Studies of immunoglobulin receptors and human proximal tubular cells

Glomerulonephritis (GN) is a major cause of progressive chronic renal failure (CRF) and accounts for less than 20% in the UK of patients requiring dialysis and transplantation. There are many forms of GN, of which IgA nephropathy (IgAN) is the most common, affecting up to 2% of the adult population. GN is characterised by irreversible and progressive glomerular and tubulointerstitial fibrosis, reduction in glomerular filtration rate (GFR), and retention of uremic toxins. The rate of progression of GN is increased by various clinical factors including hypertension, and the quantity and specificity of proteinuria. Although albuminuria is most widely studied, higher molecular weight proteins such as immunoglobulins (Ig) are more associated with progression of renal disease. In this thesis I have explored the hypothesis that an interaction between tubular cells and filtered Ig/immuno complex (Ig/IC) may involve specific cellular receptors, and thus provide a novel mechanism for the initiation of tubular injury and fibrosis. Deposition of Ig and IC is seen in renal diseases such as membranous glomerulonephritis, and IgAN. Ig/IC are regarded as responsible for the initiation of glomerular injury in these diseases. However, whether Ig/IC contribute directly to tubular injury is unknown. We previously identified a novel IgA receptor, the Fcα/μ receptor (Fcα/μR), in mesangial cells which may contribute to IgAN. This receptor binds both IgA and IgM but not IgG. I hypothesised that Ig and IC, filtered at the glomerulus, may act on Ig receptors in human proximal tubular epithelial cells (PTEC) and may play a direct pathophysiological role in the development of interstitial fibrosis. Specifically, that filtered IgA may bind to the Fcα/μR in IgAN. The activation of Ig receptors may stimulate tubular cells to alter cell proliferation and extracellular matrix formation (e.g fibronectin (FN)), which are pathophysiological characteristics of tubulointerstitial fibrosis in GN. I studied primary and immortalised human PTEC using qualitative RT-PCR and quantitative real-time PCR (qRT-PCR) for expression of candidate Ig receptors. I investigated the expression of Ig receptors and their regulation by cytokines (e.g. IFN-γ, TGF-β1 and IL-1α) known to be implicated in GN. The receptors studied include the polymeric immunoglobulin receptor (pIgR), the neonatal receptor (FcRn), the Fcα/μR, the classical IgG receptors (FcγR1, γIIa, γIIb, γIII and the related FcR γ-chain) and the classical IgA receptor (FcαR). None of the classical IgG receptors were expressed by PTEC, nor was the classical IgA receptor. However, the FcRn, pIgR and the Fcα/μR were expressed. Gene expression of these receptors was investigated under cytokine regulation. IFN-γ, IL-1α and TGF-β1 had no effect on FcRn gene expression. The expression of the pIgR gene was up-regulated by IFN-γ and the Fcα/μR transcript level was up-regulated by IL-1α and IFN-γ but down-regulated by TGF-β1. Expression of Fcα/µR protein by tubular cells was confirmed by western blot analysis by using specific Fcα/µR monoclonal antibody. Immunohistochemistry confirmed the expression of Fcα/µR by PTEC in both normal and diseased kidney and that IgG, IgA and IgM binding varies in parallel with gene expression