Neuroimaging of posttraumatic stress disorder in adults and youth: progress over the last decade on three leading questions of the field

Almost three decades have passed since the first posttraumatic stress disorder (PTSD) neuroimaging study was published. Since then, the field of clinical neuroscience has made advancements in understanding the neural correlates of PTSD to create more efficacious treatment strategies. While gold-standard psychotherapy options are available, many patients do not respond to them, prematurely drop out, or never initiate treatment. Therefore, elucidating the neurobiological mechanisms that define the disorder can help guide clinician decision-making and develop individualized mechanisms-based treatment options. To this end, this narrative review highlights progress made in the last decade in adult and youth samples on three outstanding questions in PTSD research: (1) Which neural alterations serve as predisposing (pre-exposure) risk factors for PTSD development, and which are acquired (post-exposure) alterations? (2) Which neural alterations can predict treatment outcomes and define clinical improvement? and (3) Can neuroimaging measures be used to define brain-based biotypes of PTSD? While the studies highlighted in this review have made progress in answering the three questions, the field still has much to do before implementing these findings into clinical practice. Overall, to better answer these questions, we suggest that future neuroimaging studies of PTSD should (A) utilize prospective longitudinal designs, collecting brain measures before experiencing trauma and at multiple follow-up time points post-trauma, taking advantage of multi-site collaborations/consortiums; (B) collect two scans to explore changes in brain alterations from pre-to-post treatment and compare changes in neural activation between treatment groups, including longitudinal follow up assessments; and (C) replicate brain-based biotypes of PTSD. By synthesizing recent findings, this narrative review will pave the way for personalized treatment approaches grounded in neurobiological evidence.

The Relations Among Childhood Maltreatment and Later Intimate Partner Violence Victimization With and Without a Weapon in a Sample of Pregnant Black Individuals

Black pregnant and postpartum individuals are at risk for intimate partner violence (IPV), and those with a history of childhood maltreatment and IPV are even more likely to be re-victimized during pregnancy. However, it is unknown if specific types of child maltreatment predict later IPV with and without a weapon better than others. The current study sought to (i) document the prevalence of childhood maltreatment and IPV and (ii) examine the relations among types of childhood maltreatment and later IPV with and without a weapon within a sample of Black individuals seeking prenatal care at a large public hospital in the southeastern United States. Participants (n = 186; mean age = 27.2 years, SD = 5.3) completed measures assessing childhood maltreatment and IPV with and without a weapon. Approximately 68.5% of participants (n = 124) endorsed experiencing childhood maltreatment, while 42.6% (n = 78) endorsed experiencing IPV. The bivariate relations among five childhood maltreatment types (i.e., sexual, physical, and emotional abuse, physical and emotional neglect) and IPV with and without a weapon were assessed. All childhood maltreatment subtype scores-except childhood physical neglect-were significantly higher among participants who reported a history of IPV with or without a weapon compared to participants who denied a history of IPV with or without a weapon. Logistic regression models revealed childhood sexual abuse emerged as the only significant predictor of experiencing IPV with a weapon (B = 0.10, p = .003) and IPV without a weapon (B = 0.11, p = .001). For every point increase in childhood sexual abuse subtype score, the odds of experiencing IPV with and without a weapon increased by 10% (OR = 1.10, 95%CI [1.04, 1.18]) and 12% (OR = 1.12, [1.05, 1.20]), respectively. Findings suggest that screening for childhood sexual abuse may provide a critical opportunity for maternity care providers to identify individuals at increased risk for IPV victimization with and without a weapon.

Indirect effect of negative evaluations of therapy on the association between racial stress and posttraumatic stress disorder symptoms in pregnant Black persons

OBJECTIVE

Black pregnant individuals are at disproportionate risk for posttraumatic stress disorder (PTSD) compared to other groups. A wealth of literature suggests racial stress contributes to this inequity, but cultural and structural mechanisms, such as perceived barriers to mental health treatment, underlying the relationship between racial stress and PTSD symptoms remain understudied. Negative evaluations of psychotherapy and stigma represent potential mechanisms, though no previous studies have examined these associations. To address this gap, we tested an indirect effect of racial stress on PTSD symptoms through perceived barriers to mental health treatment in pregnant Black individuals.

METHOD

Mediation analyses were used to assess an indirect relationship between racial stress and PTSD symptoms through perceived barriers to mental health treatment.

RESULTS

At the bivariate level, racial stress was significantly associated with PTSD symptoms (r = .20, p = .03) and negative evaluations of therapy (r = .22, p = .02), but not with stigma (r = .140, p = .147). Negative evaluations of therapy were also associated with PTSD symptoms (r = .43, p < .001). There was an indirect effect of racial stress on PTSD symptoms through a negative evaluation of therapy, β = .08, SE = 0.04, CI [0.01, 0.18]. More specifically, racial stress was associated with a more negative evaluation of therapy, which was in turn associated with more PTSD symptoms.

CONCLUSIONS

Results highlight the need for accessible and culturally competent mental health care for pregnant Black individuals. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Associations of alcohol and cannabis use with change in posttraumatic stress disorder and depression symptoms over time in recently trauma-exposed individuals

BACKGROUND

Several hypotheses may explain the association between substance use, posttraumatic stress disorder (PTSD), and depression. However, few studies have utilized a large multisite dataset to understand this complex relationship. Our study assessed the relationship between alcohol and cannabis use trajectories and PTSD and depression symptoms across 3 months in recently trauma-exposed civilians.

