Building a network for multicenter, prospective research of central nervous system infections in South America: Process and lessons learned

Multicenter collaborative networks are essential for advancing research and improving clinical care for a variety of conditions. Research networks are particularly important for central nervous system infections, which remain difficult to study due to their sporadic occurrence and requirement for collection and testing of cerebrospinal fluid. Establishment of long-term research networks in resource-limited areas also facilitates diagnostic capacity building, surveillance for emerging pathogens, and provision of appropriate treatment where needed. We review our experience developing a research network for encephalitis among twelve hospitals in five Peruvian cities since 2009. We provide practical suggestions to aid other groups interested in advancing research on central nervous system infections in resource-limited areas.

Comparison of neutron organ and effective dose coefficients for PIMAL stylized phantom in bent postures in standard irradiation geometries

Neutron dose coefficients for standard irradiation geometries have been reported in International Commission on Radiological Protection (ICRP) Publication 116 for the ICRP Publication 110 adult reference phantoms. In the present work, organ and effective dose coefficients have been calculated for a receptor in both upright and articulated (bent) postures representing more realistic working postures exposed to a mono-energetic neutron radiation field. This work builds upon prior work by Dewji and co-workers comparing upright and bent postures for exposure to mono-energetic photon fields. Simulations were conducted using the Oak Ridge National Laboratory's articulated stylized adult phantom, "Phantom wIth Moving Arms and Legs" (PIMAL) software package, and the Monte Carlo N-Particle (MCNP) version 6.1.1 radiation transport code. Organ doses were compared for the upright and bent (45° and 90°) phantom postures for neutron energies ranging from 1 × 10^- 9 to 20 MeV for the ICRP Publication 116 external exposure geometries-antero-posterior (AP), postero-anterior (PA), and left and right lateral (LLAT, RLAT). Using both male and female phantoms, effective dose coefficients were computed using ICRP Publication 103 methodology. The resulting coefficients for articulated phantoms were compared to those of the upright phantom. Computed organ and effective dose coefficients are discussed as a function of neutron energy, phantom posture, and source irradiation geometry. For example, it is shown here that for the AP and PA irradiation geometries, the differences in the organ coefficients between the upright and bent posture become more pronounced with increasing bending angle. In the AP geometry, the brain dose coefficients are expectedly higher in the bent postures than in the upright posture, while all other organs have lower dose coefficients, with the thyroid showing the greatest difference. Overall, the effective dose estimated for the upright phantom is more conservative than that for the articulated phantom, which may have ramifications in the estimation or reconstruction of radiation doses.

Distinguishing Petroleum (Crude Oil and Fuel) From Smoke Exposure within Populations Based on the Relative Blood Levels of Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX), Styrene and 2,5-Dimethylfuran by Pattern Recognition Using Artificial Neural Networks

Studies of exposure to petroleum (crude oil/fuel) often involve monitoring benzene, toluene, ethylbenzene, xylenes (BTEX), and styrene (BTEXS) because of their toxicity and gas-phase prevalence, where exposure is typically by inhalation. However, BTEXS levels in the general U.S. population are primarily from exposure to tobacco smoke, where smokers have blood levels on average up to eight times higher than nonsmokers. This work describes a method using partition theory and artificial neural network (ANN) pattern recognition to classify exposure source based on relative BTEXS and 2,5-dimethylfuran blood levels. A method using surrogate signatures to train the ANN was validated by comparing blood levels among cigarette smokers from the National Health and Nutrition Examination Survey (NHANES) with BTEXS and 2,5-dimethylfuran signatures derived from the smoke of machine-smoked cigarettes. Classification agreement for an ANN model trained with relative VOC levels was up to 99.8% for nonsmokers and 100.0% for smokers. As such, because there is limited blood level data on individuals exposed to crude oil/fuel, only surrogate signatures derived from crude oil and fuel were used for training the ANN. For the 2007-2008 NHANES data, the ANN model assigned 7 out of 1998 specimens (0.35%) and for the 2013-2014 NHANES data 12 out of 2906 specimens (0.41%) to the crude oil/fuel signature category.

A high throughput instrument to measure mechanical losses in thin film coatings

Brownian thermal noise generated by mechanical losses in thin film coatings limits the sensitivity of gravitational wave detectors, as well as several high precision metrology experiments. Improving the sensitivity of the next generation of gravitational wave detectors will require optical coatings with significantly reduced mechanical losses. In this paper, we describe a system that we developed to measure the mechanical loss angle of thin film coatings deposited on fused silica substrates. The novelty of this system resides in the capability of parallel measurement of up to four samples and the ability to simultaneously probe all the resonant modes of each sample. This high throughput measurement system allows the exploration of a large number of deposition and material parameters, which can be tuned to achieve low loss coatings.

