Spindle morphology changes between meiosis and mitosis driven by CK2 regulation of the Ran pathway.

The transition from meiotic divisions in the oocyte to embryonic mitoses is a critical step in animal development. Despite negligible changes to cell size and shape, following fertilization the small, barrel-shaped meiotic spindle is replaced by a large zygotic spindle that nucleates abundant astral microtubules at spindle poles. To probe underlying mechanisms, we applied a drug screening approach using eggs and found that inhibition of Casein Kinase 2 (CK2) caused a shift from meiotic to mitotic-like spindle morphology with nucleation of robust astral microtubules, an effect reproduced in cytoplasmic extracts prepared from eggs.

Pediatric Patch Testing at Mayo Clinic Between 2016 and 2020.

Allergic contact Dermatitis (ACD) is a common condition within the pediatric population. Patch testing is an important way to identify relevant allergens. To provide an update of the common contact allergens seen in children based on patch testing data at our institution from 2016 to 2020.

Trends in Patch Testing With the Mayo Clinic Standard Series, 2017-2021.

Patch testing to a standard series is used to identify culprit allergens in patients with contact dermatitis. The reaction rates evolve over time based on trends in cutaneous exposures by the general population. The aim of this study was to analyze the patch test results of the Mayo Clinic standard series in patients tested from 2017 to 2021.

Cutaneous involvement in VEXAS syndrome: clinical and histopathologic findings.

Background: VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is an autoinflammatory disease with frequent cutaneous manifestations.

Methods: We conducted a retrospective study of all patients with genetically confirmed VEXAS syndrome seen at our institution. Available clinical photographs and skin biopsy slides were reviewed.

Reactive granulomatous dermatitis as a clinically relevant and unifying term: a retrospective review of clinical features, associated systemic diseases, histopathology and treatment for a series of 65 patients at Mayo Clinic.

Background: Reactive granulomatous dermatitis (RGD) is an umbrella term used to describe interstitial granulomatous dermatitis (IGD), palisaded neutrophilic and granulomatous dermatitis (PNGD), and interstitial granulomatous drug eruption (IGDR).

Objective: The aim of this study was to describe systemic associations of RGD, explore possible associations between histopathologic findings and systemic RGD associations and determine clinical relevance of RGD subtypes.

Methods: We retrospectively studied clinical and histopathologic characteristics of patients with RGD from 1990 through 2020.

Nuclear size and shape control.

The nucleus displays a wide range of sizes and shapes in different species and cell types, yet its size scaling and many of the key structural constituents that determine its shape are highly conserved. In this review, we discuss the cellular properties and processes that contribute to nuclear size and shape control, drawing examples from across eukaryotes and highlighting conserved themes and pathways. We then outline physiological roles that have been uncovered for specific nuclear morphologies and disease pathologies associated with aberrant nuclear morphology.

The spectrum of pediatric scarring alopecia: A retrospective review of 27 patients seen at Mayo Clinic.

Background/objective: There are few studies examining pediatric scarring alopecia. The objective of this study is to characterize the clinicopathologic findings, comorbidities, and treatment outcomes of pediatric patients with scarring alopecia.

Methods: Retrospective review of patients under age 18 diagnosed with scarring alopecia at Mayo Clinic from 01/01/1992 through 02/05/2019.

Lichen planopilaris in men: a retrospective clinicopathologic study of 19 patients.

Background: Lichen planopilaris (LPP) is a scarring alopecia rarely described in men.

Objective: To investigate the clinical and histopathologic features of LPP in men.

Methods: We performed a retrospective cohort study of male patients with LPP seen at Mayo Clinic between 1992 and 2016.

Characteristics of exceptional responders to autologous stem cell transplantation in multiple myeloma.

Autologous stem cell transplantation (ASCT) is an important treatment modality in multiple myeloma (MM). However, relapse following ASCT is considered almost inevitable. This study aimed to characterize exceptional responders to ASCT, defined as progression-free survival (PFS) >8 years in the absence of maintenance therapy.

