Pre-operative MRI radiomics model non-invasively predicts key genomic markers and survival in glioblastoma patients.

PURPOSE: Although glioblastoma (GBM) is the most common primary brain malignancy, few tools exist to pre-operatively risk-stratify patients by overall survival (OS) or common genetic alterations. We developed an MRI-based radiomics model to identify patients with EGFR amplification, MGMT methylation, GBM subtype, and OS greater than 12 months. METHODS: We retrospectively identified 235 patients with pathologically confirmed GBMs from the Cancer Genome Atlas (88; TCGA) and MD Anderson Cancer Center (147; MDACC). After two neuroradiologists segmented MRI tumor volumes, we extracted first-order and second-order radiomic features (gray-level co-occurrence matrices). We used the Maximum Relevance Minimum Redundancy technique to identify the 100 most relevant features and validated models using leave-one-out-cross-validation and validation on external datasets (i.e., TCGA). Our results were reported as the area under the curve (AUC). RESULTS: The MDACC patient cohort had significantly higher OS (22 months) than the TCGA dataset (14 months). On both LOOCV and external validation, our radiomics models were able to identify EGFR amplification (all AUCs > 0.83), MGMT methylation (all AUCs > 0.85), GBM subtype (all AUCs > 0.92), and OS (AUC > 0.91 on LOOCV and 0.71 for TCGA validation). CONCLUSIONS: Our robust radiomics pipeline has the potential to pre-operatively discriminate common genetic alterations and identify patients with favorable survival.

WIF1 re-expression in glioblastoma inhibits migration through attenuation of non-canonical WNT signaling by downregulating the lncRNA MALAT1.

Glioblastoma is the most aggressive primary brain tumor in adults and due to the invasive nature cannot be completely removed. The WNT inhibitory factor 1 (WIF1), a secreted inhibitor of WNTs, is systematically downregulated in glioblastoma and acts as strong tumor suppressor. The aim of this study was the dissection of WIF1-associated tumor-suppressing effects mediated by canonical and non-canonical WNT signaling. We found that WIF1 besides inhibiting the canonical WNT pathway selectively downregulates the WNT/calcium pathway associated with significant reduction of p38-MAPK (p38-mitogen-activated protein kinase) phosphorylation. Knockdown of WNT5A, the only WNT ligand overexpressed in glioblastoma, phenocopied this inhibitory effect. WIF1 expression inhibited cell migration in vitro and in an orthotopic brain tumor model, in accordance with the known regulatory function of the WNT/Ca(2+) pathway on migration and invasion. In search of a mediator for this function differential gene expression profiles of WIF1-expressing cells were performed. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a long non-coding RNA and key positive regulator of invasion, emerged as the top downregulated gene. Indeed, knockdown of MALAT1 reduced migration in glioblastoma cells, without effect on proliferation. Hence, loss of WIF1 enhances the migratory potential of glioblastoma through WNT5A that activates the WNT/Ca(2+) pathway and MALAT1. These data suggest the involvement of canonical and non-canonical WNT pathways in glioblastoma promoting key features associated with this deadly disease, proliferation on one hand and invasion on the other. Successful targeting will require a dual strategy affecting both canonical and non-canonical WNT pathways.

Src homology domain-containing phosphatase 2 suppresses cellular senescence in glioblastoma.

BACKGROUND: Epidermal growth factor receptor (EGFR) signalling is frequently altered during glioblastoma de novo pathogenesis. An important downstream modulator of this signal cascade is SHP2 (Src homology domain-containing phosphatase 2). METHODS: We examined the The Cancer Genome Atlas (TCGA) database for SHP2 mutations. We also examined the expression of a further 191 phosphatases in the TCGA database and used principal component and comparative marker analysis available from the Broad Institute to recapitulate the TCGA-defined subgroups and identify the specific phosphatases defining each subgroup. We identified five siRNAs from two independent commercial sources that were reported by the vendor to be pre-optimised in their specificity of SHP2 silencing. The specificity and physiological effects of these siRNAs were tested using an in vitro glioma model. RESULTS: TCGA data demonstrate SHP2 to be mutated in 2% of the glioblastoma multiforme's studied. Both mutations identified in this study are likely to be activating mutations. We found that the four subgroups of GBM as defined by TCGA differ significantly with regard to the expression level of specific phosphatases as revealed by comparative marker analysis. Surprisingly, the four subgroups can be defined solely on the basis of phosphatase expression level by principal component analysis. This result suggests that critical phosphatases are responsible for the modulation of specific molecular pathways within each subgroup. Src homology domain-containing phosphatase 2 constitutes one of the 12 phosphatases that define the classical subgroup. We confirmed the biological significance by siRNA knockdown of SHP2. All five siRNAs tested reduced SHP2 expression by 70-100% and reduced glioblastoma cell line growth by up to 80%. Profiling the established molecular targets of SHP2 (ERK1/2 and STAT3) confirmed specificity of these siRNAs. The loss of cell viability induced by SHP2 silencing could not be explained by a significant increase in apoptosis alone as demonstrated by terminal deoxyribonucleotidyl transferase-mediated nick-end labelling and propidium iodide staining. Src homology domain-containing phosphatase 2 silencing, however, did induce an increase in ß-galactosidase staining. Propidium iodide staining also showed that SHP2 silencing increases the population of glioblastoma cells in the G1 phase of the cell cycle and reduces the population of such cells in the G2/M- and S-phase. CONCLUSION: Src homology domain-containing phosphatase 2 promotes the growth of glioblastoma cells by suppression of cellular senescence, a phenomenon not described previously. Selective inhibitors of SHP2 are commercially available and may be considered as a strategy for glioblastoma therapy.

