Low Mannose-Binding Lectin Concentration Is Associated with Severe Infection in Patients with Hematological Cancer Who Are Undergoing Chemotherapy

Background. Mannose-binding lectin (MBL) is a serum lectin involved in innate immune response. Low serum MBL concentration may constitute a risk factor for infection in patients receiving myelosuppressive chemotherapy. Methods. We conducted a prospective, observational study that assessed MBL concentration as a risk factor for infection in patients with hematological malignancy who were hospitalized to undergo at least 1 chemotherapy cycle. MBL deficiency was defined using an algorithm that considered the serum MBL concentration and the MBL genotype. The primary end point was the ratio of duration of febrile neutropenia to the duration of neutropenia. Secondary end points included the incidence of severe infection (e.g., sepsis, pneumonia, bacteremia, and invasive fungal infection). Logistic regression analysis was conducted, and Fisher's exact test was used to analyze binary outcomes, and Kaplan-Meier estimates and log rank tests were used for time-to-event variables. Results. We analyzed 255 patients who received 569 cycles of chemotherapy. The median duration of neutropenia per cycle was 7 days (interquartile range, 0-13 days). Sixty-two patients (24%) were found to have MBL deficiency. Febrile neutropenia occurred at least once in 200 patients. No difference in the primary outcome was seen. The incidence of severe infection was higher among MBL-deficient patients than among non-MBL-deficient patients (1.96 vs. 1.34 cases per 100 days for analysis of all patients [P = .008] and 1.85 vs. 0.94 cases per 100 days excluding patients with acute leukemia [P < .001]). Conclusions. MBL deficiency does not predispose adults with hematological cancer to more-frequent or more-prolonged febrile episodes during myelosuppressive chemotherapy, but MBL-deficient patients have a greater number of severe infections and experience their first severe infection earlier, compared with nondeficient patient

Spatial and temporal regulation of cerebral cortex development by the transcription factor pax6

Lamina formation in the developing cortex requires precise generation, migration and differentiation of cortical neurons. Cortical projection neurons originate from progenitors of the embryonic dorsal telencephalon. The transcription factor Pax6 is expressed in apical progenitors (APs) throughout corticogenesis in a rostro-lateralhigh to caudo-mediallow gradient. The current studies focus on elucidating the spatial and temporal role of Pax6 in cortical development. I first analysed the cortex of PAX77 transgenic mice that overexpress Pax6 in its normal domains of expression. I show that Pax6 overexpression acts cell-autonomously to reduce the proliferation of late cortical progenitors specifically, resulting in the formation of thinner superficial layers in the PAX77 cortex. Increased levels of Pax6 lengthen the cell cycle of APs and drive the system towards neurogenesis. These effects are specific to late stages of corticogenesis, when superficial layer neurons are normally generated, in cortical regions that express Pax6 at the highest levels. The number of superficial layer neurons is reduced in postnatal PAX77 mice, while radial migration and lamina specification of cortical neurons are not affected by Pax6 overexpression. Then, Pax6 was conditionally inactivated in cortical progenitors at mid- or late-stages of corticogenesis by using a tamoxifen-inducible Emx1-CreER line. I report a novel requirement of Pax6 for continuous suppression of ventral fates and concurrent maintenance of an appropriate dorsal identity in cortical progenitors. Pax6 ablation at either mid- or late-stages of corticogenesis increases the proliferation of late cortical progenitors at all levels across the rostral-caudal axis. In the absence of Pax6 from mid-corticogenesis, late-born neurons are severely under-represented and misspecified in superficial layers of the mutant cortex. Notably, Pax6 inactivation during late corticogenesis also affects superficial laminar fate; although the numbers of late-born cortical neurons are not severely affected in superficial layers of the mutant cortex, substantial numbers of late-born cells fail to migrate to appropriate laminar positions and accumulate in the ventricular zone (VZ) of the postnatal mutant cortex. Collectively, these gain- and loss-of-function studies suggest that disruption of Pax6 levels during different developmental time points leads ultimately to impaired formation of superficial cortical layers but through different cellular and molecular mechanisms

