Sferični kristali celekoksiba za poboljšanje topljivosti, oslobađanja i mikromeričnih svojstava

Celecoxib spherical agglomerates were prepared with polyvinylpyrrolidone (PVP) using acetone, water and chloroform as solvent, non-solvent and bridging liquid, respectively. The agglomerates were characterized by differential scanning calorimetry (DSC), X-ray diffraction (XRD), IR spectroscopic studies and scanning electron microscopy (SEM). The IR spectroscopy and DSC results indicated the absence of any interactions between drug and additives. XRD studies showed a decrease in crystallinity in agglomerates. The crystals exhibited significantly improved micromeritic properties compared to pure drug. The loading efficiency (% or mg drug per 100 mg crystals) was in the range of 93.9 ± 2.3 and 97.3 ± 1.3% (n = 3), with all formulations. The aqueous solubility and dissolution rate of the drug from crystals was significantly (p < 0.05) increased (nearly two times). The solubility and in vitro drug release rates increased with an increase in PVP concentration (from 2.5 to 10%). The SEM studies showed that the crystal possesses a good spherical shape with smooth and regular surface.U radu je opisana priprava sferičnih aglomerata sa celekoksibom koristeći polivinilpirolidon (PVP), aceton, vodu i kloroform. Aglomerati su karakterizirani diferencijalnom pretražnom kalorimetrijom (DSC), rentgenskom difrakcijom (XRD), IR spektroskopijom i pretražnom elektronskom mikroskopijom (SEM). IR i DSC su pokazale odsutnost bilo kakvih interakcija između ljekovite tvari i aditiva. XRD je pokazala smanjenje kristaliničnosti u aglomeratima. Aglomerati su pokazali značajno poboljšana mikromerična svojstva u odnosu na čisti lijek. Udio lijeka u njima bio je između 93.89 ± 2.26 i 97.32 ± 1.29%. Topljivost u vodi i oslobađanje ljekovite tvari iz aglomerata povećalo se skoro dva puta. Topljivost i in vitro oslobađanje se povećava s povećanjem koncentracije PVP (od 2,5 do 10%). SEM studije su pokazale da kristali imaju pravilan sferični oblik te glatku i pravilnu površinu

Sferični kristali celekoksiba za poboljšanje topljivosti, oslobađanja i mikromeričnih svojstava

Celecoxib spherical agglomerates were prepared with polyvinylpyrrolidone (PVP) using acetone, water and chloroform as solvent, non-solvent and bridging liquid, respectively. The agglomerates were characterized by differential scanning calorimetry (DSC), X-ray diffraction (XRD), IR spectroscopic studies and scanning electron microscopy (SEM). The IR spectroscopy and DSC results indicated the absence of any interactions between drug and additives. XRD studies showed a decrease in crystallinity in agglomerates. The crystals exhibited significantly improved micromeritic properties compared to pure drug. The loading efficiency (% or mg drug per 100 mg crystals) was in the range of 93.9 ± 2.3 and 97.3 ± 1.3% (n = 3), with all formulations. The aqueous solubility and dissolution rate of the drug from crystals was significantly (p < 0.05) increased (nearly two times). The solubility and in vitro drug release rates increased with an increase in PVP concentration (from 2.5 to 10%). The SEM studies showed that the crystal possesses a good spherical shape with smooth and regular surface.U radu je opisana priprava sferičnih aglomerata sa celekoksibom koristeći polivinilpirolidon (PVP), aceton, vodu i kloroform. Aglomerati su karakterizirani diferencijalnom pretražnom kalorimetrijom (DSC), rentgenskom difrakcijom (XRD), IR spektroskopijom i pretražnom elektronskom mikroskopijom (SEM). IR i DSC su pokazale odsutnost bilo kakvih interakcija između ljekovite tvari i aditiva. XRD je pokazala smanjenje kristaliničnosti u aglomeratima. Aglomerati su pokazali značajno poboljšana mikromerična svojstva u odnosu na čisti lijek. Udio lijeka u njima bio je između 93.89 ± 2.26 i 97.32 ± 1.29%. Topljivost u vodi i oslobađanje ljekovite tvari iz aglomerata povećalo se skoro dva puta. Topljivost i in vitro oslobađanje se povećava s povećanjem koncentracije PVP (od 2,5 do 10%). SEM studije su pokazale da kristali imaju pravilan sferični oblik te glatku i pravilnu površinu

HPV-induced field cancerisation: Transformation of adult tissue stem cell into cancer stem cell

