Solitary Isolated Oropharyngeal Neurofibroma Presenting With Dysphagia in the Setting of Von Recklinghausen's Disease.

A 24-year-old man with von Recklinghausen's disease presented with complaints of difficulty in swallowing for 6 months and change of voice for 3 months. He also had recent-onset difficulty in breathing. Telelaryngoscopy and subsequent contrast-enhanced computed tomography scan revealed a well-defined, smooth submucosal mass in the oropharynx (attached to the posterior pharyngeal wall, superior to the level of left aryepiglottic fold), obscuring the ipsilateral pyriform fossa, and nearly blocking the pharyngeal lumen. The mass was removed with endoscopic coblation-assisted laryngeal surgery, and subsequent histopathology revealed it to be neurofibroma. Neurofibromas are rare neoplasms to be encountered in the oropharynx. However, in the setting of von Recklinghausen's disease (neurofibromatosis type 1), one or more well-demarcated, submucosal nodular lesions in the upper aerodigestive tract may be considered as neurofibromas, and workup and treatment should be directed accordingly based on this clinical presumption. Endoscopic coblation during laryngeal surgery can effectively be used as a surgical tool to excise such lesions. It provides a relatively bloodless field compared to the conventional cold steel excision, and reduces the risk of complications at surgery and during the follow-up period. This clinical record illustrates the presentation and management of a solitary, isolated oropharyngeal neurofibroma in a man suffering from von Recklinghausen's disease. It further emphasizes the role of endoscopic coblation-assisted laryngeal surgery in this setup, and the need to maintain a low threshold of suspicion in having a provisional clinical diagnosis of such lesions.

How Does Preoperative Pure Tone Audiometry Relate to the Findings at Surgery to Explain the Hearing Status in Chronic Otitis Media?

Objective: Pure tone audiometry (PTA) guides surgical decision-making in chronic otitis media (COM), and PTA values depend upon the type and extent of COM. Methods: Our cross-sectional study included patients with COM with/without cholesteatoma who were scheduled for surgery. Findings on examination of the middle ear under the microscope and at surgery which could explain the hearing loss were corroborated with preoperative PTA through appropriate statistical methods. Results: The study included 114 patients (mean age: 31.07 years; range: 7-57). Following preoperative PTA, 50% of patients had moderate hearing loss and ~73% had air-bone gap (ABG) <35 dB. Conductive hearing loss affected 109 patients (97.61%); five had mixed hearing loss. At surgery, 27 patients (23.68%) had ossicular discontinuity, with the incus being the most affected. Twenty-one patients in this group had ABG ≥35 dB. Perforations involving the anterior and posterior halves of the pars tensa, and subtotal perforations, demonstrated the maximum mean hearing loss [45.39±8.29 dB HL (p=0.075), 51.08±12.51 dB HL (p=0.26), respectively]. The mean pure tone average in the intact ossicles group was 43.62±8.07 dB HL and that in the absent/eroded ossicles group was 58.15±11.05 dB HL (p<0.0001); the mean ABG was 27.89±4.77 dB and 38.88±6.47 dB, respectively (p<0.0001). Conclusions: Hearing loss was significantly associated with the size but not the site of the central perforation. With ossicular discontinuity, hearing loss and ABG deteriorated significantly. The findings re-establish the relationship between preoperative PTA and the middle ear status which should help surgeons plan surgery and counsel patients regarding hearing outcomes.

Sequestered, Iatrogenic Epidermoid Implantation Cysts Associated With Retroauricular (Wilde's) Incision.