Lichen Planopilaris in Women: A Retrospective Review of 232 Women Seen at Mayo Clinic From 1992 to 2016.

Objective: To characterize the clinicopathologic findings, comorbidities, and treatment outcomes of women with lichen planopilaris (LPP).

Method: In this retrospective review of women with LPP at Mayo Clinic from 1992 to 2016, we searched for scarring alopecia in all female patients aged 1 to 100 years from January 1, 1992, through December 31, 2016. Men were excluded from this study to more accurately determine the association of hormonal factors in LPP pathogenesis.

The Final Patch Test Read: Day 5 or Day >7?

Background: A major question in patch testing is when to perform the final reading. Our current standard practice is to place patches on day 1, remove them on day 3, and perform readings on days 3 and 5. For certain allergens, another reading is performed sometime from days 7 to 14≥.

A homeostatic mechanism rapidly corrects aberrant nucleocytoplasmic ratios maintaining nuclear size in fission yeast.

Nuclear size scales with cell size across a wide range of cell types. The mechanism by which this scaling is maintained in growing cells remains unclear. Here, we investigate the mechanism of nuclear size homeostasis in the simple eukaryote fission yeast, by monitoring the recovery of aberrant nuclear volume to cell volume (N/C) ratios following perturbation.

Unravelling nuclear size control.

Correlation between nuclear and cell size, the nucleocytoplasmic ratio, is a cellular phenomenon that has been reported throughout eukaryotes for more than a century but the mechanisms that achieve it are not well understood. Here, we review work that has shed light on the cellular processes involved in nuclear size control. These studies have implicated nucleocytoplasmic transport, LINC complexes, RNA processing, regulation of nuclear envelope expansion and partitioning of importin α in nuclear size control, moving us closer to a mechanistic understanding of this phenomenon.

Nuclear membrane protein Lem2 regulates nuclear size through membrane flow.

The size of the membrane-bound nucleus scales with cell size in a wide range of cell types but the mechanisms determining overall nuclear size remain largely unknown. Here we investigate the role of fission yeast inner nuclear membrane proteins in determining nuclear size, and propose that the Lap2-Emerin-Man1 domain protein Lem2 acts as a barrier to membrane flow between the nucleus and other parts of the cellular membrane system. Lem2 deletion increases membrane flow into and out of the nuclear envelope in response to changes in membrane synthesis and nucleocytoplasmic transport, altering nuclear size.

A systematic genetic screen identifies essential factors involved in nuclear size control.

Nuclear size correlates with cell size, but the mechanism by which this scaling is achieved is not known. Here we screen fission yeast gene deletion mutants to identify essential factors involved in this process. Our screen has identified 25 essential factors that alter nuclear size, and our analysis has implicated RNA processing and LINC complexes in nuclear size control.

A systematic genomic screen implicates nucleocytoplasmic transport and membrane growth in nuclear size control.

How cells control the overall size and growth of membrane-bound organelles is an important unanswered question of cell biology. Fission yeast cells maintain a nuclear size proportional to cellular size, resulting in a constant ratio between nuclear and cellular volumes (N/C ratio). We have conducted a genome-wide visual screen of a fission yeast gene deletion collection for viable mutants altered in their N/C ratio, and have found that defects in both nucleocytoplasmic mRNA transport and lipid synthesis alter the N/C ratio.

Determination of nitroimidazole residues in aquaculture tissue using ultra high performance liquid chromatography coupled to tandem mass spectrometry.

An UHPLC-MS/MS method was developed for the quantitative confirmatory analysis of residues of nitroimidazole drugs (dimetridazole, ipronidazole, metronidazole, ornidazole and ronidazole) and their corresponding hydroxy metabolites (HMMNI, ipronidazile-OH and metronidazole-OH) in aquaculture tissue. Samples were extracted by shaking in acetonitrile, water, MgSO4 and NaCl before being defatted with n-hexane pre-saturated with acetonitrile and concentrated under nitrogen. Nitroimidazole residues were determined by UHPLC-MS/MS operating in positive electrospray ionisation mode using a reversed phase BEH C18 column.