Collagen IV differentially regulates planarian stem cell potency and lineage progression.

The extracellular matrix (ECM) provides a precise physical and molecular environment for cell maintenance, self-renewal, and differentiation in the stem cell niche. However, the nature and organization of the ECM niche is not well understood. The adult freshwater planarian Schmidtea mediterranea maintains a large population of multipotent stem cells (neoblasts), presenting an ideal model to study the role of the ECM niche in stem cell regulation. Here we tested the function of 165 planarian homologs of ECM and ECM-related genes in neoblast regulation. We identified the collagen gene family as one with differential effects in promoting or suppressing proliferation of neoblasts. col4-1, encoding a type IV collagen α-chain, had the strongest effect. RNA interference (RNAi) of col4-1 impaired tissue maintenance and regeneration, causing tissue regression. Finally, we provide evidence for an interaction between type IV collagen, the discoidin domain receptor, and neuregulin-7 (NRG-7), which constitutes a mechanism to regulate the balance of symmetric and asymmetric division of neoblasts via the NRG-7/EGFR pathway.

Nerve-associated transient receptor potential ion channels can contribute to intrinsic resistance to bacterial adhesion in vivo.

The cornea of the eye differs from other mucosal surfaces in that it lacks a viable bacterial microbiome and by its unusually high density of sensory nerve endings. Here, we explored the role of corneal nerves in preventing bacterial adhesion. Pharmacological and genetic methods were used to inhibit the function of corneal sensory nerves or their associated transient receptor potential cation channels TRPA1 and TRPV1. Impacts on bacterial adhesion, resident immune cells, and epithelial integrity were examined using fluorescent labeling and quantitative confocal imaging. TRPA1/TRPV1 double gene-knockout mice were more susceptible to adhesion of environmental bacteria and to that of deliberately-inoculated Pseudomonas aeruginosa. Supporting the involvement of TRPA1/TRPV1-expressing corneal nerves, P. aeruginosa adhesion was also promoted by treatment with bupivacaine, or ablation of TRPA1/TRPV1-expressing nerves using RTX. Moreover, TRPA1/TRPV1-dependent defense was abolished by enucleation which severs corneal nerves. High-resolution imaging showed normal corneal ultrastructure and surface-labeling by wheat-germ agglutinin for TRPA1/TRPV1 knockout murine corneas, and intact barrier function by absence of fluorescein staining. P. aeruginosa adhering to corneas after perturbation of nerve or TRPA1/TRPV1 function failed to penetrate the surface. Single gene-knockout mice showed roles for both TRPA1 and TRPV1, with TRPA1-/- more susceptible to P. aeruginosa adhesion while TRPV1-/- corneas instead accumulated environmental bacteria. Corneal CD45+/CD11c+ cell responses to P. aeruginosa challenge, previously shown to counter bacterial adhesion, also depended on TRPA1/TRPV1 and sensory nerves. Together, these results demonstrate roles for corneal nerves and TRPA1/TRPV1 in corneal resistance to bacterial adhesion in vivo and suggest that the mechanisms involve resident immune cell populations.

Bladder Cancer and Google Trends: Associations Between US Search Patterns and Disease Outcomes May Show Need for Improved Awareness Strategies.

Interest in and awareness of bladder cancer may translate to better health-seeking behaviors and earlier detection, given modifiable risk factors such as smoking. We assessed bladder cancer interest in the USA over the past 15 years as reflected by Internet search trends, and correlated these trends with epidemiologic patterns in bladder cancer. Google Trends was used to estimate US bladder cancer interest in the unit search volume index (SVI), which estimates the volume of online search activity for a specified period relative to the highest volume of searches within a specified location. Between January 2004 and June 2019, SVIs were collected for the search term "bladder cancer" and other related search terms. To evaluate the effect of public awareness campaigns, the SVIs for the month of May (US bladder cancer awareness month) were compared with the SVIs of all other months. Correlations between "bladder cancer" SVI and incidence, mortality, and mortality-to-incidence ratio (proxy for survival) by state were evaluated. There was no increase in the relative search volumes for "bladder cancer" during the national bladder cancer awareness month compared with all other months (p = 0.27). By state, there were positive correlations between SVIs of "bladder cancer" and incidence (R = 0.72, p < 0.001) and mortality (R = 0.47, p < 0.001). However, there was no correlation between SVIs and mortality-to-incidence ratio (R = - 0.24, p = 0.08). Interest in bladder cancer is positively associated with disease incidence and mortality but not survival, suggesting interest is driven by new diagnoses or deaths, and not early detection that can improve survival. Our findings may show the need for better public education endeavors.