METHODS

In total, 1618 (1037 female) participants provided self-report data on past 30-day alcohol and cannabis use and PTSD and depression symptoms during their emergency department (baseline) visit. We reassessed participant's substance use and clinical symptoms 2, 8, and 12 weeks posttrauma. Latent class mixture modeling determined alcohol and cannabis use trajectories in the sample. Changes in PTSD and depression symptoms were assessed across alcohol and cannabis use trajectories via a mixed-model repeated-measures analysis of variance.

RESULTS

Three trajectory classes (low, high, increasing use) provided the best model fit for alcohol and cannabis use. The low alcohol use class exhibited lower PTSD symptoms at baseline than the high use class; the low cannabis use class exhibited lower PTSD and depression symptoms at baseline than the high and increasing use classes; these symptoms greatly increased at week 8 and declined at week 12. Participants who already use alcohol and cannabis exhibited greater PTSD and depression symptoms at baseline that increased at week 8 with a decrease in symptoms at week 12.

CONCLUSIONS

Our findings suggest that alcohol and cannabis use trajectories are associated with the intensity of posttrauma psychopathology. These findings could potentially inform the timing of therapeutic strategies.

Indirect effect of race-related stress on traumatic stress and depression symptoms via subjective social status in a Black community sample

Experiencing racism is linked to lower subjective social status (SSS), defined as one's perception of their position in society. SSS is influenced by power, prestige, and objective socioeconomic status (SES). Previous findings suggest that race-related stress may be related to adverse mental health outcomes through SSS in Black Americans, a population that has been deeply affected by continuing legacies of oppression. The current study examines the indirect association between race-related stress and posttraumatic stress disorder (PTSD) and depression symptoms through SSS in a community sample of largely trauma-exposed Black Americans (N = 173). Hierarchical regression analyses indicated that overall race-related stress significantly predicted lower SSS, higher PTSD symptoms, and higher depression symptoms. Analyses also revealed indirect effects of cultural race-related stress on PTSD and depression symptoms through SSS after controlling for SES. Results suggest that the experience of race-related stress, particularly cultural race-related stress, which involves the degradation and disparagement of one's culture and worldview, is associated with more severe PTSD and depression symptoms potentially due to these experiences decreasing Black Americans' SSS. Findings support the need for systemic intervention strategies to disrupt the cultural oppression of Black Americans and improve the societal value and mental health of this population.

Pre-treatment amygdala activation and habituation predict symptom change in post-traumatic stress disorder

Trauma-focused psychotherapy approaches are the first-line treatment option for post-traumatic stress disorder (PTSD); however, up to a third of patients remain symptomatic even after completion of the treatment. Predicting which patients will respond to a given treatment option would support personalized treatments and improve the efficiency of healthcare systems. Although previous neuroimaging studies have examined possible pre-treatment predictors of response to treatment, the findings have been somewhat inconsistent, and no other study has examined habituation to stimuli as a predictor. In this study, 16 treatment-seeking adults (M_Age = 43.63, n = 10 women) with a primary diagnosis of PTSD passively viewed pictures of emotional facial expressions during functional magnetic resonance imaging (fMRI). After scanning, participants rated facial expressions on both valence and arousal. Participants then completed eight weekly sessions of prolonged exposure (PE) therapy. PTSD symptom severity was measured before and after treatment. Overall, participants showed symptomatic improvement with PE. Consistent with hypotheses, lesser activation in the amygdala and greater activation in the ventromedial prefrontal cortex during the presentation of fearful vs. happy facial expressions, as well as a greater decline in amygdala activation across blocks of fearful facial expressions at baseline, were associated with greater reduction of PTSD symptoms. Given that the repeated presentation of emotional material underlies PE, changes in brain responses with repeated stimulus presentations warrant further studies as potential predictors of response to exposure therapies.

Alcohol self-administration and nicotine withdrawal alter biomarkers of stress and inflammation and prefrontal cortex changes in Gβ subunits

Background: Although alcohol and nicotine are often used together, the biological consequences of these substances are not well understood. Identifying shared targets will inform cessation pharmacotherapies and provide a deeper understanding of how co-use of alcohol and nicotine impacts health, including biomarkers of stress and inflammation.Objective: We examined the effects of nicotine exposure and withdrawal on alcohol self-administration (SA), stress and inflammatory biomarkers, and a G-protein coupled receptor subunit (Gβ) in brain areas associated with drug use.Methods: Male rats were trained to SA alcohol and then received a nicotine pump (n = 7-8 per group). We assessed alcohol intake for 12 days during nicotine exposure and then following pump removal to elicit withdrawal. After the behavioral studies, we assessed plasma leptin, corticosterone, and interleukin-1β (IL-1β), and Gβ protein expression in the amygdala, nucleus accumbens (NAc), and prefrontal cortex (PFC).Results: Nicotine exposure or withdrawal did not alter alcohol intake (p > .05). Alcohol and nicotine withdrawal elevated corticosterone levels (p = .015) and decreased Gβ levels in the PFC (p = .004). In the absence of nicotine, alcohol SA suppressed IL-1β levels (p = .039). Chronic exposure to nicotine or withdrawal during alcohol SA did not alter leptin levels or Gβ expression in the amygdala or NAc (p's > .05).Conclusions: The combination of alcohol SA and nicotine withdrawal produced a persistent increase in stress biomarkers and a suppression in Gβ expression in the PFC, providing an important first step toward understanding the common biological mechanisms of alcohol/nicotine misuse.

