c, a potent JAK2 (IC(50) = 23 and 19 nM for JAK2(WT) and JAK2(V617F), respectively) and FLT3 (IC(50) = 22 nM) inhibitor with selectivity against JAK1 and JAK3 (IC(50) = 1280 and 520 nM, respectively). Further profiling of 21c in preclinical species and mouse xenograft and allograft models is described. Compound 21c (SB1518) was selected as a development candidate and progressed into clinical trials where it is currently in phase 2 for MF and lymphoma.

Astrocytic protection of spinal motor neurons but not cortical neurons against loss of Als2/alsin function

Three neurodegenerative diseases affecting upper and/or lower motor neurons have been associated with loss of ALS2/Alsin function: juvenile amyotrophic lateral sclerosis, primary lateral sclerosis and infantile-onset ascending hereditary spastic paralysis. The distinct neuronal vulnerability and the role of glia in these diseases remains, however, unclear. We here demonstrate that alsin-depleted spinal motor neurons can be rescued from defective survival and axon growth by co-cultured astrocytes. The astrocytic rescue is mediated by a soluble protective factor rather than by cellular contact. Cortical neurons are intrinsically as vulnerable to alsin depletion as spinal motor neurons but cannot be rescued by co-cultured astrocytes. To our knowledge, these data provide the first example of non-cell-autonomous glial effects in a recessive form of motor neuron disease and a potential rationale for the higher vulnerability of upper versus lower motor neurons in ALS2/Alsin-linked disorders.

Structure-based design of Aurora A & B inhibitors

The Aurora family of serine/threonine kinases are mitotic regulators involved in centrosome duplication, formation of the bipolar mitotic spindle and the alignment of the chromosomes along the spindle. These proteins are frequently overexpressed in tumor cells as compared to normal cells and are therefore potential therapeutic oncology targets. An Aurora A high throughput screen revealed a promising sub-micromolar indazole-benzimidazole lead. Modification of the benzimidazole portion of the lead to a C2 linker with a phenyl ring was proposed to achieve novelty. Docking revealed that a conjugated linker was optimal and the resulting compounds were equipotent with the lead. Further structure-guided optimization of substituents on the 5 & 6 position of the indazole led to single digit nanomolar potency. The homology between the Aurora A & Aurora B kinase domains is 71% but their binding sites only differ at residues 212 & 217 (Aurora A numbering). However interactions with only the latter residue may be used for obtaining selectivity. An analysis of published Aurora A and Aurora B X-ray structures reveals subtle differences in the shape of the binding sites. This was exploited by introduction of appropriately sized substituents in the 4 & 6 position of the indazole leading to Aurora B selective inhibitors. Finally we calculate the conformational energy penalty of the putative bioactive conformation of our inhibitors and show that this property correlates well with the Aurora A binding affinity.

Impact of plasmid supercoiling on the efficacy of a rabies DNA vaccine to protect cats

As of today, most DNA vaccination trials have been performed with plasmid preparations highly enriched in supercoiled molecules (sc) and the importance of supercoiled versus open circular (oc) plasmid isoforms for vaccine immunogenicity has only received limited attention. This study demonstrated that a single rabies DNA vaccination fully protected cats against a lethal rabies challenge as early as 3 weeks post vaccination provided that the proportion of supercoiled isoform in the vaccinal solution is at least 48%. In contrast, vaccination with a plasmid containing only 20% of supercoiled molecules induced significant but only partial protection. Further, a single rabies DNA vaccination with plasmids containing at least 70% of supercoiled molecules triggered statistically significant specific antibody titers and specific Th-1 oriented cell-based immunity as early as 2 and 3 weeks post vaccination, respectively. It is concluded that the oc isoforms are less efficient than supercoiled isoforms at inducing a complete profile of immune responses. Therefore, it is proposed that the target threshold of supercoiling that must be met by a rabies DNA vaccine to guarantee optimal immune responses and protection, be set at 70% of supercoiled molecules in the vaccine solution.

