Functional interrogation of lymphocyte subsets in alopecia areata using single-cell RNA sequencing

Alopecia areata (AA) is among the most prevalent autoimmune diseases, but the development of innovative therapeutic strategies has lagged due to an incomplete understanding of the immunological underpinnings of disease. Here, we performed single-cell RNA sequencing (scRNAseq) of skin-infiltrating immune cells from the graft-induced C3H/HeJ mouse model of AA, coupled with antibody-based depletion to interrogate the functional role of specific cell types in AA in vivo. Since AA is predominantly T cell-mediated, we focused on dissecting lymphocyte function in AA. Both our scRNAseq and functional studies established CD8+ T cells as the primary disease-driving cell type in AA. Only the depletion of CD8+ T cells, but not CD4+ T cells, NK, B, or γδ T cells, was sufficient to prevent and reverse AA. Selective depletion of regulatory T cells (Treg) showed that Treg are protective against AA in C3H/HeJ mice, suggesting that failure of Treg-mediated immunosuppression is not a major disease mechanism in AA. Focused analyses of CD8+ T cells revealed five subsets, whose heterogeneity is defined by an "effectorness gradient" of interrelated transcriptional states that culminate in increased effector function and tissue residency. scRNAseq of human AA skin showed that CD8+ T cells in human AA follow a similar trajectory, underscoring that shared mechanisms drive disease in both murine and human AA. Our study represents a comprehensive, systematic interrogation of lymphocyte heterogeneity in AA and uncovers a novel framework for AA-associated CD8+ T cells with implications for the design of future therapeutics.

T cell egress via lymphatic vessels is tuned by antigen encounter and limits tumor control

Antigen-specific CD8+ T cell accumulation in tumors is a prerequisite for effective immunotherapy, and yet the mechanisms of lymphocyte transit are not well defined. Here we show that tumor-associated lymphatic vessels control T cell exit from tumors via the chemokine CXCL12, and intratumoral antigen encounter tunes CXCR4 expression by effector CD8+ T cells. Only high-affinity antigen downregulates CXCR4 and upregulates the CXCL12 decoy receptor, ACKR3, thereby reducing CXCL12 sensitivity and promoting T cell retention. A diverse repertoire of functional tumor-specific CD8+ T cells, therefore, exit the tumor, which limits the pool of CD8+ T cells available to exert tumor control. CXCR4 inhibition or loss of lymphatic-specific CXCL12 boosts T cell retention and enhances tumor control. These data indicate that strategies to limit T cell egress might be an approach to boost the quantity and quality of intratumoral T cells and thereby response to immunotherapy.

1011 CONTINUUM OF GERIATRIC CARE FOR OLDER ADULTS WITH DUAL SENSORY LOSS DURING THE COVID-19 PANDEMIC IN CANADA: LESSONS LEARNED

Introduction

Around 1.1 million older Canadians live with combined hearing and vision impairment (dual sensory loss/DSL). Evidence highlights that they are at a high risk of cognitive impairment, functional decline, social isolation, falls, depression, and mortality. Compared to their non-DSL peers, older adults with DSL experience various challenges in accessing healthcare, which were exacerbated during the COVID-19 pandemic. This study aimed to explore the continuum of geriatric care for older adults with DSL by integrating their perspectives, those of caregivers who accompany them on healthcare visits, and their healthcare providers in Canada during the pandemic.

Method

We conducted a qualitative study with 32 older Canadians with DSL and their caregivers, and an online survey with 228 healthcare providers across the country. Qualitative interviews were audio-recorded using Zoom and transcribed verbatim, while the survey data were collected using Lime Survey. Thematic analysis was used to analyse qualitative data, whereas descriptive statistics were used for quantitative survey data.

Results

The findings highlighted the gaps in the continuum of care for this population. The reported gaps were lack of training on DSL among healthcare providers, lack of time and comfort to go beyond one’s specialty, lack or limited support to overcome communication challenges while providing care to older adults with DSL, difficulty in using technologies for virtual/telehealth, presence of comorbidities such as cognitive impairment, and restrictions in caregiver accompaniment during the pandemic.

