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"Ho, Tiffany"
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Mechanisms of neuroplasticity linking early adversity to depression: developmental considerations
2021
Early exposure to psychosocial adversity is among the most potent predictors of depression. Because depression commonly emerges prior to adulthood, we must consider the fundamental principles of developmental neuroscience when examining how experiences of childhood adversity, including abuse and neglect, can lead to depression. Considering that both the environment and the brain are highly dynamic across the period spanning gestation through adolescence, the purpose of this review is to discuss and integrate stress-based models of depression that center developmental processes. We offer a general framework for understanding how psychosocial adversity in early life disrupts or calibrates the biobehavioral systems implicated in depression. Specifically, we propose that the sources and nature of the environmental input shaping the brain, and the mechanisms of neuroplasticity involved, change across development. We contend that the effects of adversity largely depend on the developmental stage of the organism. First, we summarize leading neurobiological models that focus on the effects of adversity on risk for mental disorders, including depression. In particular, we highlight models of allostatic load, acceleration maturation, dimensions of adversity, and sensitive or critical periods. Second, we expound on and review evidence for the formulation that distinct mechanisms of neuroplasticity are implicated depending on the timing of adverse experiences, and that inherent within certain windows of development are constraints on the sources and nature of these experiences. Finally, we consider other important facets of adverse experiences (e.g., environmental unpredictability, perceptions of one’s experiences) before discussing promising research directions for the future of the field.
Journal Article
Psychobiological risk factors for suicidal thoughts and behaviors in adolescence: a consideration of the role of puberty
2022
Suicide is the second leading cause of death among adolescents. While clinicians and researchers have begun to recognize the importance of considering multidimensional factors in understanding risk for suicidal thoughts and behaviors (STBs) during this developmental period, the role of puberty has been largely ignored. In this review, we contend that the hormonal events that occur during puberty have significant effects on the organization and development of brain systems implicated in the regulation of social stressors, including amygdala, hippocampus, striatum, medial prefrontal cortex, orbitofrontal cortex, and anterior cingulate cortex. Guided by previous experimental work in adults, we also propose that the influence of pubertal hormones and social stressors on neural systems related to risk for STBs is especially critical to consider in adolescents with a neurobiological sensitivity to hormonal changes. Furthermore, facets of the pubertal transition, such as pubertal timing, warrant deeper investigation and may help us gain a more comprehensive understanding of sex differences in the neurobiological and psychosocial mechanisms underlying adolescent STBs. Ultimately, advancing our understanding of the pubertal processes that contribute to suicide risk will improve early detection and facilitate the development of more effective, sex-specific, psychiatric interventions for adolescents.
Journal Article
Breast cancer survivorship and sexual dysfunction: a population-based cohort study
by
Ho, Tiffany F
,
Snyder, John
,
Chang, Chun-Pin
in
Breast cancer
,
Cancer research
,
Cancer therapies
2023
BackgroundBreast cancer is the most common non-skin cancer in women and an increasing number of people are living as breast cancer survivors. While the prognosis of breast cancer continues to improve, the rates of sexual dysfunction and the risk related to cancer treatments have not been well characterized in a population-based study.MethodsWe identified a cohort of 19,709 breast cancer survivors diagnosed between 1997 and 2017 from the Utah Cancer Registry, and 93,389 cancer-free women who were matched by age and birth state from the Utah Population Database. Sexual dysfunction diagnoses were identified through ICD-9 and ICD-10 codes from electronic medical records and statewide healthcare facilities data. Cox proportional hazard models were used to estimate hazard ratios for risk of sexual dysfunction.ResultsBreast cancer survivors were at higher risk of sexual dysfunction diagnosis (9.1% versus 6.9%, HR 1.60, 95% CI 1.51–1.70) compared to the general population. This risk increased 2.05-fold within 1 to 5 years after cancer diagnosis (95% CI 1.89–2.22) and 3.05-fold in individuals diagnosed with cancer at < 50 years of age (95% CI 2.65–3.51). Cancer treatments including endocrine therapy, chemotherapy and radiation therapy were associated with an increased risk of sexual dysfunction among breast cancer survivors.ConclusionsRisk of sexual dysfunction in breast cancer survivors is higher than in the general population, but may be underdiagnosed in the clinical setting. Health care professionals should be encouraged to address the topic of sexual health early on in the treatment of breast cancer, and routinely screen patients for symptoms of sexual dysfunction.