Antenatal glucocorticoids blunt the functioning of the hypothalamic-pituitary-adrenal axis of neonates and disturb some behaviors in juveniles

Antenatal glucocorticoids are highly effective in preventing respiratory distress of premature babies but can induce physiological and behavioral disturbances in young infants as well as in animals. Therefore, the hypothalamic-pituitary-adrenal (HPA) axis of rat neonates, and the consequences on behavioral development of offspring have been studied after five antenatal injections of dexamethasone (DEX) or vehicle. DEX decreased offspring body weight at birth, and significantly delayed the normal growth for the first 3 weeks of life. This paralleled diminished behavioral performances measured on postnatal day 3 (righting reflex) and postnatal day 10 (grasping test). Circulating levels of adrenocorticotrophin (ACTH) and corticosterone were significantly decreased on postnatal day 1 and this was related to a diminution of HPA axis activity shown by the decrease of central expression of corticotropin releasing hormone (CRH) mRNA, immunoreactive content in paraventricular neurons (PVN) and in the median eminence endings were significantly decreased. On the other hand, expression of another secretagogue of ACTH, arginine vasopressin (AVP), was differently affected in the PVN parvocellular neurons of offspring of the DEX group since AVP mRNA increased whereas immunoreactive content of the PVN parvocellular neurons was lowered. Simultaneously, the co-production of AVP and CRH in PVN neurons was stimulated. This can support the view that antenatal DEX reached the fetus and produced some damage which did not parallel that induced by prenatal stress of the pregnant females, especially the low body weight of offspring. The harmful consequence of antenatal DEX treatment was not restrictively due to the blunting of the HPA axis but also to the low body weight, which disturbed behavioral performances for the first weeks of life and could participate in other disorders in adult life.

Sarcome granulocytique orbitaire révélant l’acutisation d’un syndrome myélodysplasique

Granulocytic sarcoma is a rare orbital complication of acute leukemia. It concerns primarily children under 10 years of age suffering from primitive acute myeloid leukemia. As this type of symptom can sometimes affect the elderly during the acute phase of myelodysplastic syndrome, it raises a problem with diagnosis and consequently with therapeutic treatments. We report the case of a 77-year-old female patient who had acute inflammatory proptosis during regressive right ethmoiditis. The diagnosis was reached by computed tomography showing an extraconical intraorbital tumor sprouting from the sinus, and by clinical examination and confirmed by the hematological investigation. Acute proptosis developing in an acute myeloblastic leukemia context heavily swayed diagnosis towards orbital granulocytic sarcoma. Chemotherapy by cytarabine and hydroxycarbamide associated with intravenous corticoid therapy resulted in complete disappearance of the proptosis within 10 days. This case report is a reminder of this peculiar sign of tumoral syndrome in acute myeloid leukemia. We also discuss different diagnostic methods and various therapeutic approaches, and analyze the disease course and patient follow-up.

Direct transition from Bose glass to normal state in the (K,Ba)BiO3 superconductor

The introduction of columnar defects in (K,Ba )Bi O3 single crystals shifts both the irreversibility and thermodynamic transition lines, respectively, deduced from ac susceptibility (and/or transport) and specific heat measurements, upwards. This shift can be attributed to the defect-induced decrease of the difference (Delta F) between the free energies in the superconducting and the normal states, assuming that the position of the superconducting transition is given by the condition absolute value Delta F approximately k(B )T/xi(3 ). This criterion also perfectly reproduces the influence of the angle between the tracks and the external field. This result suggests that no vortex liquid phase exists in this system.

Synthesis of Mono- and Bisdihydrodipyridopyrazines and Assessment of Their DNA Binding and Cytotoxic Properties

Aminoalkyl-substituted monomeric and dimeric dihydrodipyridopyrazines have been synthesized and evaluated as antitumor agents. Potent cytotoxic compounds were identified in both series. Biochemical and biophysical studies indicated that all these compounds strongly stabilized the duplex structure of DNA and some of them elicited a selectivity for GC-rich sequences. Sequence recognition by of the dimeric dihydrodipyridopyrazines is reminiscent of that of certain antitumor bisnaphthalimides. Compared to monomers, corresponding dimeric derivatives showed higher affinity for DNA. This property was attributed to a bisintercalative binding to DNA. This assumption was indirectly probed by electric linear dichroism and DNA relaxation experiments. DNA provides a bioreceptor for these dihydrodipyridopyrazine derivatives, but no poisoning of human topoisomerases I or II was detected. Most of the compounds efficiently inhibited the growth of L1210 murine leukemia cells and perturbed the cell cycle progression (with a G2/M block in most cases). A weak but noticeable in vivo antitumor activity was observed with one of the dimeric compounds. This studies identifies monomeric and dimeric dihydrodipyridopyrazines as a new class of DNA-targeted antitumor agents.