Conclusion

Our findings indicate that the continuum of care for this group is negatively affected due to the pandemic, in a disproportionate manner, and structural barriers are experienced by older adults with DSL and their caregivers for access to care. To ensure effective care, healthcare professionals need training on DSL-specific accessibility and communication. A collaborative, cross-disciplinary geriatric care approach with the active involvement of essential care partners is an utmost need.

An activation to memory differentiation trajectory of tumor-infiltrating lymphocytes informs metastatic melanoma outcomes

There is a need for better classification and understanding of tumor-infiltrating lymphocytes (TILs). Here, we applied advanced functional genomics to interrogate 9,000 human tumors and multiple single-cell sequencing sets using benchmarked T cell states, comprehensive T cell differentiation trajectories, human and mouse vaccine responses, and other human TILs. Compared with other T cell states, enrichment of T memory/resident memory programs was observed across solid tumors. Trajectory analysis of single-cell melanoma CD8+ TILs also identified a high fraction of memory/resident memory-scoring TILs in anti-PD-1 responders, which expanded post therapy. In contrast, TILs scoring highly for early T cell activation, but not exhaustion, associated with non-response. Late/persistent, but not early activation signatures, prognosticate melanoma survival, and co-express with dendritic cell and IFN-γ response programs. These data identify an activation-like state associated to poor response and suggest successful memory conversion, above resuscitation of exhaustion, is an under-appreciated aspect of successful anti-tumoral immunity.

Symptomatology, prognosis, and clinical findings of COVID 19 induced myocarditis: a systematic review

Background

With the advent of the novel coronavirus (COVID-19) in December 2019, numerous case studies have been reported on its impact on cardiac cells, and we purpose to perform a systematic review that explains the symptomatology, prognosis, and clinical findings of COVID-19-related myocarditis patients.

Methods

PRISMA guidelines were employed and peer–reviewed journals in English related to COVID – 19 were included. Exclusion criteria included <50 y, known heart problems. Age criteria was guided by prior systematic report by Kariyanna et al (2020). Search engines included Pubmed, Google scholar, Cochrane Central and Web of Science database using “SARS-CoV-2” or “COVID 19” and “myocarditis”. The data were analyzed and synthesized qualitatively using MS Excel PIVOT and quality was rated using the “Research and Quality Scoring Method” by Sackett and Haynes, the Jadad scale, and the items published by Cho and Bero (Han et al., 2011).

Results

A total of 22 studies on 37 patients were included; 6 were confirmed myocarditis while the rest have possible myocarditis. Among all these 62% were male and showing dominance. The most common presenting symptoms appear to be fever, chest pain, shortness of breath, and cough. Most of the patients have shown elevation in cardiac biomarkers (troponin levels, CRP, CK level, CK-MB, NT-pro BNP). Electrocardiogram changes include sinus rhythm, tachycardia, and non specific ST - segment elevation and T wave changes. Echocardiography results commonly found were left ventricular dysfunction and increased wall thickness. CMR was performed in 8 patients, with features of reduced ejection fraction, myocardial edema, and hypokinesia, whereas biopsy has been performed among 3 patients due to the invasive nature of the procedure and common findings include inflammatory biomarkers were raised. Overall Prognosis appears to be bad in which 25% of patients were not able to survive and 75% of them were recovered.

Conclusions

Myocarditis-related COVID-19 mortality continues to be high and under-estimated. The patient manifestations are identical and difficult to distinguish from COVID-19-related symptoms. Just a limited number of patients undergo confirmatory tests, such as an MRI or an endomyocardial biopsy, which may not be available. Further studies are needed to confirm and quantify the actual prognosis and outcomes of patients with COVID-19 myocarditis. Moreover, available data on the usage of glucocorticoids in the coronavirus infection is controversial to our knowledge. Corticosteroid therapy is unsuccessful in the treatment of viral myocarditis, according to a Cochrane systematic review conducted in 2013. It also allows viral clearance to be overdue. Corticosteroids, on the other hand, reduce the chance of mortality for ICU patients in Wuhan. To concede, more studies, clinical trials, and duration is needed for a thorough understanding of COVID – 19, and its impact on cardiac health

Funding Acknowledgement

Type of funding sources: Other.

