Enchondral cartilage rests collagen-induced autoimmunity: a possible pathogenetic mechanism of otosclerosis

Collagen autoimmunity has been suggested as one etiologic mechanism to otosclerosis. Although substantial studies relating this disease to collagen autoimmunity have been reported, a basic understanding of the pathogenic mechanism involved is lacking. Some otosclerosis patients have a high level of antibody to type II collagen. In addition, complement and antibody were deposited in the stapes from otosclerosis patients. Furthermore, the otic capsule and stapes have been found to contain type II collagen by immunohistologic studies and biochemical analysis. Otospongiosis-like lesions have also been produced in rats by immunizing them with type II collagen. This finding led us to postulate a hypothesis of an autoimmunity to type II collagen as an etiopathogenesis of this illness. Our initial hypothesis has been updated to incorporate new findings in the field of cell biology. The role of interleukin 1, osteoclasts, osteoblasts, bone resorption, and other factors such as minor collagens, calcitonin, vitamin D, parathyroid hormone, collagenase, and prostaglandins are incorporated in this updated hypothesis.     

Engineering the follicle microenvironment

In vitro ovarian follicle culture provides a tool to investigate folliculogenesis, and may one day provide women with fertility-preservation options. The application of tissue engineering principles to ovarian follicle maturation may enable the creation of controllable microenvironments that will coordinate the growth of the multiple cellular compartments within the follicle. Three-dimensional culture systems can preserve follicle architecture, thereby maintaining critical cell-cell and cell-matrix signaling lost in traditional two-dimensional attached follicle culture systems. Maintaining the follicular structure while manipulating the biochemical and mechanical environment will enable the development of controllable systems to investigate the fundamental biological principles underlying follicle maturation. This review describes recent advances in ovarian follicle culture, and highlights the tissue engineering principles that may be applied to follicle culture, with the ultimate objective of germline preservation for females facing premature infertility.     

Improving diversity in study participation: Patient perspectives on barriers,racial differences and the role of communities

IntroductionThe lack of racial/ethnic diversity in research potentially limits the generalizability of findings to a broader population, highlighting the need for greater diversity and inclusion in clinical research. Qualitative research (i.e., focus groups) was conducted to identify (i) the potential motivators and barriers to study participation across different races and ethnicities; (ii) preferred delivery of education and information to support healthcare decision‐making and the role of the community.MethodsPatient focus groups were conducted with 26 participants from the sponsor''s Patient Engagement Research Councils selected through subjective sampling. Recruitment prioritized adequate representation across different race/ethnic groups. Participation was voluntary and participants underwent a confidential interview process before selection. Narrative analysis was used to identify themes and draw insights from interactions. Experienced research specialists identified emerging concepts, and these were tested against new observations. The frequency of each concept was examined to understand its importance.ResultsBased on self‐selected race/ethnicity, participants were divided into five focus groups (Groups: African American/Black: 2; Hispanic/Latino, Asian American, and white: 1 each) and were asked to share their experiences/opinions regarding the stated objectives. Barriers to study participation included: limited awareness of opportunities to participate in research, fears about changes in standard therapy, breaking cultural norms/stigma, religion‐related concerns and mistrust of clinical research. Participants identified the importance of transparency by pharmaceutical companies and other entities to build trust and partnership and cited key roles that communities can play. The perceptions of the African American group regarding diversity/inclusion in research studies appeared to be different from other groups; a lack of trust in healthcare providers, concerns about historical instances of research abuse and the importance of prayer were cited.ConclusionThis study provided insights into barriers to study participation, and also highlighted the need for pharmaceutical companies and other entities to authentically engage in strategies that build trust within communities to enhance recruitment among diverse populations.Patient or Public ContributionThe data collected in the present study was provided by the participants in the focus groups.     

Potentiation of arsenic neurotoxicity by folate deprivation: Protective role of S-adenosyl methionine

Folate deficiency contributes to a variety of age-related neurological and psychological disorders including amyotrophic lateral sclerosis (ALS). The environmental neurotoxin arsenic has recently been linked with decreased neurofilament (NF) content in peripheral nerve. We examined herein, whether or not folate deprivation potentiated the impact of arsenic on NF dynamics. Arsenic inhibited translocation of NFs into axonal neurites in culture and increased perikaryal NF phosphoepitopes. Folate deprivation potentiated the impact of arsenic on these phenomena. Supplementation with S-adenosyl methionine (SAM) attenuated the impact of folate deprivation on arsenic neurotoxicity, consistent with the decrease in SAM following folate deprivation and the requirement for SAM-mediated methylation for arsenic bioelimination. These findings demonstrate how key nutritional deficiencies can potentiate the impact of enrivonmental neurotoxins.     