Recommendations for Intersectoral Collaboration for the Prevention and Control of Vector-Borne Diseases: Results From a Modified Delphi Process.

BACKGROUND: Intersectoral collaboration in the context of the prevention and control of vector-borne diseases has been broadly described in both the literature and the current global strategy by the World Health Organization. Our aim was to develop a framework that will distill the currently known multiple models of collaboration. METHODS: Qualitative content analysis and logic modeling of data abstracted from 69 studies included in a scoping review done by the authors were used to develop 9 recommendation statements that summarized the composition and attributes of multisectoral approaches, which were then subjected to a modified Delphi process with 6 experts in the fields of health policy and infectious diseases. RESULTS: Consensus for all statements was achieved during the first round. The recommendation statements were on (1-3) sectoral engagement to supplement government efforts and augment public financing; (4) development of interventions for most systems levels; (5-6) investment in human resource, including training; (7-8) intersectoral action to implement strategies and ensure sustainability of initiatives; and (9) research to support prevention and control efforts. CONCLUSIONS: The core of intersectoral action to prevent vector-borne diseases is collaboration among multiple stakeholders to develop, implement, and evaluate initiatives at multiple levels of intervention.

Ipilimumab/nivolumab-induced pseudolymphoma in a patient with malignant melanoma.

Combination therapy with ipilimumab and nivolumab is an adjuvant treatment approach for metastatic melanoma that boasts increased 3-year survival when compared with a single immunotherapy agent. Combination therapy, however, is associated with increased toxicities, especially cutaneous side-effects. Here we present a patient with metastatic melanoma and a sudden eruption of painful nodules on the face and arms 10 days after the administration of the fourth dose of combination ipilimumab/nivolumab. Biopsies demonstrated lymphoid hyperplasia, not clinically or pathologically consistent with an infectious, malignant or autoimmune etiology; a diagnosis of pseudolymphoma secondary to ipilimumab/nivolumab was made. After a steroid taper, the lesions resolved, and the patient was restarted on nivolumab monotherapy 2 weeks later without recurrence of symptoms or disease.

Expression of p15 in a spectrum of spitzoid melanocytic neoplasms.

BACKGROUND: Accurate classification of spitzoid melanocytic lesions is difficult due to overlapping clinical and histopathologic features between Spitz nevi, atypical Spitz tumors (ASTs), and spitzoid melanomas. Expression of p16 (CDKN2A) has been used as a marker of spitzoid lesions. However, its expression may be variable. p15 is a tumor suppressor encoded by CDKN2B, loss of which has been recently shown to promote transition from nevus to melanoma. We sought to determine whether p15 is a useful immunohistochemical marker to distinguish Spitz nevi from spitzoid melanomas and to compare p15 and p16 staining in this population. METHODS: Immunohistochemistry for p15 and p16 was performed on Spitz nevi (n = 19), ASTs (n = 41), and spitzoid melanomas (n = 17). Immunoexpression was categorized by a four-tiered system: 0 (negative), 1+ (weak), 2+ (moderate), 3+ (strong). RESULTS: 3+/strong p15 staining was observed in 68.4% of Spitz nevi, 34.2% of ASTs, and 17.7% of spitzoid melanomas. By contrast, we observed 3+ p16 staining in roughly equivalent percentages of Spitz nevi (57.9%), ASTs (56.1%), and spitzoid melanomas (58.8%). CONCLUSION: These data illustrate that p15 may be more useful than p16 as a biomarker to help distinguish benign from malignant spitzoid lesions.