Validating the primary care posttraumatic stress disorder screen for DSM-5 (PC-PTSD-5) in a substance misusing, trauma-exposed, socioeconomically vulnerable population

The co-occurrence of substance use disorder (SUD) and posttraumatic stress disorder (PTSD) is common, and is associated with greater severity of symptoms, poorer treatment prognosis, and increased risk of return to substance use following treatment. Screening for PTSD is not routinely implemented in substance use treatment programs, despite clinical relevance. Identifying screening tools that minimize patient burden and allow for comprehensive treatment in this patient population is critical. The current study examined the utility of the Primary Care PTSD Screen for DSM-5 (PC-PTSD-5) in identifying probable PTSD in a predominantly Black sample of 81 socioeconomically disadvantaged substance misusing hospital patients. The majority of the sample (75.3 %; n = 61) were found to meet criteria for probable PTSD using a suggested clinical cut score of 33 on the PTSD Checklist for DSM-5 (PCL-5). Diagnostic utility analyses were completed and determined a cut-score of 5 for the PC-PTSD-5 to demonstrate the best performance (SE = 0.62, κ(1) = 0.22; SP =.80, κ(0) = 0.61; EEF = 0.67, κ(0.5) = 0.32) in this sample. Results provide preliminary support for the use of the PC-PTSD-5 as a brief screening tool for probable PTSD in substance misusing patient populations. Routine use of the PC-PTSD-5 during assessment may be beneficial when treatment planning with those undergoing treatment for SUD because comprehensive assessment and treatment will provide a better chance of long-term recovery.

Exaggerated amygdala activation to ambiguous facial expressions is a familial vulnerability factor for posttraumatic stress disorder

OBJECTIVE

Previous research has reported hyperresponsivity in the amygdala and hyporesponsivity in ventral portions of the medial prefrontal cortex to threat-related stimuli in posttraumatic stress disorder (PTSD). Whether such findings generalize to more ambiguous stimuli and whether such brain activation abnormalities reflect familial vulnerabilities, trauma-exposure, or acquired characteristics of PTSD remain unclear. In this study, we measured brain responses to emotionally ambiguous stimuli (i.e., surprised facial expressions) in identical twin pairs discordant for trauma exposure to elucidate the origin of brain activation abnormalities.

METHODS

Participants with PTSD (n = 12) and their trauma-unexposed identical cotwins (n = 12), as well as trauma-exposed participants without PTSD (n = 15) and their trauma-unexposed identical cotwins (n = 15), passively viewed surprised and neutral facial expressions during functional magnetic resonance imaging (fMRI). Afterward, participants labeled and rated each facial expression on valence and arousal.

RESULTS

Amygdala activation to Surprised and Neutral facial expressions (versus Fixation) was greater in the participants with PTSD and their trauma-unexposed identical cotwins without PTSD, compared to the control twin pairs. In contrast, medial frontal gyrus (MFG) activation to Surprised facial expressions (versus Fixation) was diminished in the PTSD group relative to the other three groups.

CONCLUSIONS

Amygdala hyperresponsivity to emotionally ambiguous facial expressions may be a familial vulnerability factor that increases the likelihood of developing PTSD after experiencing a traumatic event. In contrast, MFG hyporesponsivity may be an acquired characteristic of the disorder.

Right inferior frontal gyrus and ventromedial prefrontal activation during response inhibition is implicated in the development of PTSD symptoms

Background

Inhibition is a critical executive control process and an established neurobiological phenotype of PTSD, yet to our knowledge, no prospective studies have examined this using a contextual cue task that enables measurement of behavioural response and neural activation patterns across proactive and reactive inhibition.

Objective

The current longitudinal study utilised functional magnetic resonance imaging (fMRI) to examine whether deficits in proactive and reactive inhibition predicted PTSD symptoms six months after trauma.

Method

Twenty-three (65% males) medical patients receiving emergency medical care from a level 1 trauma centre were enrolled in the study and invited for an MRI scan 1-2-months post-trauma. PTSD symptoms were measured using self-report at scan and 6-months post-trauma. A stop-signal anticipation task (SSAT) during an fMRI scan was used to test whether impaired behavioural proactive and reactive inhibition, and reduced activation in right inferior frontal gyrus (rIFG), ventromedial prefrontal cortex (vmPFC), and bilateral hippocampus, were related to PTSD symptoms. We predicted that lower activation levels of vmPFC and rIFG during reactive inhibition and lower activation of hippocampus and rIFG during proactive inhibition would relate to higher 6-month PTSD symptoms.

Results

No significant associations were found between behavioural measures and 6-month PTSD. Separate linear regression analyses showed that reduced rIFG activation (F_1,21= 9.97, R²= .32, p = .005) and reduced vmPFC activation (F_1,21= 5.19, R²= .20, p = .03) significantly predicted greater 6-month PTSD symptoms; this result held for rIFG activation controlling for demographic variables and baseline PTSD symptoms (β = -.45, p = .04) and Bonferroni correction.

Conclusion

Our findings suggest that impaired rIFG and, to a lesser extent, vmPFC activation during response inhibition may predict the development of PTSD symptoms following acute trauma exposure. Given the small sample size, future replication studies are needed.

HIGHLIGHTS

Impaired inhibition may be an important risk factor for the development of PTSD following trauma, with less right inferior frontal gyrus and ventromedial prefrontal cortex activation during response inhibition predicting PTSD development.

New public health policy intervention for diabetic foot management in Mexico

Problem

In Mexico, an estimated 12 million people have diabetes, with complications of diabetes contributing to 25-90% of non-traumatic amputations.

Description of the Problem

We conducted a review through the literature of available studies in English-language databases and libraries, including PubMed and UNAM digital Library to determine the role of teaching first contact health workers and the creation of limb salvage teams in the prevention of amputations. Through this review, we present the basis of our proposal about implementing these strategies to improve a care coordination system for diabetic foot management in Mexico.

