The journey of a generation: advances and promises in the study of primordial germ cell migration.

The germline provides the genetic and non-genetic information that passes from one generation to the next. Given this important role in species propagation, egg and sperm precursors, called primordial germ cells (PGCs), are one of the first cell types specified during embryogenesis. In fact, PGCs form well before the bipotential somatic gonad is specified. This common feature of germline development necessitates that PGCs migrate through many tissues to reach the somatic gonad. During their journey, PGCs must respond to select environmental cues while ignoring others in a dynamically developing embryo. The complex multi-tissue, combinatorial nature of PGC migration is an excellent model for understanding how cells navigate complex environments in vivo. Here, we discuss recent findings on the migratory path, the somatic cells that shepherd PGCs, the guidance cues somatic cells provide, and the PGC response to these cues to reach the gonad and establish the germline pool for future generations. We end by discussing the fate of wayward PGCs that fail to reach the gonad in diverse species. Collectively, this field is poised to yield important insights into emerging reproductive technologies.

Impact of altered mental status on antibiotic prescribing and outcomes in hospitalized patients presenting with pyuria.

BACKGROUND: Pyuria is nonspecific and may result in over-treatment of asymptomatic bacteriuria (ASB). The Infectious Diseases Society of America recommends against antibiotic treatment of ASB for most patients including those presenting with altered mental status (AMS). Close observation is recommended over treatment to avoid missing alternative causes of AMS and overuse of antibiotics resulting in adverse events and resistance. OBJECTIVES: The purpose of this study was to evaluate patient outcomes associated with antibiotic treatment of pyuria in patients presenting with AMS at hospital admission without specific urinary tract infection (UTI) symptoms. The primary objective was to compare 30-day readmission rates of patients with pyuria and AMS treated with antibiotics (AMS+Tx) versus those who were not treated (AMS-NoTx). Secondary outcomes included identifying risk factors for antibiotic treatment, comparing alternative diagnoses for AMS, and comparing safety outcomes. METHODS: This retrospective cohort study evaluated adult patients with AMS and pyuria (10 WBC/hpf) admitted between February 1, 2020 and October 1, 2021, in a 350-bed community teaching hospital. Patients with documented urinary symptoms were excluded. Additional exclusion criteria included admission to critical care, history of renal transplant, urological surgery, coinfections, pregnancy, and neutropenia. RESULTS: Two-hundred patients were included (AMS+Tx, n = 162; AMS-NoTx, n=38). There was no difference in 30-day hospital readmission rate for AMS between groups (AMS+Tx 16.7% vs AMS-NoTx 23.7%, P = 0.311). An alternative diagnosis of AMS occurred more frequently when antibiotics were withheld (AMS+Tx 66% vs. AMS-NoTx 86.8%, P = 0.012). Urinalyses showing bacteria (odds ratio 2.52; 95% CI, 1.11-5.731) and positive urine culture (OR 3.36; 95% CI, 1.46-7.711) were associated with antibiotic prescribing. CONCLUSIONS: Inappropriate antibiotic use is common among hospitalized patients presenting with AMS and pyuria; however, treatment of asymptomatic pyuria did not decrease rates of subsequent readmission for AMS or retreatment of symptomatic UTI. Patients who were monitored off antibiotics had higher rates of alternative AMS diagnosis.

Juvenile hormones direct primordial germ cell migration to the embryonic gonad.

Germ cells are essential to sexual reproduction. Across the animal kingdom, extracellular signaling isoprenoids, such as retinoic acids (RAs) in vertebrates and juvenile hormones (JHs) in invertebrates, facilitate multiple processes in reproduction. Here we investigated the role of these potent signaling molecules in embryonic germ cell development, using JHs in Drosophila melanogaster as a model system. In contrast to their established endocrine roles during larval and adult germline development, we found that JH signaling acts locally during embryonic development. Using an in vivo biosensor, we observed active JH signaling first within and near primordial germ cells (PGCs) as they migrate to the developing gonad. Through in vivo and in vitro assays, we determined that JHs are both necessary and sufficient for PGC migration. Analysis into the mechanisms of this newly uncovered paracrine JH function revealed that PGC migration was compromised when JHs were decreased or increased, suggesting that specific titers or spatiotemporal JH dynamics are required for robust PGC colonization of the gonad. Compromised PGC migration can impair fertility and cause germ cell tumors in many species, including humans. In mammals, retinoids have many roles in development and reproduction. We found that like JHs in Drosophila, RA was sufficient to impact mouse PGC migration in vitro. Together, our study reveals a previously unanticipated role of isoprenoids as local effectors of pre-gonadal PGC development and suggests a broadly shared mechanism in PGC migration.

