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1.
Article in English | MEDLINE | ID: mdl-39351789

ABSTRACT

INTRODUCTION: Suicide prevention training that teaches skills to support a person experiencing thoughts of suicide and create community support networks, often termed, "gatekeeper" training (GKT), has been a longstanding pillar of international, national, and local suicide prevention efforts. GKT aims to improve knowledge, attitudes, and self-efficacy in identifying individuals at risk for suicide, hopefully enhancing one's willingness and ability to intervene with a person experiencing a crisis. However, little is known about GKT's effectiveness in creating the essential behavior change (e.g., increase in intervening behaviors) it sets out to accomplish. METHODS: This paper explores the history and theoretical background of GKT, reviews the current state of research on GKT, and provides framing and recommendations for next steps to advance research and practice around GKT. RESULTS & CONCLUSION: Through positioning GKT appropriately within the field of suicide prevention, we argue that the field of suicide prevention needs more rigorous research around GKT that includes long-term follow-up data on usage of skills learned during training, data on outcomes of those who have received an intervention from a trained gatekeeper, and the integration of implementation science to further our understanding of which trainings are appropriate for which helpers.

2.
Cureus ; 16(7): e65206, 2024 Jul.
Article in English | MEDLINE | ID: mdl-39045025

ABSTRACT

Psoriasis is a chronic inflammatory disease characterized by clearly marginated silvery plaques that affect men and women equally. Symptoms can vary among individuals; typically, it presents on the scalp, elbows, and knees. We present two cases of patients initially diagnosed with tinea pedis who showed no improvement with medical treatment. The first patient is an African American male in his 50s who arrived at a free clinic for unhoused persons with lesions to both feet initially diagnosed as tinea pedis. Although the patient was compliant with applying topical formulations of tolnaftate and clotrimazole, there was no discernible improvement in his symptoms and the skin lesions. After a thorough examination of the skin throughout the entire body, the diagnosis of psoriasis was considered. The patient started treatment with steroidal cream with improvement of the symptoms and lesions. The second patient is a Caucasian male in his 20s who also presented initially with complaints of a dry, intensely pruritic, and scaly rash on the dorsum of both his feet, as well as in between the digits of his feet for which an initial diagnosis of tinea pedis was also made. The patient remained non-compliant with treatment and, after reevaluation of his lesions along with an extensive survey of his body, was deemed to have psoriasis and prescribed topical hydrocortisone. The patient continued to remain non-compliant with his therapeutic regimen and subsequently developed cellulitis which is yet to resolve with treatment.

3.
J Clin Psychol ; 79(12): 2974-2985, 2023 12.
Article in English | MEDLINE | ID: mdl-37672631

ABSTRACT

OBJECTIVE: Suicidal ideation and suicidal behaviors are major public health concerns in the United States and are difficult to treat and predict. Risk factors that are incrementally informative are needed to improve prediction and inform prevention of suicidal thoughts and behaviors. Uncontrollability of suicidal ideation, one parameter of suicidal ideation, is one such candidate. METHOD: In the current study, we assessed the predictive power of uncontrollability of suicidal ideation, over and above overall suicidal ideation, for future suicidal ideation in a large sample of active-duty service members. A total of 1044 suicidal military service members completed baseline assessments, of whom 664 (63.6%) completed 3-month follow-up assessments. RESULTS: While baseline overall suicidal ideation itself was the strongest predictor of future suicidal ideation, uncontrollability of suicidal ideation added some incremental explanatory power. CONCLUSION: Further study of uncontrollability of suicidal thought is needed to elucidate its impact on suicidal outcomes.


