Asymmetric Histone Inheritance: Establishment, Recognition, and Execution.

The discovery of biased histone inheritance in asymmetrically dividing Drosophila melanogaster male germline stem cells demonstrates one means to produce two distinct daughter cells with identical genetic material. This inspired further studies in different systems, which revealed that this phenomenon may be a widespread mechanism to introduce cellular diversity. While the extent of asymmetric histone inheritance could vary among systems, this phenomenon is proposed to occur in three steps: first, establishment of histone asymmetry between sister chromatids during DNA replication; second, recognition of sister chromatids carrying asymmetric histone information during mitosis; and third, execution of this asymmetry in the resulting daughter cells. By compiling the current knowledge from diverse eukaryotic systems, this review comprehensively details and compares known chromatin factors, mitotic machinery components, and cell cycle regulators that may contribute to each of these three steps. Also discussed are potential mechanisms that introduce and regulate variable histone inheritance modes and how these different modes may contribute to cell fate decisions in multicellular organisms.

A single N-terminal amino acid determines the distinct roles of histones H3 and H3.3 in the Drosophila male germline stem cell lineage.

Adult stem cells undergo asymmetric cell divisions to produce 2 daughter cells with distinct cell fates: one capable of self-renewal and the other committed for differentiation. Misregulation of this delicate balance can lead to cancer and tissue degeneration. During asymmetric division of Drosophila male germline stem cells (GSCs), preexisting (old) and newly synthesized histone H3 are differentially segregated, whereas old and new histone variant H3.3 are more equally inherited. However, what underlies these distinct inheritance patterns remains unknown. Here, we report that the N-terminal tails of H3 and H3.3 are critical for their inheritance patterns, as well as GSC maintenance and proper differentiation. H3 and H3.3 differ at the 31st position in their N-termini with Alanine for H3 and Serine for H3.3. By swapping these 2 amino acids, we generated 2 mutant histones (i.e., H3A31S and H3.3S31A). Upon expressing them in the early-stage germline, we identified opposing phenotypes: overpopulation of early-stage germ cells in the H3A31S-expressing testes and significant germ cell loss in testes expressing the H3.3S31A. Asymmetric H3 inheritance is disrupted in the H3A31S-expressing GSCs, due to misincorporation of old histones between sister chromatids during DNA replication. Furthermore, H3.3S31A mutation accelerates old histone turnover in the GSCs. Finally, using a modified Chromatin Immunocleavage assay on early-stage germ cells, we found that H3A31S has enhanced occupancy at promoters and transcription starting sites compared with H3, while H3.3S31A is more enriched at transcriptionally silent intergenic regions compared to H3.3. Overall, these results suggest that the 31st amino acids for both H3 and H3.3 are critical for their proper genomic occupancy and function. Together, our findings indicate a critical role for the different amino acid composition of the N-terminal tails between H3 and H3.3 in an endogenous stem cell lineage and provide insights into the importance of proper histone inheritance in specifying cell fates and regulating cellular differentiation.

Histone locus regulation by the Drosophila dosage compensation adaptor protein CLAMP.

The conserved histone locus body (HLB) assembles prior to zygotic gene activation early during development and concentrates factors into a nuclear domain of coordinated histone gene regulation. Although HLBs form specifically at replication-dependent histone loci, the cis and trans factors that target HLB components to histone genes remained unknown. Here we report that conserved GA repeat cis elements within the bidirectional histone3-histone4 promoter direct HLB formation in Drosophila In addition, the CLAMP (chromatin-linked adaptor for male-specific lethal [MSL] proteins) zinc finger protein binds these GA repeat motifs, increases chromatin accessibility, enhances histone gene transcription, and promotes HLB formation. We demonstrated previously that CLAMP also promotes the formation of another domain of coordinated gene regulation: the dosage-compensated male X chromosome. Therefore, CLAMP binding to GA repeat motifs promotes the formation of two distinct domains of coordinated gene activation located at different places in the genome.

