A Learnable Prior Improves Inverse Tumor Growth Modeling

Biophysical modeling, particularly involving partial differential equations (PDEs), offers significant potential for tailoring disease treatment protocols to individual patients. However, the inverse problem-solving aspect of these models presents a substantial challenge, either due to the high computational requirements of model-based approaches or the limited robustness of deep learning (DL) methods. We propose a novel framework that leverages the unique strengths of both approaches in a synergistic manner. Our method incorporates a DL ensemble for initial parameter estimation, facilitating efficient downstream evolutionary sampling initialized with this DL-based prior. We showcase the effectiveness of integrating a rapid deep-learning algorithm with a high-precision evolution strategy in estimating brain tumor cell concentrations from magnetic resonance images. The DL-Prior plays a pivotal role, significantly constraining the effective sampling-parameter space. This reduction results in a fivefold convergence acceleration and a Dice-score of 95.

Distinct molecular profiles of skull bone marrow in health and neurological disorders

The bone marrow in the skull is important for shaping immune responses in the brain and meninges, but its molecular makeup among bones and relevance in human diseases remain unclear. Here, we show that the mouse skull has the most distinct transcriptomic profile compared with other bones in states of health and injury, characterized by a late-stage neutrophil phenotype. In humans, proteome analysis reveals that the skull marrow is the most distinct, with differentially expressed neutrophil-related pathways and a unique synaptic protein signature. 3D imaging demonstrates the structural and cellular details of human skull-meninges connections (SMCs) compared with veins. Last, using translocator protein positron emission tomography (TSPO-PET) imaging, we show that the skull bone marrow reflects inflammatory brain responses with a disease-specific spatial distribution in patients with various neurological disorders. The unique molecular profile and anatomical and functional connections of the skull show its potential as a site for diagnosing, monitoring, and treating brain diseases.

On the Limit of Detection in Infrared Spectroscopic Imaging

Infrared (IR) spectroscopic imaging instruments' performance can be characterized and optimized by an analysis of their limit of detection (LOD). Here we report a systematic analysis of the LOD for Fourier transform IR (FT-IR) and discrete frequency IR (DFIR) imaging spectrometers. In addition to traditional measurements of sample and blank data, we propose a decision theory perspective to pose the determination of LOD as a binary classification problem under different assumptions of noise uniformity and correlation. We also examine three spectral analysis approaches, namely, absorbance at a single frequency, average of absorbance over selected frequencies and total spectral distance - to suit instruments that acquire discrete or contiguous spectral bandwidths. The analysis is validated by refining the fabrication of a bovine serum albumin protein microarray to provide eight uniform spots from ∼2.8 nL of solution for each concentration over a wide range (0.05-10 mg/mL). Using scanning parameters that are typical for each instrument, we estimate a LOD of 0.16 mg/mL and 0.12 mg/mL for widefield and line scanning FT-IR imaging systems, respectively, using the spectral distance approach, and 0.22 mg/mL and 0.15 mg/mL using an optimal set of discrete frequencies. As expected, averaging and the use of post-processing techniques such as minimum noise fraction transformation results in LODs as low as ∼0.075 mg/mL that correspond to a spotted protein mass of ∼112 fg/pixel. We emphasize that these measurements were conducted at typical imaging parameters for each instrument and can be improved using the usual trading rules of IR spectroscopy. This systematic analysis and methodology for determining the LOD can allow for quantitative measures of confidence in imaging an analyte's concentration and a basis for further improving IR imaging technology.