OBJECTIVE: To report two patients with iatrogenic, epidermoid implantation cysts associated with the standard retroauricular (Wilde's) incision, to establish their etiology, to explore means to prevent them, and to ensure that this experience adds to the learning curve of the surgical training of the residents. METHODS: Case series with the review of literature. RESULTS: One of the two patients, who had an unremarkable follow-up period after cortical mastoidectomy and cartilage tympanoplasty performed three years back, presented with a retroauricular cystic swelling visible since two months. It was hyperintense on T2-weighted magnetic resonance imaging. A sequestered cystic mass was encountered at surgery in the subcutaneous plane in association with the retroauricular scar tissue from previous surgery. In the other patient, two similar cysts (one of them sequestered) were incidental findings at revision tympanomastoid surgery. Histopathology in both instances was consistent with epidermoid cyst. Given their subcuticular location and intimate association with a pre-existing surgical scar, they were considered to be of implantation in origin. This was a potential outcome of persistent inversion of one or both skin edges following simple interrupted suturing. The reason could be a faulty surgical technique, due to improper placement of the needle with respect to skin, inadequate or uneven tissue bite, a tight knot, or failure to manually evert the apposing edges at the point(s) of suspicion. CONCLUSIONS: Sequestered epidermoid implantation cysts due to persistent inversion of sutured skin edges are unusual complications. The illustrations in this case series emphasize the need to adhere to the basic principles of surgical practice. They provide a caveat to the resident surgeons and the faculties who supervise them, that inadvertent and apparently innocuous misses, even at the elementary steps of surgery (like suturing), could lead to complications that are unwanted and potentially avoidable.

Contamination of Indian sea salts with microplastics and a potential prevention strategy.

This study reports the contamination of Indian sea salts with different microplastic particles, as a consequence of using contaminated sea water. Samples from all eight brands of investigated sea salts were found contaminated, and concentrations of these particles ranged from 103 ± 39 to 56 ± 49 particles kg-1 of salt. Both fibers and fragments were observed with large variation in size. Eighty percent of the extracted fibers and the fragments were smaller than 2000 µm and 500 µm respectively. Extracted particles were mostly polyesters, polyethylene terephthalate (PET), polyamide, polyethylene, and polystyrene. Their total mass concentration was also estimated as 63.76 µg kg-1 of salt. These results are significant, since India is a leading producer and exporter of sea salts. A simple sand filtration of artificially contaminated sea water could effectively (> 85% removal by weight and > 90% removal by number) remove these microplastics and has the potential for preventing the transfer of microplastics into the salt from contaminated sea waters.

Metastases and Colon Cancer Tumor Growth Display Divergent Responses to Modulation of Canonical WNT Signaling.

Human colon cancers commonly harbor loss of function mutations in APC, a repressor of the canonical WNT pathway, thus leading to hyperactive WNT-TCF signaling. Re-establishment of Apc function in mice, engineered to conditionally repress Apc through RNAi, resolve the intestinal tumors formed due to hyperactivated Wnt-Tcf signaling. These and other results have prompted the search for specific WNT pathway antagonists as therapeutics for clinically problematic human colon cancers and associated metastases, which remain largely incurable. This widely accepted view seems at odds with a number of findings using patient-derived material: Canonical TCF targets are repressed, instead of being hyperactivated, in advanced colon cancers, and repression of TCF function does not generally result in tumor regression in xenografts. The results of a number of genetic mouse studies have also suggested that canonical WNT-TCF signaling drives metastases, but direct in vivo tests are lacking, and, surprisingly, TCF repression can enhance directly seeded metastatic growth. Here we have addressed the abilities of enhanced and blocked WNT-TCF signaling to alter tumor growth and distant metastases using xenografts of advanced human colon cancers in mice. We find that endogenous WNT-TCF signaling is mostly anti-metastatic since downregulation of TCF function with dnTCF generally enhances metastatic spread. Consistently, elevating the level of WNT signaling, by increasing the levels of WNT ligands, is not generally pro-metastatic. Our present and previous data reveal a heterogeneous response to modulating WNT-TCF signaling in human cancer cells. Nevertheless, the findings that a fraction of colon cancers tested require WNT-TCF signaling for tumor growth but all respond to repressed signaling by increasing metastases beg for a reevaluation of the goal of blocking WNT-TCF signaling to universally treat colon cancers. Our data suggest that WNT-TCF blockade may be effective in inhibiting tumor growth in only a subset of cases but will generally boost metastases.

Correction: Metastases and Colon Cancer Tumor Growth Display Divergent Responses to Modulation of Canonical WNT Signaling.

[This corrects the article DOI: 10.1371/journal.pone.0150697.].

Long-Lasting WNT-TCF Response Blocking and Epigenetic Modifying Activities of Withanolide F in Human Cancer Cells.