Integrating humanities in healthcare: a mixed-methods study for development and testing of a humanities curriculum for front-line health workers in Karachi, Pakistan.

Lady health workers (LHWs) provide lifesaving maternal and child health services to >60% of Pakistan's population but are poorly compensated and overburdened. Moreover, LHWs' training does not incorporate efforts to nurture attributes necessary for equitable and holistic healthcare delivery. We developed an interdisciplinary humanities curriculum, deriving its strengths from local art and literature, to enhance character virtues such as empathy and connection, interpersonal communication skills, compassion and purpose among LHWs. We tested the curriculum's feasibility and impact to enhance character strengths among LHWs.We conducted a multiphase mixed-methods pilot study in two towns of Karachi, Pakistan. We delivered the humanities curriculum to 48 LHWs via 12 weekly sessions, from 15 June to 2 September 2021. We developed a multiconstruct character strength survey that was administered preintervention and postintervention to assess the impact of the training. In-depth interviews were conducted with a subset of randomly selected participating LHWs.Of 48 participants, 47 (98%) completed the training, and 34 (71%) attended all 12 sessions. Scores for all outcomes increased between baseline and endline, with highest increase (10.0 points, 95% CI 2.91 to 17.02; p=0.006) observed for empathy/connection. LHWs provided positive feedback on the training and its impact in terms of improving their confidence, empathy/connection and ability to communicate with clients. Participants also rated the sessions highly in terms of the content's usefulness (mean: 9.7/10; SD: 0.16), the success of the sessions (mean: 9.7/10; SD: 0.17) and overall satisfaction (mean: 8.2/10; SD: 3.3).A humanities-based training for front-line health workers is a feasible intervention with demonstrated impact of nurturing key character strengths, notably empathy/connection and interpersonal communication. Evidence from this study highlights the value of a humanities-based training, grounded in local literature and cultural values, that can ultimately translate to improved well-being of LHWs thus contributing to better health outcomes among the populations they serve.

Predicting Positive Youth Development from Self-Regulation and Purpose in Early Adolescence.

A Positive Youth Development (PYD) perspective emphasizes adolescents' potential for healthy, successful development. Researchers have introduced a variety of constructs that may promote PYD. For example, Intentional Self-Regulation (ISR) enables youth to seek out and use resources in the environment; purpose can help youth navigate and overcome obstacles. We examine connections between ISR, purpose and two PYD outcomes: confidence and connection. Data come from 763 Scottish youth (ages 12-14). We estimated fixed-effects regression models predicting confidence and connection from both ISR and purpose, confirming outcomes were independently associated with one or both predictors. Our findings are especially salient to the field of youth purpose, linking purpose with specific PYD outcomes.

Rippled ß-Sheet Formation by an Amyloid-ß Fragment Indicates Expanded Scope of Sequence Space for Enantiomeric ß-Sheet Peptide Coassembly.

In 1953, Pauling and Corey predicted that enantiomeric ß-sheet peptides would coassemble into so-called "rippled" ß-sheets, in which the ß-sheets would consist of alternating l- and d-peptides. To date, this phenomenon has been investigated primarily with amphipathic peptide sequences composed of alternating hydrophilic and hydrophobic amino acid residues. Here, we show that enantiomers of a fragment of the amyloid-ß (Aß) peptide that does not follow this sequence pattern, amyloid-ß (16-22), readily coassembles into rippled ß-sheets. Equimolar mixtures of enantiomeric amyloid-ß (16-22) peptides assemble into supramolecular structures that exhibit distinct morphologies from those observed by self-assembly of the single enantiomer pleated ß-sheet fibrils. Formation of rippled ß-sheets composed of alternating l- and d-amyloid-ß (16-22) is confirmed by isotope-edited infrared spectroscopy and solid-state NMR spectroscopy. Sedimentation analysis reveals that rippled ß-sheet formation by l- and d-amyloid-ß (16-22) is energetically favorable relative to self-assembly into corresponding pleated ß-sheets. This work illustrates that coassembly of enantiomeric ß-sheet peptides into rippled ß-sheets is not limited to peptides with alternating hydrophobic/hydrophilic sequence patterns, but that a broader range of sequence space is available for the design and preparation of rippled ß-sheet materials.