Investigation of hormonal male contraception in African men: suppression of spermatogenesis by oral desogestrel with depot testosterone.

BACKGROUND: Suppression of spermatogenesis to azoospermia is required for effective hormonal male contraception, but the degree of suppression varies between ethnic groups. We here report the first study of hormonal suppression of spermatogenesis in two African centres using a regimen of oral progestogen with depot testosterone. METHODS A total of 31 healthy men (21 black) were recruited in Cape Town and 21 men in Sagamu, Nigeria. Subjects were randomized to take either 150 or 300 micro g desogestrel daily p.o. with testosterone pellets. In Cape Town, desogestrel was administered for 24 weeks with 400 mg testosterone re-administered 12 weekly. In Sagamu, desogestrel was administered for 52 weeks with 200 mg testosterone (later increased to 400 mg) re-administered 12-weekly. RESULTS: In Cape Town, 22 men completed at least 20 weeks treatment. Azoospermia was achieved in 8/10 and 8/12 men in the 150 micro g and 300 micro g desogestrel groups. Four men in Sagamu withdrew. Azoospermia was achieved in all 17 men in the two groups. There were no significant changes in lipoprotein or haemoglobin concentrations in any group. CONCLUSION: These data demonstrate that the combination of oral desogestrel with depot testosterone is an effective regimen for suppression of spermatogenesis in African as in Caucasian and Chinese men, with azoospermia achieved in a total of 83/98 (85%) men.

Inhibition of progesterone secretion with trilostane for mid-trimester termination of pregnancy: randomized controlled trials.

BACKGROUND: Progesterone is central to the maintenance of pregnancy, and is thus the ideal target for fertility regulation. Two mechanisms by which progesterone can be targeted are: receptor blockade and reduction of progesterone production through enzyme inhibition. Mifepristone, a receptor blocker, is usually given as 'pretreatment' prior to prostaglandin administration in mid-trimester termination of pregnancy (TOP). Unfortunately, there are difficulties accessing mifepristone in developing countries, and TOP is therefore performed using prostaglandins alone, which results in unacceptably long induction-to-abortion intervals. Trilostane is a 3beta-hydroxysteroid dehydrogenase inhibitor which reduces progesterone production. In these mid-trimester studies it is evaluated as a method of pretreatment prior to misoprostol administration. METHODS: Three consecutive randomized controlled trials comparing different trilostane regimens for pretreatment were performed. In study 1, trilostane was compared with placebo; in study 2, two doses of trilostane were compared (1080 mg and 720 mg); in study 3, the effect of adding danazol to trilostane as combination therapy was evaluated. The primary outcome in all the studies was the induction-to-abortion interval. Serum progesterone, estradiol and cortisol were measured serially during treatment. RESULTS: In study 1, 48 women were randomized. The median induction-to-abortion interval was 9 h in the trilostane group and 18.5 h in the placebo group (P < 0.0001). Progesterone and estradiol production was significantly reduced in the women receiving trilostane, with maintenance of diurnal cortisol variation. Twenty-eight women were randomized in study 2, which demonstrated that there was no significant difference in the induction-to-abortion interval using 1080 mg and 720 mg trilostane when compared with the higher doses used in study 1. Study 3, in which 40 women were included, failed to show any additional benefit using combination therapy with danazol and trilostane. CONCLUSIONS: Trilostane is an effective pretreatment agent in mid-trimester TOP.

Separation of selected anticancer drugs using superheated water as the mobile phase.