Subject(s)
Military Personnel , Suicidal Ideation , Humans , United States , Suicide, Attempted/prevention & control , Risk Factors
4.
Assessment ; 30(4): 1321-1333, 2023 06.
Article in English | MEDLINE | ID: mdl-35575070

ABSTRACT

The Beck Scale for Suicide Ideation (BSS) is one of the most used and empirically supported suicide risk assessment measures for behavioral health clinicians and researchers. However, the 19-item BSS is a relatively long measure and can take 5 to 10 minutes to administer. This study used Item Response Theory (IRT) techniques across two samples of mostly U.S. military service members to first identify (n1 = 1,899) and then validate (n2 = 757) an optimized set of the most informative BSS items. Results indicated that Items 1, 2, 4, 6, and 15 provided a similar-shaped test information curve across the same range of the latent trait as the full-length BSS and showed reliable item functioning across participant characteristics. The sum score of these five items showed a linear score linkage with the full-scale score, ρ > 0.87, and was equally as sensitive as the full scale for prospectively predicting near-term suicidal behavior at 74% with a cut score ≥1 (equivalent to full-scale score ≥6). Results are consistent with those from civilian samples. In time- or length-limited assessments, using these five BSS items may improve administration efficiency over the full BSS, while maintaining classification sensitivity.This study suggests that summing Items 1, 2, 4, 6, and 15 of the Beck Scale for Suicide Ideation (BSS) is an acceptable approach for shortening the full-length measure.


Subject(s)
Military Personnel , Suicidal Ideation , Humans
5.
Psychol Serv ; 20(1): 66-73, 2023 Feb.
Article in English | MEDLINE | ID: mdl-34968124

ABSTRACT

The purpose of this study was to determine the long-term effects of a suicide prevention-focused group therapy for veterans recently discharged from an inpatient psychiatry setting following a suicidal crisis. There was interest in examining the impact of mechanisms of change identified in previous research on the group, including group cohesion, working alliance, and group sessions attended. Data were abstracted from the electronic medical record 3 years following completion of a previous study that involved the group therapy. A series of generalized linear and logistic mixed models were conducted to measure the associations between group cohesion, working alliance, session attendance, and health service utilization and suicide attempts. Thirty randomly selected veterans from the original sample completed a semistructured interview to discuss their experience in the group therapy. Study team members reviewed each transcription to identify themes related to veterans' experiences in the suicide prevention-focused group therapy. No suicides were observed in the 3-year follow-up period. When examining the full sample (N = 134), session attendance and inpatient hospitalization were not significantly associated but were positively associated after removing subjects who attended zero sessions (N = 93). Higher group cohesion was associated with a reduced likelihood of inpatient psychiatric hospitalization and greater engagement in outpatient mental health services. Four themes emerged regarding veterans' experience in the group through an analysis of the semistructured interviews. Suicide prevention-focused group therapy among veteran service members was not associated with an elevated risk of mortality. Future research is needed to further elucidate mechanisms of change and moderators of response. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Subject(s)
Mental Health Services , Psychotherapy, Group , Veterans , Humans , Veterans/psychology , Suicide Prevention , Follow-Up Studies , Suicidal Ideation
6.
Psychiatry ; 85(4): 334-335, 2022.
Article in English | MEDLINE | ID: mdl-36344472

Subject(s)
Suicide Prevention , Humans
7.
Dis Mon ; 68(9): 101387, 2022 09.
Article in English | MEDLINE | ID: mdl-35644661
8.
Pediatr Emerg Care ; 38(3): e1085-e1086, 2022 Mar 01.
Article in English | MEDLINE | ID: mdl-35226635

ABSTRACT

ABSTRACT: Point-of-care ultrasound has been instrumental in allowing providers to make prompt diagnoses at the bedside but has been historically underutilized for the diagnosis of upper airway processes, including paradoxical vocal fold motion (PVFM), also known as vocal cord dysfunction. PVFM is characterized by adduction of the vocal cords during inspiration, resulting in stridor and shortness of breath. This case report describes a teenage girl who presented to the pediatric emergency department (ED) with difficulty breathing. Point-of-care ultrasound diagnosed PVFM, which was confirmed with bedside flexible laryngoscopy by otorhinolaryngology (ENT) in the ED.