Journal Article
Characteristics of a transgender and gender-diverse patient population in Utah: Use of electronic health records to advance clinical and health equity research
2024
Transgender and gender-diverse (TGD) people, individuals whose gender identity differs from their sex assigned at birth, face unique challenges in accessing gender-affirming care and often experience disparities in a variety of health outcomes. Clinical research on TGD health is limited by a lack of standardization on how to best identify these individuals. The objective of this retrospective cohort analysis was to accurately identify and describe TGD adults and their use of gender-affirming care from 2003-2023 in a healthcare system in Utah, United States. International Classification of Disease (ICD)-9 and 10 codes and surgical procedure codes, along with sexual orientation and gender identity data were used to develop a dataset of 4,587 TGD adults. During this time frame, 2,985 adults received gender-affirming hormone therapy (GAHT) and/or gender-affirming surgery (GAS) within one healthcare system. There was no significant difference in race or ethnicity between TGD adults who received GAHT and/or GAS compared to TGD adults who did not receive such care. TGD adults who received GAHT and/or GAS were more likely to have commercial insurance coverage, and adults from rural communities were underrepresented. Patients seeking estradiol-based GAHT tended to be older than those seeking testosterone-based GAHT. The first GAS occurred in 2013, and uptake of GAS have doubled since 2018. This study provides a methodology to identify and examine TGD patients in other health systems and offers insights into emerging trends and access to gender-affirming care.
Journal Article
Default mode and salience network alterations in suicidal and non-suicidal self-injurious thoughts and behaviors in adolescents with depression
2021
Suicidal ideation (SI) and non-suicidal self-injury (NSSI) are two distinct yet often co-occurring risk factors for suicide deaths in adolescents. Elucidating the neurobiological patterns that specifically characterize SI and NSSI in adolescents is needed to inform the use of these markers in intervention studies and to develop brain-based treatment targets. Here, we clinically assessed 70 adolescents—49 adolescents with depression and 21 healthy controls—to determine SI and NSSI history. Twenty-eight of the depressed adolescents had a history of SI and 29 had a history of NSSI (20 overlapping). All participants underwent a resting-state fMRI scan. We compared groups in network coherence of subdivisions of the central executive network (CEN), default mode network (DMN), and salience network (SN). We also examined group differences in between-network connectivity and explored brain-behavior correlations. Depressed adolescents with SI and with NSSI had lower coherence in the ventral DMN compared to those without SI or NSSI, respectively, and healthy controls (all ps < 0.043, uncorrected). Depressed adolescents with NSSI had lower coherence in the anterior DMN and in insula-SN (all ps < 0.030, uncorrected), and higher CEN–DMN connectivity compared to those without NSSI and healthy controls (all ps < 0.030, uncorrected). Lower network coherence in all DMN subnetworks and insula-SN were associated with higher past-month SI and NSSI (all ps < 0.001, uncorrected). Thus, in our sample, both SI and NSSI are related to brain networks associated with difficulties in self-referential processing and future planning, while NSSI specifically is related to brain networks associated with disruptions in interoceptive awareness.
Journal Article
The cell cycle regulator GpsB functions as cytosolic adaptor for multiple cell wall enzymes
by
Rismondo, Jeanine
,
Lewis, Richard J.