Organ-specific immunity: A tissue analysis framework for investigating local immune responses to SARS-CoV-2.

Local immune activation at mucosal surfaces, mediated by mucosal lymphoid tissues, is vital for effective immune responses against pathogens. While pathogens like severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can spread to multiple organs, patients with coronavirus disease 2019 (COVID-19) primarily experience inflammation and damage in their lungs. To investigate this apparent organ-specific immune response, we develop an analytical framework that recognizes the significance of mucosal lymphoid tissues. This framework combines histology, immunofluorescence, spatial transcript profiling, and mathematical modeling to identify cellular and gene expression differences between the lymphoid tissues of the lung and the gut and predict the determinants of those differences. Our findings indicate that mucosal lymphoid tissues are pivotal in organ-specific immune response to SARS-CoV-2, mediating local inflammation and tissue damage and contributing to immune dysfunction. The framework developed here has potential utility in the study of long COVID and may streamline biomarker discovery and treatment design for diseases with differential pathologies at the organ level.

Implementation of antimicrobial stewardship weekend coverage within a community hospital with a PGY-2 infectious diseases pharmacy resident.

OBJECTIVES: The goal of this study was to describe the impact of expanding inpatient ASP weekend coverage with a newly established infectious diseases postgraduate second-year (ID-PGY-2) pharmacy residency program through quantification of inpatient ASP interventions. Secondary end points included comparing weekend stewardship activities before and after an ID-PGY-2 incorporated staffing model shift based on intervention quantity, type, and impact to weekends. METHODS: This retrospective cohort study was conducted evaluating weekend Antimicrobial stewardship program (ASP) interventions documented within the electronic health record between July 1, 2021, and December 31, 2022. Groups included a single clinical pharmacist, 2 new postgraduate first-year (PGY-1) pharmacy residents, 2 experienced PGY-1 pharmacy residents, and an ID-PGY-2 responsible only for ASP coverage. RESULTS: Eight weekends of interventions were collected per group. The median (interquartile range [IQR]) number of ASP interventions per weekend increased during ID-PGY-2 resident weekends (34 [28.75-35]) compared to a clinical pharmacist alone (5 [4-10], P < 0.001), and both new (2.5 [1.25-4], P < 0.001) and experienced (6 [3.5-10.5], P < 0.001) PGY-1 resident groups. The ID-PGY-2 resident initiated statistically significantly more interventions per protocol and interventions requiring communication with providers. The acceptance rate for interventions made via communication was similar between groups (ID-PGY-2 86.3% vs. clinical pharmacist 87.7% vs. new PGY-1 100% vs. experienced PGY-1 90.5%, P = 0.541). CONCLUSION: Expansion of ASP services to include weekend clinical coverage with an ID-PGY-2 pharmacy resident significantly increased weekend ASP interventions in a community teaching hospital.

Three-day ceftriaxone versus longer durations of therapy for inpatient treatment of uncomplicated urinary tract infection.

Current guidelines do not address a recommended duration of parenteral therapy for uncomplicated urinary tract infection (uUTI) treatment in the inpatient setting. We compared a 3-day course of ceftriaxone with longer antibiotic durations for inpatients with a uUTI. Our findings indicate that a 3-day course of ceftriaxone was as efficacious as longer antibiotic courses.

High frequency properties of a planar ion trap fabricated on a chip.

We report on the measurement of the high frequency properties of a planar Penning ion trap fabricated on a chip. Two types of chips have been measured: the first manufactured by photolithographic metal deposition on a p-doped silicon substrate and the second made with printed circuit board technology on an alumina substrate. The input capacitances and the admittances between the different trap's electrodes play a critical role in the electronic detection of the trapped particles. The measured input capacitances of the photolithographic chip amount to 65-76 pF, while the values for the printed circuit board chips are in the range of 3-5 pF. The latter are small enough for detecting non-destructively a single trapped electron or ion with a specifically tuned LC resonator. We have also measured a mutual capacitance of ∼85 fF between two of the trap's electrodes in the printed circuit board chip. This enables the detection of single, or very few, trapped particles in a broader range of charge-to-mass ratios with a simple resistor on the chip. We provide analytic calculations of the capacitances and discuss their origin and possible further reduction.