Pneumatosis intestinalis and diarrhea in a child following renal transplantation

Pneumatosis intestinalis is an uncommon finding beyond the neonatal period, but it has been reported in immunocompromized pediatric patients. The association of pneumatosis intestinalis in children following renal transplantation has to the best of our knowledge been only reported once in children. We describe a 4-year-old female who developed intermittent emesis, weight loss, and intermittently loose bloody stools after cadaveric renal transplantation at age 3.5 years. An abdominal x-ray demonstrated extensive pneumatosis in the colon. The infectious work-up was negative. Histologically, she had increased eosinophils throughout the lamina propria in the rectum. A glucose breath test was suggestive of small bowel bacterial overgrowth. She was treated with 10 days of metronidazole with resolution of the diarrhea and occult blood in stools. One month after the treatment she had radiologic resolution of her pneumatosis. Based on this report, pneumatosis intestinalis should be considered in the differential diagnosis of children after organ transplant suffering from diarrhea, abdominal pain, or blood in the stool.

Anisotropic enhancement of superconductivity in heavy-ion irradiated (K, Ba)BiO3

We have measured the specific heat, resistivity, and ac susceptibility of (K,Ba)BiO3 single crystals before and after introduction of either point or columnar defects by electron (EI) or heavy-ion irradiation (HII). While the magnetic field dependence of these properties remains mainly unaffected by EI, the irreversibility line and the location of the specific heat anomaly are both shifted up in temperature after HII. The shift is apparent only if the magnetic field is applied parallel to the ion tracks. For perpendicularly applied fields, both lines lie at the same field as in the pristine sample. These experiments call the nature of the vortex liquid state into question.

Anomalous magnetic field dependence of the thermodynamic transition line in the isotropic superconductor (K,Ba)BiO3

Thermodynamic (specific heat, reversible magnetization, tunneling spectroscopy) and transport measurements have been performed on high quality (K,Ba)BiO3 single crystals. The temperature dependence of the magnetic field H(C(p)) corresponding to the onset of the specific heat anomaly presents a clear positive curvature. H(C(p)) is significantly smaller than the field H(Delta) for which the superconducting gap vanishes but is closely related to the irreversibility line deduced from transport data. Moreover, the temperature dependence of the reversible magnetization presents a strong deviation from the Ginzburg-Landau theory emphasizing the peculiar nature of the superconducting transition in this material.

Mutations in a new gene encoding a protein of the hair bundle cause non-syndromic deafness at the DFNB16 locus

Hearing impairment affects about 1 in 1,000 children at birth. Approximately 70 loci implicated in non-syndromic forms of deafness have been reported in humans and 24 causative genes have been identified (see also http://www.uia.ac.be/dnalab/hhh). We report a mouse transcript, isolated by a candidate deafness gene approach, that is expressed almost exclusively in the inner ear. Genomic analysis shows that the human ortholog STRC (so called owing to the name we have given its protein-stereocilin), which is located on chromosome 15q15, contains 29 exons encompassing approximately 19 kb. STRC is tandemly duplicated, with the coding sequence of the second copy interrupted by a stop codon in exon 20. We have identified two frameshift mutations and a large deletion in the copy containing 29 coding exons in two families affected by autosomal recessive non-syndromal sensorineural deafness linked to the DFNB16 locus. Stereocilin is made up of 1,809 amino acids, and contains a putative signal petide and several hydrophobic segments. Using immunohistolabeling, we demonstrate that, in the mouse inner ear, stereocilin is expressed only in the sensory hair cells and is associated with the stereocilia, the stiff microvilli forming the structure for mechanoreception of sound stimulation.

A Bragg glass phase in the vortex lattice of a type II superconductor

Although crystals are usually quite stable, they are sensitive to a disordered environment: even an infinitesimal amount of impurities can lead to the destruction of crystalline order. The resulting state of matter has been a long-standing puzzle. Until recently it was believed to be an amorphous state in which the crystal would break into 'crystallites'. But a different theory predicts the existence of a novel phase of matter: the so-called Bragg glass, which is a glass and yet nearly as ordered as a perfect crystal. The 'lattice' of vortices that contain magnetic flux in type II superconductors provide a good system to investigate these ideas. Here we show that neutron-diffraction data of the vortex lattice provides unambiguous evidence for a weak, power-law decay of the crystalline order characteristic of a Bragg glass. The theory also predicts accurately the electrical transport properties of superconductors; it naturally explains the observed phase transitions and the dramatic jumps in the critical current associated with the melting of the Bragg glass. Moreover, the model explains experiments as diverse as X-ray scattering in disordered liquid crystals and the conductivity of electronic crystals.