Subject(s)
Vocal Cord Dysfunction , Vocal Cords , Adolescent , Child , Dyspnea/etiology , Female , Humans , Laryngoscopy , Respiratory Sounds/etiology , Vocal Cord Dysfunction/diagnostic imaging , Vocal Cords/diagnostic imaging
9.
Suicide Life Threat Behav ; 52(2): 244-255, 2022 04.
Article in English | MEDLINE | ID: mdl-34780099

ABSTRACT

INTRODUCTION: Few evidence-based options exist for outpatient treatment of patients at risk of suicide, and to-date almost all research has focused on individually delivered psychotherapy. Group therapy for veterans at risk of suicide is a promising alternative. METHODS: Thirty veterans receiving care at an urban Veterans Affairs Medical Center in the southern United States were randomized to either care as usual (CAU) or to CAU plus the Collaborative Assessment and Management of Suicide-Group (CAMS-G). Veterans were assessed prior to randomization to condition and at 1, 3, and 6 months post-randomization on a range of suicide-specific measures, burdensomeness, belonging, treatment satisfaction, and group cohesion. RESULTS: Across measures and follow-up assessments, veterans in CAMS-G reported good satisfaction with the intervention, a sense of cohesion with other members of the group, and reduced symptom distress. Veterans in both conditions reported decreases in suicidal ideation and behavior, with CAMS-G participants potentially improving slightly faster. CONCLUSION: This description of CAMS-G for veterans adds to the growing literature on suicide-specific interventions and supports the need for additional research to determine if wide-spread rollout is justifiable.


Subject(s)
Suicide Prevention , Veterans , Humans , Pilot Projects , Psychotherapy , Suicidal Ideation , United States
10.
Assessment ; 29(8): 1611-1621, 2022 12.
Article in English | MEDLINE | ID: mdl-34151586

ABSTRACT

Suicide risk screening depends heavily on accurate patient self-report. However, past negative experiences with mental health care may contribute to intentional nondisclosure of suicide risk during screening. This study investigated among 282 men older than age 50 whether likelihood for current explicit risk nondisclosure was associated with previous highest level of mental health care received. This sample was selected post hoc out of a larger sample of participants from higher risk and lower help-seeking populations (i.e., military service members and veterans, men older than age 50, and lesbian gay bisexual, transgender, and queer young adults), however, the other groups were underpowered for analysis. Among these men, history of psychiatric hospitalization was significantly associated with likelihood for explicit nondisclosure of current suicide risk, while history of receiving only outpatient therapy for suicidal thoughts or behaviors was significantly associated with likelihood for full reporting of suicide risk. Severity of suicidal ideation and internalized stigma against mental illness were significant indirect contributors to the effect. Although causality could not be determined, results suggest that a potential cost to consider for psychiatric hospitalization may be future nondisclosure of suicide risk. Conversely, outpatient interventions that appropriately manage suicidal thoughts or behaviors may encourage future full reporting of suicide risk and improve screening detection.


Subject(s)
Suicide Prevention , Suicide , Veterans , Young Adult , Male , Female , Humans , Middle Aged , Suicide, Attempted/prevention & control , Suicide/psychology , Mental Health , Suicidal Ideation , Veterans/psychology
11.
JMIR Form Res ; 5(7): e27018, 2021 Jul 14.
Article in English | MEDLINE | ID: mdl-34259163