,
Rutter, Zoe J.
in
631/326/41/2536
,
631/326/41/88
,
631/535/1266
2019
Bacterial growth and cell division requires precise spatiotemporal regulation of the synthesis and remodelling of the peptidoglycan layer that surrounds the cytoplasmic membrane. GpsB is a cytosolic protein that affects cell wall synthesis by binding cytoplasmic mini-domains of peptidoglycan synthases to ensure their correct subcellular localisation. Here, we describe critical structural features for the interaction of GpsB with peptidoglycan synthases from three bacterial species (
Bacillus subtilis
,
Listeria monocytogenes
and
Streptococcus pneumoniae
) and suggest their importance for cell wall growth and viability in
L. monocytogenes
and
S. pneumoniae
. We use these structural motifs to identify novel partners of GpsB in
B. subtilis
and extend the members of the GpsB interactome in all three bacterial species. Our results support that GpsB functions as an adaptor protein that mediates the interaction between membrane proteins, scaffolding proteins, signalling proteins and enzymes to generate larger protein complexes at specific sites in a bacterial cell cycle-dependent manner.
GpsB is a cytosolic protein that modulates bacterial cell wall synthesis by interacting with cytoplasmic domains of peptidoglycan synthases. Here, Cleverley et al. describe structural features that are important for these interactions, and identify new interacting partners of GpsB in three bacterial species.
Journal Article
Reliability of telemedicine for real-time paediatric ophthalmology consultations
2022
Background/aimsTo assess the accuracy of real-time telemedicine to diagnose and manage paediatric eye conditions.Methods Design: Prospective, non-inferiority study analysing agreement in diagnoses and management plans between telemedicine and in-person examinations. Setting: Paediatric ophthalmology clinic. Population: Children 0–17 years, English-speaking or Spanish-speaking, able to participate in age-appropriate manner, either previously seen by the optometrist and required ophthalmology referral or newly referred from outside source. Procedures: Paediatric optometrist conducted examinations using digital equipment and streamed live to a paediatric ophthalmologist who recorded diagnoses and management plans, then re-examined patients in-person. Subjects were masked to the fact they would see the ophthalmologist in-person, same-day. Main outcome measures: Discrepancy in management plan or diagnosis between telemedicine and in-person examinations. Non-inferiority threshold was <1.5% for management plan or <15% for diagnosis discrepancies.Results210 patients participated in 348 examinations. 131 (62.4%) had strabismus as primary diagnosis. In these patients, excellent and almost perfect agreement was observed for angle measurements (intraclass correlation coefficients=0.98–1.00) and disease categorisation (kappa=0.94–1.00) (p<0.0001 in all cases). No primary diagnoses changed, and no management plans changed following in-person examination. 54/55 patients who consented for surgery at the initial visit did so while masked to receiving an in-person examination. Families felt comfortable with the quality of the telemedicine examination (98.5%) and would participate in another in the future (97.1%).ConclusionPaediatric ophthalmic conditions can be reliably diagnosed and managed via telemedicine. Access for underserved populations may be improved by collaboration between ophthalmologists and optometrists using this technology.
Journal Article
Early life stress moderates the relation between systemic inflammation and neural activation to reward in adolescents both cross-sectionally and longitudinally
by
Coury, Saché M
,
Yuan, Justin P
,
Ho, Tiffany C
in
Adolescent
,
Adolescents
,
Adverse Childhood Experiences
2024
Elevated levels of systemic inflammation are associated with altered reward-related brain function in ventral striatal areas of the brain like the nucleus accumbens (NAcc). In adolescents, cross-sectional research indicates that exposure to early life stress (ELS) can moderate the relation between inflammation and neural activation, which may contribute to atypical reward function; however, no studies have tested whether this moderation by ELS of neuroimmune associations persists over time. Here, we conducted a cross-sectional analysis and the first exploratory longitudinal analysis testing whether cumulative severity of ELS moderates the association of systemic inflammation with reward-related processing in the NAcc in adolescents (n = 104; 58F/46M; M[SD] age = 16.00[1.45] years; range = 13.07-19.86 years). For the cross-sectional analysis, we modeled a statistical interaction between ELS and levels of C-reactive protein (CRP) predicting NAcc activation during the anticipation and outcome phases of a monetary reward task. We found that higher CRP was associated with blunted NAcc activation during the outcome of reward in youth who experienced higher levels of ELS (β = -0.31; p = 0.006). For the longitudinal analysis, we modeled an interaction between ELS and change in CRP predicting change in NAcc activation across 2 years. This analysis similarly showed that increasing CRP over time was associated with decreasing NAcc during reward outcomes in youth who experienced higher levels of ELS (β = -0.47; p = 0.022). Both findings support contemporary theoretical frameworks involving associations among inflammation, reward-related brain function, and ELS exposure, and suggest that experiencing ELS can have significant and enduring effects on neuroimmune function and adolescent neurodevelopment.
