Paricalcitol reduces oxidative stress and inflammation in hemodialysis patients

Background

Treatment with selective vitamin D receptor activators such as paricalcitol have been shown to exert an anti-inflammatory effect in patients on hemodialysis, in addition to their action on mineral metabolism and independently of parathyroid hormone (PTH) levels. The objective of this study was to evaluate the additional antioxidant capacity of paricalcitol in a clinical setting.

Methods

The study included 19 patients with renal disease on hemodialysis, of whom peripheral blood was obtained for analysis at baseline and three months after starting intravenous paricalcitol treatment. The following oxidizing and inflammatory markers were quantified: malondialdehyde (MDA), nitrites and carbonyl groups, indoleamine 2,3-dioxygenase (IDO), tumor necrosis factor alfa (TNF-α), interleukin-6 (IL-6), interleukin-18 (IL-18) and C-reactive protein (CRP). Of the antioxidants and anti-inflammatory markers, superoxide dismutase (SOD), catalase, reduced glutathione (GSH), thioredoxin, and interleukin-10 (IL-10) levels were obtained.

Results

Baseline levels of oxidation markers MDA, nitric oxide and protein carbonyl groups significantly decreased after three months on paricalcitol treatment, while levels of GSH, thioredoxin, catalase and SOD activity significantly increased. After paricalcitol treatment, levels of the inflammatory markers CRP, TNF-α, IL-6 and IL-18 were significantly reduced in serum and the level of anti-inflammatory cytokine IL-10 was increased.

Conclusions

In renal patients undergoing hemodialysis, paricalcitol treatment significantly reduces oxidative stress and inflammation, two well known factors leading to cardiovascular damage.

     

Radiographic detection and characteristic patterns of residual excess cement associated with cement-retained implant restorations: a clinical report

Residual excess cement (REC) is a common complication of cement-retained prostheses and has been linked to periimplant disease. Removal of the cement residue may result in resolution of the issue if addressed early in the disease process. However, this is dependent upon the ability to locate and adequately remove the foreign material. This series of patient scenarios describes the ability to detect REC by using dental radiography. Characteristics related to cements and flow patterns specific to implants are addressed.     

Chairing the internal medicine department- analysis of current state and future trends in Israel

Background

Professional skills and academic records of the highest degree are essential requirements for the chairmanship of internal medicine departments. Whether the new generation and future successors of Israeli chairmen is endowed with these attributes is not known.

Purpose

To determine whether there is a lack of future suitable successors for the current heads of internal medicine departments in Israel and to compare the demographic, academic and professional characteristics of the older and newer generations of department heads.

Methods

An online anonymous questionnaire was nationally distributed during 2016 to all active heads of internal medicine departments in Israel (n?=?101). First round was followed by two runs of personal phone calls to promote participation.

Results

Sixty-seven (67%) of chairmen responded. The vast majority of current chairs of internal medicine departments are males (N?=?59, 88%) over 50 years of age (N?=?58, 86%) with established academic background with lecturer degree or higher (N?=?57, 85%).Only 19 (28%) of current heads assigned a future successor. Comparison of chairmen who did and did not assigned successors demonstrated that assignment of successors was associated with higher academic status (P?<?0.02) and longer chairmanship (p?<?0.01) but not with mean age of current chairmen (p?<?0.08). Nevertheless, most assignments (55%) were done by chairmen in the 61 to 67 years age group. As compared to current chairmen, the designated successors have lesser academic status (p?<?0.01) and are characterized by a higher female prevalence (P?<?0.03).

Conclusions

Significant demographic, professional and academic differences exist between the current chairs of internal medicine departments in Israeli hospitals and their future successors. This underscores the need for reassessment of the availability and requirements of this crucial position.

     

Role of amino acids 261-418 in proteolytic cleavage of the extracellular region of the human thyrotropin receptor.

Previous in vivo cross-linking studies of TSH to the recombinant TSH receptor revealed that the receptor exists at least in part as a single chain glycoprotein of approximately about 100 kilodaltons (kDa), with intramolecular disulfide bonds. TSH also binds to a 54-kDa amino-terminal fragment of the TSH receptor (cleaved up-stream of amino acid residue 317). In the present study in order to better understand the structure of the TSH receptor, we covalently cross-linked radiolabeled TSH to six TSH-LH receptor extracellular region chimeras and the wild-type TSH receptor expressed on Chinese hamster ovary cells in vivo. In these chimeras, different regions of the TSH receptor were substituted with the homologous regions of the LH receptor. When analyzed under nonreducing conditions by polyacrylamide gel electrophoresis, the TSH-cross-linked products were similar to all TSH-LH receptor chimeras and the wild-type receptor. In contrast, differences among the receptors were noted when the TSH-cross-linked products were examined under reducing conditions. With the exception of two chimeras, as noted previously with the wild-type receptor, two TSH-cross-linked products were observed, representing TSH cross-linked to a holoreceptor of about approximately 100 kDa and a fragment of the receptor of about approximately 54 kDa. However, in the two chimeras in which both domains D and E (amino acids 261-418) of the TSH receptor were substituted, only the holoreceptor and not the smaller fragment was detected. Substitution of domains ABC (amino acids 1-260) did not prevent proteolytic cleavage of the TSH receptor. In conclusion, amino acids 261-418 are necessary for proteolytic cleavage of the extracellular region of the human TSH receptor.     