The use of SPECT/CT quantification of 99mTc-PYP uptake to assess tafamidis treatment response in ATTR cardiac amyloidosis

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

Nuclear scintigraphy with bone-avid radiotracers such as Tc-99m-PYP, Tc99m-DPC and Tc-99m-HMDP are used to diagnose transthyretin (ATTR) cardiac amyloidosis with limited quantification employing a semi-quantitative visual score and a heart to contralateral lung ratio. Therapy for ATTR cardiac amyloid currently is limited to a single FDA approved agent, tafamidis, however, there is no data regarding the longitudinal assessment of imaging findings in patients undergoing therapy. SPECT/CT acquisition and analysis with dedicated software can provide volumetric assessment and quantification of cardiac tracer uptake.

Purpose

The purpose of this study was to perform longitudinal assessment of cardiac ATTR amyloid 99mTc-PYP imaging findings to determine if treatment with tafamidis results in any change in quantitative measures of tracer uptake. There is no data on if treatment results in a decrease in cardiac amyloid burden as assessed by 99mTc-PYP imaging.

Methods

A prospective, single center, study of patients with ATTR cardiac amyloid being treated with tafamidis (either 80mg or 61mg dose) who have baseline and follow-up 99mTc-PYP studies. SPECT/CT quantification software was used to quantify heart, lung, and bone tracer uptake and generate standardized uptake values (SUVs). Comparison of baseline (before treatment) total SUVs, mean SUV value, percentage of the injected dose, mean SUV of heart to mean SUV of bone ratio and to mean SUV of right lung ratio was made to the values obtained at follow-up after tafamidis treatment. Measurements were obtained from the whole heart and the isolated left ventricle. Data was obtained by two physicians and the results averaged.

Results

5 patients were analyzed with a mean age 73.8 ± 7.7, 80% were males, and a mean length of tafamidis therapy at repeat imaging of 12.5 ± 3.8 months. At follow-up there was an average decrease in whole heart total SUV counts by -25.9 ± 10.3%, in the mean SUV value by -18.2 ± 18.2% and in the percentage of injected dose by -23.7 ± 14.0%. Similar decreases were seen in the isolated left ventricle measures. Heart to bone and heart to lung ratios showed a mixed response to therapy. Detailed results are provided in the table.

Conclusion

The measurements of total SUV counts, mean SUV value, and percentage of the injected dose showed improvement with tafamidis treatment. The ratios did not uniformly show improvement and the reason for this finding is unclear. This new technique offers a potential method for following tafamidis therapy and assessing the cardiac amyloid burden.

Blockade of IDO/TDO downstream effectors restricts cancer immune suppression

Immune checkpoint blockade (ICB) results in clinical benefit for a subset of cancer patients, yet multiple mechanisms of resistance can impair optimal response. The catabolism of tryptophan into metabolites known as kynurenines (Kyn) by the expression of enzymes such as IDO or TDO is a frequent phenomenon that plays a suppressive role in tumor immunity. Recently it was shown that Kyn acts as agonist of the aryl hydrocarbon receptor (AHR). Here we sought to characterize the mechanisms of immune suppression associated with the AHR pathway and to evaluate its potential as therapeutic target. RNAseq analysis of human cancers revealed a correlation between the expressions of AHR-related genes with markers associated with immunotherapy resistance (PD-1, FOXP3, CD206). By using IDO or TDO-overexpressing variants of a melanoma cell model (B16-F10), we found that myeloid cells, such as tumor-associated macrophages (TAMs) and dendritic cells (DCs), present up-regulation of the AHR. IDO-expressing tumors (B16-IDO) show higher myeloid cell infiltration, which present a tolerogenic phenotype. Tumor-antigen specific CD8T cells present reduced expression of activation markers and proliferation rate when primed by Kyn-treated BMDCs. Treatment of B16-IDO-bearing mice with an AHR-specific antagonist (CH-223191) leads to an increase of MHC II in TAMs, of activation markers in CD8 T cells and reduced frequency of T-regs. AHR inhibition delays progression of tumors with an active IDO/TDO/Kyn pathway (B16-IDO and B16-TDO), and efficacy is further improved when ICB is used in combination. In summary, our findings demonstrate that targeting the Kyn pathway through AHR inhibition could overcome key suppressive mechanisms and sensitize tumors to ICB.

