Inhibiting Substance Research Articles

Roles of Microbial Extracellular Polymeric Substances in Corrosion and Scale Inhibition of Circulating Cooling Water

Circulating cooling water plays a major role in petrochemical electric power, steel, metallurgical, and other industries. Corrosion and scale inhibitors in circulating cooling water systems face the challenges of high cost, low efficiency, and heavy pollution. Extracellular polymeric substances (EPS) were considered as novel, efficient, and environmentally friendly corrosion and scale inhibitors in circulating cooling water systems due to their availability, high efficiency, and lack of benefit from secondary pollution. However, roles of EPS in corrosion and scale inhibition remain unknown yet. Herein, Gram-negative (Pseudomonas putida) and Gram-positive (Bacillus megaterium) bacteria were selected to explore the corrosion and scale performance and mechanisms of soluble EPS (s-EPS). Performances of s-EPS from P. putida (s-EPS-P. putida) in corrosion and scale inhibition were obviously superior to those of s-EPS from B. megaterium (s-EPS-B. megaterium). The previously undiscovered roles of s-EPS in corrosion and scale were uncovered: (1) the chelating ability of s-EPS (mainly humic substances) prevented the formation and growth of CaCO3 crystals; (2) s-EPS (mainly carbohydrates) formed a dense protective film by integrating with metal ions on a carbon steel surface to prevent the corrosion of A3 carbon steel. Our work provides a deeper mechanistic understanding of corrosion and scale inhibitory performances, allowing advanced development and optimization of s-EPS as a corrosion and scale inhibitor.

PH-responsive smart composite coating with active anticorrosion and efficient scale inhibition properties

In this work, porous polysulfone (PSF) microcapsules were prepared using the method of mixed solvent volatilization, these microcapsules were used as a carrier, 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP) was used as an active substance for scale and corrosion inhibition, and stearic acid (SA) was used as a coating to prepare a pH-responsive smart microcapsule slow-release filler. Then, the smart microcapsules were added to a polyurea resin to prepare a pH-responsive smart composite coating with anti-corrosion and scale inhibition properties. The results showed that SA/PSF/HEDP microcapsules have significant pH-triggering activity in an alkaline environment. The alkaline supersaturated CaCO3 solution test showed that the composite coating has excellent scale inhibition performance. This is attributed to the in the microcapsules being released to the coating surface, achieving the purpose of complexation and solubilization. Local electrochemical impedance spectroscopic (EIS) proved that the SP/SA/PSF/HEDP composite coating has good corrosion resistance. This is attributed to the release of corrosion inhibitors, which can form a dense protective film on the metal. The scale inhibition efficiency of the composite coating was as high as 78.57 %, and the impedance modulus value is increased by three orders of magnitude.

A novel nitrogen- and sulfur-grafted reduced graphene oxide doped with zinc cations for corrosion mitigation of mild steel

Grafting of N- and S- compounds on the reduced graphene oxide results in an increase in corrosion protection properties. In this work, for the first time, simultaneous grafting of both N- and S- atoms on the graphene oxide was accomplished using a natural source, Allium Sativum extract (ALS), which is rich in nitrogen and sulfur functionalities. The synthesis of sulfur- and nitrogen-grafted reduced graphene oxide (FrGO) was conducted using the hydrothermal route, and zinc cations were loaded on the FrGO consecutively. X-ray photoelectron microscopy (XPS) substantiated the successful grafting of ALS on the graphene oxide surface. The obtained products were characterized using diverse means, including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Raman, UV–Vis, contact angle measurement, and thermogravimetric analysis (TGA). The morphology of the samples was determined using field emission scanning electron microscopy (FE-SEM). The incorporation of S, N, and Zn atoms was ascertained using dispersive X-ray spectroscopy (EDS) analysis. The synthesized substances, including graphene oxide (GO), functionalized/reduced graphene oxide (FrGO), and Zn loaded FrGO (Zn@FrGO), were used to prepare anti-corrosion epoxy coatings. The formulated coatings were evaluated using FE-SEM, electrochemical impedance spectroscopy (EIS), and salt spray test (SST). A considerable impact of the Zn@FrGO on the active corrosion protection properties was observed, which makes it a good candidate to be used as a replacement for toxic inhibitive substances.