Inflammatory features of frontal fibrosing alopecia.

INTRODUCTION: Frontal fibrosing alopecia (FFA) is a cicatricial alopecia typically occurring in postmenopausal women. The etiology and pathophysiology of FFA is poorly understood but thought to be immune mediated. This study aims to further explore the extent of fibrosis and the inflammatory microenvironment by characterizing Langerhans cells (LCs), helper T cells, cytotoxic T cells and B cells near hair follicles in FFA. METHODS: Eleven paraffin-embedded tissues from patients with a clinical and histopathologic diagnosis of FFA were selected for immunohistochemical studies using CD3, CD4, CD8, CD1a and CD20. The lymphocytes and LCs were counted around involved follicles. The CD4/CD8 T-lymphocyte ratios were calculated and compared to the CD4/CD8 T-lymphocyte ratios in uninvolved areas. RESULTS: On histopathologic review, at least 35% of follicles in each case were affected by the disease with concentric perifollicular fibrosis and a perifollicular lichenoid lymphocytic infiltrate around the infundibuloisthmic portion of the hair follicle. There was an increase of perifollicular LCs (mean of 18, SD of 5.5) and intrafollicular LCs (mean of 14, SD of 4.3) in involved follicles compared to uninvolved follicles (P < .0001). The involved follicles also showed a relative decrease in the CD4/CD8 ratio indicating increased numbers of CD8+ T cells; a finding distinct from the CD4-predominant population in uninvolved follicles (P < .0001). CONCLUSION: The inflammatory features of FFA show a CD8-biased T-cell infiltrate with increased numbers of LCs in the infundibuloisthmic region. The increased LCs may represent an aberrant immune reaction promoting a CD8+ T-cell response.

Vaccination in the Philippines: experiences from history and lessons for the future.

In anticipation of a potential vaccine for COVID-19, vaccine uptake may be critical in overcoming the pandemic, especially in countries like the Philippines, which has among the highest rates of infection in the region. Looking at the progress of vaccination in the country - its promises, pitfalls, and challenges - may provide insight for public health professionals and the public. The history of vaccination in the Philippines is marked by strong achievements, such as the establishment and growth of a national programme for immunization, and importantly, the eradication of poliomyelitis and maternal and neonatal tetanus. It is also marred by critical challenges which provide a springboard for improvement across all sectors - vaccine stock-outs,strong opposition from certain advocacy groups, and the widely publicized Dengvaxia controversy. Moving forward, with recent surveys having shown that vaccine confidence has begun to improve, these experiences may inform the approaches taken to address vaccine uptake. These lessons from the past highlight the importance of a strong partnership between health leaders and the local community, bearing in mind cultural appropriateness and humility; the engagement of multidisciplinary stakeholders; and the importance of foresight in preparing public health infrastructure for the arrival of a COVID-19 vaccine.

Utility of flow cytometry and gene rearrangement analysis in tissue and blood of patients with suspected cutaneous T­cell lymphoma.

Cutaneous T­cell lymphoma (CTCL) is difficult to diagnose at an early stage. Current diagnostic tools include clinical examination, histomorphologic analysis, immunohistochemistry, flow cytometry of peripheral blood and/or lesional tissue, and evaluation of T­cell receptor (TCR) clonality by gene rearrangement analysis (TCRGR). Advances in genomic sequencing, including high­throughput sequencing (HTS), can be used to identify specific clones of rearranged TCR genes. Even with all of these tools, CTCL can take as long as a decade to definitively diagnose, potentially delaying treatment options and causing patient anxiety. This study aimed to evaluate the performance of the various ancillary testing modalities used to diagnose early­stage CTCL. In a subset of patients the performance of HTS was compared to flow cytometry and conventional TCRGR analysis via polymerase chain reaction (PCR). Fifty­five patients, with a total of 68 skin biopsies and peripheral blood draws, were evaluated using flow cytometry, PCR­TCRGR, and HTS­TCRGR to determine the sensitivity and specificity of each ancillary test. In tissue biopsies, flow cytometry (64%), PCR (71%) and HTS (69%) shared similar sensitivities; flow cytometry had the highest specificity (93%), followed by HTS (86%) and PCR (76.9%). However, flow cytometry and PCR had insufficient DNA quantities in 29 and 15% of the specimens, respectively. Peripheral blood testing was less sensitive than tissue testing (flow cytometry 14%, PCR 41%, HTS 33%); in peripheral blood, HTS was the most specific test (flow cytometry, 70%; PCR, 62.5%; and HTS, 100%). HTS is a highly specific molecular test for identifying CTCL in peripheral blood and skin biopsy specimens; however, our findings suggest a need for a continued search for more sensitive tests for early­stage CTCL.