Results

There were 25 publications from different countries, 12 eligible for this review. The review emphasizes that the creation of Specialized Diabetic Foot Teams to treat patients and teach first contact medical workers could help to achieve the following objectives which result in the reduction of amputations and improved patient outcomes: Standardize and simplify the diabetic foot clinical examination.

Timely reference of patients with DM with a moderate and high risk of diabetic foot complications.

Timely reference of patients with diabetic foot and peripheral arterial disease to third-level hospitals.

Periodic first-contact health workers training on risk detection and stratification of diabetic foot.

Lessons

Implementing the policy of creation of Specialized Diabetic Foot Teams to treat patients and teach first contact medical workers will contribute to reducing major amputations due to diabetes in our country. We aim to implement a successful policy in Mexico to strengthen the health system and improve outcomes and therefore the quality of life of patients with diabetic foot complications. We aim to serve as a legislative voice for all patients in Mexico facing major amputations and other diabetes complications.

Key messages

New public health policy implementation for diabetic foot management in Mexico. Prevention of major amputations.

Omega-3 fatty acids in contrast to omega-6 protect against pneumococcal pneumonia

PURPOSE

The aim of this study was to assess if long-term supplementation of omega-3 fatty acids or a diet rich in omega-6 fatty acids ameliorates disease severity in a murine model of pneumococcal pneumonia. We hypothesize that long-term dietary supplementation of omega-3 fatty acids will reduce inflammation, disease severity and improve survival compared to omega-6 fatty acids.

METHODS

Mice receiving diets supplemented with Omega-3 or Omega-6 for two months were intranasally infected with Streptococcus pneumoniae. We analyzed survival, bacterial burden, histopathology and inflammatory biomarkers.

RESULTS

Our results showed that Omega-3 supplementation had increased survival (p = 0.005), less bacteremia (p = 0.0001) and lower bacterial burden in the lungs (p = 0.0002) when compared to the Omega-6 supplementation. Overall, Omega-3 reduced lung pathology, in particular peribronchial inflammation and cell death. Analyses of lung homogenates showed the Omega-3 cohort had decreased levels of the inflammatory cytokine interleukin-6 and an increase in anti-inflammatory cytokine interleukin-10.

CONCLUSIONS

Supplementation of mouse diets with Omega-3 fatty acids improved survival, bacterial invasion in the blood and lungs as well as decreased overall lung tissue inflammation and cell death when compared to the Omega-6 supplemented diets. Translation of these findings in humans may improve outcomes of patients at risk for pneumonia.

Diminished medial prefrontal cortex activation during the recollection of stressful events is an acquired characteristic of PTSD

BACKGROUND

Previous research has shown relatively diminished medial prefrontal cortex activation and heightened psychophysiological responses during the recollection of personal events in post-traumatic stress disorder (PTSD), but the origin of these abnormalities is unknown. Twin studies provide the opportunity to determine whether such abnormalities reflect familial vulnerabilities, result from trauma exposure, or are acquired characteristics of PTSD.

METHODS

In this case-control twin study, 26 male identical twin pairs (12 PTSD; 14 non-PTSD) discordant for PTSD and combat exposure recalled and imagined trauma-unrelated stressful and neutral life events using a standard script-driven imagery paradigm during functional magnetic resonance imaging and concurrent skin conductance measurement.

RESULTS

Diminished activation in the medial prefrontal cortex during Stressful v. Neutral script-driven imagery was observed in the individuals with PTSD, relative to other groups.

CONCLUSIONS

Diminished medial prefrontal cortex activation during Stressful v. Neutral script-driven imagery may be an acquired characteristic of PTSD. If replicated, this finding could be used prospectively to inform diagnosis and the assessment of treatment response.

Severe Pneumococcal Pneumonia Causes Acute Cardiac Toxicity and Subsequent Cardiac Remodeling

RATIONALE

Up to one-third of patients hospitalized with pneumococcal pneumonia experience major adverse cardiac events (MACE) during or after pneumonia. In mice, Streptococcus pneumoniae can invade the myocardium, induce cardiomyocyte death, and disrupt cardiac function following bacteremia, but it is unknown whether the same occurs in humans with severe pneumonia.

OBJECTIVES

We sought to determine whether S. pneumoniae can (1) translocate the heart, (2) induce cardiomyocyte death, (3) cause MACE, and (4) induce cardiac scar formation after antibiotic treatment during severe pneumonia using a nonhuman primate (NHP) model.

METHODS

We examined cardiac tissue from six adult NHPs with severe pneumococcal pneumonia and three uninfected control animals. Three animals were rescued with antibiotics (convalescent animals). Electrocardiographic, echocardiographic, and serum biomarkers of cardiac damage were measured (troponin T, N-terminal pro-brain natriuretic peptide, and heart-type fatty acid binding protein). Histological examination included hematoxylin and eosin staining, immunofluorescence, immunohistochemistry, picrosirius red staining, and transmission electron microscopy. Immunoblots were used to assess the underlying mechanisms.

MEASUREMENTS AND MAIN RESULTS

Nonspecific ischemic alterations were detected by electrocardiography and echocardiography. Serum levels of troponin T and heart-type fatty acid binding protein were increased (P < 0.05) after pneumococcal infection in both acutely ill and convalescent NHPs. S. pneumoniae was detected in the myocardium of all NHPs with acute severe pneumonia. Necroptosis and apoptosis were detected in the myocardium of both acutely ill and convalescent NHPs. Evidence of cardiac scar formation was observed only in convalescent animals by transmission electron microscopy and picrosirius red staining.

CONCLUSIONS

S. pneumoniae invades the myocardium and induces cardiac injury with necroptosis and apoptosis, followed by cardiac scarring after antibiotic therapy, in an NHP model of severe pneumonia.