Controlled overexpression of Pax6 in vivo negatively autoregulates the Pax6 locus, causing cell-autonomous defects of late cortical progenitor proliferation with little effect on cortical arealization

Levels of expression of the transcription factor Pax6 vary throughout corticogenesis in a rostro-lateral(high) to caudo-medial(low) gradient across the cortical proliferative zone. Previous loss-of-function studies have indicated that Pax6 is required for normal cortical progenitor proliferation, neuronal differentiation, cortical lamination and cortical arealization, but whether and how its level of expression affects its function is unclear. We studied the developing cortex of PAX77 YAC transgenic mice carrying several copies of the human PAX6 locus with its full complement of regulatory regions. We found that PAX77 embryos express Pax6 in a normal spatial pattern, with levels up to three times higher than wild type. By crossing PAX77 mice with a new YAC transgenic line that reports Pax6 expression (DTy54), we showed that increased expression is limited by negative autoregulation. Increased expression reduces proliferation of late cortical progenitors specifically, and analysis of PAX77↔wild-type chimeras indicates that the defect is cell autonomous. We analyzed cortical arealization in PAX77 mice and found that, whereas the loss of Pax6 shifts caudal cortical areas rostrally, Pax6 overexpression at levels predicted to shift rostral areas caudally has very little effect. These findings indicate that Pax6 levels are stabilized by autoregulation, that the proliferation of cortical progenitors is sensitive to altered Pax6 levels and that cortical arealization is not

Pax6 Is Required at the Telencephalic Pallial-Subpallial Boundary for the Generation of Neuronal Diversity in the Postnatal Limbic System

During embryogenesis, the pallial-subpallial boundary (PSB) divides the two main progenitor domains in the telencephalon: the pallium, the major source of excitatory neurons, and the subpallium, the major source of inhibitory neurons. The PSB is formed at the molecular interface between the pallial (high Pax6+) and subpallial (high Gsx2+) ventricular zone (VZ) compartments. Initially, the PSB contains cells that express both Pax6 and Gsx2, but during later stages of development this boundary is largely refined into two separate compartments. In this study we examined the developmental mechanisms underlying PSB boundary formation and the postnatal consequences of conditional loss of Pax6 function at the PSB on neuronal fate in the amygdala and olfactory bulb, two targets of PSB-derived migratory populations. Our cell fate and time-lapse imaging analyses reveal that the sorting of Pax6+ and Gsx2+ progenitors during embryogenesis is the result of a combination of changes in gene expression and cell movements. Interestingly, we find that in addition to giving rise to inhibitory neurons in the amygdala and olfactory bulb, Gsx2+ progenitors generate a subpopulation of amygdala excitatory neurons. Consistent with this finding, targeted conditional ablation of Pax6 in Gsx2+ progenitors results in discrete local embryonic patterning defects that are linked to changes in the generation of subsets of postnatal excitatory and inhibitory neurons in the amygdala and inhibitory neurons in the olfactory bulb. Thus, in PSB progenitors, Pax6 plays an important role in the generation of multiple subtypes of neurons that contribute to the amygdala and olfactory bulb

Approaches to discontinuing efalizumab: an open-label study of therapies for managing inflammatory recurrence

