Intrathecal Colistin and Intravenous Fosfomycin as a combination therapy for the treatment of Acinetobacter baumannii Ventriculitis and meningitis: a case report from Nepal

Treatment of central nervous system infection may be troublesome due to multi-drug resistance. Colistin is less successful as a treatment option due to poor CNS penetration when used intravenously. We present the successful management of a case with ventriculitis and meningitis due to MDR Acinetobacter baumannii species with the combined intraventricular administration of colistin and IV fosfomycin after the initial regimen of colistin given alone through both IVT and IV routes had failed.

Chronic exposure to perfluorohexane sulfonate leads to a reproduction deficit by suppressing hypothalamic kisspeptin expression in mice

Background Perfluorohexane sulfonate (PFHxS) is a six-carbon perfluoroalkyl sulfonic acid found as an environmental contaminant. This study aims to investigate the effects of PFHxS exposure on female reproduction and the underlying mechanism in mice. Methods Eight-week-old ICR mice were divided randomly into four groups administered corn oil (vehicle) and PFHxS at doses of 0.5, 5, and 50 mg/kg/day for 42 days by intragastric administration. Body weight, ovarian weight, estrous cycle, follicle counts, and serum sex hormone levels were evaluated. The expression of kisspeptin and gonadotropin releasing hormone (GnRH) in the hypothalamus was also detected. Results Compared to vehicle exposure, 5 mg/kg/day PFHxS treatment prolonged the estrous cycle, especially the duration of diestrus, after 42 days of treatment. The numbers of secondary follicles, antral follicles and corpus lutea were significantly reduced in the PFHxS-treated mice. Moreover, compared with the control mice, the PFHxS-treated mice showed decreases in the serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estrogen (E2), and reduced GnRH mRNA levels, along with the lack of an LH surge. Furthermore, the PFHxS-treated mice had lower levels of kisspeptin immunoreactivity and kiss-1 mRNA in the arcuate nucleus (ARC) and anteroventral periventricular nucleus (AVPV) than the control mice. After intraventricular administration of kisspeptin-10, the numbers of secondary follicles, antral follicles and corpus lutea recovered, along with the levels of GnRH mRNA, FSH, and LH in the mice treated with 5 mg/kg/day PFHxS. Conclusion These results indicate that chronic exposure of mice to 5 mg/kg/day PFHxS affects reproductive functions by inhibiting kisspeptin expression in the ARC and AVPV regions, leading to deficits in follicular development and ovulation.

Chronic Exposure to Perfluorohexane Sulfonate Leads to a Reproduction Deficit by Suppressing Hypothalamic Kisspeptin Expression in Mice

BackgroundPerfluorohexane sulfonate (PFHxS) is a six-carbon perfluoroalkyl sulfonic acid found as an environmental contaminant. This study aims to investigate the effects of PFHxS exposure on female reproduction and the underlying mechanism in mice. MethodsEight-week-old ICR mice were divided randomly into four groups: corn oil (vehicle) and PFHxS at doses of 0.5, 5, and 50 mg/kg/day for 42 days by intragastric administration. Body weight, ovarian weight, estrous cycle, follicle counts, and serum sex hormone levels were evaluated. Expression of kisspeptin and gonadotropin releasing hormone (GnRH) in the hypothalamus was also detected. ResultsCompared to vehicle exposure, 5 mg/kg/day PFHxS prolonged the estrous cycle, especially the duration of diestrus, after 42 days of treatment. The numbers of antral follicles and corpus lutea were significantly reduced in PFHxS-treated mice. Moreover, compared with the control group, PFHxS-treated mice showed decreases in serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estrogen (E2), and reduced GnRH mRNA levels, along with the lack of an LH surge. Furthermore, PFHxS-treated mice had lower levels of kisspeptin immunoreactivity and kiss-1 mRNA in the arcuate nucleus (ARC) and anteroventral periventricular nucleus (AVPV). After intraventricular administration of kisspeptin-10, the numbers of antral follicles and corpus lutea recovered, along with the levels of GnRH mRNA, FSH, and LH in mice treated with 5 mg/kg/day PFHxS. ConclusionThese results indicate that chronic exposure of mice to 5 mg/kg/day PFHxS affects reproductive functions by inhibiting kisspeptin expression in the ARC and AVPV regions, leading to the deficit of follicular development and ovulation.

Correction to: Mast cell proliferation in the cerebrospinal fluid after intraventricular administration of anti‑B7H3 immunotherapy

A correction to this paper has been published: https://doi.org/10.1007/s00262-021-02942-3

Mast cell proliferation in the cerebrospinal fluid after intraventricular administration of anti-B7H3 immunotherapy

Omburtamab is a B7H3-specific murine monoclonal antibody. B7H3 (CD 276) is a member of the B7 family of immune checkpoint co-inhibitory receptors overexpressed on many human malignancies. Radioimmunotherapy with 124I- or 131I-omburtamab administered in the cerebrospinal fluid (CSF), intraperitoneal or intratumoral cavity is currently under investigation for the treatment of CNS malignancies. The immunologic effects of anti-B7H3 therapy are not fully elucidated. A 6-year-old male was diagnosed with metastates of neuroblastoma to the received intraventricular 131I-omburtamab on an IRB-approved protocol. A treatment cycle consisted of a 2 mCi dosimetry dose and a 50 mCi treatment dose. Dosimetry by serial imaging, pharmacokinetics and safety were investigated. Clinical status, magnetic resonance imaging, CSF cell count and cytology were evaluated pre- and post-131I-omburtamab at 5 and 26 weeks. The patient did well with cycle 1. Three hours after the dosimetry dose of cycle 2, he developed a fever (39 °C), chills and headache. Blood and CSF samples were sent for culture. CSF was notable for nucleated cell pleocytosis with profound mast cell proliferation consistent with chemical meningitis. He was treated with supportive care; symptoms resolved over 48 h. Further therapy with 131I-omburtamab was electively discontinued. CSF cell count 5 weeks later demonstrated resolution of CSF pleocytosis. Local–regional administration of intraventricular 131I-omburtamab targeting B7H3 can result in a profound nucleated CSF pleocytosis with mastocytosis consistent with an acute allergic reaction.