Antipseudomonal Versus Narrow-Spectrum Agents for the Treatment of Community-Onset Intra-abdominal Infections.

BACKGROUND: Antipseudomonal antibiotics are often used to treat community-acquired intra-abdominal infections (CA-IAIs) despite common causative pathogens being susceptible to more narrow-spectrum agents. The purpose of this study was to compare treatment-associated complications in adult patients treated for CA-IAI with antipseudomonal versus narrow-spectrum regimens. METHODS: This retrospective cohort study included patients >18 years admitted for CA-IAI treated with antibiotics. The primary objective of this study was to compare 90-day treatment-associated complications between patients treated empirically with antipseudomonal versus narrow-spectrum regimens. Secondary objectives were to compare infection and treatment characteristics along with patient outcomes. Subgroup analyses were planned to compare outcomes of patients with low-risk and high-risk CA-IAIs and patients requiring surgical intervention versus medically managed. RESULTS: A total of 350 patients were included: antipseudomonal, n=204; narrow spectrum, n=146. There were no differences in 90-day treatment-associated complications between groups (antipseudomonal 15.1% vs narrow spectrum 11.3%, P=.296). In addition, no differences were observed in hospital length of stay, 90-day readmission, Clostridiodes difficile, or mortality. In multivariate logistic regression, treatment with a narrow-spectrum regimen (odds ratio [OR], 0.75; 95% confidence interval, 0.39-1.45) was not independently associated with the primary outcome. No differences were observed in 90-day treatment-associated complications for (1) patients with low-risk (antipseudomonal 15% vs narrow spectrum 9.6%, P=.154) or high-risk CA-IAI (antipseudomonal 15.8% vs narrow spectrum 22.2%, P=.588) or (2) those who were surgically (antipseudomonal 8.5% vs narrow spectrum 9.2%, P=.877) or medically managed (antipseudomonal 23.1 vs narrow spectrum 14.5, P=.178). CONCLUSIONS: Treatment-associated complications were similar among patients treated with antipseudomonal and narrow-spectrum antibiotics. Antipseudomonal therapy is likely unnecessary for most patients with CA-IAI.

Syndromic diagnostic testing: a new way to approach patient care in the treatment of infectious diseases.

Advanced microbiology technologies such as multiplex molecular assays (i.e. syndromic diagnostic tests) are a novel approach to the rapid diagnosis of common infectious diseases. As the global burden of antimicrobial resistance continues to rise, the judicious use of antimicrobials is of utmost importance. Syndromic panels are now being recognized in some clinical practice guidelines as a 'game-changer' in the diagnosis of infectious diseases. These syndromic panels, if implemented thoughtfully and interpreted carefully, have the potential to improve patient outcomes through improved clinical decision making, optimized laboratory workflow, and enhanced antimicrobial stewardship. This paper reviews the potential benefits of and considerations regarding various infectious diseases syndromic panels, and highlights how to maximize impact through collaboration between clinical microbiology laboratory and antimicrobial stewardship programmes.

A Postmortem Portrait of the Coronavirus Disease 2019 (COVID-19) Pandemic: A Large Multi-institutional Autopsy Survey Study.