Factors Associated With Need for Revascularisation in Non-coronary Arterial Occlusive Lesions Secondary to Takayasu's Arteritis

OBJECTIVE/BACKGROUND

Takayasu's arteritis (TA) is rare inflammatory large vessel form of vasculitis. The objective of this study was to evaluate experience in the management of TA patients and to identify the influence of inflammatory markers and clinical variables associated with disease progression, worsening ischaemic symptoms, and the need for interventions.

METHODS

Demographics, and laboratory and clinical variables in patients that required revascularisation procedures were compared with those who had adequate symptomatic control with medical management. Categorical data were analysed with Fisher's exact test, continuous variables with two-sample t test, and a life table analysis was used to study the recurrence of symptoms in intervened patients.

RESULTS

From January 1995 to May 2016, 47 patients (mean age 30 years; range 14-59 years) were managed; 44 (94%) were female. During the mean follow-up period of 120 months, 21 (45%) underwent 23 procedures (17 of these [74%] open, six [26%] endovascular). From the intervened group, eight (38%) patients presented with transient ischaemic attacks, five (24%) with renovascular hypertension, and four (19%) with upper extremity and four (19%) lower extremity claudication. Comparative analysis demonstrated that elevation of erythrocyte sedimentation rate (ESR) at the time of the diagnosis (revascularisation group: median value 28 mm/hour; medical management group: median value 15 mm/hour) was associated with progression of the disease, worsening symptoms, and subsequent need for intervention (p = .04). Active smoking was a factor connected with the need for revascularisation (p = .05). Immediate symptomatic improvement occurred in 19 (90%) patients that underwent surgical or endovascular revascularisation.

CONCLUSION

Patients with TA who underwent interventions had higher ESR at the time of diagnosis; this factor and active smoking were associated with progression of the disease and worsening ischaemic symptoms despite medical therapy. Revascularisation procedures are effective at relieving symptoms; lifelong surveillance is necessary.

Transcriptional organization of pneumococcal psrP-secY2A2 and impact of GtfA and GtfB deletion on PsrP-associated virulence properties

Pneumococcal serine-rich repeat protein (PsrP) is a glycoprotein that mediates Streptococcus pneumoniae attachment to lung cells and promotes biofilm formation. Herein, we investigated the transcriptional organization of psrP-secY2A2, the 37-kbp pathogenicity island encoding PsrP and its accessory genes. PCR amplification of cDNA and RNA-seq analysis found psrP-secY2A2 to be minimally composed of three operons: psrP-glyA, glyB, and glyC-asp5. Transcription of all three operons was greatest during biofilm growth and immunoblot analyses confirmed increased PsrP production by biofilm pneumococci. Using gas chromatography-mass spectrometry we identified monomeric N-acetylglucosamine as the primary glycoconjugate present on a recombinant intracellular version of PsrP, i.e. PsrP_1-734. This finding was validated by immunoblot using lectins with known carbohydrate specificities. We subsequently deleted gtfA and gtfB, the GTFs thought to be responsible for addition of O-linked N-acetylglucosamine, and tested for PsrP and its associated virulence properties. These deletions negatively affected our ability to detect PsrP_1-734 in bacterial whole cell lysates. Moreover, S. pneumoniae mutants lacking these genes pheno-copied the psrP mutant and were attenuated for: biofilm formation, adhesion to lung epithelial cells, and pneumonia in mice. Our studies identify the transcriptional organization of psrP-secY2A2 and show the indispensable role of GtfA and GtfB on PsrP-mediated pneumococcal virulence.

Impact of optimal anticoagulation therapy on chronic venous ulcer healing in thrombophilic patients with post-thrombotic syndrome

OBJECTIVE

Post-thrombotic syndrome (PTS) is the long-term sequelae of deep venous thrombosis (DVT). PTS clinical manifestations include chronic leg pain, oedema, lipodermatosclerosis and ulcers. The objective of this study is to determine in patients with documented history of thrombophilias and DVT whether the number of previous thrombotic events and optimal anticoagulation therapy are associated with the time to venous ulcer healing following the start of compression therapy.

METHOD

Retrospective analysis performed in thrombophilic patients under the age of 50 years old with chronic venous ulcers secondary to DVT at the wound clinic in the National Institute of Medical Sciences and Nutrition 'Salvador Zubirán ' in Mexico City. Variables such as the number or episodes of thrombotic events, type of hypercoagulable disorder, optimal anticoagulation therapy with Warfarin monitored by therapeutic International Normalised Ratio (INR) (2-3) and compliance to compression therapy were examined. Patients that underwent superficial or perforator vein interruption or endovascular recanalisation of deep veins were excluded from the study.

RESULTS

From a database of 29 patients with chronic venous ulcers followed in our clinic from January 1992 to September 2012, only 13 patients (61% female) met the inclusion criteria. Mean age±standard deviation (SD) was 32±12 years old. Of these, seven (54%) patients with suboptimal INR presented with an average of two previous thrombotic events and the remaining six (46%) patients with optimal INR only one event (p=0.28), the mean time to the clinical manifestation of a venous ulcer after the first episode of DVT was 39 months (range: 12-72) for patients with suboptimal INR and 82 months (range: 12-216) for those with optimal anticoagulation therapy (p=0.11). During the mean follow-up period of 52 months, all patients in optimal anticoagulation healed their ulcer; their mean time for wound healing was 44 months (range: 4-102). In the suboptimal INR group, only four healed the ulcers with an mean of 72 months (range: 2-204) (p=0.94).

CONCLUSION

There seems to be an association between an optimal anticoagulation therapy with Warfarin monitored by INR and wound healing rates in thrombophilic patients with chronic venous ulcers. Further research is warranted.