Acetate Suppresses Lipopolysaccharide-stimulated Nitric Oxide Production in Primary Rat Microglia but not in BV-2 Microglia Cells

Aims: To show that acetate attenuates neuroinflammatory responses in activated microglia. Background: Dietary acetate supplementation alleviates neuroglial activation in a rat model of neuroinflammation induced by intraventricular administration of lipopolysaccharide (LPS). However, the precise mechanism(s) underlying the anti-inflammatory effect of acetate is not fully understood. Objective: To determine whether acetate has inhibitory effects on LPS-induced neuroinflammatory responses in microglia. Methods: We examined LPS-stimulated nitric oxide (NO) production in primary rat microglia and BV-2 cells. Protein expression of inducible NO synthase (iNOS) was determined by western blot analysis. The intracellular generation of reactive oxygen species (ROS) and glutathione (GSH) were also evaluated. Results: In primary microglia, acetate decreased LPS-stimulated NO production in a dose-dependent manner, reaching significance at greater than 10 mM, and cell viability was not affected. Acetate suppressed LPS-induced expression of iNOS protein concomitantly with the decrease in NO. The LPS-induced increase in intracellular ROS production was attenuated by acetate. In addition, acetate prevented LPSinduced reduction of GSH. Notably, such suppressive effects of acetate on NO and ROS production were not observed in BV-2 cells. Conclusion: These findings suggest that acetate may alleviate neuroinflammatory responses by attenuating NO and ROS production in primary microglia but not in BV-2 cells. Other: All animals received humane care and the animal protocols used in this study were approved by the Ethics Committees for Animal Experimentation.

DDEL-14. SAFETY OF INTERVENTRICULAR METHOTREXATE ADMINISTRATION FOLLOWING RADIATION IN PEDIATRIC PATIENTS WITH MALIGNANT BRAIN TUMORS

BACKGROUND Methotrexate has been used for intrathecal administration in leukemia as well as embryonal CNS tumors in children. Concerns about neurologic side effects including leukoencephalopathy, demyelination, and seizures have limited the use of methotrexate following exposure to focal radiation. OBJECTIVE To evaluate and determine safety of Intraventricular administration of Methotrexate in pediatric patients with recurrent malignant brain tumors along with systemic Topotecan and Cyclophosphamide after exposure to prior radiation therapy. DESIGN/METHOD: Patients with recurrent cerebellar embryonal tumors after standard treatment that included radiation were enrolled on this IRB approved phase 2 study. An Ommaya reservoir was inserted in the lateral ventricle and used to administer 4 daily doses of methotrexate (2 mg/dose) along with (Topotecan [0.75mg/m2/day] and Cyclophosphamide [250 mg/m2/day]). A neurological evaluation was performed at baseline and daily during the intraventricular administration of the Methotrexate, this evaluation was repeated prior to each subsequent cycle and at completion of the protocol. RESULTS Three patients (age range 3–20) received 2–3 cycles of intra-Ommaya Methotrexate and Topotecan/Cyclophosphamide. No MRI demyelination or white matter changes were seen after completion of the intraventricular Methotrexate therapy. None of the patients enrolled on this trial had adverse effects related to the therapy regimen received. Clinical neurological status was unchanged during the entire course of the treatment and upon completion of the scheduled therapy. CONCLUSION Intraventricular administration of daily low dose Methotrexate is well tolerated in children with recurrent embryonal CNS tumors who had prior exposure to radiation.

Treatment Considerations for CNS Infections Caused by Vancomycin-Resistant Enterococcus faecium: A Focused Review of Linezolid and Daptomycin

Objective: To review the current literature describing pharmacology, pharmacokinetics/pharmacodynamics (PK/PD), efficacy, and safety of linezolid and daptomycin for the treatment of central nervous system (CNS) infections caused by vancomycin-resistant Enterococcus (VRE) faecium. Data Sources: A literature search of PubMed/MEDLINE databases was conducted (from 1950 to April 2020) utilizing the following key terms: vancomycin-resistant Enterococcus, VRE, meningitis, ventriculitis, CNS infection, daptomycin, and linezolid. Study Selection and Data Extraction: All relevant studies and case reports describing the treatment of VRE faecium from the CNS with linezolid or daptomycin were included. Data Synthesis: A total of 17 reports describing 22 cases were identified. There were 15 of 19 cases involving linezolid that reported clinical cure, of which 53.3% were monotherapy. Only 5 of 9 cases involving intravenous (IV) daptomycin resulted in cure; all 4 cases reporting daptomycin administration via the intrathecal or intraventricular route achieved clearance from the cerebrospinal fluid (CSF). Relevance to Patient Care and Clinical Practice: The preferred treatment option for VRE faecium infections involving the CNS remains unclear. Supporting evidence through observational case reports have described varying outcomes with linezolid and daptomycin. This review compares reported outcomes between the 2 agents and provides a thorough discussion on drug- and patient-specific variables to consider. Conclusions: Linezolid monotherapy appears to be safe and effective for the treatment of susceptible-VRE faecium CNS infections, with consideration of therapeutic drug monitoring in special populations and with prolonged treatment duration. Daptomycin is an effective treatment option via intrathecal or intraventricular administration when neurosurgical access is available. The role of IV daptomycin remains inconclusive.