The WNT-TCF signaling pathway participates in adult tissue homeostasis and repair, and is hyperactive in a number of human diseases including cancers of the colon. Whereas to date there are no antagonists approved for patient use, a potential problem for their sustained use is the blockade of WNT signaling in healthy tissues, thus provoking potentially serious co-lateral damage. Here we have screened a library of plant and microorganism small molecules for novel WNT signaling antagonists and describe withanolide F as a potent WNT-TCF response blocker. This steroidal lactone inhibits TCF-dependent colon cancer xenograft growth and mimics the effects of genetic blockade of TCF and of ivermectin, a previously reported WNT-TCF blocker. However, withanolide F is unique in that it imposes a long-lasting repression of tumor growth, WNT-TCF targets and cancer stem cell clonogenicity after drug treatment. These findings are paralleled by its modulation of chromatin regulators and its alteration of overall H3K4me1 levels. Our results open up the possibility to permanently repress essential signaling responses in cancer cells through limited treatments with small molecules.

A novel genome-wide in vivo screen for metastatic suppressors in human colon cancer identifies the positive WNT-TCF pathway modulators TMED3 and SOX12.

The progression of tumors to the metastatic state involves the loss of metastatic suppressor functions. Finding these, however, is difficult as in vitro assays do not fully predict metastatic behavior, and the majority of studies have used cloned cell lines, which do not reflect primary tumor heterogeneity. Here, we have designed a novel genome-wide screen to identify metastatic suppressors using primary human tumor cells in mice, which allows saturation screens. Using this unbiased approach, we have tested the hypothesis that endogenous colon cancer metastatic suppressors affect WNT-TCF signaling. Our screen has identified two novel metastatic suppressors: TMED3 and SOX12, the knockdown of which increases metastatic growth after direct seeding. Moreover, both modify the type of self-renewing spheroids, but only knockdown of TMED3 also induces spheroid cell spreading and lung metastases from a subcutaneous xenograft. Importantly, whereas TMED3 and SOX12 belong to different families involved in protein secretion and transcriptional regulation, both promote endogenous WNT-TCF activity. Treatments for advanced or metastatic colon cancer may thus not benefit from WNT blockers, and these may promote a worse outcome.

Characterization of Leishmania donovani aquaporins shows presence of subcellular aquaporins similar to tonoplast intrinsic proteins of plants.

Leishmania donovani, a protozoan parasite, resides in the macrophages of the mammalian host. The aquaporin family of proteins form important components of the parasite-host interface. The parasite-host interface could be a potential target for chemotherapy. Analysis of L. major and L. infantum genomes showed the presence of five aquaporins (AQPs) annotated as AQP9 (230aa), AQP putative (294aa), AQP-like protein (279aa), AQP1 (314aa) and AQP-like protein (596aa). We report here the structural modeling, localization and functional characterization of the AQPs from L. donovani. LdAQP1, LdAQP9, LdAQP2860 and LdAQP2870 have the canonical NPA-NPA motifs, whereas LdAQP putative has a non-canonical NPM-NPA motif. In the carboxyl terminal to the second NPA box of all AQPs except AQP1, a valine/alanine residue was found instead of the arginine. In that respect these four AQPs are similar to tonoplast intrinsic proteins in plants, which are localized to intracellular organelles. Confocal microscopy of L. donovani expressing GFP-tagged AQPs showed an intracellular localization of LdAQP9 and LdAQP2870. Real-time PCR assays showed expression of all aquaporins except LdAQP2860, whose level was undetectable. Three-dimensional homology modeling of the AQPs showed that LdAQP1 structure bears greater topological similarity to the aquaglyceroporin than to aquaporin of E. coli. The pore of LdAQP1 was very different from the rest in shape and size. The cavity of LdAQP2860 was highly irregular and undefined in geometry. For functional characterization, four AQP proteins were heterologously expressed in yeast. In the fps1Δ yeast cells, which lacked the key aquaglyceroporin, LdAQP1 alone displayed an osmosensitive phenotype indicating glycerol transport activity. However, expression of LdAQP1 and LdAQP putative in a yeast gpd1Δ strain, deleted for glycerol production, conferred osmosensitive phenotype indicating water transport activity or aquaporin function. Our analysis for the first time shows the presence of subcellular aquaporins and provides structural and functional characterization of aquaporins in Leishmania donovani.