[Day Surgery for Endoscopic Inguinal Hernia Repair]. / Minimalinvasive Leistenhernienchirurgie ­ TEP ambulant.

BACKGROUND: Whereas international guidelines recommend day surgery for endoscopic inguinal hernia repair, this approach is still controversial in Germany. In the light of international guidelines and at the request of patients, we have established total extraperitoneal patch plastic (TEP) surgery in the outpatient setting in our hospital. METHODS: A retrospective analysis of all unilateral TEP procedures carried out between January 2013 and December 2015 in our outpatient surgery, focused on postoperative complications, conversion to admission and rate of recurrence. Patient satisfaction with the outpatient setting was evaluated by telephone interview. RESULTS: In the 3 year period analysed, 164 patients were admitted for day surgery. Outpatient surgery was carried out in 152 patients, whereas 12 patients had to be admitted overnight due to circulatory disturbance, pain or bleeding. A total of 102 patients could be questioned for follow-up. Hematoma developed in 9 patients, and recurrence of hernia in 3 patients. Infections or seromas were not described or detected. 88 patients were very satisfied with the outpatient procedure, and 82 patients would clearly prefer day surgery again. CONCLUSIONS: Unilateral endoscopic hernia repair is safe and can be performed in the outpatient setting without increased risk. Satisfaction and acceptance by the patients is high. There is a dramatic difference between day surgery and inpatient procedure in the costs for hernia repair and this is one of the major reasons why outpatient endoscopic hernia repair is still rare in Germany.

Pink verrucous plaque in a man with systemic mastocytosis.

Porokeratosis ptychotropica is a rare and commonly misdiagnosed subtype of porokeratosis involving the body folds. We present a 53-year-old man with systemic mastocytosis who presented with a pruritic, verrucous plaque in the gluteal fold that showed multiple cornoid lamellae on histopathologic evaluation, diagnostic of porokeratosis ptychotropica. Various treatments have been reported, including topical corticosteroids, retinoids, vitamin D analogs, calcineurin inhibitors, imiquimod, phototherapy, cryotherapy, or ablative laser therapy, but recurrences are common.

Balancing hydrophobicity and sequence pattern to influence self-assembly of amphipathic peptides.

Amphipathic peptides with alternating polar and nonpolar amino acid sequences efficiently self-assemble into functional ß-sheet fibrils as long as the nonpolar residues have sufficient hydrophobicity. For example, the Ac-(FKFE)2 -NH2 peptide rapidly self-assembles into ß-sheet bilayer nanoribbons, while Ac-(AKAE)2 -NH2 fails to self-assemble under similar conditions due to the significantly reduced hydrophobicity and ß-sheet propensity of Ala relative to Phe. Herein, we systematically explore the effect of substituting only two of the four Ala residues at various positions in the Ac-(AKAE)2 -NH2 peptide with amino acids of increasing hydrophobicity, ß-sheet potential, and surface area (including Phe, 1-naphthylalanine (1-Nal), 2-naphthylalanine (2-Nal), cyclohexylalanine (Cha), and pentafluorophenylalanine (F5 -Phe)) on the self-assembly propensity of the resulting sequences. It was found that double Phe variants, regardless of the position of substitution, failed to self-assemble under the conditions used in this study. In contrast, all double 1-Nal and 2-Nal variants readily self-assembled, albeit at differing rates depending on the substitution patterns. To determine whether this was due to hydrophobicity or side chain surface area, we also prepared double Cha and F5 -Phe variant peptides (both side chain groups are more hydrophobic than Phe). Each of these variants also underwent effective self-assembly, with the aromatic F5 -Phe peptides doing so with greater efficiency. These findings provide insight into the role of amino acid hydrophobicity and sequence pattern on self-assembly proclivity of amphipathic peptides and on how targeted substitutions of nonpolar residues in these sequences can be exploited to tune the characteristics of the resulting self-assembled materials.

