Bacterial Brain Abscesses Expand Despite Effective Antibiotic Treatment: A Process Powered by Osmosis Due to Neutrophil Cell Death

BACKGROUND AND OBJECTIVES

A bacterial brain abscess is an emergency and should be drained of pus within 24 hours of diagnosis, as recently recommended. In this cross-sectional study, we investigated whether delaying pus drainage entails brain abscess expansion and what the underlying mechanism might be.

METHODS

Repeated brain MRI of 47 patients who did not undergo immediate pus drainage, pus osmolarity measurements, immunocytochemistry, proteomics, and 18F-fluorodeoxyglucose positron emission tomography.

RESULTS

Time from first to last MRI before neurosurgery was 1 to 14 days. Abscesses expanded in all but 2 patients: The median average increase was 23% per day (range 0%-176%). Abscesses expanded during antibiotic therapy and even if the pus did not contain viable bacteria. In a separate patient cohort, we found that brain abscess pus tended to be hyperosmolar (median value 360 mOsm; range 266-497; n = 14; normal cerebrospinal fluid osmolarity is ∼290 mOsm). Hyperosmolarity would draw water into the abscess cavity, causing abscess expansion in a ballooning manner through increased pressure in the abscess cavity. A mechanism likely underlying pus hyperosmolarity was the recruitment of neutrophils to the abscess cavity with ensuing neutrophil cell death and decomposition of neutrophil proteins and other macromolecules to osmolytes: Pus analysis showed the presence of neutrophil proteins (protein-arginine deiminases, citrullinated histone, myeloperoxidase, elastase, cathelicidin). Previous studies have shown very high levels of osmolytes (ammonia, amino acids) in brain abscess pus. 18F-fluorodeoxyglucose positron emission tomography showed focal neocortical hypometabolism 1 to 8 years after brain abscess, indicating long-lasting damage to brain tissue.

CONCLUSION

Brain abscesses expand despite effective antibiotic treatment. Furthermore, brain abscesses cause lasting damage to surrounding brain tissue. These findings support drainage of brain abscesses within 24 hours of diagnosis.

On the Impact of the Pangenome and Annotation Discrepancies While Building Protein Sequence Databases for Bacteria Proteogenomics

In proteomics, peptide information within mass spectrometry (MS) data from a specific organism sample is routinely matched against a protein sequence database that best represent such organism. However, if the species/strain in the sample is unknown or genetically poorly characterized, it becomes challenging to determine a database which can represent such sample. Building customized protein sequence databases merging multiple strains for a given species has become a strategy to overcome such restrictions. However, as more genetic information is publicly available and interesting genetic features such as the existence of pan- and core genes within a species are revealed, we questioned how efficient such merging strategies are to report relevant information. To test this assumption, we constructed databases containing conserved and unique sequences for 10 different species. Features that are relevant for probabilistic-based protein identification by proteomics were then monitored. As expected, increase in database complexity correlates with pangenomic complexity. However, Mycobacterium tuberculosis and Bordetella pertussis generated very complex databases even having low pangenomic complexity. We further tested database performance by using MS data from eight clinical strains from M. tuberculosis, and from two published datasets from Staphylococcus aureus. We show that by using an approach where database size is controlled by removing repeated identical tryptic sequences across strains/species, computational time can be reduced drastically as database complexity increases.

Persistence of intrathecal oligoclonal B cells and IgG in multiple sclerosis

In multiple sclerosis (MS), B cells are trafficking across the blood-brain barrier, but it is not known how this relates to the synthesis of oligoclonal IgG. We used quantitative mass spectrometry of oligoclonal bands and high-throughput sequencing of immunoglobulin heavy-chain variable transcripts to study the longitudinal B cell response in the cerebrospinal fluid (CSF) and blood of two MS patients. Twenty of 22 (91%) and 25 of 28 (89%) of oligoclonal band peptides persisted in samples collected 18 months apart, in spite of a dynamic exchange across the blood-CSF barrier of B lineage cells connecting to oligoclonal IgG.