Journal Article
Social threat, fronto-cingulate-limbic morphometry, and symptom course in depressed adolescents: a longitudinal investigation
2023
Psychosocial stressors characterized by social threat, such as interpersonal loss and social rejection, are associated with depression in adolescents. Few studies, however, have examined whether social threat affects fronto-cingulate-limbic systems implicated in adolescent depression.
We assessed lifetime stressor severity across several domains using the Stress and Adversity Inventory (STRAIN) in 57 depressed adolescents (16.15 ± 1.32 years, 34 females), and examined whether the severity of social threat and non-social threat stressors was associated with gray matter volumes (GMVs) in the anterior cingulate cortex (ACC), amygdala, hippocampus, and nucleus accumbens (NAcc). We also examined how lifetime social threat severity and GMVs in these regions related to depressive symptoms at baseline and over 9 months.
General stressor severity was related to greater depression severity at baseline and over 9 months. Moreover, greater severity of social threat (but not non-social threat) stressors was associated with smaller bilateral amygdala and NAcc GMVs, and smaller bilateral surface areas of caudal and rostral ACC (all
⩽ 0.048). However, neither social threat nor non-social threat stressor severity was related to hippocampal GMVs (all
⩾ 0.318). All fronto-cingulate-limbic structures that were associated with the severity of social threat were negatively associated with greater depression severity over 9 months (all
⩽ 0.014). Post-hoc analyses suggested that gray matter morphometry of bilateral amygdala, NAcc, and rostral and caudal ACC mediated the association between social threat and depression severity in adolescents over 9 months (all
< 0.048).
Social threat specifically affects fronto-cingulate-limbic pathways that contribute to the maintenance of depression in adolescents.
Journal Article
Sex differences in myelin content of white matter tracts in adolescents with depression
2021
Depression is a chronic and debilitating condition that often emerges during adolescence, a period of significant brain maturation. Few studies, however, have examined how mechanisms of neuroplasticity, including myelination, are affected by adolescent-onset depression. Here, we used multimodal MR imaging to characterize myelin, indexed by R1, in white matter tracts previously associated with depression and compare 48 adolescents with lifetime depression (45 with current depression, 3 remitted) and 35 healthy controls in R1. Compared to healthy controls, R1 was higher in adolescents with lifetime depression in the uncinate fasciculus and corpus callosum genu (all βs > 0.42; all ps < 0.037). Sex significantly moderated the association between depression and R1 in the left uncinate fasciculus and corpus callosum genu (all βs > 0.86; all ps < 0.02), such that depressed female adolescents had significantly higher R1 in these tracts than did healthy female adolescents (all βs > 0.82; all ps < 0.0012). In contrast, depressed and non-depressed male adolescents did not differ in R1 in these tracts (all ps > 0.32). While fractional anisotropy (FA), a commonly examined measure of white matter organization based on diffusion-weighted MRI, in the left uncinate was positively associated with lifetime depression in our sample (β = 0.56; p = 0.016), we found no evidence of sex-specific effects of depression in FA. Our results suggest that R1 is more sensitive to sex-specific effects of depression than FA, particularly in female adolescents. Given evidence that myelin inhibits synapse formation and reduces brain plasticity, our findings implicate experience-driven regional myelination as a mechanism underlying depression during periods of significant neural maturation such as adolescence.
Journal Article