BACKGROUND: Efalizumab is a humanised recombinant monoclonal IgG1 antibody for the treatment of moderate-to-severe plaque psoriasis. When treatment discontinuation is necessary, however, some patients may experience inflammatory recurrence of the disease, which can progress to rebound if untreated. This analysis evaluated approaches for managing inflammatory recurrence after discontinuation of efalizumab. METHODS: An open-label, multicentre, investigational study was performed in 41 patients with moderate-to-severe plaque psoriasis who had recently completed clinical studies with efalizumab and had developed signs of inflammatory recurrence following abrupt cessation of treatment. Patients were assigned by the attending physicians to receive one of five standardised alternative systemic psoriasis treatment regimens for 12 weeks. Efficacy of the different therapy options was assessed using the physician's global assessment (PGA) of change over time. RESULTS: More favourable PGA responses were observed in patients changing to cyclosporin (PGA of 'good', 'excellent' or 'cleared': 7/10 patients, 70.0%) or methotrexate (9/20, 45.0%), compared with those receiving systemic corticosteroids (2/8, 25.0%), retinoids (0/1, 0.0%) or combined corticosteroids plus methotrexate (0/2, 0.0%). While the majority (77.8%) of patients showed inflammatory morphology at baseline, following 12 weeks of the alternative therapies the overall prevalence of inflammatory disease was decreased to 19.2%. CONCLUSION: Inflammatory recurrence after discontinuation of efalizumab therapy is a manageable event, with a number of therapies and approaches available to physicians, including short courses of cyclosporin or methotrexate

Spatiotemporal expression patterns of Pax6 in the brain of embryonic, newborn, and adult mice

The transcription factor Pax6 has been reported to specify neural progenitor cell fates during development and maintain neuronal commitments in the adult. The spatiotemporal patterns of Pax6 expression were examined in sagittal and horizontal sections of the embryonic, postnatal, and adult brains using immunohistochemistry and double immunolabeling. The proportion of Pax6-immunopositive cells in various parts of the adult brain was estimated using the isotropic fractionator methodology. It was shown that at embryonic day 11 (E11) Pax6 was robustly expressed in the proliferative neuroepithelia of the ventricular zone in the forebrain and hindbrain, and in the floor and the mesencephalic reticular formation (mRt) in the midbrain. At E12, its expression emerged in the nucleus of the lateral lemniscus in the rhombencephalon and disappeared from the floor of the midbrain. As neurodevelopment proceeds, the expression pattern of Pax6 changes from the mitotic germinal zone in the ventricular zone to become extensively distributed in cell groups in the forebrain and hindbrain, and the expression persisted in the mRt. The majority of Pax6-positive cell groups were maintained until adult life, but the intensity of Pax6 expression became much weaker. Pax6 expression was maintained in the mitotic subventricular zone in the adult brain, but not in the germinal region dentate gyrus in the adult hippocampus.There was no obvious colocalization of Pax6 and NeuN during embryonic development, suggesting Pax6 is found primarily in developing progenitor cells. In the adult brain, however, Pax6 maintains neuronal features of some subtypes of neurons, as indicated by 97.1% of Pax6-positive cells co-expressing NeuN in the cerebellum, 40.7% in the olfactory bulb, 38.3% in the cerebrum, and 73.9% in the remaining brain except the hippocampus. Differentiated tyrosine hydroxylase (TH) neurons were observed in the floor of the E11 midbrain where Pax6 was also expressed, but no obvious colocaliztion of TH and Pax6 was detected. No Pax6 expression was observed in TH-expressing areas in the midbrain at E12, E14, and postnatal day 1. These results support the notion that Pax6 plays pivotal roles in specifying neural progenitor cell commitments and maintaining certain mature neuronal fates

Olorofim for the treatment of invasive fungal diseases in patients with few or no therapeutic options: a single-arm, open-label, phase 2b study