DNA as an Inhibitor for Corrosion Mitigation of Metallic Materials

Recently, the widespread of the applications of metallic materials in various spheres and fields or discipline in material science and engineering cannot be overemphasized. Alongside this great progression in the adoption of these material for use, the corrosion problems associated with these metals are also gradually becoming alarming which has birthed a call to action for immediate and sustainable efforts to salvage the problem. Several inhibitors have been developed in a bid to mitigate this corrosive ordeal facing a lot of industries, but inorganic inhibitors have some vital some shortcomings in form of poisonous substances which on the long run affects the surrounding. The pitfalls from non-organic inhibitors poised the drive of other researchers to develop a better, non-poisonous and organic inhibitive substances like Deoxyribonucleic Acid (DNA) that will mitigate corrosion without any negative residual effect on either the metallic materials or the environment. The DNA corrosion inhibitors have very good potential and economic owing to the source of extraction which is plant and animal waste which is in line with wealth generation prospect from waste product.

Recent advances in biopolymers/carbohydrate polymers as effective corrosion inhibitive macro-molecules: A review study from experimental and theoretical views

As the researchers have focused on discovering new replacements for conventional inhibitors to address the toxicity concerns, biopolymers/carbohydrate-polymers can play a vital role among different alternatives. It has been discovered that biopolymers (i.e., chitosan/polydopamine/Cellulose/Carrageenan) can effectively mitigate the corrosion of alloys/metals. A considerable number of biopolymers have been identified, and several of them have been researched for their anti-corrosion-related properties. Different modifications have been tested on them, and diverse techniques have been employed to evaluate their efficacy. In spite of some limitations to perceive the biopolymers and carbohydrate polymers as corrosion inhibitors, still, considerably more work will need to be done for the introduction of new biopolymers as well as modification of the existing ones. In this study, the newest publications on several important biopolymers, namely lignin, tannin, inulin, extracellular polymeric substance, carrageenan, cellulose, chitosan, polydopamine, and gum, which have been regarded as corrosion inhibitive substances in the literature, were explored. The results of several assessment methods such as surface studies, corrosion techniques, and thermal analysis conducted to uncover the corrosion-inhibitive capacity of these candidates were explored. It is hoped that such effort went into collecting various research with a focus on the biopolymers as corrosion inhibitors can contribute to the process of shaping new ideas and promoting new investigations.

Development of a pseudovirus assay and evaluation to screen natural products for inhibition of HIV-1 subtype C reverse transcriptase

Ethnopharmacological relevanceMedicinal plants are used in the management of Human Immunodeficiency Virus and Acquired Immunodeficiency Syndrome (HIV/AIDS) in many developing country settings where HIV-1 subtype C drives the epidemic. Efforts to identify plant derived molecules with anti-HIV properties require reproducible assay systems for routine screening of selected plant compounds. Although a number of standardized HIV-1 pseudoviruses have been generated to assess infectivity, replicability or reproducibility, HIV-1 subtype C (HIV-1-C) pseudoviruses have not been comprehensively characterized to identify inhibitory plant substances. Aim of the studyThe current study aimed at developing an HIV-1-C pseudovirus assay, and evaluate plant substances targeting reverse transcriptase (RT) activity. Materials and methodsHIV-1 subtype C pseudoviruses containing a luciferase reporter gene were generated by transfection of human 293T cells. HIV-1 subtype B (HIV-1-B) wild type pseudoviruses and mutants resistant to nucleoside and non-nucleoside RT inhibitors were also generated and used as controls. Selected plant substances and the RT inhibitors Zidovudine (AZT) and Nevirapine (NVP), were used to evaluate inhibition. Pseudovirus infectivity was determined by luciferase measurement in CF2/CD4+/CCR5 cells, and cytotoxicity was determined using the MTT assay. AZT and NVP inhibited wild type pseudoviruses in a dose dependent manner, with IC50 values in the nanomolar range. ResultsPseudoviruses harbouring RT drug resistance mutations were poorly suppressed by AZT and NVP. Catechin, obtained from Peltophorum africanum inhibited HIV-1-C and HIV-1-B pseudoviruses with selective indices of 6304 μM (IC50: 0.49 μM, CC50: 3089 μM) and 1343 μM (IC50: 2.3 μM, CC50: 3089 μM), respectively; while the methanol root crude extract of Elaeodendron transvaalense gave IC50 values of 11.11 μg/ml and 16.86 μg/ml, respectively. ConclusionThe developed HIV-1-C pseudovirus assay can be used to screen plant substances for RT inhibition, and may have utility in settings with limited access to high level biosafety facilities.