The essential Drosophila CLAMP protein differentially regulates non-coding roX RNAs in male and females.

Heterogametic species require chromosome-wide gene regulation to compensate for differences in sex chromosome gene dosage. In Drosophila melanogaster, transcriptional output from the single male X-chromosome is equalized to that of XX females by recruitment of the male-specific lethal (MSL) complex, which increases transcript levels of active genes 2-fold. The MSL complex contains several protein components and two non-coding RNA on the X ( roX) RNAs that are transcriptionally activated by the MSL complex. We previously discovered that targeting of the MSL complex to the X-chromosome is dependent on the chromatin-linked adapter for MSL proteins (CLAMP) zinc finger protein. To better understand CLAMP function, we used the CRISPR/Cas9 genome editing system to generate a frameshift mutation in the clamp gene that eliminates expression of the CLAMP protein. We found that clamp null females die at the third instar larval stage, while almost all clamp null males die at earlier developmental stages. Moreover, we found that in clamp null females roX gene expression is activated, whereas in clamp null males roX gene expression is reduced. Therefore, CLAMP regulates roX abundance in a sex-specific manner. Our results provide new insights into sex-specific gene regulation by an essential transcription factor.

Patient Reported Improvement in Quality of Life Associated With Successful Laser Hair Reduction at Hemodialysis Site With 1064-nm Nd:YAG Laser.

Laser hair reduction is a well-established modality for a wide range of medical indications. Laser hair reduction can be beneficial for hemodialysis patients who undergo repeated adhesive tape application and removal at their hemodialysis site during hemodialysis sessions. There is a paucity of published literature on efficacious laser hair removal treatments for hemodialysis patients. Herein, we present a case of a 50-year-old male (Fitzpatrick III) with end-stage renal disease on hemodialysis, who achieved successful laser hair reduction at his hemodialysis vascular access site with five sessions of a neodymium:yttrium-aluminium-garnet (Nd:YAG) laser (1064 nm) to improve his quality of life by reducing the hair burden at the adhesive tape site application. We recommend providing this safe and effective hair reduction treatment option for hemodialysis patients given the decreased quality of life associated with end stage renal disease and hemodialysis. J Drugs Dermatol. 2018;17(7):794-795.

Treatment of recalcitrant atopic dermatitis with the oral Janus kinase inhibitor tofacitinib citrate.

BACKGROUND: Treatment of moderate to severe atopic dermatitis (AD) is often inadequate. OBJECTIVE: We sought to evaluate the efficacy of the oral Janus kinase inhibitor tofacitinib citrate in the treatment of moderate to severe AD. METHODS: Six consecutive patients with moderate to severe AD who had failed standard treatment were treated with tofacitinib citrate. Response to treatment was assessed using the Scoring of AD index. RESULTS: Decreased body surface area involvement of dermatitis and decreased erythema, edema/papulation, lichenification, and excoriation were observed in all patients. The Scoring of AD index decreased by 66.6% from 36.5 to 12.2 (P < .05) during 8 to 29 weeks of treatment. There were no adverse events. LIMITATIONS: Small sample size, lack of placebo control group, and the possibility of bias are limitations. CONCLUSION: The oral Janus kinase inhibitor tofacitinib citrate may be beneficial in the treatment of moderate to severe AD.

Congenital nevi versus metastatic melanoma in a newborn to a mother with malignant melanoma - diagnosis supported by sex chromosome analysis and Imaging Mass Spectrometry.