CONTEXT.­: This study represents the largest compilation to date of clinical and postmortem data from decedents with coronavirus disease 2019 (COVID-19). It will augment previously published small series of autopsy case reports, refine clinicopathologic considerations, and improve the accuracy of future vital statistical reporting. OBJECTIVE.­: To accurately reflect the preexisting diseases and pathologic conditions of decedents with SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection through autopsy. DESIGN.­: Comprehensive data from 135 autopsy evaluations of COVID-19-positive decedents is presented, including histologic assessment. Postmortem examinations were performed by 36 pathologists at 19 medical centers or forensic institutions in the United States and Brazil. Data from each autopsy were collected through the online submission of multiple-choice and open-ended survey responses. RESULTS.­: Patients dying of or with COVID-19 had an average of 8.89 pathologic conditions documented at autopsy, spanning a combination of prior chronic disease and acute conditions acquired during hospitalization. Virtually all decedents were cited as having more than 1 preexisting condition, encompassing an average of 2.88 such diseases each. Clinical conditions during terminal hospitalization were cited 395 times for the 135 autopsied decedents and predominantly encompassed acute failure of multiple organ systems and/or impaired coagulation. Myocarditis was rarely cited. CONCLUSIONS.­: Cause-of-death statements in both autopsy reports and death certificates may not encompass the severity or spectrum of comorbid conditions in those dying of or with COVID-19. If supported by additional research, this finding may have implications for public health decisions and reporting moving forward through the pandemic.

Histopathology and ultrastructural findings of fatal COVID-19 infections in Washington State: a case series.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of an ongoing pandemic, with increasing deaths worldwide. To date, documentation of the histopathological features in fatal cases of the disease caused by SARS-CoV-2 (COVID-19) has been scarce due to sparse autopsy performance and incomplete organ sampling. We aimed to provide a clinicopathological report of severe COVID-19 cases by documenting histopathological changes and evidence of SARS-CoV-2 tissue tropism. METHODS: In this case series, patients with a positive antemortem or post-mortem SARS-CoV-2 result were considered eligible for enrolment. Post-mortem examinations were done on 14 people who died with COVID-19 at the King County Medical Examiner's Office (Seattle, WA, USA) and Snohomish County Medical Examiner's Office (Everett, WA, USA) in negative-pressure isolation suites during February and March, 2020. Clinical and laboratory data were reviewed. Tissue examination was done by light microscopy, immunohistochemistry, electron microscopy, and quantitative RT-PCR. FINDINGS: The median age of our cohort was 73·5 years (range 42-84; IQR 67·5-77·25). All patients had clinically significant comorbidities, the most common being hypertension, chronic kidney disease, obstructive sleep apnoea, and metabolic disease including diabetes and obesity. The major pulmonary finding was diffuse alveolar damage in the acute or organising phases, with five patients showing focal pulmonary microthrombi. Coronavirus-like particles were detected in the respiratory system, kidney, and gastrointestinal tract. Lymphocytic myocarditis was observed in one patient with viral RNA detected in the tissue. INTERPRETATION: The primary pathology observed in our cohort was diffuse alveolar damage, with virus located in the pneumocytes and tracheal epithelium. Microthrombi, where observed, were scarce and endotheliitis was not identified. Although other non-pulmonary organs showed susceptibility to infection, their contribution to the pathogenesis of SARS-CoV-2 infection requires further examination. FUNDING: None.

COVID-19: Postmortem Diagnostic and Biosafety Considerations.

As a result of the 2019 novel human coronavirus (COVID-19) global spread, medical examiner/coroner offices will inevitably encounter increased numbers of COVID-19-infected decedents at autopsy. While in some cases a history of fever and/or respiratory distress (eg, cough or shortness of breath) may suggest the diagnosis, epidemiologic studies indicate that the majority of individuals infected with COVID-19 develop mild to no symptoms. Those dying with-but not of-COVID-19 may still be infectious, however. While multiple guidelines have been issued regarding autopsy protocol in cases of suspected COVID-19 deaths, there is some variability in the recommendations. Additionally, limited recommendations to date have been issued regarding scene investigative protocol, and there is a paucity of publications characterizing COVID-19 postmortem gross and histologic findings. A case of sudden unexpected death due to COVID-19 is presented as a means of illustrating common autopsy findings, as well as diagnostic and biosafety considerations. We also review and summarize the current COVID-19 literature in an effort to provide practical evidence-based biosafety guidance for medical examiner-coroner offices encountering COVID-19 at autopsy.

Nuclear lamina dysfunction triggers a germline stem cell checkpoint.