Immunization of HIV-infected children with varicella vaccine

OBJECTIVE

To determine the safety and immunogenicity of varicella vaccine in children with human immunodeficiency virus (HIV) infection. Children (n = 41) who were mildly affected by HIV (Centers for Disease Control and Prevention stage N1 or A1) and had no history or serum antibody indicative of prior varicella infection were immunized with two doses of live attenuated varicella vaccine.

RESULTS

A minority of the vaccine recipients had mild local or systemic reactions. Vaccination had no effect on the clinical stage of HIV or the HIV RNA plasma load. CD4 cell percentage and CD4 cell count were marginally decreased at week 4 after the first vaccination; this effect was no longer present at week 8 after vaccination. Two months after the second dose of vaccine, 60% of vaccine recipients had anti-varicella antibody in their serum, and 83% had a positive lymphocyte proliferation assay response to varicella antigen.

CONCLUSION

On the basis of its safety and immunogenicity, varicella vaccine should be considered in the childhood vaccines given to mildly affected HIV-infected children.

Identification of three novel mutations in the USH1C gene and detection of thirty-one polymorphisms used for haplotype analysis

Usher syndrome (USH) is a clinically and genetically heterogeneous autosomal recessive disorder in which sensorineural hearing loss is associated with retinitis pigmentosa. Usher syndrome type 1, the most severe form, is characterized by profound congenital deafness, vestibular dysfunction, and prepubertal onset of retinitis pigmentosa. Six different USH1 genes have so far been mapped, of which two have already been identified. MYO7A, encoding the unconventional myosin VIIA, underlies USH1B. Recently, the USH1C gene was shown to encode harmonin, a PDZ domain-containing protein. A previous screening of 18 unrelated USH1 patients, without a detected MYO7A mutation, for the three USH1C mutations described to date had demonstrated the presence of the 238-239insC mutation in the heterozygous state in four of them. A complete USH1C mutation screening in these four carriers of the 238-239insC mutation resulted in the detection of the second mutation in all the individuals, and the identification of three novel mutations, namely two splice site mutations (IVS1+1G>T and IVS5+1G>A) and a nonsense mutation (R31X). Thirty-one polymorphisms were detected in the USH1C gene. We observed that the E519D substitution is non-pathogenic, which is of particular interest for molecular diagnosis. Our analysis indicated that all the carriers of the 238-239insC mutation share a common haplotype. A different common haplotype was found in the two IVS1+1G>T carriers. Future studies of additional carriers and non-carriers should document the here proposed founder effect of these two mutations.

Characterization of novel safe lentiviral vectors derived from simian immunodeficiency virus (SIVmac251) that efficiently transduce mature human dendritic cells

We describe the generation and the characterization of new lentiviral vectors derived from SIVmac251, a simian immunodeficiency virus (SIV). A methodical approach was used to engineer both efficient and safe packaging constructs allowing the production of SIV viral core proteins. SIV-vectors encoding GFP (green fluorescent protein) were generated as VSV-G-pseudotyped particles upon transient expression of the vector construct and helper functions in 293 cells. The SIV vectors were able to transduce efficiently various target cell types at low multiplicity of infection, including monocyte-differentiated human dendritic cells (DCs) which retained their capacity to differentiate into mature DCs after gene transfer. Transduction of the DCs by the SIV vectors was prevented when infections were performed in the presence of AZT, a reverse-transcriptase inhibitor. After gene transfer, expression of the GFP in the target cells remained constant after several weeks, indicating that the vectors had been stably integrated into the genome of the host cells. Preparations of SIV vectors were systematically checked for the absence of replication-competent and recombinant retroviruses but remained negative, suggesting the innocuousness of these novel gene delivery vectors. Side-to-side comparisons with vectors derived from HIV-1 (human immunodeficiency virus) indicated that the SIV vectors were equally potent in transducing proliferating target cells. Finally, we have determined the infectivity of SIV vectors pseudotyped with surface glycoproteins of several membrane-enveloped viruses.