A 37-year-old pregnant woman presented with a 2-cm irregular reddish nodule on her left upper arm during pregnancy. A biopsy from the lesion showed a 2.2-mm thick malignant melanoma with intravascular invasion, 25 mitosis/mm(2) and no ulceration. Following induction of labor, the patient underwent re-excision with sentinel lymph node biopsy. This showed no residual melanoma and no lymph node metastasis. The newborn boy had multiple pigmented lesions on the trunk, some of which were large and irregular. Two were biopsied and histologic examination showed dense dermal proliferation of medium sized melanocytes with multiple mitotic figures and no maturation with their descent into the dermis, raising suspicion of transplacental metastases. Examination of the placenta failed to show metastatic lesions. Multiplex polymerase chain reaction (PCR)-based genotyping, including testing for amelogenin locus for sex chromosome determination, demonstrated the presence of Y chromosome material in the melanocytes of the newborn's lesions excluding maternal origin. A diagnosis of congenital nevi was rendered. Subsequently, Imaging Mass Spectrometric analysis of the mother's lesion showed proteomic signature expression indicative of malignant melanoma, whereas the two lesions in the newborn showed changes indicative of nevi. This case demonstrates the utility of genotyping and Mass Spectrometry analysis in this challenging clinical scenario.

Optical coherence tomography imaging of erythematotelangiectatic rosacea during treatment with brimonidine topical gel 0.33%: a potential method for treatment outcome assessment.

BACKGROUND: Patients with moderate to severe rosacea often seek treatment to reduce erythema and vascular markings. Few studies have looked at the effectiveness of the novel treatment, brimonidine topical gel 0.33%, trademark name Mirvaso®, in the treatment of rosacea. We report the use of optical coherence tomography (OCT) scanning to monitor the effectiveness of Mirvaso® on in vivo skin. OCT is a non-invasive optical imaging technique that can provide high-resolution imaging of vessel and cellular morphology. OCT may be useful as a pre-treatment assessment tool for identifying possible morphologic features in the skin that may serve as outcome predictors. OCT may also serve as a monitoring tool in the treatment of rosacea. OBJECTIVE: To examine and describe how OCT skin morphology changes when exposed to brimonidine topical gel 0.33% in the treatment of erythematotelangiectatic rosacea. METHODS: Normal in vivo telangiectasias and erythematous patches and papules were examined prior to treatment clinically, dermatoscopically, and through OCT scans. Brimonidine topical gel 0.33% was applied to the face and OCT images were acquired at defined time intervals: baseline; immediately (<5 minutes) after application; 4 hours after application; and after 2 weeks' once daily application. OCT morphology was then described. RESULTS: OCT imaging showed an increase in the mean gray value (MGV), a measure of dermal reflectivity, corresponding to a decrease in dermal edema. MGV measurements for the nasal telangiectasia were: baseline, MGV 10,471 (standard deviation [SD] 6,847); immediate, MGV 15,634 (SD 8,983); after 4 hours, MGV 16,357 (SD 7,647); and after 2 weeks, MGV 15,505 (SD 6,870). MGV measurements for the chin erythema were: baseline, MGV 8,850 (SD 4,969); immediate, MGV 10,799 (SD 5,266); after 4 hours, MGV 12,419 (SD 6,714); and after 2 weeks, MGV 13,395 (SD 6,170). No significant change in vessel lumen diameter was appreciated. Vessel lumen diameter for the facial papule ranged from 0.13 mm at baseline, 0.09 mm immediately after treatment, 0.09 mm after 4 hours, and 0.11 mm after 2 weeks. CONCLUSIONS: OCT scanning showed a decrease in the dermal hyporeflectivity of the dermis consistent with a decrease in dermal edema. The OCT scans obtained did not show any significant change in vessel lumen diameter. These results may reflect an increase in vascular tone, which can be attributable to the clinical improvement and decreased erythema noted in the patient. This technology could potentially be used for the non-invasive in vivo monitoring of other topical treatments.

[Trauma surgical relevance of bite injuries by animals and humans]. / Unfallchirurgisch Relevantes zu Bissverletzungen von Mensch und Tier.

Bite injuries require differentiated treatment due to the deeply inoculated polymicrobial pathogen spectrum, possible concomitant injuries and pronounced soft tissue damage. Dog bites are the most common bite injuries but are less complicated to heal than human and cat bites. The location of the bite greatly depends on the age and the size of the bite victim as well as the type of bite perpetrator. In every case detection of the pathogen should be carried out to provide the best possible adapted treatment in the event of an exacerbation. The primary antibiotic treatment should be empirical with amoxicillin + clavulanic acid or ampicillin + sulbactam and, if necessary, adjusted according to the antibiogram. Depending on the findings, surgical treatment includes excision of the bite canal and a customized wound debridement. It is important to check the vaccination status of those involved and if indicated, to carry out postexposure prophylaxis for tetanus and rabies.