Field cancerisation was originally described as a basis for multiple head and neck squamous cell carcinoma (HNSCC) and is a pre-malignant phenomenon that is frequently attributable to oncogenic human papillomavirus (HPV) infection. Our work on β-HPV-induced cutaneous squamous cell carcinomas identified a novel Lrig1+ hair follicle junctional zone keratinocyte stem cell population as the basis for field cancerisation. Herein, we describe the ability for HPV to infect adult tissue stem cells in order to establish persistent infection and induce their proliferation and displacement resulting in field cancerisation. By review of the HPV literature, we reveal how this mechanism is conserved as the basis of field cancerisation across many tissues. New insights have identified the capacity for HPV early region genes to dysregulate adult tissue stem cell self-renewal pathways ensuring that the expanded population preserve its stem cell characteristics beyond the stem cell niche. HPV-infected cells acquire additional transforming mutations that can give rise to intraepithelial neoplasia (IEN), from environmental factors such as sunlight or tobacco induced mutations in skin and oral cavity, respectively. With establishment of IEN, HPV viral replication is sacrificed with loss of the episome, and the tissue is predisposed to multiple cancer stem cell-driven carcinomas

Evaluation of invitro Antimutagenic Potential of Lagenaria Siceraria Using Ame’s Test

Cancer is one of the most life-threatening diseases and widespread in both developed and developing countries. Accumulation of genetic alterations is main etiology for cancer developments. Many of the Cucurbitaceae plants possess antitumor activity traditionally. Methanolic extract of Lagenaria siceraria Standley Fruit was tested for their antimutagenic potential. The extract of plant exhibited varying level of antimutagenicity. Ames test was used in the current study to evaluate antimutagenic activity in TA98 and TA100 strains of Salmonella typhimurium using direct (Sodium azide) acting mutagens. Results of the study showed significant antimutagenicity against mutagen in TA98 and TA100 strains. The antimutagenicity of the extract observed in the present study implies chemopreventive pharmacological importance of Lagenaria siceraria Standley Fruit and encourages its use as a functional food

Delayed and localized pemphigus vulgaris after breast cancer radiotherapy

Breast cancer treatment involving ionizing radiation causes characteristic radiation dermatitis in the majority of patients. The DNA damaging effects of radiation can rarely predispose to primary inflammatory dermatoses, such as pemphigus vulgaris. In such cases, the disease presents with all the hallmarks of the primary dermatosis, but the eruption is limited to the field of irradiation and is often amenable to treatment. In contrast, occurrence of generalized pemphigus vulgaris in this setting may mean cancer recurrence. The mechanism by which radiotherapy induces localized disease remains unknown, but there is likely a loss of self-tolerance which maybe coupled to antigen exposure

β-HPV infection correlates with early stages of carcinogenesis in skin tumors and patient-derived xenografts from a kidney transplant recipient cohort

Many malignancies that occur in high excess in kidney transplant recipients (KTRs) are due to viruses that thrive in the setting of immunosuppression. Keratinocyte carcinoma (KC), the most frequently occurring cancer type in KTR, has been associated with skin infection by human papillomavirus (HPV) from the beta genus. In this report, we extend our previous investigation aimed at identifying the presence of active \u3b2-HPV infection in skin tumors from KTRs through the detection of viral protein expression. Using a combination of antibodies raised against the E4 and L1 proteins of the \u3b2-genotypes, we were able to visualize infection in five tumors [one keratoacanthoma (KA), three actinic keratosis (AK) and one seborrheic keratosis (SK)] that were all removed from two patients who had been both transplanted twice, had developed multiple KC, and presented with a long history of immunosuppression (>30 years). These infected tissues displayed intraepidermal hyperplasia and increased expression of the \u394Np63 protein, which extended into the upper epithelial layers. In addition, using a xenograft model system in nude mice displaying a humanized stromal bed in the site of grafting, we successfully engrafted three AKs, two of which were derived from the aforementioned KTRs and displayed \u3b2-HPV infection in the original tumor. Of note, one AK-derived xenograft, along with its ensuing lymph node metastasis, was diagnosed as squamous cell carcinoma (SCC). In the latter, both \u3b2-HPV infection and \u394Np63 expression were no longer detectable. Although the overall success rate of engrafting was very low, the results of this study represent the first proof-of-concept that \u3b2-HPV+ and \u394Np63+ intraepidermal hyperplasia can indeed progress to an aggressive SCC able to metastasize. Consistent with a series of reports attributing a causative role of \u3b2-HPV at early stages of skin carcinogenesis through \u394Np63 induction and increased keratinocytes stemness, here we provide in vivo evidence that these events are also occurring in the affected skin of KTRs. Due to these \u3b2-HPV-driven molecular pathways, the nascent tumor cell is able to acquire a high enough number of carcinogenic insults that its proliferation and survival will eventually become independent of viral gene expression

CD200 ectodomain shedding into the tumor microenvironment leads to NK cell dysfunction and apoptosis