ABSTRACT

BACKGROUND: People with suicidal thoughts are more inclined to seek technology-delivered interventions than in-person forms of treatment, making mobile apps for suicide prevention an ideal platform for treatment delivery. This review examines apps designed for suicide prevention, with a specific focus on user engagement. OBJECTIVE: This study aims to update the literature and broadly evaluate the landscape of mobile health apps for suicide prevention; examine apps with key features and primary approaches to suicide prevention; and systematically evaluate the engagement, functionality, aesthetics, and information of the apps. METHODS: All apps related to suicidal thoughts and behaviors were identified in the Google Play and iOS app stores and were systematically reviewed for their content and quality. The mobile app rating scale (MARS) was used to evaluate app usability and engagement. RESULTS: Of the 66 apps identified, 42 (64%) were specifically designed for people with suicidal ideation, and 59 (89%) had at least one best practice feature for suicide risk reduction. The mean overall MARS score of all apps was 3.5 (range 2.1-4.5), with 83% (55/66) of apps having a minimum acceptability score of 3. The total MARS score was not associated with the user app rating (r=-0.001; P=.99) or the number of features (r=0.24; P=.09). CONCLUSIONS: This study identified many usable and engaging apps in app stores designed for suicide prevention. However, there are only limited apps for clinicians. Thus, mobile apps for suicide prevention should be carefully developed and clinically evaluated.

12.
Article in English | MEDLINE | ID: mdl-33466594

ABSTRACT

Past suicide attempts are a significant risk factor for future suicidality. Therefore, the present military-based study examined the past suicidal behavior of soldiers who recently made a severe suicide attempt. Our sample consisted of 65 active-duty soldiers (61.5% males), between the ages of 18 and 28 years old (M = 20.4, SD ± 1.3). The inclusion criterion was a recent severe suicide attempt, requiring at least a 24 h hospitalization. This sample was divided into two groups, according to previous suicidal behavior, namely whether their first suicide attempt was before or after enlistment (n = 25; 38.5% and n = 40; 61.5%, respectively). We then examined the lethality and intent of the recent event in regard to this division. Four measures were used to assess the subjects' suicidal characteristics: the Columbia Suicide Severity Rating Scale, the Self-Harm Behavior Questionnaire, the Suicidal Behaviors Questionnaire-Revised, and the Beck Scale for Suicide Ideation. No significant difference in the severity of the suicide attempts (either actual or potential severity) were found between those who had suicide attempts before enlistment and those who had their first attempt in the service. As a matter of fact, most of the suicide attempts that occurred for the first time during military service had used a violent method (58.3%, n = 21). Finally, using multivariate analyses, we found that current thoughts and behavior, rather than past suicidality, was the strongest predictor for the lethality of suicide attempts.


Subject(s)
Military Personnel , Suicide , Adolescent , Adult , Female , Humans , Male , Retrospective Studies , Risk Factors , Suicidal Ideation , Suicide, Attempted , Young Adult
13.
POCUS J ; 6(2): 80-87, 2021.
Article in English | MEDLINE | ID: mdl-36895674

ABSTRACT

We aim to quantify and categorize point-of-care ultrasound (POCUS) usage by pediatric practitioners and trainees at our tertiary care center, and assess the degree of interest from pediatric residents, fellows, and program leaders for integrating POCUS into their training. Data was collected via online survey, evaluating the current use of POCUS in clinical decision making, desire for further formal training, and opinions on the importance of POCUS to future clinical practice. In total, 14 program directors/assistant program directors (PD/APDs) representing 10 of 15 training programs, 30 of 95 fellows representing 9 of 15 fellowships, and 32 of 82 residents responded. From PD/APDs, only 2 of the programs reported active use POCUS for clinical decision making, but 13 of the fellows and 9 residents reported doing so. In regard to desire for a formal POCUS program, 30.8% of PD/APDs, 43.8% of fellows without current curricula, and 87.5% of residents were interested in participating in such a program. When considering specialty, some non-acute care-based PD/APDs and fellows at our institution felt that POCUS was important to future practice. Pediatric subspecialty PD/APDs and their fellows had divergent outlooks on the importance of POCUS in future practice. Finally, an overwhelming majority of residents at our institution expressed a desire to learn, and half believing it will be important to future practice. Based on the degree of interest, medicolegal considerations, and trajectory of patient care, pediatric residency and fellowship programs should strongly consider integrating POCUS education into their curricula.