Extracellular truncations of h beta c, the common signaling subunit for interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-5, lead to ligand-independent activation

The hypothesis that extracellular truncation of the common receptor subunit for interleukin-3 (IL-3), granulocyte-macrophage colony- stimulating factor, and IL-5 (h beta c) can lead to ligand-independent activation was tested by infecting factor-dependent hematopoietic cell lines with retroviruses encoding truncated forms of h beta c. A truncation, resembling that in v-Mpl, and retaining 45 h beta c-derived extracellular residues, led to constitutive activation in the murine myeloid cell line, FDC-P1. However, infection of cells with retrovirus encoding a more severely truncated receptor, retaining only 7 h beta c- derived extracellular residues, did not confer factor independence on these cells. These experiments show that truncation activates the receptor and define a 37-amino acid segment of h beta c (H395-A431) which contains two motifs conserved throughout the cytokine receptor superfamily (consensus Y/H XX R/Q VR and WSXWS), as essential for factor-independent signaling. The mechanism of activation was also investigated in less severe truncations. A receptor that retains the entire membrane-proximal domain (domain 4) also conferred factor independent growth on FDC-P1 cells; however, a retrovirus encoding a truncated form of h beta c having two intact membrane proximal domains did not have this ability, suggesting that domain 3 may have an inhibitory role in h beta c. The ability of these receptors to confer factor independence was cell specific as demonstrated by their inability to confer factor-independent growth when introduced into the murine IL-3-dependent pro-B cell line BaF-B03. These results are consistent with a model in which activation requires unmasking of an interactive receptor surface in domain 4 and association with a myeloid- specific receptor or accessory component. We suggest that in the absence of ligand intramolecular interactions prevent inappropriate signaling.     

Preventative ibandronate treatment has the most beneficial effect on the microstructure of bone in experimental tumor osteolysis

We investigated the effect of ibandronate on three-dimensional (3-D) microstructure and bone mass in experimentally induced tumor osteolysis. Walker carcinosarcoma cells were implanted into the left femur of female rats that received 26-day ibandronate pretreatment followed by continued therapy or ibandronate posttreatment only. A tumor-only group received isotonic saline. At endpoint, excised femurs were scanned using microcomputed tomography (μCT) to assess bone volume density, bone mineral content, trabecular number/thickness, and separation for cortical plus trabecular bone or trabecular bone alone. Compared with the nonimplanted right femur, bone volume and surface density and trabecular number and thickness were reduced in the distal left femur following tumor cell implantation. μCT analysis revealed greater cortical and trabecular bone mineral content in the preventative and interventional (pre-post tumor) ibandronate group, and the interventional (post-tumor) ibandronate group, versus the tumor-only group. Bone volume density was significantly higher in pre-post and post-tumor groups compared to the tumor-only group. After preventative and interventional ibandronate, bone volume density and trabecular thickness were 13% and 60% greater, respectively, than in the post-tumor treatment group. 3-D μCT images confirmed microstructural changes. We conclude that combined interventional and preventative ibandronate preserves bone strength and integrity more than intervention alone.     

Descriptive and longitudinal observations on the relationship of borderline personality disorder and bipolar disorder

OBJECTIVE: The purpose of this study was to test whether borderline personality disorder is a variant of bipolar disorder by examining the rates of co-occurrence in both disorders, the effects of co-occurrence on a longitudinal course, and whether the presence of either disorder confers the risk for new onsets of the other. METHOD: A prospective repeated-measures design with reliable independent diagnostic measures and 4 years of follow-up was used to assess 196 patients with borderline personality disorder and 433 patients with other personality disorders. RESULTS: Patients with borderline personality disorder had a significantly higher co-occurrence of bipolar disorder (19.4%) than did patients with other personality disorders. However, this co-occurrence did not appear to affect the subsequent course of borderline personality disorder. Although only 8.2% of the borderline personality disorder patients developed new onsets of bipolar disorder, this rate was higher than in patients with other personality disorders. Patients with other personality disorders with co-occurring bipolar disorder generally had more new onsets of borderline personality disorder (25%) than did patients with other personality disorders without co-occurring bipolar disorder (10%). CONCLUSIONS: A modest association between borderline personality disorder and bipolar disorder is reported.