BackgroundOnly a small number of antifungal therapies for invasive fungal disease (IFD) are currently available, and many pathogens are resistant to one or more of these therapies. Olorofim, the first orotomide antifungal agent to be developed, is active against fungi that are resistant to registered therapies. It impairs fungal pyrimidine biosynthesis, leading to cell death. We sought initial data on the efficacy and safety of olorofim as a therapy for IFD.MethodsIn this single-arm, open-label, phase 2b study, patients aged 16 years or older with few or no treatment options for proven IFD or probable invasive pulmonary aspergillosis were recruited from 22 centres in 11 countries. The first 58 patients received a weight-based loading dose of oral olorofim 180–300 mg in two to three divided doses on day 1 followed by 120–240 mg daily in two to three divided doses from day 2 onwards. On the basis of pharmacokinetic data from the first 25 patients, dosing was simplified from patient 59 onwards to a loading dose of 150 mg twice on day 1 followed by a fixed maintenance dose of 90 mg twice a day up to day 84 (main treatment phase) with extended therapy as needed. The primary endpoint was global response rate (based on a composite of clinical, radiological, and mycological responses) at day 42, determined as success (complete or partial improvement in all three components) or failure (stable disease or progression on any one component or death from any cause) by a data review committee (DRC). Secondary efficacy endpoints included global response rate at day 84 and all-cause mortality at day 42 and day 84. Global response rate with stable disease classified as success and response rate in the clinical component of the global response at day 42 and day 84 were also assessed. Efficacy was analysed for all patients who were confirmed by the DRC to have an IFD and who received at least one dose of olorofim (the modified intention-to-treat population). Safety was analysed in all patients who received at least one dose of olorofim (the safety population). This trial is registered with ClinicalTrials.gov, NCT03583164, and is completed.FindingsBetween June 6, 2018, and Sept 8, 2022, 204 patients were enrolled. Of these, 203 were treated with olorofim and 202 (124 male, 78 female) had DRC-adjudicated IFD. Causative pathogens were Aspergillus spp (n=101, including 22 azole-resistant strains), Lomentospora prolificans (n=26), Scedosporium spp (n=22), Coccidioides spp (n=41), and other fungi (n=12). Successful global response was confirmed in 58 of 202 patients (28·7%, 95% CI 22·6–35·5) at day 42 and in 55 patients (27·2%, 21·2–33·9) at day 84. Successful global response with stable disease included in the definition of success was seen in 152 patients (75·2%, 68·7–81·0) at day 42 and in 128 patients (63·4%, 56·3–70·0) at day 84. A successful clinical response was seen in 121 patients (59·9%, 52·8–66·7) at day 42 and in 109 patients (54·0%, 46·8–61·0) at day 84. All-cause mortality was documented in 24 patients (11·9%, 7·8–17·2) at day 42 and in 33 patients (16·3%, 11·5–22·2) at day 84. Mean dosing duration was 73 days (SD 25) for the 203 patients in the main treatment phase (median 84 days [range 2–99, IQR 78–87]) and 361 days (SD 220) for the 114 patients who received extended treatment after the main phase (median 309 days [38–988, 180–502]). Medically significant liver enzyme elevations adjudicated to be at least possibly due to olorofim occurred in 20 (10%) of 203 patients and were managed to resolution by dose modification in 14 (7%) patients or by discontinuation of treatment in six (3%). Gastrointestinal intolerance, which occurred in 20 (10%) patients, was predominantly reported as mild or moderate and self-limiting. There were no treatment-related deaths.InterpretationOlorofim showed efficacy and good tolerability in patients with IFD with few or no treatment options. Further studies will be needed to fully delineate the role of this new antifungal agent.FundingF2G.IntroductionInvasive fungal diseases (IFDs) due to mould pathogens cause substantial morbidity and mortality. Aspergillus species are the most common pathogens but other moulds, such as Scedosporium spp, Lomentospora prolificans, and the endemic dimorphic fungi (eg, Coccidioides spp), are increasing in frequency.1, 2 These moulds cause considerable morbidity, even in non-immunosuppressed individuals.3, 4, 5, 6, 7, 8, 9, 10 Early, effective antifungal therapy is essential for optimal outcomes.2, 11, 12Currently available antifungal drug classes with useful activity against invasive mould pathogens (polyenes, triazoles, and echinocandins) have microbiological limitations: triazole-resistant Aspergillus spp have emerged worldwide,3, 13, 14 and Scedosporium spp, L prolificans, and Fusarium spp are intrinsically resistant to multiple, if not all, available antifungal agents.1, 15, 16 Other limitations include the need for intravenous administration, problematic drug–drug interactions, requirements for therapeutic drug monitoring, and frequent adverse reactions.Olorofim (formerly F901318; F2G, Manchester, UK) is the first member of the novel orotomide drug class to be developed for the treatment of fungal infections. By selectively inhibiting fungal dihydroorotate dehydrogenase (DHODH), it blocks fungal pyrimidine biosynthesis, ultimately leading to cell death.17, 18 Olorofim is active in vitro against a broad range of filamentous and dimorphic fungi (eg, Coccidioides spp), including triazole-resistant Aspergillus spp and moulds with few or no antifungal treatment options (eg, L prolificans, Scedosporium spp, and Scopulariopsis [Microascus] spp), but displays no activity against yeasts or the Mucorales due to phylogenetic differences in the fungal DHODH enzyme.19, 20, 21, 22 There is no cross-resistance with existing antifungal agents.23 Olorofim is dosed orally, has 68% bioavailability following first-pass effect clearance, and shows linear systemic exposure.24Here, we report the results of an open-label, single-arm, phase 2b study that aimed to assess the efficacy, as well as tolerability, pharmacokinetics, and safety, of oral olorofim in patients who had few or no treatment options for IFDs due to moulds (including the dimorphic fungi).MethodsStudy design and participantsThis open-label, single-arm, phase 2b study was conducted at 22 study sites in Australia, Belgium, Egypt, Germany, Israel, the Netherlands, Russia, Spain, Thailand, the UK, and the USA. The study was designed, overseen, and conducted by F2G, according to international guidelines including the Declaration of Helsinki, the Council for International Organizations of Medical Sciences International Ethical Guidelines, the Good Clinical Practice Guideline of the International Council for Harmonisation, and other applicable laws and regulations. National and local ethics committees or institutional review boards at all participating sites approved the protocol, amendments, and informed consent forms. Further details on study design and procedures, including the protocol and statistical analysis plan, are provided in the appendix (pp 2–8, 23–306). The trial was registered with ClinicalTrials.gov, NCT03583164