The basis of immune evasion, a hallmark of cancer, can differ even when cancers arise from one cell type such as in the human skin keratinocyte carcinomas: basal and squamous cell carcinoma. Here we showed that the basal cell carcinoma tumor initiating cell surface protein CD200, through ectodomain shedding, was responsible for the near absence of NK cells within the basal cell carcinoma tumor microenvironment. In situ, CD200 underwent ectodomain shedding by metalloproteinases MMP3 and MMP11, which released biologically active soluble CD200 into the basal cell carcinoma microenvironment. CD200 bound its cognate receptor on NK cells, to suppress MAPK pathway signaling that in turn blocked indirect (gamma interferon release) and direct cell killing. In addition, reduced ERK phosphorylation relinquished negative regulation of PPARγ regulated gene transcription and lead to membrane accumulation of the Fas/FADD death receptor and its ligand, FasL that resulted in activation-induced apoptosis. Blocking CD200 inhibition of MAPK or PPARγ signaling restored NK cell survival and tumor cell killing, with relevance to many cancer types. Our results thus uncover a paradigm for CD200 as a potentially novel and targetable NK cell specific immune checkpoint, which is responsible for NK cell associated poor outcomes in many cancers

Pigment epithelium derived factor drives melanocyte proliferation and migration in neurofibromatosis café au lait macules

Background: RASopathies, which include neurofibromatosis type 1 (NF1), are defined by Ras/mitogen‐activated protein kinase (Ras/MAPK) pathway activation. They represent a group of clinically related disorders often characterised by multiple Café au Lait Macules (CALMs). Objectives: To determine, using in depth transcriptomic analysis of NF1 melanocytes from CALM and unaffected skin, (1) the gene(s) responsible for melanocyte proliferation and migration, and (2) the activated signalling pathway(s) in NF1 melanoma. Methods: Classical NF1 (n = 2, who develop tumours) and 3bp deletion NF1 (p. Met992del, who do not develop tumours) (n = 3) patients underwent skin biopsies from CALM and unaffected skin. Melanocytes were isolated and propagated, with five replicates from each tissue sample. DNA and RNA were extracted for mutational analysis and transcriptomic profiling with six replicates per sample. Mechanistic determination was undertaken using melanocyte and melanoma cell lines. Results: All CALMs in NF1 were associated with biallelic NF1 loss, resulting in amplification of Ras/MAPK and Wnt pathway signalling. CALMs were also associated with reduced SERPINF1 gene expression (and pigment epithelium‐derived factor (PEDF) levels, the reciprocal protein), a known downstream target of the master regulator of melanocyte differentiation microphthalmia‐associated transcription factor (MITF), leading to increased melanocyte proliferation, migration and invasion. In classical NF1 and melanoma, but not 3bp deletion NF1, there was also activation of the PI3K/AKT pathway. Pigment epithelium‐derived factor was found to reduce cell proliferation and invasion of NF1 melanoma. Conclusions: Melanocyte proliferation and migration leading to CALMs in NF1 arises from biallelic NF1 loss, resulting in RAS/MAPK pathway activation, and reduced expression of the tumour suppressor PEDF. Activation of the PI3K/AKT pathway in classical NF1 and NF1 melanoma may facilitate tumour growth

An anti-HIV-1 V3 loop antibody fully protects cross-clade and elicits T-cell immunity in macaques mucosally challenged with an R5 clade C SHIV

Neutralizing antibodies have been shown to protect macaques against SHIV challenge. However, genetically diverse HIV-1 clades have evolved, and a key question left unanswered is whether neutralizing antibodies can confer cross-clade protection in vivo. The novel human monoclonal antibody HGN194 was isolated from an individual infected with an HIV-1 clade AG recombinant circulating recombinant form (CRF). HGN194 targets an epitope in the third hypervariable loop (V3) of HIV-1 gp120 and neutralizes a range of relatively neutralization- sensitive and resistant viruses. We evaluated the potential of HGN194 to protect infant rhesus monkeys against a SHIV encoding a primary CCR5-tropic HIV-1 clade C envelope. After high- dose mucosal challenge, all untreated controls became highly viremic while all HGN194-treated animals (50 mg/kg) were completely protected. When HGN194 was given at 1 mg/kg, one out of two monkeys remained aviremic, whereas the other had delayed, lower peak viremia. Interestingly, all protected monkeys given high-dose HGN194 developed Gag-specific proliferative responses of both CD4+ and CD8+ T cells. To test whether generation of the latter involved cryptic infection, we ablated CD8+ cells after HGN194 clearance. No viremia was detected in any protected monkeys, thus ruling out virus reservoirs. Thus, induction of CD8 T-cell immunity may have resulted from transient “Hit and Run” infection or cross priming via Ag-Ab- mediated cross-presentation. Together, our data identified the HGN194 epitope as protective and provide proof-of-concept that this anti-V3 loop mAb can prevent infection with sterilizing immunity after challenge with virus of a different clade, implying that V3 is a potential vaccine target