The cardiac syndecan-4 interactome reveals a role for syndecan-4 in nuclear translocation of muscle LIM protein (MLP)

Costameres are signaling hubs at the sarcolemma and important contact points between the extracellular matrix and cell interior, sensing and transducing biomechanical signals into a cellular response. The transmembrane proteoglycan syndecan-4 localizes to these attachment points and has been shown to be important in the initial stages of cardiac remodeling, but its mechanistic function in the heart remains insufficiently understood. Here, we sought to map the cardiac interactome of syndecan-4 to better understand its function and downstream signaling mechanisms. By combining two different affinity purification methods with MS analysis, we found that the cardiac syndecan-4 interactome consists of 21 novel and 29 previously described interaction partners. Nine of the novel partners were further validated to bind syndecan-4 in HEK293 cells (i.e. CAVIN1/PTRF, CCT5, CDK9, EIF2S1, EIF4B, MPP7, PARVB, PFKM, and RASIP). We also found that 19 of the 50 interactome partners bind differently to syndecan-4 in the left ventricle lysate from aortic-banded heart failure (ABHF) rats compared with SHAM-operated animals. One of these partners was the well-known mechanotransducer muscle LIM protein (MLP), which showed direct and increased binding to syndecan-4 in ABHF. Nuclear translocation is important in MLP-mediated signaling, and we found less MLP in the nuclear-enriched fractions from syndecan-4^-/- mouse left ventricles but increased nuclear MLP when syndecan-4 was overexpressed in a cardiomyocyte cell line. In the presence of a cell-permeable syndecan-4-MLP disruptor peptide, the nuclear MLP level was reduced. These findings suggest that syndecan-4 mediates nuclear translocation of MLP in the heart.

Protein Tyrosine Phosphatase Receptor Type G (PTPRG) Controls Fibroblast Growth Factor Receptor (FGFR) 1 Activity and Influences Sensitivity to FGFR Kinase Inhibitors

Recently, FGFR1 was found to be overexpressed in osteosarcoma and represents an important target for precision medicine. However, because targeted cancer therapy based on FGFR inhibitors has so far been less efficient than expected, a detailed understanding of the target is important. We have here applied proximity-dependent biotin labeling combined with label-free quantitative mass spectrometry to identify determinants of FGFR1 activity in an osteosarcoma cell line. Many known FGFR interactors were identified (e.g. FRS2, PLCG1, RSK2, SRC), but the data also suggested novel determinants. A strong hit in our screen was the tyrosine phosphatase PTPRG. We show that PTPRG and FGFR1 interact and colocalize at the plasma membrane where PTPRG directly dephosphorylates activated FGFR1. We further show that osteosarcoma cell lines depleted for PTPRG display increased FGFR activity and are hypersensitive to stimulation by FGF1. In addition, PTPRG depletion elevated cell growth and negatively affected the efficacy of FGFR kinase inhibitors. Thus, PTPRG may have future clinical relevance by being a predictor of outcome after FGFR inhibitor treatment.

Mapping the in vitro interactome of cardiac sodium (Na+ )-calcium (Ca2+ ) exchanger 1 (NCX1)

The sodium (Na⁺ )-calcium (Ca²⁺ ) exchanger 1 (NCX1) is an antiporter membrane protein encoded by the SLC8A1 gene. In the heart, it maintains cytosolic Ca²⁺ homeostasis, serving as the primary mechanism for Ca²⁺ extrusion during relaxation. Dysregulation of NCX1 is observed in end-stage human heart failure. In this study, we used affinity purification coupled with MS in rat left ventricle lysates to identify novel NCX1 interacting proteins in the heart. Two screens were conducted using: (1) anti-NCX1 against endogenous NCX1 and (2) anti-His (where His is histidine) with His-trigger factor-NCX1_cyt recombinant protein as bait. The respective methods identified 112 and 350 protein partners, of which several were known NCX1 partners from the literature, and 29 occurred in both screens. Ten novel protein partners (DYRK1A, PPP2R2A, SNTB1, DMD, RABGGTA, DNAJB4, BAG3, PDE3A, POPDC2, STK39) were validated for binding to NCX1, and two partners (DYRK1A, SNTB1) increased NCX1 activity when expressed in HEK293 cells. A cardiac NCX1 protein-protein interaction map was constructed. The map was highly connected, containing distinct clusters of proteins with different biological functions, where "cell communication" and "signal transduction" formed the largest clusters. The NCX1 interactome was also significantly enriched with proteins/genes involved in "cardiovascular disease" which can be explored as novel drug targets in future research.