Abstract P2-06-25: A phenotypic screening and machine learning platform efficiently identifies triple negative breast cancer-selective and readily druggable targets

Identifying effective oncogenic targets is challenged by the complexity of genetic alterations in cancer and their poorly understood relation to cell function and survival. This, combined with the fact that the majority of the proteome is predicted to be undruggable, may explain why genomic approaches have had only moderate success in identifying and translating oncogenic drug targets. There is a need for methods that rapidly and accurately identify “pharmacologically effective” targets without the requirement for priori knowledge of complex signaling networks. We developed an approach that uses machine learning to relate results from unbiased phenotypic screening of kinase inhibitors to their biochemical activity data. This process, which we call idTRAX (Identification of Drug TaRgets and Anti-targets by Cellular and Molecular Cross-referencing), identifies targets that are pharmacologically responsive and readily druggable. Additionally, the identified targets are not typically overcome by the robustness of signaling networks, because only targets that effectively induce a phenotype upon pharmacological engagement are selected. We applied this methodology to triple negative breast cancer, which still lacks targeted therapy. We screened 19 breast cancer cell lines with ˜500 small-molecule kinase inhibitors with annotated kinase activity data and identified cell-line specific kinase targets, i.e. kinases whose inhibition causes cell line-specific cytotoxicity or cytostaticity. We were able to identify various unique cell line selective kinase addictions along with well-known driver kinase addictions, for example, dependence on FGFR2 in the MFM-223 cell line and AKT kinases in MFM-223, CAL-148, and others. We also found that triple negative breast cancer cell lines exhibit heterogeneous target patterns, indicating the need of personalized medicine approach to tackle them. We further compared candidate targets identified by idTRAX with those reported from RNAi- and CRISPR-based screens. Strikingly, the correlation between targets identified by the pharmacological approach and those identified by knockdown/knockout-based screens was low [average rank correlation (ρ) = 0.0273- 0.1074], suggesting that gene-silencing approaches may not be the most efficient at identifying targets for small-molecule drug discovery or repurposing. Our approach provides a platform for rapidly identifying sample-specific drug targets and potentially guiding personalised therapy regimens.

Citation Format: Gautam P, Jaiswal A, Aittokallio T, Hassan A-A, Wennerberg K. A phenotypic screening and machine learning platform efficiently identifies triple negative breast cancer-selective and readily druggable targets [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-06-25.

Evaluation of Surface Roughness of Nanofilled Composite Restorations after Simulated Tooth Brushing using Various Dentifrices

Background Teeth restored with direct composite resin are constantly exposed to specific challenges of the oral cavity. These challenges can modify the material properties and, when associated with daily brushing, eventually change its surface roughness, allowing bacterial growth and retention of extrinsic pigments. Dentifrices plays an important role in dental wear (abrasion) and over time, can also cause an increase in the surface roughness of restorative materials. Objective To assess the effect of dentifrices on the longevity of direct nanofilled composite resins restorations as far as wear and roughness is concerned. Method Class V cavity were prepared on 90 extracted human teeth and restored with Filtek Z350 composite. Teeth were randomly divided into 6 experimental groups of 15 each labelled as Group-1 (Colgate Dental cream) Group-2 (Colgate Active Salt toothpaste), Group-3 (Pepsodent Regular toothpaste), Group-4 (Dabur red toothpaste), Group-5 (Dabur Lal tooth powder) and Group-6 Control (water). The samples were fixed on tooth brushing machine and subjected to mechanical tooth brushing using various dentifrices according to respective groups in 3 phases and reading of surface roughness (Ra) was recorded. Result Surface roughness (Ra) had increased in following order: Group 6 < Group 3 < Group 2 < Group 1 < Group 4 < Group 5. All the tooth pastes were compared, their behaviour was found to be similar as there was no statistically significant difference amongst them. Though all of them were inferior to control group and the difference was statistically significant. Whereas the only tooth powder Dabur lal tooth powder gave the maximum roughness when compared with the other tooth pastes and the difference was statistically significant. Conclusion With increase in time of brushing there was increase in surface roughness in all the 5 dentifrices among them Ra was maximum for Dabur lal tooth powder.