of related Fc receptors. This binding was associated with increased FN production (assessed by ELISA) and reduced the proliferation of PTEC, demonstrated by [3H]-thymidine uptake assay. I screened the ability of PTEC to release cytokines under normal conditions and confirmed this by ProteoPlex cytokine array. Among these cytokines there was no significant effect of Ig/IC on IL-6, IL-8 and GM-CSF released by PTEC, and this was confirmed by specific ELISA for each individual cytokine. The phosphotyrosine/phospho-ERK signalling pathway was unaffected by Ig/IC; however, IgM was able to activate the phospho-ERK pathway. These results suggest that there might be alternative signalling pathways activated by Ig/IC in PTEC. I then studied the effect of calcineurin inhibitor immunosuppressive drugs as a model of tubular toxicity, and statins as immunomodulatory drugs, reputed to protect renal function and known to have immunomodulatory effects. I hypothesised that immunosuppressant agents/statins either alone or in combination with LPS might affect Ig receptors expression, cytokine release, FN production and proliferation by PTEC. My results inferred that immunosuppressive agents alone have a non-inflammatory response on Ig receptor expression. However, in combination with LPS, the study drugs showed a slight inhibitory effect on the expression of the pIgR on PTEC at the highest concentration only. There was no significant effect of immunosuppressant agents alone or in combination with LPS on IL-6, IL8 and GM-CSF released by PTEC. Cyclosporine, FK506 and sirolimus were shown to inhibit both the production of FN and the growth of PTEC at high doses, thereby exerting an antiproliferative effect. Both simvastatin and fluvastatin inhibited LPS induced production of IL-6, IL-8 and GM-CSF, FN and proliferation in a dose-dependent manner. 1 micromolar simvastatin/fluvastatin was associated with a 35% reduction in unstimulated FN production, a 51% reduction in proliferation, and reduced production of IL-6 (58%), IL-8 (65%) and GM-CSF (57%). The expression of Ig receptors was increased in a dose-dependent manner in PTEC treated with statins alone or in combination with LPS. In conclusion, the expression of tubular FcRn, pIgR and Fcα/µR by PTEC is regulated by proinflammatory cytokines. The binding of IgA and IgM, possibly through the Fcα/µR, by PTEC may contribute to immune-mediated nephropathy. The FN production and the proliferation suggest that Ig/IC binding may contribute to the pathophysiology of IC-mediated renal disease. The ability of immunosuppressant agents to reduce FN production, proliferation, and pIgR expression by PTEC may offer potential new strategies for the prevention and treatment of nephrotoxicity, proteinuria and chronic allograft nephropathy (CAN). The inhibitory effect of statins alone or in combination with LPS on FN production, proliferation and cytokines released suggest that statin therapy may have potential benefit in interstitial nephritis and fibrosis. On other hand, statins alone or in combination with LPS increased the expression of Ig receptors by PTEC. This thesis shows that the novel human Fcα/µR in PTEC may play an important role in the immune mechanisms involved in the tubular response during renal injury associated with tubular Ig/IC deposits in renal disease