Genome-wide identification of cancer/testis genes and their association with prognosis in a pan-cancer analysis

Cancer/testis (CT) genes are excellent candidates for cancer immunotherapies because of their restrict expression in normal tissues and the capacity to elicit an immune response when expressed in tumor cells. In this study, we provide a genome-wide screen for CT genes with the identification of 745 putative CT genes. Comparison with a set of known CT genes shows that 201 new CT genes were identified. Integration of gene expression and clinical data led us to identify dozens of CT genes associated with either good or poor prognosis. For the CT genes related to good prognosis, we show that there is a direct relationship between CT gene expression and a signal for CD8+ cells infiltration for some tumor types, especially melanoma.

microRNA-140 Inhibits Inflammation and Stimulates Chondrogenesis in a Model of Interleukin 1β-induced Osteoarthritis

Osteoarthritis is a serious disease of articular cartilage. The pathogenic factors contributing to this disorder are inflammation, extracellular matrix degradation and failure to rebuild the articular cartilage. Preclinical studies suggest that microRNA-140 may play a protective role in osteoarthritis development, but little is known about the mechanism by which this occurs. Here we present the results of forced expression of microRNA-140 in an in vitro model of osteoarthritis, evaluated by global proteomics analysis. We show that inflammation was reduced through the altered levels of multiple proteins involved in the nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 pathway. microRNA-140 upregulated many of the components involved in the synthesis of hyaline extracellular matrix and reduced the levels of aggrecanases and syndecan 4, thus potentially both increasing cartilage repair and reducing cartilage breakdown. These results show how forced expression of microRNA-140 is likely to counteract all three pathogenic processes, and support the idea that intra-articular injection of microRNA-140 may benefit patients suffering from early osteoarthritis.

Quantitative Proteomics of Gut-Derived Th1 and Th1/Th17 Clones Reveal the Presence of CD28+ NKG2D- Th1 Cytotoxic CD4+ T cells

T-helper cells are differentiated from CD4+ T cells and are traditionally characterized by inflammatory or immunosuppressive responses in contrast to cytotoxic CD8+ T cells. Mass-spectrometry studies on T-helper cells are rare. In this study, we aimed to identify the proteomes of human Th1 and Th1/Th17 clones derived from intestinal biopsies of Crohn's disease patients and to identify differentially expressed proteins between the two phenotypes. Crohn's disease is an inflammatory bowel disease, with predominantly Th1- and Th17-mediated response where cells of the "mixed" phenotype Th1/Th17 have also been commonly found. High-resolution mass spectrometry was used for protein identification and quantitation. In total, we identified 7401 proteins from Th1 and Th1/Th17 clones, where 334 proteins were differentially expressed. Major differences were observed in cytotoxic proteins that were overrepresented in the Th1 clones. The findings were validated by flow cytometry analyses using staining with anti-granzyme B and anti-perforin and by a degranulation assay, confirming higher cytotoxic features of Th1 compared with Th1/Th17 clones. By testing a larger panel of T-helper cell clones from seven different Crohn's disease patients, we concluded that only a subgroup of the Th1 cell clones had cytotoxic features, and these expressed the surface markers T-cell-specific surface glycoprotein CD28 and were negative for expression of natural killer group 2 member D.