The clinical utility of cycle of threshold value of GeneXpert MTB/RIF (CBNAAT) and its diagnostic accuracy in pulmonary and extra-pulmonary samples at a tertiary care center in India

BACKGROUND

There are knowledge gaps in the in-depth analysis of the most promising and robust diagnostic tool, GeneXpert MTB/RIF (CBNAAT). The cycle of threshold (CT) value of the CBNAAT test and its clinical implications has not been explored much.

AIMS AND OBJECTIVES

The study aimed at (a) estimating the diagnostic accuracy and incremental yield of Xpert MTB/RIF in various specimens (b) establishing the association between CT value category (high, medium, low, very low) and culture time-to-positivity (TTP).

METHODS

A total of 1000 samples, both pulmonary and extra-pulmonary were collected from presumptive TB cases in a large tertiary care hospital. Sensitivity and specificity of CBNAAT was calculated with culture as the gold standard. The association of CT value with culture TTP was also studied.

RESULTS

The overall sensitivity of CBNAAT was 88.5%, with bronchial washing specimen being the most sensitive (92.3%) and pleural fluid being the least (66.7%). In smear negative individuals, the sensitivity of CBNAAT was 80.9%. The additional yield of CBNAAT over smear microscopy was 10.9%. It was observed that as we move from high to very low CT category, culture positivity decreases significantly (p<0.001), whereas time taken for culture growth increases (p<0.001).

CONCLUSION

CBNAAT is a robust test for accurate diagnosis of tuberculosis both pulmonary and extra-pulmonary, smear negative as well, especially in resource-limited settings. The correlation between CT value and culture TTP has potential in predicting bacillary load, though further studies are required.

Revision shoulder arthroplasty for failed surface replacement hemiarthroplasty

PURPOSE

The aim of this study was to assess the reasons of failure of shoulder surface replacement hemiarthroplasty (SRH) and to evaluate the outcome of revision surgery.

METHOD

The study group included 25 patients (26 shoulders) with failed SRHs. The mean time to revision surgery was 3.6 years. Their functional outcome was evaluated using adjusted Constant-Murley score at mean follow-up of 5.2 years (range 2-16 years).

RESULT

Most common cause of failure was glenoid erosion (42%) and progressive failure of rotator cuff (31%). Median adjusted Constant-Murley score at mean follow-up of 5.2 years was 51.6. Median adjusted Constant-Murley score in patients who had primary diagnosis of osteoarthritis and had revision performed to anatomic TSA (14 shoulders) was 85 (range 40-100) at mean follow-up of 5 years compared to 36.3 (range 20-66.3) in the remaining patients at 5.4 years, p = 0.00008.

CONCLUSION

Revision surgery for failed SRH can be technically challenging with variable results. Most common mode of failure was glenoid erosion. Functional outcomes are better in those with revision performed to anatomic TSA.

Efficacy and Safety of Cyclosporine versus Tacrolimus in Steroid and Cyclophosphamide Resistant Nephrotic Syndrome: A Prospective Study

Calcineurin inhibitors (CNIs) are the preferred drugs for treatment of childhood steroid-resistant nephrotic syndrome (SRNS) who are also resistant to cyclophosphamide (CYC). Although few studies have shown a benefit of one over the other, efficacy and safety of either CNIs (tacrolimus [TAC] or cyclosporine [CSA]) in this special population remained to be assessed in long-term studies. Forty-five children with SRNS who were also resistant to CYC (CYC-SRNS) from January 2006 to June 2011, were included in the study. Patients were treated with CNI either TAC or CSA based on 1:1 allocations and were prospectively observed. Patients who were nonresponsive to CNIs had been treated with mycophenolate mofetil. Outcomes were measured in terms of remission of NS, adverse effects of drugs, and progression of disease. After 6 months of treatment, 16/23 (69.5%) patients on CSA achieved remission and 18/22 (81.8%) on TAC achieved remission (P = 0.3). The side effects hypertrichosis, and gum hyperplasia were significantly less in TAC group as compared to CSA group (P < 0.001). The 1-, 2-, 3-, 4-, and 5-year estimated renal survival (doubling of serum creatinine as event) in CSA group was 96%, 91%, 85%, 54%, and 33% and in TAC group was 96%, 95%, 90%, 89%, and 79%, respectively (P = 0.02). Although TAC and CSA are equally efficacious, TAC has significantly less side effects. The long-term outcome of renal function was significantly better in patients who were treated with TAC as compared to CSA.