Abstract AP29: A SINGLE CELL RNA-SEQUENCING APPROACH TO UNCOVERING HUMAN OVARIAN TUMOR AND IMMUNE CELL HETEROGENEITY, AND THEIR RESPONSE TO MULLERIAN INHIBITING SUBSTANCE USING PATIENT ASCITES SAMPLES

Abstract Mullerian inhibiting substance (MIS) has been shown to inhibit the growth of a stem-like population of ovarian cancer cells both in vivo and in vitro. We have previously shown that its receptor, MISRII, is expressed in a majority of ovarian serous adenocarcinomas. However the determinants of response and the pathways elicited by MIS treatment have been difficult to elucidate due the heterogeneity of tumors both across the patient population and within each sample. To address this complexity we have developed an assay in which patient cancer cells and immune cells are isolated from ascites of recurrent chemoresistant ovarian cancer and incubated in cleared supernatant from autologous ascites for 24h in presence of drug (MIS 10ug/ml) or vehicle control (N=3). This protocol allows for short-term culture in conditions nearly identical to the peritoneal environment. A parallel experiment was conducted using matching pure primary cancer cell lines (derived from the ascites samples) treated in media (MIS 10ug/ml or vehicle for 24h), but lacking immune cells and soluble factors otherwise present in ascites. The effect of treatment on cell sates, and the interaction between immune cells and cancer cells was interrogated by clustering analysis of single cell RNA sequencing (inDROP). We uncovered a high degree of heterogeneity of expression of known and novel markers related to epithelial-mesenchymal states and stemness markers, both across patients and within patient samples, suggesting dynamically coexisting cancer cell states and hierarchies that are patient-specific. These markers were validated in vitro across a larger cohort of primary patient cells lines (N=12) grown as tumor spheroids (with and without MIS 10ug/ml for 24h). Additionally, we have identified a varying abundance of immune cell types (Macrophages, dendritic cells, NK cells, T cells, B cells), and an unexpected effect of MIS on gene expression in both macrophage and cancer cells. The knowledge gained on the response rate in patients, and the biomarkers identified in this study will be fundamental for the successful translation of MIS to the clinic, and further our understanding of the role of non-cell autonomous inhibition of cancer cells by immune components and patient heterogeneity. Citation Format: Raghav Mohan, Motohiro Kano, Hatice Saatcioglu, Nobuhiro Takahashi, LiHua Zhang, Nicholas Nagykery, Joy Poulo, Patricia K Donahoe, David Pepin. A SINGLE CELL RNA-SEQUENCING APPROACH TO UNCOVERING HUMAN OVARIAN TUMOR AND IMMUNE CELL HETEROGENEITY, AND THEIR RESPONSE TO MULLERIAN INHIBITING SUBSTANCE USING PATIENT ASCITES SAMPLES [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr AP29.

Choosing male or female

Reproductive Biology Mammals show dimorphic development with different germ cells and reproductive systems. Mullerian inhibiting substance (MIS) is key to mammalian dimorphic development. In males, the testis secretes MIS, which causes the regression of Mullerian ducts (which are the developmental rudiments for Fallopian tubes, uterus, cervix, and vagina). Using single-cell RNA sequencing, Saatcioglu et al. investigated the persistence of a small group of Misr2+ mesenchymal cells in females. They found that these cells are retained postnatally in the rodent uterus until week 37, when they recede. Misr2+ cells specify endometrial stroma during neonatal uterine development. Applying MIS postnatally inhibits these cells and prevents endometrial stroma and dysregulates paracrine signals to cause complete infertility. This work could be relevant for understanding sexual dimorphism and reproductive developmental disorders. eLife 8 , e46349 (2019).