Service Quality Gap Model as a Predictor of Customer Satisfaction among People with Disabilities in Vocational Rehabilitation Centers

The purpose of this study was to investigate the Service Quality Gap Model as a predictor of customer satisfaction among people with disabilities in Vocational rehabilitation centers. A quantitative survey research method was employed for this study. The independent variable is Service Quality Gap Model, while the dependent variable is customer satisfaction. The data were analyzed with Pearson correlation and multiple regression. Multiple regression was used. Participants were 150 individuals with disabilities (females, n= 10, 6.66%, and males 140, 93.33%). Findings show significant correlations between service quality gap model subscales and customer satisfaction. When put together, the independent variables (tangibility, reliability, responsiveness, assurance, and empathy) yielded a coefficient of multiple regression (R) of 0.664 and a multiple correlation square of 0.621. Each of the five independent variables made significant individual contributions to the prediction of customer satisfaction

Preliminary investigation into the bioacoustics of Cicindela spp. (Coleoptera: Cicindelidae)

Initial investigations into bioacoustics of Cicindela spp. (Cicindelidae: Coleoptera) were designed to establish the systematic usefulness of acoustic variables, the possibility of auditory communication, and lay foundations for future studies of acoustic behaviour of the family. Groups were statistically compared using variables derived from photomicrographs of plectra as well as oscillograms and frequency spectrograms of recorded stridulations. The noise-like character of tiger beetle stridulations necessitated a new method of comparing stridulation frequency spectra averages: discrete frequencies from the peak-pick procedure of a Nicolet lOOn mini-analyzer were compared. The plectrum consists of a field of posteriorly oriented spines located ventrally at the elytral apex. Plectra characters show trends towards sexual dimorphism and are related to body size and habitat. Among plectra/elytra characters, plectrum field size and shape show the most promise as taxonomic characters. Stridulations, produced by a two-stroke cycle, consist of 1 to 9 low intensity buzzes (modes), signal mean 49.0 dB at 3 cm (audio range), with an average duration of 0.65 seconds. Cicindelids emit signals of broadband frequency, between approximately 20 Hz and 50 kHz, with significant energy in both audio and ultrasonic ranges. Although stridulations, for the most part, showed no sexual differentiation, species differences were quite apparent. Signal timing and amplitude parameters were based on body size, plectrum structure, phylogeny, and habitat. Stridulation frequency was based on phylogeny and may be related to specific stridulatory behaviour and structure of the pars stridens. Acoustic characters appear to show limited promise as useful taxonomic characters. Temperature at stridulation does not appear to affect stridulatory rates. Evidence suggests that stridulatatory behavior is linked to specific optimal temperatures. Tiger beetles stridulate spontaneously or when subjected to heated, lighted, or crowded conditions. In contrast to most coleopterans, tiger beetles do not stridulate in response to mechanical stimulation, a behavior associated with a disturbance function. This togther with a relatively ordered stridulatory structure, and initial behavioral observations suggest a territorial and/or calling function of cicindelid stridulations

The Impact of Fluctuating Oil Revenues on Economic Growth: New Evidence from Saudi Arabia

The fluctuations that occur in oil revenues are among the main reasons that lead to disruptions in economies that depend on them. Hence, this study aims to find out the impact of fluctuation in oil revenues on the economic growth for the Kingdom of Saudi Arabia during the period from 2000 to 2020. The study showed that the relationship between the fluctuations of oil revenues and economic growth may be either a positive relationship, and this relationship is confirmed in oil-exporting countries, which is the most common relationship, or a negative relationship, and this relationship is confirmed in oil-importing countries, which is the exceptional case. In order to find out the direction of this relationship in the Kingdom, the study used the application of the Autoregressive Distributed Lag Model (ARDL) model. The study concluded that the fluctuations of oil revenues has significant positive effects on the economic growth of the Kingdom of Saudi Arabia in the short and long terms. Therefore, the study recommends the need for the Kingdom to exploit these revenues in areas that achieve a return for it at the present time and in the future, in a manner that guarantees the diversification of the economy and its non-disruption when any disturbances occur in these revenues, as well as keeping part of these revenues in its sovereign fund to guarantee the rights of future generations

Cherenkov Glass Detectors for Gamma and Neutron Detection

Cherenkov detectors have been developed and used in several fields since the discovery of Cherenkov radiation. They do have several advantages compared with other detector types, such as low noise due to the low-energy threshold of Cherenkov radiation, and short decay constant (on the order of picoseconds). However, the light yield of Cherenkov detectors is low. Only several hundreds of Cherenkov photons can be generated per MeV. The objective of this work is to manufacture and test Cherenkov glass detectors for detection of high energy gammas and neutrons. 60Co was used for gamma ray measurements, and PuBe source was used for neutrons measurements. Gd2O3 was used as an activator to capture thermal neutrons. As a result of this capture, gamma rays were generated and interacted with Cherenkov detectors to produce Cherenkov light. The focus was to improve the light output of Cherenkov detectors by adding high Z materials and implementing Wavelength Shifting (WLS) fibers inside the glass samples. Increasing the Z number of the glass samples increases the interaction probability, and without the WLS materials, most Cherenkov photons are likely to be absorbed within the glass sample before they could reach the photon sensor. WLS fibers do not directly increase the number of Cherenkov photons, but they can reduce the energy of Cherenkov photons and direct them towards the photon sensor. A Geant4 simulation toolkit was used to create a detailed model, and to understand and confirm that the measured observations were reasonable

Is there a relationship between periodontal conditions and number of medications among the elderly?