Direct-acting Antiviral Agents in Hepatitis C Virus-infected Renal Allograft Recipients: Treatment and Outcome Experience from Single Center

Hepatitis C virus (HCV) infection in renal allograft recipient is associated with increased morbidity and mortality. At present, only few studies related to treatment and outcomes of HCV-infected renal allograft recipients with DAAs have been published. We aimed the study to assess the efficacy and safety of sofosbuvir-based regimens in HCV-infected renal allograft recipients. We analyzed data of 22 eligible HCV-infected renal allograft recipients (14 genotype-3, 6 genotype-1, one each genotype-2 and 4) who were treated with DAAs at our institute. DAA regimen included sofosbuvir and ribavirin with or without ledipasvir or daclatasvir for 12–24 weeks. Patients were followed up for 24 weeks after completion of treatment. A rapid viral response of 91%, end of therapy response of 100%, and sustained viral response at 12 and 24 weeks of 100% with rapid normalization of liver enzymes were observed. Therapy was well tolerated except for ribavirin-related anemia. A significant decrease in tacrolimus trough levels was observed and most patients required increase in tacrolimus dose during the study. Treatment with newer DAAs is effective and safe for the treatment of HCV-infected renal allograft recipients.

Association and expression of the antigen-processing gene PSMB8, coding for low-molecular-mass protease 7, with vitiligo in North India: case-control study

BACKGROUND

Vitiligo is a multifactorial, autoimmune, depigmenting disorder of the skin where aberrant presentation of autoantigens may have a role.

OBJECTIVES

To study the association of two antigen-processing genes, PSMB8 and PSMB9, with vitiligo.

METHODS

In total 1320 cases of vitiligo (1050 generalized and 270 localized) and 752 healthy controls were studied for the PSMB9 exon 3 G/A single-nucleotide polymorphism (SNP), PSMB8 exon 2 C/A SNP and PSMB8 intron 6 G/T SNP at site 37 360 using polymerase chain reaction (PCR)-restriction fragment length polymorphism. Real-time PCR was used for transcriptional expression of PSMB8 and cytokines. Expression of ubiquitinated proteins and phosphorylated-p38 (P-p38) was studied by Western blotting.

RESULTS

Significant increases in PSMB8 exon 2 allele A (P < 2.07 × 10^-6 , odds ratio 1·93) and genotypes AA (P < 1.03 × 10^-6 , odds ratio 2·51) and AC (P < 1.29 × 10^-6 , odds ratio 1·63) were observed in patients with vitiligo. Interferon-γ stimulation induced lower expression of PSMB8 in peripheral blood mononuclear cells of cases compared with controls, suggesting impaired antigen processing, which was confirmed by accumulation of ubiquitinated proteins in both lesional and nonlesional skin of patients with vitiligo. Expression of proinflammatory cytokines - interleukin (IL)-6, IL-1β and IL-8 - was higher in the lesional skin. P-p38 expression was variable but correlated with the amount of ubiquitinated proteins in the lesional and nonlesional skin, suggesting that the inflammatory cytokine responses in lesional skin could be a result of both P-p38-dependent and -independent pathways.

CONCLUSIONS

The PSMB8 exon 2 SNP is significantly associated with vitiligo. Accumulation of ubiquitinated proteins in skin of cases of vitiligo suggests their aberrant processing, which may promote the development of the disease.