Concomitant cisplatin plus radiotherapy and high-dose-rate brachytherapy versus radiotherapy alone for stage IIIB epidermoid cervical cancer: a randomized controlled trial

PURPOSE

The benefits of chemoradiotherapy (CRT) for cervical cancer compared with radiation (RT) alone seem to diminish in later-stage disease. However, these modalities have not been directly compared for disease-free interval (DFI) and overall survival (OS) of women with stage IIIB cervical cancer.

PATIENTS AND METHODS

We conducted a randomized controlled clinical trial comparing DFI and OS of 147 women with stage IIIB squamous cervical cancer who received either cisplatin plus RT (CRT) or RT alone (72 patients in the CRT group and 75 patients in the RT-only group).

RESULTS

The CRT group had significantly better DFI (hazard ratio [HR], 0.52; 95% CI, 0.29 to 0.93; P = .02). However, patients in the CRT group did not have significantly better OS than those in the RT-only group (HR, 0.67; 95% CI, 0.38 to 1.17; P = .16). Toxicity was graded according to criteria of the Radiation Therapy Oncology Group. The organs affected (excluding hematologic effects) did not differ significantly between groups. Also, late toxicity events and organs affected were not significantly disproportionate between the study groups.

CONCLUSION

For stage IIIB cervical cancer, the addition of cisplatin offers a small but significant benefit in DFI, with acceptable toxicity.

Adjuvant radiotherapy in early stage endometrial cancer

OBJECTIVE

To compare the rates of overall survival (OS), disease-free survival (DFS) and toxicity in different techniques of postoperative radiotherapy for stage IA endometrioid adenocarcionoma of endometrium, histological grades 1and 2.

METHODS

A historical comparison between treatment regimens was performed, and 133 women with a minimum follow-up of 5 years were included. Teletherapy (TELE group), with 22 patients treated from 1988 to 1996, with a 10 MV linear accelerator, average dose 46.2 Gy. Low dose rate brachytherapy (LDRB group) was performed between 1992 and 1995, in 19 women, with an insertion of Cesium 137, at a 60 Gy dose. Fourteen women operated between 1990 and 1996 did not receive radiotherapy (NO RT group). High dose rate brachytherapy was performed in 78 patients (HDRB group), from 1996 to 2004, in five weekly 7 Gy insertions, prescribed at 0.5 cm from the vaginal cylinder.

RESULTS

The 5-year disease-free survival was 94.6% for the HDRB group, 94.1% for the LDRB group, 100% for the TELE group and NO RT groups (p = 0.681). The 5-year overall survival was 86.6% for the HDRB group, 89.5% for the LDRB group and 90% for the TELE group and NO RT groups (p = 0.962). Grades 3-5 late toxicity was 5.3% in LDRB group and 27.3% for the TELE group (p < 0.001).

CONCLUSION

Patients submitted to adjuvant teletherapy showed very high toxicity, which contraindicates that treatment for those patients. There may be a role for adjuvant HDRB, but randomized controlled trials are still needed to evaluate its benefit.

Efeitos adversos no pós-operatório de cirurgias ginecológicas e mamárias

OBJECTIVES

To analyze the occurrence of adverse effects in the first 24-hour postoperative/postanesthetic period in women undergoing minor gynecologic or minor breast surgeries and to identify main associated factors.

METHODS

A cross-sectional study was conducted with 159 women who underwent minor gynecologic or breast surgeries. The women were admitted to the hospital one day before surgery and remained hospitalized for at least 24 hours after surgery. The anesthetic techniques performed were intercostal nerve blockade, spinal anesthesia, and general anesthesia.

RESULTS

The most frequent adverse effects were vomiting, nausea and pain that occurred in 40.3% of women. Of these effects, 60% were observed in the first four hours and 80% were observed in up to six hours after surgical intervention. Women submitted to intercostal blockade received earlier postanesthetic release. Spinal anesthesia was most frequently associated with postoperative pain, although with a lower incidence of nausea and vomiting when compared to general anesthesia and intercostal blockade. The incidence of pain was higher in women who smoked.