Genetic variation in the 22q11 locus and susceptibility to schizophrenia

An increased prevalence of microdeletions at the 22q11 locus has been reported in samples of patients with schizophrenia. 22q11 microdeletions represent the highest known genetic risk factor for the development of schizophrenia, second only to that of the monozygotic cotwin of an affected individual or the offspring of two schizophrenic parents. It is therefore clear that a schizophrenia susceptibility locus maps to chromosome 22q11. In light of evidence for suggestive linkage for schizophrenia in this region, we hypothesized that, whereas deletions of chromosome 22q11 may account for only a small proportion of schizophrenia cases in the general population (up to approximately 2%), nondeletion variants of individual genes within the 22q11 region may make a larger contribution to susceptibility to schizophrenia in the wider population. By studying a dense collection of markers (average one single nucleotide polymorphism20 kb over 1.5 Mb) in the vicinity of the 22q11 locus, in both family- and population-based samples, we present here results consistent with this assumption. Moreover, our results are consistent with contribution from more than one gene to the strikingly increased disease risk associated with this locus. Finer-scale haplotype mapping has identified two subregions within the 1.5-Mb locus that are likely to harbor candidate schizophrenia susceptibility genes.     

Pre-B acute lymphoblastic leukemia cells may induce T-cell anergy to alloantigen

Even if neoplastic cells express tumor associated antigens they still may fail to function as antigen presenting cells (APC) if they lack expression of one or more molecules critical for the induction of productive immunity. These cellular defects can be repaired by physiologic activation, transfection, or fusion of tumor cells with professional APC. Although such defects can be repaired, antitumor specific T cells may still fail to respond in vivo if they may have been tolerized. Here, human pre-B cell acute lymphoblastic leukemia (pre-B ALL) was used as a model to determine if primary human tumor cells can function as alloantigen presenting cells (alloAPC) or alternatively whether they induce anergy. In the present report, we show that pre-B cell ALL express alloantigen and adhesion molecules but uniformly lack B7-1 (CD80) and only a subset express B7-2 (CD86). Pre-B ALL cells are inefficient or ineffective alloAPC and those cases that lack expression of B7-1 and B7-2 also induce alloantigen specific T- cell unresponsiveness. Under these circumstances, T-cell unresponsiveness could be prevented by physiologic activation of tumor cells via CD40, cross-linking CD28, or signaling through the common gamma chain of the interleukin-2 receptor on T cells. Taken together, these results suggest that pre-B ALL may be incapable of inducing clinically significant T-cell-mediated antileukemia responses. This defect may be not only due to their inability to function as APC, but also due to their potential to induce tolerance. Attempts to induce clinically significant antitumor immune responses may then require not only mechanisms to repair the antigen presenting capacity of the tumor cells, but also reversal of tolerance.     

New treatments for headache

Migraine and cluster headache are primary headache disorders commonly encountered in clinical practice. Despite the profound disability caused by these primary headache disorders, available acute and preventive treatment options are limited. Recent understanding of headache pathophysiology has led to the development of new drug formulations and novel drug targets that are extremely promising. This article will highlight several of the new treatments that are currently under investigation including novel delivery mechanisms of already existing medications, calcitonin gene-related peptide (CGRP) receptor antagonists, antibodies to CGRP and its receptor, serotonin receptor agonists, transient receptor potential vanilloid receptor modulators, orexin receptor antagonists, glial cell modulators, and neuromodulation. If data is supportive, these therapies will be welcome additions to the headache specialist’s armamentarium.     

The Headache Pipeline: Excitement and Uncertainty

There are many new treatment options available for migraine and more are coming. Three calcitonin gene-related peptide (CGRP) antagonist monoclonal antibodies have been approved and a 4th is due in early 2020. Small molecule CGRP receptor-blocking oral compounds, both for acute care and prevention, are also coming. Four neurostimulators are available, with others on the way. New acute treatments coming soon include the 5HT_1F agonist lasmiditan, a zolmitriptan intradermal micro-needle patch, and a nasal mist sumatriptan with a permeability enhancer. Farther out, three novel dihydroergotamine delivery systems, and a liquid-filled capsule of celecoxib show early promise. A new, safer form of methysergide is in the works, as is a longer-duration onabotulinumtoxinA. As always with new products, questions regarding safety, tolerability, cost, and insurance coverage will need to be addressed. Despite these concerns and uncertainties, a robust headache treatment pipeline is good for patients who are not satisfied with the results of their treatment and/or cannot tolerate existing treatments.