DECLARATION OF INTEREST

The authors have no conflict of interest.

A Non-Human Primate Model of Severe Pneumococcal Pneumonia

RATIONALE

Streptococcus pneumoniae is the leading cause of community-acquired pneumonia and infectious death in adults worldwide. A non-human primate model is needed to study the molecular mechanisms that underlie the development of severe pneumonia, identify diagnostic tools, explore potential therapeutic targets, and test clinical interventions during pneumococcal pneumonia.

OBJECTIVE

To develop a non-human primate model of pneumococcal pneumonia.

METHODS

Seven adult baboons (Papio cynocephalus) were surgically tethered to a continuous monitoring system that recorded heart rate, temperature, and electrocardiography. Animals were inoculated with 109 colony-forming units of S. pneumoniae using bronchoscopy. Three baboons were rescued with intravenous ampicillin therapy. Pneumonia was diagnosed using lung ultrasonography and ex vivo confirmation by histopathology and immunodetection of pneumococcal capsule. Organ failure, using serum biomarkers and quantification of bacteremia, was assessed daily.

RESULTS

Challenged animals developed signs and symptoms of pneumonia 4 days after infection. Infection was characterized by the presence of cough, tachypnea, dyspnea, tachycardia and fever. All animals developed leukocytosis and bacteremia 24 hours after infection. A severe inflammatory reaction was detected by elevation of serum cytokines, including Interleukin (IL)1Ra, IL-6, and IL-8, after infection. Lung ultrasonography precisely detected the lobes with pneumonia that were later confirmed by pathological analysis. Lung pathology positively correlated with disease severity. Antimicrobial therapy rapidly reversed symptomology and reduced serum cytokines.

CONCLUSIONS

We have developed a novel animal model for severe pneumococcal pneumonia that mimics the clinical presentation, inflammatory response, and infection kinetics seen in humans. This is a novel model to test vaccines and treatments, measure biomarkers to diagnose pneumonia, and predict outcomes.

Endothelial adhesion molecules and multiple organ failure in patients with severe sepsis

OBJECTIVE

To determine if serum levels of endothelial adhesion molecules were associated with the development of multiple organ failure (MOF) and in-hospital mortality in adult patients with severe sepsis.

DESIGN

This study was a secondary data analysis of a prospective cohort study.

SETTING

Patients were admitted to two tertiary intensive care units in San Antonio, TX, between 2007 and 2012.

PATIENTS

Patients with severe sepsis at the time of intensive care unit (ICU) admission were enrolled. Inclusion criteria were consistent with previously published criteria for severe sepsis or septic shock in adults. Exclusion criteria included immunosuppressive medications or conditions.

INTERVENTIONS

None.

MEASUREMENTS

Baseline serum levels of the following endothelial cell adhesion molecules were measured within the first 72h of ICU admission: Intracellular Adhesion Molecule 1 (ICAM-1), Vascular Cell Adhesion Molecule-1 (VCAM-1), and Vascular Endothelial Growth Factor (VEGF). The primary and secondary outcomes were development of MOF (⩾2 organ dysfunction) and in-hospital mortality, respectively.

MAIN RESULTS

Forty-eight patients were enrolled in this study, of which 29 (60%) developed MOF. Patients that developed MOF had higher levels of VCAM-1 (p=0.01) and ICAM-1 (p=0.01), but not VEGF (p=0.70) compared with patients without MOF (single organ failure only). The area under the curve (AUC) to predict MOF according to VCAM-1, ICAM-1 and VEGF was 0.71, 0.73, and 0.54, respectively. Only increased VCAM-1 levels were associated with in-hospital mortality (p=0.03). These associations were maintained even after adjusting for APACHE and SOFA scores using logistic regression.

CONCLUSIONS

High levels of serum ICAM-1 was associated with the development of MOF. High levels of VCAM-1 was associated with both MOF and in-hospital mortality.

Chromogranin A levels and mortality in patients with severe sepsis

CONTEXT

Chromogranin A (CgA) is a novel biomarker with potential to assess mortality risk of patients with severe sepsis.

OBJECTIVE

Assess association of CgA levels and mortality risk of severely septic patients.

METHODS

Serum CgA levels were measured in 50 hospitalized, severely septic patients with organ failure <48 h.

RESULTS

Higher CgA levels trended toward higher ICU and hospital mortality. Patients without cardiovascular disease who died in the ICU had higher median (IQR) CgA levels 602.3 (343.3, 1134.3) ng/ml versus 205.5 (130.7, 325.9) ng/ml, p = 0.01.

CONCLUSIONS

High CgA levels predict ICU mortality in severely septic patients without prior cardiovascular disease.