CONCLUSIONS

A six-hour period of postoperative observation appeared to be adequate for assessment of most complications and adverse effects occurring in women who undergo minor gynecologic or minor breast surgeries.

A clinical trial of the efficacy and safety of montelukast as monotherapy in patients with chronic stable bronchial asthma

This study is aimed to evaluate the efficacy and safety of montelukast, as monotherapy, in the treatment of chronic stable bronchial asthma in adults. This was a multicentre, open label, non-comparative, prospective, 4-week study. Eligible patients discontinued all anti-inflammatory medication (steroids, chromoglycate sodium) 2 weeks prior to starting therapy with montelukast (10 mg daily). The primary efficacy criteria were improvements in forced expiratory volume in one second (FEV1), peak exploratory flow rate (PEFR) after 4 weeks of therapy. Secondary efficacy criteria were improvement in the patients' symptoms (assessed on an ordinal scale), decrease in discomfort levels (scored on a scale of 0-100), change in peripheral eosinophil counts, decrease in total daily dose of inhaled beta2 agonist (salbutamol). A total of 148 patients, mean age (+/- SD) 40.21 +/- 13.70 years, were enrolled into the study. At the end of the study there were significant improvements in FEV1 and PEFR (29% and 28% increase respectively from baseline values, p<0.000001). The mean total daily dose of inhaled salbutamol decreased significantly from prestudy values of 461 +/- 332 microg/day to 161 +/- 207 microg/day (p<0.000001). The mean eosinophil counts fell from 5.80 +/- 4.90% (+/- SD) to 4.84 +/- 4.42% (+/- SD) (p=0.02). Symptom scores improved significantly as did subjective assessment of discomfort. A total of 29 (19.6%) adverse events were reported, all of which were of mild to moderate intensity. Monotherapy with montelukast significantly improved parameters of asthma control. It was well tolerated with no reports of serious or severe adverse events.

Uterine artery embolization for the treatment of symptomatic myomas in Brazilian women

CONTEXT

Uterine myomas are benign tumors that mostly occur in women of reproductive age at a frequency ranging from 20 to 25%. The symptoms are increased menstrual flow, pain and compressive signs. New treatments have been proposed and uterine artery embolization is one of them.

OBJECTIVE

To evaluate the effects of treatment by embolization of the uterine artery, in women with symptomatic myomas. Uterine and dominant myoma volumes and the major symptoms were evaluated before treatment and 12 weeks later.

TYPE OF STUDY

Open clinical trial.

SETTING

A tertiary-care women's hospital.

PARTICIPANTS

The study was conducted on 32 women with symptomatic single or multiple myomas of the uterine body, seen at the outpatient unit from May 2000 to September 2001.

MAIN MEASUREMENTS

The patients were submitted to gynecological examination and abdominal and endovaginal pelvic ultrasonography, and the examinations were repeated 12 weeks after the first procedure. Uterine artery embolization using PVA (polyvinyl alcohol) particles of 355-700 was performed by catheterization of the right femoral artery in 30 women and by bilateral catheterization in two.

RESULTS

Before embolization, the mean uterine volume of the 32 women was 455 cm and the mean volume of the dominant myoma was 150 cm . Twelve weeks after embolization, the mean uterine volume was 256 cm and the mean volume of the dominant myoma was 91 cm , with p < 0.01 in both cases. Twelve weeks after the treatment, all the women answered a questionnaire, which showed that 71% had improvement in menstrual regularity, 90% decreased menstrual volume and 81% shortened menstrual duration. The most frequent immediate post-procedure symptoms, established as complications, were pain (100%) and fatigue (34%). One woman had myoma degeneration and was submitted to myomectomy.

CONCLUSION

The significant reduction in uterine and dominant myoma volume confirms the validity of the treatment of symptomatic myomas by the technique of uterine artery embolization in Brazilian women. There was significant reduction in menstrual flow and duration, as well as better cycle regularity in the women studied. The few adverse effects observed in the sample studied mainly involved pain immediately after embolization.