Transitioning from rich to lean reinforcement as a form of error correction.

Discrete trial instruction (DTI) is a ubiquitous tool used by practitioners in early intervention programs. A common approach to correcting errors during DTI involves providing a single prompt of the target response when a mistake is made (i.e., single-response repetition). Modifications to the single-response repetition approach have been developed to improve acquisition; however, these modifications are often aversive techniques (e.g., increased effort, response cost) and may not be preferred by the children or considered socially acceptable by caregivers. We conducted this study to evaluate the use of a transition from rich to lean reinforcement as a form of error correction. We compared the rich-lean condition to the single-response repetition approach during DTI for 4 boys diagnosed with autism. The rich-lean condition was (a) more efficient in improving accuracy in 6 out of 9 tasks, (b) more preferred by all participants, and (c) socially validated by caregivers.

Post-renal transplant urolithiasis in children: an increasingly diagnosed complication: a retrospective cohort study.

OBJECTIVE: Urolithiasis in renal transplant (RTx) recipients is a potential cause of allograft loss if obstruction is untreated. It is not clear if paediatric transplant recipients are following the global trend for increased prevalence of urolithiasis over time. DESIGN/SETTING/PATIENTS: A retrospective chart review was undertaken to evaluate the frequency, risk factors and characteristics of post-RTx urolithiasis over two decades (1995-2016), in a tertiary Australian paediatric hospital. RESULTS: Stones were diagnosed in 8 of 142 (5.6%) recipients, 6 of whom were transplanted in the latter decade. All patients were male, with a median age 4.9 years and median weight 11.8 kg. Presentation was with haematuria (n=4), pain (n=2), dysuria (n=2), stone passage (n=1) and asymptomatic (n=1). Time to presentation was bimodal; three stones were identified in the initial 3 months post RTx and the remainder after 31-53 months. Two stones were in association with retained suture material and two patients had recurrent urinary tract infections. The average stone size was 8.4 mm. Five stones were analysed; all contained calcium oxalate, three were mixed, including one with uric acid. Five (83.3%) children had hypercalciuria but none had hypercalcaemia. Cystolithotripsy was the the most common treatment (n=5), in combination with citrate supplementation. No graft was lost due to stones. CONCLUSIONS: Calculi occur with increasing frequency after renal transplantation. Clinicians need a high index of suspicion as symptoms may be atypical in this population. The cause for the increased frequency of stones in transplant recipients is not clear but is in keeping with the increase seen in the general paediatric population.

Resistance of the murine cornea to bacterial colonization during experimental dry eye.