Mullerian inhibiting substance, sex hormone binding globulin and sex hormone levels in stimulant-naïve, first-diagnosed prepubertal boys with attention-deficit/hyperactivity disorder: comparison with matched healthy controls as well as before and after oros-methylpenidate treatment

Objectives: Attention-Deficit/Hyperactivity Disorder (ADHD) is a complex neurodevelopmental disorder with strong male predominance. Since Müllerian Inhibiting Substance (MIS) produces sex-linked bias in animal studies, we aimed to investigate the role of MIS, Sex Hormone Binding Globulin (SHBG) and sex hormone levels in boys with ADHD.Methods: We compared prepubertal, psychostimulant-naïve boys with ADHD with age-matched healthy control boys (HCs). Patients were re-evaluated after 30 days of methylphenidate treatment assessing ADHD severity, and serum MIS, testosterone, estradiol, and albumin concentrations.Results: Compared to 30 HCs, with ADHD (n = 49, age = 6.9 ± 0.2 years) had lower SHBG (p = .014), and higher free testosterone (p = 0.006) and bioavailable testosterone (p = .002) percentages. Methylphenidate improved ADHD measures (all p < .0001) and abnormal baseline hormonal levels, increasing SHBG levels (p = .024), and lowering free (p = .001) and bioavailable testosterone (p = .016) percentages so that only free testosterone percentages remained higher versus HCs post-treatment (p = .02).Conclusions: Compared to age- and sex-matched HCs, prepubertal, stimulant-naïve boys with ADHD had significantly lower SHBG and higher free and bioavailable testosterone percentages, suggesting a possible contribution of sex hormones to ADHD. Osmotic-release oral system methylphenidate treatment for 30 days significantly improved ADHD symptoms and abnormal sex hormone levels, normalizing SHBG and bioavailable testosterone percentages that were similar to HCs while free testosterone remained elevated versus HCs.Key pointsCompare to healthy matched controls prepubertal stimulant-naïve boys with ADHD had significantly lower SHBG and higher free and bioavailable testosterone percentages, suggesting a possible effect on sex hormones to ADHD.After 30-day methylphenidate treatment, ADHD symptoms significantly improved, and SHBG and bioavailable testosterone percentages normalized which were similar to HCs, while free testosterone remained elevated versus HCs.We found a negative relationship between MIS levels and hyperactivity scores in ADHD boys. This finding suggests that MIS may contribute to hyperactivity symptoms, either directly by affecting behavior or indirectly by affecting sex hormone levels.

Biofilm systems as tools in biotechnological production.

The literature provides more and more examples of research projects that develop novel production processes based on microorganisms organized in the form of biofilms. Biofilms are aggregates of microorganisms that are attached to interfaces. These viscoelastic aggregates of cells are held together and are embedded in a matrix consisting of multiple carbohydrate polymers as well as proteins. Biofilms are characterized by a very high cell density and by a natural retentostat behavior. Both factors can contribute to high productivities and a facilitated separation of the desired end-product from the catalytic biomass. Within the biofilm matrix, stable gradients of substrates and products form, which can lead to a differentiation and adaptation of the microorganisms' physiology to the specific process conditions. Moreover, growth in a biofilm state is often accompanied by a higher resistance and resilience towards toxic or growth inhibiting substances and factors. In this short review, we summarize how biofilms can be studied and what most promising niches for their application can be. Moreover, we highlight future research directions that will accelerate the advent of productive biofilms in biology-based production processes.

Three (-)-cytisine derivatives and 1-hydroxyquinopimaric acid as acetylcholinesterase inhibitors.

In vitro acetylcholinesterase (AChE) inhibition was studied using novel derivatives of (-)-cytisine derivatives N-allylcytisine-12-carbamide (A-63), cytisine-12-carbamide (A-36), N-1-adamantylcytisine-12-thiocarbamide (U-12), and 1-hydroxyquinopimaric acid (U-201). Inhibition of acetylcholinesterase with compound A-63 was described as mixed inhibition. Substances (A-36) and (U-201) acted as competitive inhibitors with Ki equal to 6.71 mM and 3.89 mM, respectively, while (U-12) behaved as an uncompetitive inhibitor with Ki at 0.07 mM. The IC50 values were estimated at 1.47, 13.73, 3.39, and 7.81 mM, respectively. According to toxicity assessment, compound A-63 was non-toxic; it did not affect A. salina viability at a concentration less than 1000 ppm, while at 1000 ppm, only 3% mortality was observed. Mortality of A. salina was less than 50% in the same concentration range for the other three compounds that allow classifying them as moderately toxic. Although tested compounds have the characteristics of weak inhibitors, they could be useful as protectors against potent organophosphates. The present research may be fundamental to the design of new substances for acetylcholinesterase inhibition.