Molecular, clinical and neuropsychological study in 31 patients with Kabuki syndrome and KMT2D mutations

Kabuki syndrome (KS-OMIM 147920) is a rare developmental disease characterized by the association of multiple congenital anomalies and intellectual disability. This study aimed to investigate intellectual performance in children with KS and link the performance to several clinical features and molecular data. We recruited 31 children with KMT2D mutations who were 6 to 16 years old. They all completed the Weschler Intelligence Scale for Children, fourth edition. We calculated all indexes: the Full Scale Intellectual Quotient (FSIQ), Verbal Comprehension Index (VCI), Perceptive Reasoning Index (PRI), Processing Speed Index (PSI), and Working Memory Index (WMI). In addition, molecular data and several clinical symptoms were studied. FSIQ and VCI scores were 10 points lower for patients with a truncating mutation than other types of mutations. In addition, scores for FSIQ, VCI and PRI were lower for children with visual impairment than normal vision. We also identified a discrepancy in indexes characterized by high WMI and VCI and low PRI and PSI. We emphasize the importance of early identification and intensive care of visual disorders in patients with KS and recommend individual assessment of intellectual profile.

Clozapine induced diarrhea

Introduction

Clozapine (CZP) is the only antipsychotic approved for resistant schizophrenia 1. Due to its side effects, CZP is not the first therapeutic option in a psychotic episode. Its anticholinergic effects often cause constipation, however, diarrhea have also been described in literature.

Objectives

We describe a patient with two episodes of severe diarrhea after clozapine initiation, which lead to CZP discontinuation.

Aims

Discuss about the differential diagnosis of diarrhea in CZP patients and the needing of a further studies for clarify the more appropriate management in CZP induced diarrhea.

Methods

We present a case report of a 46 years man diagnosed with schizoaffective disorder who presented two episodes of severe diarrhea with fever, which forced his transfer to internal medicine and UCI after CZP initiation.

Results

At the first episode analytical, radiological and histological findings led to Crohn's disease diagnosis, which required budesonide and mesalazine treatment. In the second episode, the digestive team concluded that the episode was due to clozapine toxicity despite the controversial findings (clostridium toxin and Crohn's compatible biopsies)

Conclusions

Diarrhea caused by CZP has been controversial in the literature. However due to the severity of digestive episodes and the paucity of alternative treatments further studies for a better understanding of its physiopathology are warranted.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Polydipsia and intermittent hyponatremia

Introduction

Hyponatraemia occurs in 4% of schizophrenic patients. Dilutional hyponatraemia, due to inappropriate retention of water and excretion of sodium, occurs with different psychotropic medications and could lead to hippocampal dysfunction. This complication is usually asymptomatic but can cause severe problems, as lethargy and confusion, difficult to diagnose in mentally ill patients.

Objectives

To describe a case of a patient with psychotropic poli-therapy, admitted three times due to hyponatremia and the pharmacological changes that improved his condition.

Aims

To broadcast the intermittent hyponatraemia and polydipsia (PIP), a not rare condition, suffered by treated schizophrenic patients and discuss its physiopathology and treatment thorough a case report.

Methods

A 56-year schizophrenic male was admitted for presenting disorganized behavior, agitation, auditory hallucinations, disorientation, ataxia, vomits and urinary retention. He was on clomipramine, haloperidol and clotiapine (recently added), quetiapine, fluphenazine and clonazepam. After water restriction his symptoms improved and he was discharged. Twenty-five days later, he was readmitted for presenting the same symptoms and after water restriction, he was discharged. Five days later, he was again admitted and transferred to the psychiatric ward.

Results

Haloperidol, fluphenazine and clomipramine were replaced by clozapine. These changes lead him to normalize the hypoosmolality and reduce his water-voracity. Endocrinology team did not label this episode of SIADH due to its borderline blood and urine parameters.

Conclusions

Hyponatremia is frequent in schizophrenic patients and may have severe consequences. Therefore, a prompt recognition and treatment is warranted.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Serum B-cell maturation antigen: a novel biomarker to predict outcomes for multiple myeloma patients

B-cell maturation antigen is expressed on plasma cells. In this study, we have identified serum B-cell maturation antigen as a novel biomarker that can monitor and predict outcomes for multiple myeloma patients. Compared to healthy donors, patients with multiple myeloma showed elevated serum B-cell maturation antigen levels (P<0.0001). Serum B-cell maturation antigen levels correlated with the proportion of plasma cells in bone marrow biopsies (Spearman's rho = 0.710; P<0.001), clinical status (complete response vs partial response, P=0.0374; complete response vs progressive disease, P<0.0001), and tracked with changes in M-protein levels. Among patients with non-secretory disease, serum B-cell maturation antigen levels correlated with bone marrow plasma cell levels and findings from positron emission tomography scans. Kaplan-Meier analysis demonstrated that serum B-cell maturation antigen levels above the median levels were predictive of a shorter progression-free survival (P=0.0006) and overall survival (P=0.0108) among multiple myeloma patients (n=243). Specifically, patients with serum B-cell maturation antigen levels above the median level at the time of starting front-line (P=0.0043) or a new salvage therapy (P=0.0044) were found to have shorter progression-free survival. Importantly, serum B-cell maturation antigen levels did not show any dependence on renal function and maintained independent significance when tested against other known prognostic markers for multiple myeloma such as age, serum β2 microglobulin, hemoglobin, and bone disease. These data identify serum B-cell maturation antigen as a new biomarker to manage multiple myeloma patients.