Elevated A20 contributes to age-dependent macrophage dysfunction in the lungs

Advanced age is associated with chronic low-grade inflammation (i.e. inflamm-aging) and poor macrophage function that includes a weak pro-inflammatory cytokine response to bacteria and diminished phagocytosis (i.e. age-dependent macrophage dysfunction [ADMD]). One reason for this is that ADMD is associated with poor NFκB and MAPK activation following Toll-like receptor stimulation. Herein, we tested the hypothesis that inflamm-aging induces production of A20, a cytosolic and homeostatic suppressor of the NFκB and MAPK signaling cascades that deubiquitinates (i.e. inactivates) the common upstream signaling molecule TRAF6, and this is responsible for ADMD. Western blots and immunohistochemistry comparing tissues from young, mature, and aged C57BL/6 mice indicated that A20 was strongly elevated in the lungs of aged mice but not in other tissues. Elevated A20 was also detected in alveolar macrophages (AM) from aged mice. In contrast CYLD, a second deubiquitinase that also negatively regulates the NFκB pathway was decreased with aging. Following co-incubation of AM with the bacteria Streptococcus pneumoniae, TRAF6 polyubiquitination was diminished in AM isolated from aged versus young mice. A20 production was inducible in the J774A.1 macrophage cell line and C57BL/6AM by overnight incubation with TNFα but not IL-6. Retrovirus-induced expression of A20 in J774A.1 cells resulted in their diminished production of IL-6 following exposure to S. pneumoniae but had no effect on levels of phagocytosis. Overnight incubation of AM from young mice with TNFα also resulted in a dampened IL-6 response to S. pneumoniae. Finally, dietary supplementation of aged mice with anti-inflammatory n-3 polyunsaturated fatty acids in the form of fish oil lowered lung A20 levels and enhanced resistance, including a 100-fold reduction in bacterial titers in the lungs, to experimental challenge with S. pneumoniae. We conclude that elevated A20 due to TNFα partially explains the ADMD phenotype and that ADMD is potentially reversible.

Enteric-delivered rapamycin enhances resistance of aged mice to pneumococcal pneumonia through reduced cellular senescence

Rapamycin, a potent immunomodulatory drug, has shown promise in the amelioration of numerous age-associated diseases including cancer, Alzheimer's disease and cardiac hypertrophy. Yet the elderly, the population most likely to receive therapeutic rapamycin, are already at increased risk for infectious disease; thus concern exists that rapamycin may exacerbate age-associated immune dysfunctions and worsen infection outcomes. Herein, we examined the impact of enteric delivered rapamycin monotherapy (eRapa) on the susceptibility of aged (22-24month) C57BL/6 mice to Streptococcus pneumoniae, the leading bacterial cause of community-acquired pneumonia. Following challenge with S. pneumoniae, administration of eRapa conferred modest protection against mortality. Reduced mortality was the result of diminished lung damage rather than reduced bacterial burden. eRapa had no effect on basal levels of Interleukin (IL)-1α, IL-6, IL-10, IL-12p70, KC, Interferon-γ, Tumor necrosis factor α and Monocyte chemotactic protein-1 in whole lung homogenates or during pneumococcal pneumonia. Previously we have demonstrated that cellular senescence enhances permissiveness for bacterial pneumonia through increased expression of the bacterial ligands Laminin receptor (LR), Platelet-activating factor receptor (PAFr) and Cytokeratin 10 (K10). These proteins are co-opted by S. pneumoniae and other respiratory tract pathogens for host cell attachment during lung infection. UM-HET3 mice on eRapa had reduced lung cellular senescence as determined by levels of the senescence markers p21 and pRB, but not mH2A.1. Mice on eRapa also had marked reductions in PAFr, LR, and K10. We conclude that eRapa protected aged mice against pneumonia through reduced lung cellular senescence, which in turn, lowered bacterial ligand expression.

Impact of oral simvastatin therapy on acute lung injury in mice during pneumococcal pneumonia

Background

Recent studies suggest that the reported protective effects of statins (HMG-CoA reductase inhibitors) against community-acquired pneumonia (CAP) and sepsis in humans may be due to confounders and a healthy user-effect. To directly test whether statins are protective against Streptococcus pneumoniae, the leading cause of CAP, we examined the impact of prolonged oral simvastatin therapy at physiologically relevant doses in a mouse model of pneumococcal pneumonia. BALB/c mice were placed on rodent chow containing 0 mg/kg (control), 12 mg/kg (low simvastatin diet [LSD]; corresponds to 1.0 mg/kg/day), or 120 mg/kg (high simvastatin diet [HSD]; corresponds to 10 mg/kg/day) simvastatin for four weeks, infected intratracheally with S. pneumoniae serotype 4 strain TIGR4, and sacrificed at 24, 36, or 42 h post-infection for assessment of lung histology, cytokine production, vascular leakage and edema, bacterial burden and bloodstream dissemination. Some mice received ampicillin at 12-h intervals beginning at 48 h post-infection and were monitored for survival. Immunoblots of homogenized lung samples was used to assess ICAM-1 production.

Results

Mice receiving HSD had reduced lung consolidation characterized by less macrophage and neutrophil infiltration and a significant reduction in the chemokines MCP-1 (P = 0.03) and KC (P = 0.02) and ICAM-1 in the lungs compared to control mice. HSD mice also had significantly lower bacterial titers in the blood at 36 (P = 0.007) and 42 (P = 0.03) hours post-infection versus controls. LSD had a more modest effect against S. pneumoniae but also resulted in reduced bacterial titers in the lungs and blood of mice after 42 h and a reduced number of infiltrated neutrophils. Neither LSD nor HSD mice had reduced mortality in a pneumonia model where mice received ampicillin 48 h after challenge.

Conclusions

Prolonged oral simvastatin therapy had a strong dose-dependent effect on protection against S. pneumoniae as evidenced by reduced neutrophil infiltration, maintenance of vascular integrity, and lowered chemokine production in the lungs of mice on HSD. Statin therapy also protected through reduced bacterial burden in the lungs. Despite these protective correlates, mortality in the simvastatin-receiving cohorts was equivalent to controls. Thus, oral simvastatin at physiologically relevant doses only modestly protects against pneumococcal pneumonia.