Mullerian inhibiting substance type II receptor as a potential target for antineoplastic therapy

The review considers properties of the type II anti-Mullerian hormone receptor (mullerian inhibiting substance receptor type II, MISRII), a transmembrane sensor with its own serine/threonine protein kinase activity, triggering apoptosis of the Mullerian ducts in mammalian embryogenesis and providing formation of the male type reproductive system. According to recent data, MISRII overexpression in the postnatal period is found in cells of a number of ovarian, mammary gland, and prostate tumors, and anti-Mullerian hormone (AMH) has a pro-apoptotic effect on MISRII-positive tumor cells. This fact makes MISRII a potential target for targeted anti-cancer therapy. Treatment based on targeting MISRII seems to be a much more effective alternative to the traditional one and will significantly reduce the drug dose. However, the mechanism of MISRII-AMH interaction is still poorly understood, so the development of new anticancer drugs is complicated. The review analyzes MISRII molecular structure and expression levels in various tissues and cell lines, as well as current understanding of the AMH binding mechanisms and data on the possibility of using MISRII as a target for the action of AMH-based antineoplastic drugs.

Bitkisel Gıdalarda Probiyotik Mikroorganizmaların Kullanımı

Günümüzde tüketicilerin sağlıklı beslenmeye olan ilgisi ve bu konudaki farkındalığı her geçen gün artmaktadır. Hayvansal gıdaların tüketilmesinin bazı olumsuz yönleri ve bitkisel gıdaların hem kolay erişilebilir olması hem de sağlığa birçok olumlu etki göstermesi nedenleriyle, bitkisel gıdaların tüketimi artmaktadır. Probiyotiklerin laktoz sindirilebilirliğini arttırma ve bağışıklık sistemini düzenleme gibi işlevlerinin yanında, yüksek tansiyon, kanser, bağırsak ve vajinal enfeksiyonlar gibi bazı hastalıklara karşı olumlu etkileri birçok çalışmada ortaya konmuştur. Probiyotiklerin asit dirençliliği, antimikrobiyal madde üretme yeteneği ile patojenlere karşı inhibisyon etkileri de bu mikroorganizmaların gıdalarda kullanımını teşvik edici özelliklerdir. Probiyotikler yaygın olarak süt ürünlerinde kullanılmakla birlikte, bitkisel gıdaların probiyotikler için uygun bir gıda matrisi özelliği göstermesinden dolayı, bitkisel gıdalarda da probiyotiklerin kullanımı ile ilgili çalışmalar yapılmaktadır. Bu derleme çalışmasında, probiyotik mikroorganizmaların meyve, sebze ve tahıl ürünlerinde kullanımı, yaygın olarak kullanılan probiyotikler ve bu mikroorganizmaların gıdalarda canlılığını etkileyen faktörler araştırılmıştır.

Role of extracellular polymeric substances in the acute inhibition of activated sludge by polystyrene nanoparticles

Microplastics and nanoplastics in aquatic systems have become a global concern because of their persistence and adverse consequences to ecosystems and potentially human health. Though wastewater treatment plants (WWTPs) are considered a potential source of microplastics in the environment, the role of extracellular polymeric substances (EPS) of activated sludge on the fate of nanoplastics is not clear. In this study, the role of EPS in the influence of polystyrene nanoparticles (PS-NPs) on the endogenous respiration of activated sludge was investigated for the first time. The results showed that the acute inhibition of activated sludge by PS-NPs was enhanced with increasing PS-NPs concentration. X-ray photoelectron spectroscopy (XPS) results indicate that the functional groups involved in the interactions between PS-NPs and EPS were carbonyl and amide groups and the side chains of lipids or amino acids. Furthermore, the Fourier transform infrared (FTIR) spectroscopy results show that the protein secondary structures in EPS were changed by PS-NPs and lead to the bioflocculation of activated sludge, which provides a better understanding on the fate of nanoplastics in WWTPs.