14.
Psychol Serv ; 18(3): 377-388, 2021 Aug.
Article in English | MEDLINE | ID: mdl-32105121

ABSTRACT

Suicide rates within the U.S. military are elevated. The interpersonal theory of suicide, supported within military samples, suggests that social disconnectedness confers risk for suicide. Autism spectrum disorder (ASD) is characterized by symptoms-difficulties in social communication/interaction (SCI) and restricted and repetitive behaviors (RRBs)-that contribute to social disconnectedness. To our knowledge, no study has examined ASD-related traits and suicide risk among active duty U.S. military service members. Participants included 292 active duty U.S. military service members (M [SD] age = 28.67 [7.40] years, 68.5% male, 78.1% White). The Autism Spectrum Quotient, Repetitive Behaviours Questionnaire-2 for Adults, Self-Injurious Thoughts and Behaviors Interview-Short Form, and Interpersonal Needs Questionnaire assessed for SCI difficulties, RRBs, suicidal symptoms, and interpersonal theory of suicide constructs (i.e., perceived burdensomeness, thwarted belongingness), respectively. Elevated levels of SCI difficulties and RRBs were associated with increased odds of reporting suicidal thoughts and behaviors occurring since joining the military, controlling for the number of years of service and suicidal symptoms occurring prior to joining the military. Perceived burdensomeness and thwarted belongingness statistically accounted for the relationship between ASD-related traits and suicidal ideation occurring since joining the military; a rival mediator, emotion dysregulation, was not a significant mediator. Among active duty U.S. military service members, greater ASD-related traits were associated with an increased likelihood of reporting suicidal thoughts and behaviors occurring since joining the military. Clinical efforts targeting perceived burdensomeness and thwarted belongingness might reduce suicide risk among military service members with elevated ASD-related traits. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Subject(s)
Autism Spectrum Disorder , Autistic Disorder , Military Personnel , Suicide , Adult , Autism Spectrum Disorder/epidemiology , Female , Humans , Interpersonal Relations , Male , Psychological Theory , Risk Factors , Suicidal Ideation
15.
Pediatr Emerg Care ; 37(1): 11-16, 2021 Jan 01.
Article in English | MEDLINE | ID: mdl-32195977

ABSTRACT

INTRODUCTION: This study describes the experience at a level 1 pediatric trauma center before and after the centralization of prehospital trauma triage, focusing on the rate of undertriage of trauma patients. Before centralization, emergency physicians were responsible for triaging these patients with mainly physiology-based criteria; after centralization, paramedics in a communication center performed this function using the same criteria. METHODS: This retrospective study includes 10 years of pediatric trauma registry patients at our institution, 5 years before and after centralization of prehospital triage. Rates of undertriage were calculated by both the Cribari Method and by disposition from the emergency department. Logistic regression was used to assess the effect of centralization on the incidence of undertriage while adjusting for differences in case-mix. RESULTS: Over the 10-year study period, 1862 trauma activations meeting inclusion and exclusion criteria were recorded in the trauma registry: 893 patients in the precentralization and 969 in the postcentralization groups. After centralization of the triage process, there were statistically significant decreases in the rates of undertriage from 8.7% to 4.2% (adjusted odds ratio, 0.49; 95% confidence interval, 0.33-0.73) when analyzed by the Cribari Method and from 37.7% to 27.7% when analyzed by disposition from the emergency department (adjusted odds ratio, 0.66; 95% confidence interval, 0.64-0.81). This represents a reduction in undertriage by 51.7% and 26.5%, respectively. CONCLUSIONS: Centralization of prehospital trauma triage at a level 1 pediatric trauma facility significantly reduced undertriage rates. Trauma centers should consider similar processes to improve prehospital triage.