LEM domain (LEM-D) proteins are conserved components of the nuclear lamina (NL) that contribute to stem cell maintenance through poorly understood mechanisms. The Drosophila emerin homolog Otefin (Ote) is required for maintenance of germline stem cells (GSCs) and gametogenesis. Here, we show that ote mutants carry germ cell-specific changes in nuclear architecture that are linked to GSC loss. Strikingly, we found that both GSC death and gametogenesis are rescued by inactivation of the DNA damage response (DDR) kinases, ATR and Chk2. Whereas the germline checkpoint draws from components of the DDR pathway, genetic and cytological features of the GSC checkpoint differ from the canonical pathway. Instead, structural deformation of the NL correlates with checkpoint activation. Despite remarkably normal oogenesis, rescued oocytes do not support embryogenesis. Taken together, these data suggest that NL dysfunction caused by Otefin loss triggers a GSC-specific checkpoint that contributes to maintenance of gamete quality.

Carbon Chemistry in IRC+10216: Infrared Detection of Diacetylene.

We present the detection of C4H2 for first time in the envelope of the C-rich AGB star IRC+10216 based on high spectral resolution mid-IR observations carried out with the Texas Echelon-cross-Echelle Spectrograph (TEXES) mounted on the Infrared Telescope Facility (IRTF). The obtained spectrum contains 24 narrow absorption features above the detection limit identified as lines of the ro-vibrational C4H2 band ν6+ν8(σu+). The analysis of these lines through a ro-vibrational diagram indicates that the column density of C4H2 is (2.4 ± 1.5) × 1016 cm-2. Diacetylene is distributed in two excitation populations accounting for 20 and 80% of the total column density and with rotational temperatures of 47 ± 7 and 420 ± 120 K, respectively. This two-folded rotational temperature suggests that the absorbing gas is located beyond ≃0·"4≃20R⋆ from the star with a noticeable cold contribution outwards from ≃ 10″ ≃ 500R⋆. This outer shell matches up with the place where cyanoacetylenes and carbon chains are known to form due to the action of the Galactic dissociating radiation field on the neutral gas coming from the inner layers of the envelope.

Metabolism of 2,4-dichlorophenoxyacetic acid contributes to resistance in a common waterhemp (Amaranthus tuberculatus) population.

BACKGROUND: Synthetic auxins such as 2,4-dichlorophenoxyacetic acid (2,4-D) have been widely used for selective control of broadleaf weeds since the mid-1940s. In 2009, an Amaranthus tuberculatus (common waterhemp) population with 10-fold resistance to 2,4-D was found in Nebraska, USA. The 2,4-D resistance mechanism was examined by conducting [14 C] 2,4-D absorption, translocation and metabolism experiments. RESULTS: No differences were found in 2,4-D absorption or translocation between resistant and susceptible A. tuberculatus plants. Resistant plants metabolized [14 C] 2,4-D more rapidly than did susceptible plants. The half-life of [14 C] 2,4-D in susceptible plants was 105 h, compared with 22 h in resistant plants. Pretreatment with the cytochrome P450 inhibitor malathion inhibited [14 C] 2,4-D metabolism in resistant plants and reduced the 2,4-D dose required for 50% growth inhibition (GR50 ) of resistant plants by 7-fold to 27 g ha-1 , similar to the GR50 for susceptible plants in the absence of malathion. CONCLUSION: Our results demonstrate that rapid 2,4-D metabolism is a contributing factor to resistance in A. tuberculatus, potentially mediated by cytochrome P450. Metabolism-based resistance to 2,4-D could pose a serious challenge for A. tuberculatus control because of the potential for cross-resistance to other herbicides. © 2017 Society of Chemical Industry.

A patient with oxaliplatin immune-induced syndrome (OIIS) who also developed leucovorin and palonosetron-associated thrombocytopenia.