English

The aims of this study were to investigate antimicrobial activities of what so-called wild strains of LAB isolated from different sources of Egyptian environment including raw and fermented milk, cheeses, other dairy products, sausage and silage. Isolation of lactobacilli and lactococci were carried out onto plates of MRS and M17 agar, respectively, grouped to identification and the obtained treated supernatants were tested for their antimicrobial activities against the indicators bacteria. The proteinaceous nature of each cell-free supernatant fluid was evaluated by heat sensitivity test as well as treating with some proteolytic enzymes. Furthermore, the antimicrobial activity, of seventy-eight isolates of LAB against the reference strains, was determined by the agar diffusion method. Some environmental LAB isolated in Egypt are capable of synthesizing inhibitive substance(s) against some pathogenic/spoilage bacteria being these inhibitive substances, a proteinaceous in nature which act differently against the tested indicators bacteria. Key words: Antimicrobial activity, Egyptian environment, food, LAB, food safety.

Müllerian inhibiting substance inhibits an ovarian cancer cell line via β-catenin interacting protein deregulation of the Wnt signal pathway.

Müllerian inhibiting substance/anti-Müllerian hormone (MIS/AMH) has been suggested as a biotherapeutic agent in gynecological cancers that highly express the MIS/AMH type II receptors (MISRII/AMHRII) but the anticancer mechanisms by which MIS/AMH acts are not fully understood. Our experiments show that MIS/AMH inhibits ovarian cancer by deregulating the Wnt signal pathway via the β-catenin interacting protein (ICAT). MIS/AMH inhibition of ICAT by small interfering RNAs (siRNA) decreased ICAT driven ovarian cancer cell viability as measured by the methylthiazoltetrazolium assay, reversed cell cycle arrest and annexinV expression and diminished migration by scratch wound assay. Changes in expression of regulatory proteins were shown by western blotting. We determined that MIS/AMH upregulated ICAT in ovarian cancer cell line which caused decreased cell viability, cell cycle arrest and apoptosis. This effect, however, was blocked when ICAT was downregulated by siRNA. The present study demonstrates a role for ICAT in MIS/AMH mediated inhibition of the Wnt signaling pathway in ovarian cancer.

Aspergillus fumigatus DBM 4057 biofilm formation is inhibited by chitosan, in contrast to baicalein and rhamnolipid.

The biofilms of filamentous-forming fungi are a novel and still insufficiently understood research topic. We have studied Aspergillus fumigatus, an ubiquitous opportunistic pathogenic fungus, as a representative model for a study of biofilm formation by filamentous fungi and for assessing the potential anti-biofilm activity of natural substances. The activity of antibiotic amphotericin B and selected natural substances: baicalein, chitosan and rhamnolipid was studied. The minimum suspension inhibitory concentrations (MIC) were determined and the biofilm susceptibility was investigated by determining the metabolic activity of sessile cells (XTT assay) and total biofilm biomass (crystal violet staining). Significant time-dependent differences in substances' anti-biofilm activity were observed. Images of A. fumigatus biofilm were obtained by Cellavista automatic light microscope and spinning disc confocal microscopy. Baicalein and rhamnolipid were not found as suitable substances for inhibition of the A. fumigatus biofilm formation, as neither of the substances inhibited the sessile cells metabolic activity or the total biofilm biomass even at tenfold MIC after 48h. In contrast, chitosan at 10×MIC (25µgmL-1), suppressed the biofilm metabolic activity by 90% and the total biofilm biomass by 80% even after 72h of cultivation. Amphotericin B inhibited only 14% of total biofilm biomass (crystal violet staining) and 35% of metabolic activity (XTT assay) of adherent cells under the same conditions. Our results therefore suggest chitosan as potential alternative for treating A. fumigatus biofilm-associated infections.