The healthy cornea is remarkably resistant to infection, quickly clearing deliberately inoculated bacteria such as Pseudomonas aeruginosa and Staphylococcus aureus. Contrasting with the adjacent conjunctiva and other body surfaces, it also lacks a resident viable bacterial microbiome. Corneal resistance to microbes depends on intrinsic defenses involving tear fluid and the corneal epithelium. Dry eye, an ocular surface disease associated with discomfort and inflammation, can alter tear fluid composition and volume, and impact epithelial integrity. We previously showed that experimentally-induced dry eye (EDE) in mice does not increase corneal susceptibility to P. aeruginosa infection. Here, we explored if EDE alters corneal resistance to bacterial colonization. EDE was established in mice using scopolamine injections and dehumidified air-flow, and verified by phenol-red thread testing after 5 and 10 days. As expected, EDE corneas showed increased fluorescein staining versus controls consistent with compromised epithelial barrier function. Confocal imaging using mT/mG knock-in mice with red-fluorescent membranes revealed no other obvious morphological differences between EDE corneas and controls for epithelium, stroma, and endothelium. EDE corneas were imaged ex vivo and compared to controls after alkyne-functionalized D-alanine labeling of metabolically-active colonizing bacteria, or by FISH using a universal 16S rRNA gene probe. Both methods revealed very few viable bacteria on EDE corneas after 5 or 10 days (median of 0, upper quartile of ≤ 1 bacteria per field of view for each group [9-12 eyes per group]) similar to control corneas. Furthermore, there was no obvious difference in abundance of conjunctival bacteria, which included previously reported filamentous forms. Thus, despite reduced tear flow and apparent compromise to corneal barrier function (fluorescein staining), EDE murine corneas continue to resist bacterial colonization and maintain the absence of a resident viable bacterial microbiome.

Extracellular Matrix and Cellular Plasticity in Musculoskeletal Development.

Cellular plasticity refers to the ability of cell fates to be reprogrammed given the proper signals, allowing for dedifferentiation or transdifferentiation into different cell fates. In vitro, this can be induced through direct activation of gene expression, however this process does not naturally occur in vivo. Instead, the microenvironment consisting of the extracellular matrix (ECM) and signaling factors, directs the signals presented to cells. Often the ECM is involved in regulating both biochemical and mechanical signals. In stem cell populations, this niche is necessary for maintenance and proper function of the stem cell pool. However, recent studies have demonstrated that differentiated or lineage restricted cells can exit their current state and transform into another state under different situations during development and regeneration. This may be achieved through (1) cells responding to a changing niche; (2) cells migrating and encountering a new niche; and (3) formation of a transitional niche followed by restoration of the homeostatic niche to sequentially guide cells along the regenerative process. This review focuses on examples in musculoskeletal biology, with the concept of ECM regulating cells and stem cells in development and regeneration, extending beyond the conventional concept of small population of progenitor cells, but under the right circumstances even "lineage-restricted" or differentiated cells can be reprogrammed to enter into a different fate.

Topical Vitamin D May Modulate Human Sinonasal Mucosal Responses to House Dust Mite Antigen.

BACKGROUND: Respiratory epithelium is a key defense against inhaled pathogens. Vitamin D3 (VD) has been suggested to modulate airway inflammation; however, its effect on innate airway defenses, the physical barrier, mucociliary apparatus, and cytokine release remains unclear. OBJECTIVE: To investigate the outcomes of VD application prior to challenge in an in vitro model of human sinonasal epithelium, through assessment of epithelial transepithelial resistance (TER), cilia beat frequency (CBF), and interleukin (IL)-6 release, and secondarily to determine whether topical VD is beneficial to patients with inflammatory sinonasal pathology. METHODS: Primary human sinonasal epithelial cells from patients with eosinophilic chronic rhinosinusitis (eCRS) and healthy controls were cultured in air-liquid interface (ALI). Well-differentiated cultures from each patient were pretreated for 24 hours with 4 different VD doses. Toxicity was quantified at 24 hours in unchallenged ALI by lactate dehydrogenase (LDH) assay. Innate responses were assessed by measuring TER and CBF before and up to 24 hours after house dust mite Dermatophagoides pteronyssinus challenge. IL-6 release was evaluated 24-hour postchallenge. RESULTS: Fifteen patients (53 ± 13.5 years, 60% females, 53% eCRS) representing 120 ALI wells were assessed. VD (0, 25, 50, 150 IU/mL) released less LDH than vehicle, indicating noncytotoxicity (0.15 ± 0.02; 0.15 ± 0.00; 0.14 ± 0.02; 0.11 ± 0.01 vs 0.17 ± 0.03, P = .004). VD increased TER for eCRS wells at 5 minutes (50 IU/mL: Δ6.76 ± 3.93 vs Δ3.87 ± 2.46, P = .04) and 24 hours (50 IU/mL: Δ0.88 ± 0.49 vs Δ0.40 ± 0.42, P = .02; 150 IU/mL: Δ1.06 ± 0.58 vs Δ0.47 ± 0.46, P = .01). CBF increased at 1 hour for eCRS wells (50 IU/mL: Δ0.62 ± 0.14 vs Δ0.41 ± 0.13, P = .001; 150 IU/ml: Δ0.60 ± 0.13 vs Δ0.38 ± 0.11, P < .001). IL-6 release was similar between normal and eCRS wells. CONCLUSION: Topical VD supplementation in eCRS patients may be beneficial for innate epithelial defenses. VD is noncytotoxic and does not adversely affect the physical barrier, mucociliary apparatus, or IL-6 release. Further studies should clarify its potential as a therapeutic agent.