Hybrid Amyloid Quantum Dot Nano-Bio Assemblies to Probe Neuroinflammatory Damage.

Various oligomeric species of amyloid-beta have been proposed to play different immunogenic roles in the cellular pathology of Alzheimer's Disease. The dynamic interconversion between various amyloid oligomers and fibrillar assemblies makes it difficult to elucidate the role each potential aggregation state may play in driving neuroinflammatory and neurodegenerative pathology. The ability to identify the amyloid species that are key and essential drivers of these pathological hallmarks of Alzheimer's Disease is of fundamental importance for also understanding downstream events including tauopathies that mediate neuroinflammation with neurologic deficits. Here, we report the design and construction of a quantum dot mimetic for larger spherical oligomeric amyloid species as an "endogenously" fluorescent proxy for this cytotoxic assembly of amyloid to investigate its role in inducing inflammatory and stress response states in neuronal and glial cell types. The design parameters and construction protocol developed here may be adapted for developing quantum dot nano-bio assemblies for other biological systems of interest, particularly neurodegenerative diseases involving other protein aggregates.

Sex-specific splicing occurs genome-wide during early Drosophila embryogenesis.

Sex-specific splicing is an essential process that regulates sex determination and drives sexual dimorphism. Yet, how early in development widespread sex-specific transcript diversity occurs was unknown because it had yet to be studied at the genome-wide level. We use the powerful Drosophila model to show that widespread sex-specific transcript diversity occurs early in development, concurrent with zygotic genome activation. We also present a new pipeline called time2Splice to quantify changes in alternative splicing over time. Furthermore, we determine that one of the consequences of losing an essential maternally deposited pioneer factor called CLAMP (chromatin-linked adapter for MSL proteins) is altered sex-specific splicing of genes involved in diverse biological processes that drive development. Overall, we show that sex-specific differences in transcript diversity exist even at the earliest stages of development..

Hybrid Amyloid Quantum Dot Nanoassemblies to Probe Neuroinflammatory Damage.

Various oligomeric species of amyloid-beta have been proposed to play different immunogenic roles in the cellular pathology of Alzheimer's Disease. However, investigating the role of a homogenous single oligomeric species has been difficult due to highly dynamic oligomerization and fibril formation kinetics that convert between many species. Here we report the design and construction of a quantum dot mimetic for larger spherical oligomeric amyloid species as an "endogenously" fluorescent proxy for this cytotoxic species to investigate its role in inducing inflammatory and stress response states in neuronal and glial cell types.

A Multi-Stakeholder Perspective on Factors Affecting Successful Transition to Adulthood for Youth with Severe Emotional Disturbances.

This study elicited the perspectives of youth, caregivers, service providers and researchers to explore how communities can best support the transition to adulthood for youth ages 16-21 with mental health and functional impairments, who are at risk of disconnecting from health and human services. Framed by Relational Systems Evaluation (RSE) and Positive Youth Development (PYD), our study demonstrates the importance of engagement with youth experts. Group Concept Mapping (GCM), a collaborative multiphase mixed-methods approach, was used as a systematic process for participants to make meaning of qualitative data using multidimensional scaling and hierarchical cluster analysis (Kane and Trochim in Concept mapping for planning and evaluation, Sage Publications Inc., Thousand Oaks, 2007). Across all participant groups, Life Skills were perceived as highly important and highly feasible for a successful transition to adulthood. However, Positive Social Support & Connectedness were viewed as less important and less feasible by all groups. When examined closely, youth perspectives differed from caregiver and provider perspectives in the factors they prioritized and deemed feasible. Our findings have implications for community mental health services and positive youth development program practitioners.