Changes in capsular serotype alter the surface exposure of pneumococcal adhesins and impact virulence

We examined the contribution of serotype on Streptococcus pneumoniae adhesion and virulence during respiratory tract infection using a panel of isogenic TIGR4 (serotype 4) mutants expressing the capsule types 6A (+6A), 7F (+7F) and 23F (+23F) as well as a deleted and restored serotype 4 (+4) control strain. Immunoblots, bacterial capture assays with immobilized antibody, and measurement of mean fluorescent intensity by flow cytometry following incubation of bacteria with antibody, all determined that the surface accessibility, but not total protein levels, of the virulence determinants Pneumococcal surface protein A (PspA), Choline binding protein A (CbpA), and Pneumococcal serine-rich repeat protein (PsrP) changed with serotype. In vitro, bacterial adhesion to Detroit 562 pharyngeal or A549 lung epithelial cells was modestly but significantly altered for +6A, +7F and +23F. In a mouse model of nasopharyngeal colonization, the number of +6A, +7F, and +23F pneumococci in the nasopharynx was reduced 10 to 100-fold versus +4; notably, only mice challenged with +4 developed bacteremia. Intratracheal challenge of mice confirmed that capsule switch strains were highly attenuated for virulence. Compared to +4, the +6A, +7F, and +23F strains were rapidly cleared from the lungs and were not detected in the blood. In mice challenged intraperitoneally, a marked reduction in bacterial blood titers was observed for those challenged with +6A and +7F versus +4 and +23F was undetectable. These findings show that serotype impacts the accessibility of surface adhesins and, in particular, affects virulence within the respiratory tract. They highlight the complex interplay between capsule and protein virulence determinants.

Acute bile duct injury. The need for a high repair

BACKGROUND

An immediate repair is considered optimal in acute biliary duct injuries; however, it may prove to be a challenge, because such repairs are usually performed on small ducts whose viability cannot always be determined.

METHODS

We performed a retrospective review of the charts of patients with acute bile duct injury who underwent repair at a tertiary care academic university hospital. A total of 204 patients with acute bile duct injury were seen between 1989 and 2002. Of these, 30 were repaired within minutes to hours after the injury. These patients were divided into two groups. Group I patients had a Roux-en-Y hepatojejunostomy below the hepatic junction; Group II patients had a Roux-en-Y hepatojejunostomy at the junction level. We then performed a long-term evaluation of anastomosis function in these patients, using clinical, radiological, and laboratory.

RESULTS

Twenty-eight injuries were secondary to a laparoscopy; the other two resulted from open cholecystectomies. All of the patients suffered complex injuries with complete section of the duct and substance loss (Strasberg E). There were 12 patients in group I and 18 in group II. Three cases in group I (25%) and one in group II (5%) developed anastomosis dysfunction. Mean follow-up was 56 months (range, 12-80) in group I and 52 months (range, 10-76) in group II. Two cases in group I (16%) and none in group II (0) required reoperation (p < 0.05).

CONCLUSIONS

In the acute setting, complex lesions should be treated with a high bilioenteric anastomosis (at the junction level) in the first attempt at repair. Lower-level anastomoses are associated with a higher dysfunction rate and the need for radiological manipulation and reoperation. Also, stenosis of the anastomosis secondary to undetected duct ischemia in the acute repair is more frequent in low bilioenteric anastomoses.

[Evaluation of 20 years of experience and quality of life in patients surgically treated for liver cystic disease]

Surgical treatment of liver cystic disease is reserved for symptomatic patients. The surgical approach is chosen according to the size and distribution of the cysts. In patients with massive hepatomegaly secondary to polycystic liver disease, liver transplantation is indicated with excellent results and quality of life.

OBJECTIVE

To evaluate over 20-year period, the results in terms of clinical outcome of three groups of patients with cystic liver disease (EQ) who received surgical treatment and to determine postoperative quality of life.

MATERIALS AND METHODS

In a 20-year period, 44 patients were operated on; 24 had simple liver cyst, 13 had polycystic liver disease, and seven cystadenomas. Using the SF36 questionnaire, self-perception of quality of life was evaluated using eight scales in two major categories: Physical component summary (PCS) and mental component summary (MCS).

RESULTS

Upper abdominal pain was the main clinical symptom. Fenestration was the most frequent procedure performed. No differences in quality of life were observed in all, while good quality of life was recorded in all groups at a median follow-up of 39 months.

CONCLUSIONS

Surgical treatment of cystic liver disease is reserved for symptomatic patients or complications such as rupture, infection, and hemorrhage. Therapeutic alternatives should been chosen on an individual basis. Good quality of life is obtained after surgery in these patients.

Diminished morbidity and mortality in portal hypertension surgery: relocation in the therapeutic armamentarium

Although several effective therapeutic options are available for bleeding from portal hypertension, surgery has a well-defined role in the management of patients with good liver function who are electively operated. The aim of this investigation was to evaluate the operative mortality and morbidity of portal blood flow-preserving procedures in a highly select patient population. The records of 148 patients operated on between 1996 and 2000 using one of two techniques (selective shunts or a Sugiura-Futagawa operation [complete portoazygos disconnection]) were analyzed with particular attention to operative mortality, postoperative rebleeding, and encephalopathy. Survival was calculated according to the Kaplan-Meier method. Sixty-one patients had distal splenorenal shunts placed, and 87 patients had a devascularization procedure. Operative mortality for the group as a whole was 1.2%. In the group with selective shunts, the rebleeding rate was 4.9%, the encephalopathy rate was 9.8%, and the shunt obstruction rate was 1.6%. Survival at 24 months was 94% and at 48 months was 92%. In those undergoing devascularization, the encephalopathy rate was 5% and the rebleeding rate was 14%. Survival at 24 months was 90% and at 48 months was 86%. Portal blood flow-preserving procedures have very low morbidity and mortality rates at specialized centers. In addition, a low rebleeding rate is associated with a good quality of life. Low-risk patients with bleeding portal hypertension should be considered for surgical treatment.