Objective: To investigate possible correlations of clinical attachment level and pocket depth with number of medications in elderly individuals.Methods: Intra-oral examinations for 139 patients visiting Tufts dental clinic were done. Periodontal assessments were performed with a manual UNC-15 periodontal probe to measure probing depth (PD) and clinical attachment level (CAL) at 6 sites. Complete lists of patients’ medications were obtained during the examinations. Statistical analysis involved Kruskal-Wallis, chi square and multivariate logistic regression analyses.Results: Age and health status attained statistical significance (p< 0.05), in contingency table analysis with number of medications. Number of medications had an effect on CAL: increased attachment loss was observed when 4 or more medications were being taken by the patient. Number of medications did not have any effect on periodontal PD. In multivariate logistic regression analysis, 6 or more medications had a higher risk of attachment loss (>3mm) when compared to the no-medication group, in crude OR (1.20, 95% CI:0.22-6.64), and age adjusted (OR=1.16, 95% CI:0.21-6.45), but not with the multivariate model (OR=0.71, 95% CI:0.11-4.39).Conclusion: CAL seems to be more sensitive to the number of medications taken, when compared to PD. However, it is not possible to discriminate at exactly what number of drug combinations the breakdown in CAL will happen. We need to do further analysis, including more subjects, to understand the possible synergistic mechanisms for different drug and periodontal responses.Keywords: periodontal disease, medications, elderly, clinical attachment level, probing dept

Konstribusi Persepsi Siswa Keluarga Harmonis dan Guru Sebagai Konselor Terhadap Perkembangan Moral

Penelitian bertujuan untuk mengetahui besarnya konstribusi persepsi keluarga yang harmonis dan Guru sebagai konselor terhadap perkembangan moral siswa di kelas VII SMP Negeri 1 Pancur Batu. Peneliti menetapkan sampel penelitian sebanyak 30 orang. Angket digunakan sebagai Instrumen penelitian untuk menjaring data penelitian pada variabel Keluarga Harmonis (X1), Guru sebagai Konselor (X2) dan Perkembangan Moral Siswa (Y). Teknik analisis yang digunakan untuk menguji hipotesis menggunakan rumus statistik parametrik karena hasil perhitungan memenuhi hasil normalitas, kelinearan dan keberartian. Hasil penelitian menyimpulkan terdapat konstribusi Keluarga Harmonis terhadap Perkembangan Moral siswa pada jenjang nihil ry1= 0,551. Terdapat Konstribusi Guru sebagai Konselor terhadap Perkembangan Moral siswa pada jenjang nihil ry2=0,539 dan terdapat konstribusi secara bersama-sama anatara Keluarga Harmonis dan Guru sebagai Konselor terhadap Perkembangan Moral Siswa dengan koefisien ganda R2= 0,426. Jika anggota keluarga merasa bahagia yang ditandai oleh berkurangnya ketegangan, kekecewaan dan menerima seluruh keadaan dan keberadaan dirinya yang meliputi aspek fisik, mental dan sosial, maka dari itu sangat mempengaruhi perkembangan moral seorang siswa. Keluarga yang harmonis adalah keluarga yang rukun berbahagia, tertib, disiplin, saling menghormati dan memiliki etos kerja yang baik. Dari keluarga harmonis memberi pengaruh pada perkembangan Moral Siswa

Clinical, microbiological and immunological short, medium and long-term effects of different strains of probiotics as an adjunct to non-surgical periodontal therapy in patients with periodontitis. Systematic review with meta-analysis

Introduction/objectives: Probiotics have been proposed as adjuncts to non-surgical periodontal therapy (NSPT), however, the effect of their use remains unclear. The aim of this systematic review and meta-analysis was to analyze the evidence regarding the use of probiotics as an adjunct to NSPT in patients with periodontitis at a clinical, microbiological and immunological level. Data/sources: A comprehensive search to identify clinical studies investigating the use of probiotics as an adjunct to NSPT in patients treated for periodontitis was performed. The data were grouped according to probiotic strain, frequency, form and duration of the probiotic intake. Study selection: A total of 25 articles were included, all articles analysed clinical parameters, 10 included also microbiological findings and only 4 had immunological findings. The difference in probing depth (PD) between the test and the control group was statistically significant in favour of the test group when the probiotics were in the form of lozenges, administered twice a day and when the strain was L. reuteri. In terms of Clinical Attachment Level (CAL) gain the difference was statistically significant in the short and in the medium term but not in the long term. Due to the heterogeneity of the data, it was not possible to compare trough a meta analysis the immunological and the microbiological findings that were therefore analysed only descriptively. Conclusions: The use of probiotics as an adjunct to NSPT in patients with periodontitis appears to provide additional clinical benefits that depend on the duration, the frequency, the form and the strain of probiotic used. Clinical significance: This review not only shows data on the efficacy of probiotics in non-surgical periodontal therapy, but provides important information on their effects over time and which forms of probiotic administration might be most clinically useful