Cancer stem cell drugs target K-ras signaling in a stemness context

Cancer stem cells (CSCs) are considered to be responsible for treatment relapse and have therefore become a major target in cancer research. Salinomycin is the most established CSC inhibitor. However, its primary mechanistic target is still unclear, impeding the discovery of compounds with similar anti-CSC activity. Here, we show that salinomycin very specifically interferes with the activity of K-ras4B, but not H-ras, by disrupting its nanoscale membrane organization. We found that caveolae negatively regulate the sensitivity to this drug. On the basis of this novel mechanistic insight, we defined a K-ras-associated and stem cell-derived gene expression signature that predicts the drug response of cancer cells to salinomycin. Consistent with therapy resistance of CSC, 8% of tumor samples in the TCGA-database displayed our signature and were associated with a significantly higher mortality. Using our K-ras-specific screening platform, we identified several new candidate CSC drugs. Two of these, ophiobolin A and conglobatin A, possessed a similar or higher potency than salinomycin. Finally, we established that the most potent compound, ophiobolin A, exerts its K-ras4B-specific activity through inactivation of calmodulin. Our data suggest that specific interference with the K-ras4B/calmodulin interaction selectively inhibits CSC.

Cellular stress induces TRB3/USP9x-dependent Notch activation in cancer

Expression of the Notch ligand JAG1 and Notch pathway activation promote poor prognosis, basal-like breast cancer. We have recently shown that the pseudokinase Tribbles homolog 3 (TRB3) regulates JAG1 expression in this malignancy. TRB3 is a stress and metabolic sensor, and here we show that nutrient deprivation or endoplasmic reticulum stress markedly upregulate TRB3, which serves as a scaffold for the deubiquitinase USP9x. USP9x in turn stimulates JAG1 activity through two mechanisms: (1) through TRB3 deubiquitination and stabilization, and (2) through deubiquitination and activation of Mind Bomb 1, an E3 ligase required for JAG1 ubiquitination-mediated endocytosis and Notch activation. These USP9x activities are confined to the signal-sending cell of a cell pair undergoing Notch signaling. We demonstrate that USP9x is required for TRB3 upregulation and Notch activation in response to cellular stress in basal-like breast cancer cells. These data suggest that TRB3 functions as a sensor of tumor microenvironmental stress and together with USP9x induces the cell survival and tumor-promoting activities of Notch. These findings identify a novel mechanism by which cancer cells survive in their hostile environment and provide potential therapeutic targets in breast cancer.

One-step, subwavelength patterning of plasmonic gratings in metal–polymer composites

Two photon patterning of sub-wavelength resolved metallic nanostructures using single photon absorbing photo initiator.

A unique case of rituximab-related posterior reversible encephalopathy syndrome in a heart transplant recipient with posttransplant lymphoproliferative disorder

Rituximab is commonly used as a first line therapy to treat posttransplant lymphoproliferative disorders (PTLDs). It has also proved useful in the management of refractory antibody mediated graft rejection. We report an unusual case in which a heart transplant recipient being treated with rituximab for PTLD developed altered mental status, hallucinations and visual symptoms and magnetic resonance imaging (MRI) findings of symmetrical enhancement suggestive of posterior reversible leukoencephalopathy syndrome (PRES). Resolution of these clinical symptoms and radiological findings after discontinuation of therapy confirmed the diagnosis. This is the first case of PRES seen due to rituximab in a heart transplant recipient. Another unique feature of the case is the development of PRES after second cycle of rituximab as compared to prior reports in nonheart transplant patients in which the syndrome developed after first dose administration. The objective of this case report is to increase the awareness of this rare entity amongst immunocompromised transplant patients.

Regulatory and effector T cells changes in remission and resistant state of childhood nephrotic syndrome

Idiopathic minimal change disease is a disorder of T-cell dysfunction. The relative predominance of regulatory T cells (Tregs), Th1, and Th2 cells in nephrotic syndrome (NS) remains controversial. Imbalance in peripheral blood regulatory and effector T cells (Teff) are linked to cell mediated immune response and may be associated with steroid response in NS. Peripheral blood CD4 + CD25 + FoxP3 + (Tregs), CD4 + IFN-γ⁺ (Th1), and CD4 + IL-4 + (Th2) lymphocytes were analyzed in 22 steroid-sensitive NS (SSNS) patients in sustained remission, 21 steroid-resistant NS (SRNS) and 14 healthy controls. The absolute percentage values and ratio of Th1/Tregs, Th2/Tregs, and Th1/Th2 were compared between SSNS, SRNS and control subjects. The percentage of Tregs was lower in SRNS patients (P = 0.001) compared with that of SSNS and healthy control. The percentage of Th1 cells was higher in SRNS (P = 0.001) compared to that of SSNS patients; however, it was similar to healthy controls (P = 1.00). The percentage of Th2 cells in SRNS (P = 0.001) was higher as compared to SSNS and controls. The ratio of Th1/Treg cells in SRNS (P = 0.001) was higher as compared to SSNS patients and controls. The ratio of Th2/Treg was also higher in SRNS as compared to SSNS and controls. The ratio of Th1/Th2 cells in SSNS, SRNS, and healthy controls were similar. The cytokines secretion complemented the change in different T-cell subtypes in SSNS, SRNS and healthy controls. However, the IFN-γ secretion in healthy controles was low inspite of similar percentage of Th1 cells among SRNS cases. We conclude that greater ratio of Tregs compared to that Th1 and Th2 favor steroid sensitivity and reverse ratio results in to SRNS. The difference in ratio is related to pathogenesis or it can be used as marker to predict steroid responsiveness needs further evaluation.