Six anticancer drugs have been eluted on a polystyrene-divinylbenzene (PS-DVB) column with buffered superheated water as the mobile phase. The temperature range studied was from ambient temperature up to 160 degrees C, and the pH of the water was adjusted to 11.5 and 3.5 with phosphate buffer. It was possible to separate the substances 5-fluorouracil (5-FU), methotrexate (MTX), 7-hydroxymethotrexate (7-OH-MTX), and etoposide (VP-16) in one chromatographic run. The separation of these substances was optimized when adjusting the pH from 11.5 to 3.5, resulting in a total elution time of less than 13 min. Furthermore, retention factors of all of the investigated substances were measured at different temperatures and pH values.

Automation of the GC/MS analysis of mineral oil contaminations in water.

An automation of the sample preparation and analysis of mineral oil contaminations in water was developed. The automated sample preparation was carried out according to ISO/DIS 9377-4 [1]. The standard is applicable to the determination of hydrocarbons in the boiling range of n-decane (n-C10) up to n-tetracontane (n-C40) by GC. Extraction of the sample and clean-up of the extract were performed by an autosampler with a movable head which is capable of carrying different syringes for gas and liquid handling. A GC/MS-system with a programmed temperature vaporizing (PTV) injector including the possibility of large volume injections (LVI) was employed for the analysis. The recovery of analytes was 101.8%, the repeatability 2.9% relative standard deviation (RSD). The linear range covered 0.3 to 40 mg/L oil but may be larger since no higher concentrations were measured. With an FID, being the detector of choice mentioned in the standard, it should be possible to achieve at least four orders of magnitude in the linear range. The limit of determination was found to be 0.3-0.4 mg/L, the limit of detection 0.1-0.2 mg/L [2]. Measurements of spiked deionized, bidistilled water and spiked water from a lake confirmed the accuracy of the analysis. Due to automation and miniaturization of the analysis it is possible to economize time and chemicals without loss of precision and accuracy.

Platelet-associated IgG, IgM, and C3 in paediatric infectious disease.

Elevated amounts of platelet-associated serum proteins (PASP) can be detected in idiopathic thrombocytopenic purpura (ITP) and are considered to be of patho-aetiological importance especially in the case of acute ITP, that commonly follows acute febrile illnesses. Using a micro-enzyme-linked immunoassay we examined PASP (IgG, IgM, and C3) in 120 paediatric patients with acute fever caused by viral (n = 45), bacterial (n = 48), or non-detectable agents (n = 27) and compared those values to the levels of PASP of an own paediatric control group (n = 21). Two of the patients presented mild temporary thrombocytopenia without clinical signs in the course of their infectious disease. While having normal platelet counts, the majority of our patients (69.2%) however, showed increased levels of PASP (IgG, IgM, C3; single or combined). Significant differences of PASP levels by discrimination of viral and bacterial diseases could not be demonstrated. Elevated platelet-associated complement was of special interest, because - in the absence of low platelet counts due to platelet-specific antibodies - it must be regarded as an indicator for immune complexes (IC) binding to thrombocyte surface IgG Fc-receptors. Thus we suggest that platelets play a considerable role in the elimination of circulating IC.

Acute total aortic occlusion during cardiac catheterization associated with polycythemia vera.

We present a case of acute total aortic occlusion at the time of cardiac catheterization in a 62-yr-old female with an acute myocardial infarction and newly diagnosed polycythemia vera. Despite normalization of serum viscosity and red cell mass by phlebotomy, her predisposition to thrombosis persisted. Caution is advised when considering cardiac catheterization in patients with this disease.

Chronic acetazolamide intoxication.

Severe acidosis associated with acetazolamide therapy is rare. We report the first case in which plasma and whole blood acetazolamide concentrations were measured. A 61 year-old patient receiving oral acetazolamide for treatment of glaucoma presented with a 7 day history of declining mental status. The patient was lethargic and oriented only to name. The respiratory rate was 36 per minute in a Kussmaul pattern with arterial blood gases revealing a pH of 7.23, pO2 68 mmHg, paCO2 14 mmHg and bicarbonate 6 mEq/L. Serum creatinine was 3.1 mg%, Cl 126 mEq/L, and anion gap 15. Urine pH was 6.0. Infection and other causes of acidosis and bicarbonate loss were excluded, and he was discharged with normal mental status and improving acid-base balance 18 days after admission. Acetazolamide concentrations four days after the last dose were 26.38 mcg/ml and 38.84 mcg/ml in serum and whole blood, respectively. The serum half-life was 34 hours, compared to a range of 1.5 to 6 hours in subjects with normal renal function. Monitoring acetazolamide concentrations may be useful in adjusting dosage and preventing toxicity in patients with decreased renal function.