AAV9 delivering a modified human Mullerian inhibiting substance as a gene therapy in patient-derived xenografts of ovarian cancer

To improve ovarian cancer patient survival, effective treatments addressing chemoresistant recurrences are particularly needed. Mullerian inhibiting substance (MIS) has been shown to inhibit the growth of a stem-like population of ovarian cancer cells. We have recently engineered peptide modifications to human MIS [albumin leader Q425R MIS (LRMIS)] that increase production and potency in vitro and in vivo. To test this novel therapeutic peptide, serous malignant ascites from highly resistant recurrent ovarian cancer patients were isolated and amplified to create low-passage primary cell lines. Purified recombinant LRMIS protein successfully inhibited the growth of cancer spheroids in vitro in a panel of primary cell lines in four of six patients tested. Adeno-associated virus (AAV) -delivered gene therapy has undergone a clinical resurgence with a good safety profile and sustained gene expression. Therefore, AAV9 was used as a single i.p. injection to deliver LRMIS to test its efficacy in inhibiting growth of palpable tumors in patient-derived ovarian cancer xenografts from ascites (PDXa). AAV9-LRMIS monotherapy resulted in elevated and sustained blood concentrations of MIS, which significantly inhibited the growth of three of five lethal chemoresistant serous adenocarcinoma PDXa models without signs of measurable or overt toxicity. Finally, we tested the frequency of MIS type II receptor expression in a tissue microarray of serous ovarian tumors by immunohistochemistry and found that 88% of patients bear tumors that express the receptor. Taken together, these preclinical data suggest that AAV9-LRMIS provides a potentially well-tolerated and effective treatment strategy poised for testing in patients with chemoresistant serous ovarian cancer.

The effect of baicalin in a mouse model of retinopathy of prematurity.

Baicalin is a flavonoid derived from the dried root of Scutellaria baicalensis. In this study, oxygen-induced retinopathy was used to characterize the anti-angiogenic properties of baicalin in mice. Pups were exposed to a hyperbaric oxygen environment to induce retinal angiogenesis and were subjected to intraperitoneal injection of baicalin. Avascular area, neovascular tufts, and neovascular lumens were quantified from digital images. Compared to the vehicle, baicalin clearly reduced the central avascular zone and the number of neovascular tufts and lumens. High-dose baicalin (10 mg/kg) significantly reduced the expression of matrix metalloproteinase-2 (MMP-2), MMP-9, angiotensin II, and vascular endothelial growth factor (VEGF). These results show that baicalin is a powerful antiangiogenic compound that attenuates new vessel formation in the retina after systemic administration, and is a candidate substance for therapeutic inhibition of retinal angiogenesis. [BMB Reports 2015; 48(5): 271-276]

Possible mechanism for inhibition of morphine formation from 6-acetylmorphine after intake of street heroin

Heroin is de-acetylated in the body to morphine in two steps. The intermediate 6-acetylmorphine (6-AM) is formed rapidly and is considered important for the pharmacological effect of heroin. In urine drug testing, an atypical pattern of morphine and 6-AM is known to occur in low frequency. The aim of this study was to investigate this atypical pattern in more detail and to identify responsible substances for a possible inhibition of the conversion from 6-AM to morphine. Urine samples were selected from a routine flow of samples sent for drug testing. Out of 695 samples containing morphine and 6-acetylmorphine, 11.5% had the atypical pattern of a 6-AM to morphine ratio above 0.26 as derived from a bimodal frequency distribution. An in vitro study of the conversion of 6-acetylmorphine to morphine in human liver homogenates demonstrated that a number of known carboxylesterase inhibitors were able to inhibit the reaction mimicking the situation in vivo. Compound 3 (3,6-Dimethoxy-4-acetoxy-5-[2-(N-methylacetamido)ethyl]phenanthrene) a substance formed from thebaine during the production of heroin was found to be a strong inhibitor. Liquid chromatography–mass spectrometry was used to identify possible inhibitors present in vivo. This part of the investigation demonstrated that several components may contribute to the effect. It is concluded that inhibition of liver carboxylesterase activity is a possible mechanism causing the atypical pattern and that one candidate compound is the result of the heroin production process. An inhibition of 6-AM metabolism is likely to increase the pharmacological effect of heroin and may be related to a higher risk of lethal toxicity.