Anconeus pedicle olecranon flip osteotomy: an approach for the fixation of complex intra-articular distal humeral fractures

In order to achieve satisfactory reduction of complex distal humeral fractures, adequate exposure of the fracture fragments and the joint surface is required. Several surgical exposures have been described for distal humeral fractures. We report our experience using the anconeus pedicle olecranon flip osteotomy approach. This involves detachment of the triceps along with a sliver of olecranon, which retains the anconeus pedicle. We report the use of this approach in ten patients (six male, four female) with a mean age of 38.4 years (28 to 51). The mean follow-up was 15 months (12 to 18) with no loss to follow-up. Elbow function was graded using the Mayo Score. The results were excellent in four patients, good in five and fair in one patient. The mean time to both fracture and osteotomy union was 10.6 weeks (8 to 12) and 7.1 weeks (6 to 8), respectively. We found this approach gave reliably good exposure for these difficult fractures enabling anatomical reduction and bicondylar plating without complications.

Diffuse pigmented villonodular synovitis (diffuse-type giant cell tumour) of the foot and ankle

Pigmented villonodular synovitis (PVNS) is a rare benign disease of the synovium of joints and tendon sheaths, which may be locally aggressive. We present 18 patients with diffuse-type PVNS of the foot and ankle followed for a mean of 5.1 years (2 to 11.8). There were seven men and 11 women, with a mean age of 42 years (18 to 73). A total of 13 patients underwent open or arthroscopic synovectomy, without post-operative radiotherapy. One had surgery at the referring unit before presentation with residual tibiotalar PVNS. The four patients who were managed non-operatively remain symptomatically controlled and under clinical and radiological surveillance. At final follow-up the mean Musculoskeletal Tumour Society score was 93.8% (95% confidence interval (CI) 85 to 100), the mean Toronto Extremity Salvage Score was 92 (95% CI 82 to 100) and the mean American Academy of Orthopaedic Surgeons foot and ankle score was 89 (95% CI 79 to 100). The lesion in the patient with residual PVNS resolved radiologically without further intervention six years after surgery. Targeted synovectomy without adjuvant radiotherapy can result in excellent outcomes, without recurrence. Asymptomatic patients can be successfully managed non-operatively. This is the first series to report clinical outcome scores for patients with diffuse-type PVNS of the foot and ankle.

The Oswestry Risk Index: an aid in the treatment of metastatic disease of the spine

The revised Tokuhashi, Tomita and modified Bauer scores are commonly used to make difficult decisions in the management of patients presenting with spinal metastases. A prospective cohort study of 199 consecutive patients presenting with spinal metastases, treated with either surgery and/or radiotherapy, was used to compare the three systems. Cox regression, Nagelkerke's R(2) and Harrell's concordance were used to compare the systems and find their best predictive items. The three systems were equally good in terms of overall prognostic performance. Their most predictive items were used to develop the Oswestry Spinal Risk Index (OSRI), which has a similar concordance, but a larger coefficient of determination than any of these three scores. A bootstrap procedure was used to internally validate this score and determine its prediction optimism. The OSRI is a simple summation of two elements: primary tumour pathology (PTP) and general condition (GC): OSRI = PTP + (2 - GC). This simple score can predict life expectancy accurately in patients presenting with spinal metastases. It will be helpful in making difficult clinical decisions without the delay of extensive investigations.