Production of Active Recombinant Hyaluronidase Inclusion Bodies from Apis mellifera in E. coli Bl21(DE3) and characterization by FT-IR Spectroscopy

The bacterium E. coli is one of the most important hosts for recombinant protein production. The benefits are high growth rates, inexpensive media, and high protein titers. However, complex proteins with high molecular weight and many disulfide bonds are expressed as inclusion bodies (IBs). In the last decade, the overall perception of these IBs being not functional proteins changed, as enzyme activity was found within IBs. Several applications for direct use of IBs are already reported in literature. While fluorescent proteins or protein tags are used for determination of IB activity to date, direct measurements of IB protein activity are scacre. The expression of recombinant hyaluronidase from Apis mellifera in E. coli BL21(DE3) was analyzed using a face centered design of experiment approach. Hyaluronidase is a hard to express protein and imposes a high metabolic burden to the host. Conditions giving a high specific IB titer were found at 25 °C at low specific substrate uptake rates and induction times of 2 to 4 h. The protein activity of hyaluronidase IBs was verified using (Fourier transform) FT-IR spectroscopy. Degradation of the substrate hyaluronan occurred at increased rates with higher IB concentrations. Active recombinant hyaluronidase IBs can be immediately used for direct degradation of hyaluronan without further down streaming steps. FT-IR spectroscopy was introduced as a method for tracking IB activity and showed differences in degradation behavior of hyaluronan dependent on the applied active IB concentration.

pH titration of β-lactoglobulin monitored by laser-based Mid-IR transmission spectroscopy coupled to chemometric analysis

A novel external cavity-quantum cascade laser (EC-QCL)-based setup for mid-IR transmission spectroscopy in the amide I and amide II region was employed for monitoring pH-induced changes of protein secondary structure. pH titration of β-lactoglobulin revealed unfolding of the native β-sheet secondary structure occurring at basic pH. Chemometric analysis of the dynamic IR spectra was performed by multivariate curve resolution-alternating least squares (MCR-ALS). Using this approach, spectral and abundance distribution profiles of the conformational transition were obtained. A proper post-processing procedure was implemented allowing to extract information about pure protein spectra and spurious signals that may interfere in the interpretation of the system. This work demonstrates the potential and versatility of the EC-QCL-based IR transmission setup for flow-through applications, benefitting from the high available optical path length.

Immediate-release and extended-release formulations of second-generation antidepressants for the treatment of major depressive disorder in adults

Introduction

Extended-release formulations of antidepressants have been marketed as a strategy to increase patient adherence. Changes in the formulation of drugs, however, could be related to changes in efficacy and tolerability. Among second-generation antidepressants, bupropion, fluoxetine, mirtazapine, paroxetine, and venlafaxine are available in immediate- and extended-release formulations.

Objectives

To compare the efficacy, tolerability, and adherence of immediate- versus extended-release formulations of second-generation antidepressants for the treatment of major depressive disorder (MDD) in adults.

Aim

To provide an evidence base for clinicians when choosing immediate- or extended-release formulations of antidepressants for the treatment of MDD.

Methods

We conducted a comparative effectiveness review for the U.S. Agency for Healthcare Research and Quality searching PubMed, EMBASE, The Cochrane Library, and the International Pharmaceutical Abstracts up to May 2010. Two people independently reviewed the literature, abstracted data, and rated the risk of bias.

Results

Six RCTs and one observational study provided evidence about the comparative efficacy, tolerability, and adherence of bupropion SR (sustained release) versus bupropion XL (extended release), fluoxetine daily vs. fluoxetine weekly, paroxetine IR (immediate release) versus paroxetine CR (continuous release), and venlafaxine IR versus venlafaxine XR (extended release). Overall, no substantial differences in efficacy and safety could be detected. Open-label and observational evidence indicated better adherence for bupropion XL and fluoxetine weekly than for immediate-release medications. No differences in adherence could be detected between paroxetine IR and paroxetine CR.

Conclusions

Our findings indicate similar efficacy and tolerability between immediate- and extended-release formulations. Whether extended-release formulations lead to better adherence remains unclear.

[Pre- and postoperative results of spirography and blood gas analysis in patients with atrial septal defect or mitral stenosis]

In patients with atrial septum defect and mitral stenosis, respectively, the ventilation and blood gas parameters were compared before and after cardiac operation. In general postoperatively no reversibility of preoperatively proved pulmonary functional disturbances could be established. Only in individual cases a discrete improvement of some of the functional indicators could be observed. Therefore, the operative intervention on the heart should be performed possibly before the onset of irreversible pulmonary structural changes.