Subject(s)
Trauma Centers/organization & administration , Triage , Wounds and Injuries , Child , Humans , Injury Severity Score , Logistic Models , Registries , Retrospective Studies , Triage/organization & administration , Wounds and Injuries/diagnosis
16.
Psychol Assess ; 33(1): 1-13, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33180522

ABSTRACT

To date, the field has been unable to provide a definitive answer on which suicide risk assessment measure or set of measures is most useful in applied clinical settings. This study pits several psychometrically sound suicide risk assessment measures against one another, to determine which tool optimally assesses the likelihood of future suicide-related outcomes over a 3-month period, in a large sample of military personnel seeking and/or referred to services due to suicide risk concerns. The risk assessment measures were (a) Columbia-Suicide Severity Rating Scale; (b) Self-Harm Behavior Questionnaire; (c) Suicidal Behaviors Questionnaire-Revised; and (d) Beck Scale for Suicide Ideation. A total of 1,044 suicidal military service members completed baseline assessments, of whom 758 (72.6%) completed 3-month follow-up assessments. The data indicate that there is no best measure for suicide risk assessment and clinicians are therefore encouraged to select the measure, from among the four studied, for use in regular practice that best suits the demands of their setting. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Subject(s)
Military Personnel/psychology , Psychiatric Status Rating Scales , Suicidal Ideation , Suicide, Attempted/psychology , Adolescent , Adult , Female , Follow-Up Studies , Humans , Male , Middle Aged , Psychometrics , Risk Assessment , Surveys and Questionnaires , United States , Young Adult
17.
Pediatr Emerg Care ; 37(1): e48-e50, 2021 Jan 01.
Article in English | MEDLINE | ID: mdl-29768298

ABSTRACT

ABSTRACT: An 8-year-old male presented to the pediatric emergency department with subjective fever, blurry vision, and left eye pain. On physical examination, there was mild left lower lid erythema and a subtle left eye elevation deficit. Computed tomography demonstrated preseptal soft tissue swelling without orbital involvement; however, there was varying amounts of paranasal sinus opacification. Despite the negative scan, a diagnosis of orbital cellulitis associated with sinusitis was made and treatment with intravenous antibiotics was initiated. A magnetic resonance imaging performed subsequently revealed orbital fat stranding and inferior rectus enlargement and enhancement near the orbital apex, indicating the presence of orbital cellulitis. This case demonstrates the utility of magnetic resonance imaging when initial computed tomography imaging is negative in patients with concern for orbital cellulitis.


Subject(s)
Magnetic Resonance Imaging , Orbital Cellulitis , Tomography, X-Ray Computed , Child , Humans , Male , Orbit/diagnostic imaging , Orbital Cellulitis/diagnostic imaging , Sinusitis
18.
Psychiatry ; 83(3): 244-258, 2020.
Article in English | MEDLINE | ID: mdl-32960163

ABSTRACT

Objective: Rates of some psychological disorders are higher among enlisted U.S. military personnel than socio-demographically matched civilians. Indirect evidence suggests some internalizing and externalizing psychological problems among enlistees onset prior to enlistment. However, the consistency and strength of the associations between pre-enlistment psychological problems and enlistment over time is unknown. We address this uncertainty by examining whether internalizing and externalizing problems in high school predicted subsequent military enlistment using a large cohort-sequential panel study. Method: The Monitoring the Future study administered baseline surveys from 1989-2014 and biennial follow-up surveys two and four years later to national samples of high-school seniors (N = 20,823). Validated self-report scales assessed internalizing (depression, low self-esteem) and externalizing (risk-taking, school misbehavior, conduct disorder, interpersonal violence, alcohol, and drug use) problems in each survey. Follow-up surveys assessed military enlistment. Logistic regression models were used to estimate associations of problems scales with subsequent enlistment. Results: School misbehavior in 12th grade, and risk-taking in 12th grade and two years after graduation were associated with significantly elevated odds of enlistment at follow-up. Although modest, these associations were linear and invariant across respondent sex and baseline survey year. Conclusions: School misbehavior and risk-taking predicted subsequent enlistment and there was no evidence of historical changes in these associations over the course of 25 years; these pre-enlistment psychological problems do not fully explain the high rates of psychological disorders among enlisted military personnel. Further research is needed to determine whether these predictors are associated with negative outcomes during or after military service.