Factors associated with the willingness of primary caregivers to avail of a dengue vaccine for their 9 to 14-year-olds in an urban community in the Philippines.

To help address the need for preventive measures against dengue fever, a leading cause of child mortality in the Philippines, vaccine trials are ongoing and a tetravalent vaccine (Dengvaxia™, Sanofi Pasteur) has been developed. It is hypothesized that while acceptability would be high among primary caregivers (i.e., parents/guardians), the willingness to have one's child immunized against dengue would be associated with socio-demographic variables, attitudes and knowledge regarding dengue and vaccination, and past experience with dengue. This study aimed to assess the aforementioned factors' association with primary caregivers' willingness to avail of a dengue vaccine for their 9 to 14-year-old children in an urban community in the Philippines. A cross-sectional study utilizing interviews was conducted to determine which factors were associated with willingness-to-avail assuming a free vaccine, and a case study utilizing a focus group discussion was employed to capture some underlying reasons for their willingness. Data were analyzed using multiple logistic regression and thematic analysis. Among the 202 study participants, 193 (95.54%) were willing to avail of the vaccine. There was a high probability of vaccine acceptance by primary caregivers (95.54%), with good attitude towards vaccination (≥12/15 points) [aOR 10.62, 90% CI (1.73-26.28)] and large household size (>5) [aOR 9.63, 90% CI (2.04-45.58)] being positively associated with willingness-to-avail, and good knowledge regarding dengue fever [aOR 0.10, 90% CI (0.03-0.74)] and older age (>44 years) [aOR 0.14, 90% CI (0.03-0.61)] being negatively associated. Crude analysis showed that household size, knowledge regarding dengue, and attitude towards vaccination were significantly associated with willingness. Multivariate analysis revealed that these factors and the primary caregiver's age were associated with willingness. Thematic analysis showed various perceptions regarding dengue and vaccination. Knowing these factors are associated with willingness-to-avail of the vaccine may help in understanding the audience of health promotion projects aimed at increasing immunization coverage.

Lymphomatoid Papulosis and Other Lymphoma-Like Diseases.

Pityriasis lichenoides et varioliformis acuta and pityriasis lichenoides chronica are the 2 main subtypes of pityriasis lichenoides. They represent the acute and chronic forms of the disease; both may have clonal T cells. Several treatment modalities are used, but it has been difficult to determine efficacy because of the possibility of spontaneous remission. Cutaneous CD30+ lymphoproliferative disorders constitute many cutaneous T-cell lymphomas and comprise lymphomatoid papulosis and primary cutaneous anaplastic large cell lymphoma (ALCL). Both have an excellent prognosis. Lymphomatoid papulosis often only requires observation or treatment of symptoms. First-line therapies for primary cutaneous ALCL are surgical excision or radiotherapy.

Intra-abdominal Complications After Pediatric Kidney Transplantation: Incidence and Risk Factors.