The caudo-ventral pallium is a novel pallial domain expressing Gdf10 and generating Ebf3-positive neurons of the medial amygdala

In rodents, the medial nucleus of the amygdala receives direct inputs from the accessory olfactory bulbs and is mainly implicated in pheromone-mediated reproductive and defensive behaviors. The principal neurons of the medial amygdala are GABAergic neurons generated principally in the caudo-ventral medial ganglionic eminence and preoptic area. Beside GABAergic neurons, the medial amygdala also contains glutamatergic Otp-expressing neurons cells generated in the lateral hypothalamic neuroepithelium and a non-well characterized Pax6-positive population. In the present work, we describe a novel glutamatergic Ebf3-expressing neuronal subpopulation distributed within the periphery of the postero-ventral medial amygdala. These neurons are generated in a pallial domain characterized by high expression of Gdf10. This territory is topologically the most caudal tier of the ventral pallium and accordingly, we named it Caudo-Ventral Pallium (CVP). In the absence of Pax6, the CVP is disrupted and Ebf3-expressing neurons fail to be generated. Overall, this work proposes a novel model of the neuronal composition of the medial amygdala and unravels for the first time a new novel pallial subpopulation originating from the CVP and expressing the transcription factor Ebf3.This work was supported by Grants of the French National Research Agency (Agence Nationale de la Recherche; ANR) [ANR-13-BSV4-0011] and by the French Government through the ‘Investments for the Future’ LABEX SIGNALIFE [ANR-11-LABX-0028-01] to M.S., by the Spanish Government (BFU2007-60263 and BFU2010-17305) to A.F, and by the Medical Research Council (MR/K013750/1) to T.T. N.R.-R. is funded by a postdoctoral fellowship from the Ville de Nice, France (“Aide Individuelle aux Jeunes Chercheurs 2016”).Peer reviewe