In and out of the minor groove: Interaction of an AT-rich DNA with the drug CD27

The DNA of several pathogens is very rich in AT base pairs. Typical examples include the malaria parasite Plasmodium falciparum and the causative agents of trichomoniasis and trypanosomiases. This fact has prompted studies of drugs which interact with the minor groove of DNA, some of which are used in medical practice. Previous studies have been performed almost exclusively with the AATT sequence. New features should be uncovered through the study of different DNA sequences. In this paper, the crystal structure of the complex of the DNA duplex d(AAAATTTT)2 with the dicationic drug 4,4'-bis(imidazolinylamino) diphenylamine (CD27) is presented. The drug binds to the minor groove of DNA as expected, but it shows two new features that have not previously been described: (i) the drugs protrude from the DNA and interact with neighbouring molecules, so that they may act as cross-linking agents, and (ii) the drugs completely cover the whole minor groove of DNA and displace bound water. Thus, they may prevent the access to DNA of proteins such as AT-hook proteins. These features are also expected for other minor-groove binding drugs when associated with all-AT DNA. These findings allow a better understanding of this family of compounds and will help in the development of new, more effective drugs. New data on the biological interaction of CD27 with the causative agent of trichomoniasis, Trichomonas vaginalis, are also reported.Postprint (published version

Trypanosoma brucei aquaglyceroporin 2 is a high-affinity transporter for pentamidine and melaminophenyl arsenic drugs and the main genetic determinant of resistance to these drugs.

OBJECTIVES: Trypanosoma brucei drug transporters include the TbAT1/P2 aminopurine transporter and the high-affinity pentamidine transporter (HAPT1), but the genetic identity of HAPT1 is unknown. We recently reported that loss of T. brucei aquaglyceroporin 2 (TbAQP2) caused melarsoprol/pentamidine cross-resistance (MPXR) in these parasites and the current study aims to delineate the mechanism by which this occurs. METHODS: The TbAQP2 loci of isogenic pairs of drug-susceptible and MPXR strains of T. brucei subspecies were sequenced. Drug susceptibility profiles of trypanosome strains were correlated with expression of mutated TbAQP2 alleles. Pentamidine transport was studied in T. brucei subspecies expressing TbAQP2 variants. RESULTS: All MPXR strains examined contained TbAQP2 deletions or rearrangements, regardless of whether the strains were originally adapted in vitro or in vivo to arsenicals or to pentamidine. The MPXR strains and AQP2 knockout strains had lost HAPT1 activity. Reintroduction of TbAQP2 in MPXR trypanosomes restored susceptibility to the drugs and reinstated HAPT1 activity, but did not change the activity of TbAT1/P2. Expression of TbAQP2 sensitized Leishmania mexicana promastigotes 40-fold to pentamidine and >1000-fold to melaminophenyl arsenicals and induced a high-affinity pentamidine transport activity indistinguishable from HAPT1 by Km and inhibitor profile. Grafting the TbAQP2 selectivity filter amino acid residues onto a chimeric allele of AQP2 and AQP3 partly restored susceptibility to pentamidine and an arsenical. CONCLUSIONS: TbAQP2 mediates high-affinity uptake of pentamidine and melaminophenyl arsenicals in trypanosomes and TbAQP2 encodes the previously reported HAPT1 activity. This finding establishes TbAQP2 as an important drug transporter