OBJECTIVES: We report a case of an 83 year old man who developed oxaliplatin immune-induced syndrome (OIIS) after his 19th cycle of FOLFOX (5FU, leucovorin, oxaliplatin). When oxaliplatin was omitted from his next cycle of chemotherapy he continues to show signs of drug-induced immune thrombocytopenia (DITP) and was found to have drug-dependent, platelet-reactive antibodies (DDPA) to leucovorin and palonosetron as well as oxaliplatin. METHODS: The patient was admitted for monitoring but required no transfusions and thrombocytopenia resolved without treatment during his first admission. Drug-dependent antibody testing was performed on his blood by the Blood Center of Wisconsin (Diagnostic Laboratories; Milwaukee, WI). RESULTS: No RBC or platelet IgG or IgM antibodies were detected in the absence of any drugs, but upon addition of palonosetron, leucovorin, or oxaliplatin, the tests became strongly positive for anti-RBC IgG and anti-platelet IgG antibodies. DISCUSSION: Repeated administration of oxaliplatin can result in drug-induced immune thrombocytopenia (DITP) or autoimmune hemolytic anemia (AIHA). This phenomenon has recently been termed OIIS and may additionally include Evan's syndrome or thrombotic microangiopathy (TMA). Here we describe a patient who developed OIIS with drug-dependent, platelet-reactive antibodies (DDPA) to leucovorin and palonosetron. To our knowledge, these two drugs have never been described in the literature as a cause of DDPA. We suggest that OIIS in addition to oxaliplatin-induced thrombocytopenia may be associated with the development of DDPAs to other drugs causing clinically significant thrombocytopenia which is important to recognize and manage with discontinuation of provoking agents.

Characterizing Nature and Participant Experience in Studies of Nature Exposure for Positive Mental Health: An Integrative Review.

A growing number of studies demonstrate significant associations between nature experiences and positive mental health outcomes (e.g., improved mood, decreased stress). However, implementation of this research by practitioners in fields such as urban design or public health has been limited. One reason for this is that it remains unclear what elements of nature and types of participant experience are consistently associated with mental health benefits. As a result, decision-makers who aim to enhance mental health in cities have little guidance about which elements of nature and types of experiences in natural areas may lead to positive mental health outcomes. We reviewed 30 studies with 41 distinct exposures in nature that elicited positive mental health benefits and characterized the elements of nature found at these sites, as well as aspects of participants' experience. Elements of natural areas considered include: forest, managed grass, and water as dominant land cover types, specific water features (e.g., small ponds, fountains) and built features (e.g., trails, paths). The majority of the studies we reviewed assessed the experiences of individuals (vs. in groups) participating in walks during warmer seasons. Most studies did not describe the "nature of the nature" associated with positive mental health outcomes. We contacted authors and used Google Earth imagery to reconstruct the specific natural elements, landscape typology, and site adjacencies present in past studies. We recommend specific ways researchers could better and more transparently document important elements of nature and participant experience in study design and reporting that will enhance the planning and design relevance of their work.

Finding their way: themes in germ cell migration.

Embryonic germ cell migration is a vital component of the germline lifecycle. The translocation of germ cells from the place of origin to the developing somatic gonad involves several processes including passive movements with underlying tissues, transepithelial migration, cell adhesion dynamics, the establishment of environmental guidance cues and the ability to sustain directed migration. How germ cells accomplish these feats in established model organisms will be discussed in this review, with a focus on recent discoveries and themes conserved across species.

Drosophila male and female germline stem cell niches require the nuclear lamina protein Otefin.

The nuclear lamina is an extensive protein network that underlies the inner nuclear envelope. This network includes the LAP2-emerin-MAN1-domain (LEM-D) protein family, proteins that share an association with the chromatin binding protein Barrier-to-autointegration factor (BAF). Loss of individual LEM-D proteins causes progressive, tissue-restricted diseases, known as laminopathies. Mechanisms associated with laminopathies are not yet understood. Here we present our studies of one of the Drosophila nuclear lamina LEM-D proteins, Otefin (Ote), a homologue of emerin. Previous studies have shown that Ote is autonomously required for the survival of female germline stem cells (GSCs). We demonstrate that Ote is also required for survival of somatic cells in the ovarian niche, with loss of Ote causing a decrease in cap cell number and altered signal transduction. We show germ cell-restricted expression of Ote rescues these defects, revealing a non-autonomous function for Ote in niche maintenance and emphasizing that GSCs contribute to the maintenance of their own niches. Further, we investigate the requirement of Ote in the male fertility. We show that ote mutant males become prematurely sterile as they age. Parallel to observations in females, this sterility is associated with GSC loss and changes in somatic cells of the niche, phenotypes that are largely rescued by germ cell-restricted Ote expression. Taken together, our studies demonstrate that Ote is required autonomously for survival of two stem cell populations, as well as non-autonomously for maintenance of two somatic niches. Finally, our data add to growing evidence that LEM-D proteins have critical roles in stem cell survival and tissue homeostasis.