BACKGROUND: The incidence and types of intra-abdominal complications after pediatric transplantation are not well established, and specific risk groups have not been clearly identified. METHODS: A retrospective chart review of all pediatric transplant recipients between 1995 and 2016 was undertaken. Intra-abdominal complications were grouped into 4 categories: fluid collections, gastrointestinal, vascular, and urogenital. Donor, recipient, and transplant characteristics were evaluated using univariate and multivariate logistic regressions. RESULTS: There were 146 transplants meeting the inclusion criteria. The mean follow-up time was 4.6 ± 3.7 years (range, 0.3-18 y). The mean weight at transplantation was 31.5 ± 16.5 kg (range, 9-78), with 24 (16%) recipients being <15 kg and 23% younger than 5 years. Thirty-four (23%) patients had previous abdominal surgery. There were 32 complications identified in 27 (18%) transplant recipients. Fluid collections requiring surgical drainage developed in 9 (6.2%), gastrointestinal surgical complications in 12 (8.2%), vascular complications in 5 (3.5%), and urogenital complications in 6 (4.1%). There were only 3 graft losses due to abdominal complications, all after renal vein thrombosis. Weight <15 kg at the time of transplant (P = 0.016), previous abdominal surgery (P = 0.047), and intraperitoneal surgical technique (P = 0.008) were risk factors in the univariate analysis using Cox regression models, whereas only weight <15 kg (P = 0.003) and previous abdominal surgery (P = 0.008) were retained in the multivariate analysis. CONCLUSIONS: Intraabdominal complications occur in almost 1 in 5 pediatric renal transplant recipients. Weight <15 kg and previous abdominal surgery are risk factors for developing such complications.

DMBT1 inhibition of Pseudomonas aeruginosa twitching motility involves its N-glycosylation and cannot be conferred by the Scavenger Receptor Cysteine-Rich bacteria-binding peptide domain.

The scavenging capacity of glycoprotein DMBT1 helps defend mucosal epithelia against microbes. DMBT1 binding to multiple bacterial species involves its conserved Scavenger Receptor Cysteine-Rich (SRCR) domains, localized to a 16-mer consensus sequence peptide, SRCRP2. Previously, we showed that DMBT1 bound Pseudomonas aeruginosa pili, and inhibited twitching motility, a pilus-mediated movement important for virulence. Here, we determined molecular characteristics required for twitching motility inhibition. Heat-denatured DMBT1 lost capacity to inhibit twitching motility and showed reduced pili binding (~40%). Size-exclusion chromatography of Lys-C-digested native DMBT1 showed that only high-Mw fractions retained activity, suggesting involvement of the N-terminal containing repeated SRCR domains with glycosylated SRCR-Interspersed Domains (SIDs). However, individual or pooled consensus sequence peptides (SRCRPs 1 to 7) showed no activity and did not bind P. aeruginosa pili; nor did recombinant DMBT1 (aa 1-220) or another SRCR-rich glycoprotein, CD163. Enzymatic de-N-glycosylation of DMBT1, but not de-O-glycosylation, reduced its capacity to inhibit twitching motility (~57%), without reducing pili binding. Therefore, DMBT1 inhibition of P. aeruginosa twitching motility involves its N-glycosylation, its pili-binding capacity is insufficient, and it cannot be conferred by the SRCR bacteria-binding peptide domain, either alone or mixed with other unlinked SRCRPs, suggesting an additional mechanism for DMBT1-mediated mucosal defense.

Malignant Mixed Epithelial and Stromal Tumor of the Kidney With 2 Simultaneous Renal Carcinomas in a Male Patient: Case Report and Review of the Literature.

The majority of mixed epithelial and stromal tumors (MEST) of the kidney are benign entities found in female patients. Malignant MEST of the kidney is an extremely rare entity that often behaves clinically similar to an undifferentiated sarcoma. We report a case of a malignant MEST with synchronous papillary and clear cell renal cell carcinomas (RCCs) in a 61-year-old Caucasian man who presented with an incidental finding of a left renal mass on workup for back pain. The patient underwent a left radical nephrectomy, with histopathology confirming a malignant MEST, intimately associated papillary RCC, and separate adjacent focus of clear cell RCC.