Subject(s)
Adolescent Behavior , Behavioral Symptoms/epidemiology , Military Personnel/statistics & numerical data , Students/statistics & numerical data , Adolescent , Adult , Female , Follow-Up Studies , Humans , Male , United States/epidemiology , Young Adult
19.
Behav Res Ther ; 132: 103688, 2020 Jun 28.
Article in English | MEDLINE | ID: mdl-32731055

ABSTRACT

The interpersonal theory of suicide hypothesizes that perceived burdensomeness, thwarted belongingness, and hopelessness lead to active suicidal thoughts and individuals with active suicidal thoughts and elevated capability for suicide are most likely to attempt suicide. We retrospectively and prospectively tested this theory in a large sample of 7677 U.S. Army soldiers followed post-deployment for up to nine months. The interaction of perceived burdensomeness and hopelessness (OR = 2.59) was significantly associated with lifetime suicidal thoughts; however, the interactions of thwarted belongingness and perceived burdensomeness and of thwarted belongingness and hopelessness were not. Consistent with the theory, capability for suicide prospectively predicted suicide attempts during and following deployment (OR = 1.22); however, among soldiers reporting lifetime suicidal thoughts, capability did not predict attempts, only perceived burdensomeness did (OR = 1.36). Results supported some, but not all, theory hypotheses, suggesting that additional constructs may be needed to better identify the psychological factors that lead soldiers to attempt suicide.

20.
Development ; 147(11)2020 06 04.
Article in English | MEDLINE | ID: mdl-32439759

ABSTRACT

The anchor cell (AC) in C. elegans secretes an epidermal growth factor (EGF) homolog that induces adjacent vulval precursor cells (VPCs) to differentiate. The EGF receptor in the nearest VPC sequesters the limiting EGF amounts released by the AC to prevent EGF from spreading to distal VPCs. Here, we show that not only EGFR localization in the VPCs but also EGF polarity in the AC is necessary for robust fate specification. The AC secretes EGF in a directional manner towards the nearest VPC. Loss of AC polarity causes signal spreading and, when combined with MAPK pathway hyperactivation, the ectopic induction of distal VPCs. In a screen for genes preventing distal VPC induction, we identified sra-9 and nlp-26 as genes specifically required for polarized EGF secretion. sra-9(lf) and nlp-26(lf) mutants exhibit errors in vulval fate specification, reduced precision in VPC to AC alignment and increased variability in MAPK activation. sra-9 encodes a seven-pass transmembrane receptor acting in the AC and nlp-26 a neuropeptide-like protein expressed in the VPCs. SRA-9 and NLP-26 may transduce a feedback signal to channel EGF secretion towards the nearest VPC.


Subject(s)
Caenorhabditis elegans Proteins/metabolism , Caenorhabditis elegans/metabolism , Epidermal Growth Factor/metabolism , Vulva/metabolism , Animals , Animals, Genetically Modified/growth & development , Animals, Genetically Modified/metabolism , CRISPR-Cas Systems/genetics , Caenorhabditis elegans/growth & development , Caenorhabditis elegans Proteins/antagonists & inhibitors , Caenorhabditis elegans Proteins/genetics , Epidermal Growth Factor/antagonists & inhibitors , Epidermal Growth Factor/genetics , ErbB Receptors/metabolism , Female , Gene Editing , Larva/metabolism , Mitogen-Activated Protein Kinases/metabolism , Mutagenesis , Netrins/genetics , Netrins/metabolism , RNA Interference , RNA-Dependent RNA Polymerase/genetics , RNA-Dependent RNA Polymerase/metabolism , Signal Transduction , Stem Cells/cytology , Stem Cells/metabolism , Vulva/cytology , Vulva/growth & development , ras GTPase-Activating Proteins/antagonists & inhibitors , ras GTPase-Activating Proteins/genetics , ras GTPase-Activating Proteins/metabolism
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