bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fitness cost of mcr-1-mediated polymyxin resistance in Klebsiella pneumoniae
Authors: Nang Sue C , Morris Faye C , McDonald Michael J , Han Mei-Ling , Wang Jiping , Strugnell Richard A , Velkov Tony , Li Jian 
Published: February 2018

AbstractObjectivesThe discovery of mobile colistin resistance mcr-1, a plasmid-borne polymyxin resistance gene, highlights the potential for widespread resistance to the last-line polymyxins. In the present study, we investigated the impact of mcr-1 acquisition on polymyxin resistance and biological fitness in Klebsiella pneumoniae.MethodsK. pneumoniae B5055 was used as the parental strain for the construction of strains carrying vector only (pBBR1MCS-5) and mcr-1 recombinant plasmids (pmcr-1). Plasmid stability was determined by serial passaging for 10 consecutive days in antibiotic-free LB broth, followed by patching on gentamicin-containing and antibiotic-free LB agar plates. Lipid A was analysed using LC–MS. The biological fitness was examined using an in vitro competition assay analysed with flow cytometry. The in vivo fitness cost of mcr-1 was evaluated in a neutropenic mouse thigh infection model.ResultsIncreased polymyxin resistance was observed following acquisition of mcr-1 in K. pneumoniae B5055. The modification of lipid A with phosphoethanolamine following mcr-1 addition was demonstrated by lipid A profiling. The plasmid stability assay revealed the instability of the plasmid after acquiring mcr-1. Reduced in vitro biological fitness and in vivo growth were observed with the mcr-1-carrying K. pneumoniae strain.ConclusionsAlthough mcr-1 confers a moderate level of polymyxin resistance, it is associated with a significant biological fitness cost in K. pneumoniae. This indicates that mcr-1-mediated resistance in K. pneumoniae could be attenuated by limiting the usage of polymyxins.
Postpartum depression in older women
Authors: Strelow Brittany , Fellows Nicole , Fink Stephanie R. , O'Laughlin Danielle J. , Radke Gladys , Stevens Joy , Tweedy Johanna M. 
Published: February 2018

ABSTRACT
Postpartum depression, which affects 10% to 20% of women in the United States, can significantly harm the health and quality of life for mother, child, and family. This article reviews the risk factors, pathophysiology, clinical manifestations, diagnosis, and treatment of postpartum depression with specific focus on women of advanced maternal age.
The emerging spectrum of exposure-related bronchiolitis
Authors: Krefft Silpa D. , Cool Carlyne D. , Rose Cecile S. 
Published: February 2018

Purpose of review
Exposure-related bronchiolitis is increasingly recognized as an important but challenging clinical diagnosis. Acute and chronic inhalational exposures are associated with variable clinical presentations and a spectrum of histopathologic abnormalities affecting the small airways. This review provides an overview of the histologic patterns and occupational settings for exposure-related bronchiolitis, along with recent advances in disease diagnosis and management.

Recent findings
The entire histopathologic spectrum of bronchiolitis (constrictive, obliterative, proliferative, lymphocytic, respiratory) has been reported in exposure-related bronchiolitis. Recent studies have shown that lung clearance index testing and impulse oscillometry are more sensitive than spirometry in detecting small airways abnormalities and may augment the diagnosis of occupational bronchiolitis. Prognosis in indolent occupational bronchiolitis appears more favorable than some other types of bronchiolitis but is variable depending on the extent of bronchiolar inflammation and the stage of disease at which exposure removal occurs.

Summary
No specific histopathologic pattern of bronchiolitis is pathognomonic for occupational bronchiolitis as one or more histologic patterns may be present. A high index of suspicion is needed for exposure and disease recognition. Recent advances that may aid in diagnosis include transbronchial cryobiopsy, lung clearance index testing, and impulse oscillometry, although further research is needed.
Comparing Functional Outcomes After Injury-Specific Fixation of Posterior Malleolar Fractures and Equivalent Ligamentous Injuries in Rotational Ankle Fractures
Authors: Levack Ashley E. , Warner Stephen J. , Gausden Elizabeth B. , Helfet David L. , Lorich Dean G. 
Published: February 2018

Objectives:
To evaluate the effect of posterior bony versus ligamentous injury pattern on functional outcomes in operatively treated rotational ankle fractures.

Design:
Retrospective cohort analysis of prospective registry.

Setting:
Academic Level I trauma center.

Patients/Participants:
Operatively treated supination external rotation IV and pronation external rotation IV ankle fractures.

Intervention:
Lateral malleolus plate fixation with either posterior malleolus (PM) plate fixation or posterior inferior tibiofibular ligament (PITFL) repair.

Main Outcome Measurements:
Foot and ankle outcome scores at minimum 12 months postoperatively.

Results:
One hundred seventy-eight fractures were treated with injury-specific anatomic fixation of a PM fracture (n = 122) or torn PITFL (n = 56). The PM group was significantly older, contained more women, and had lower mean body mass index versus the PITFL group. There was a higher rate of medial malleolar fracture in the PM group; other fracture and baseline characteristics were similar between groups. Univariate and multivariable analysis revealed no difference in foot and ankle outcome scores for any of the 5 summary domains (symptoms, pain, activities of daily living, sports, or quality of life) at the time of most recent follow-up. The median length of follow-up was 16.3 and 12.8 months in the PM and PITFL groups, respectively.

Conclusions:
In our cohort of ankle fractures, we have demonstrated comparable outcomes in stage IV rotational ankle fractures with and without PM fractures, indicating that the presence of a PM fracture may not result in inferior outcomes compared with ligamentous equivalent injuries if these fractures are addressed in an injury-specific manner.

Level of Evidence:
Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
Pathoanatomy of the Tongue-Type Calcaneus Fracture: Assessment Using 2- and 3-Dimensional Computed Tomography
Authors: Mitchell Phillip M. , O'Neill David E. , Gallagher Bethany , Collinge Cory A. 
Published: February 2018

Objective:
To define the pathoanatomy of the tongue-type calcaneus fracture and assess the appropriateness of percutaneous techniques in addressing all planes of deformity in this injury.

Design:
Retrospective cohort.

Setting:
ACS Level I trauma center.

Patients/Participants:
Fifty-six displaced Sanders 2B and 2C tongue-type calcaneus fractures identified from an initial cohort of 1118 calcaneus fractures treated over a 16-year period.

Main Outcome Measurements:
We reviewed cross-sectional imaging and documented the presence of a varus/valgus (coronal plane) or adduction/abduction (axial plane) position of the tongue fragment in relation to the intact posterior facet, with greater than 10 degrees of angulation being diagnostic of displacement.

Results:
When assessing for displacement and angulation in the coronal plane, 98% of tongue fragments were either in a position of valgus (77%) or neutral (21%), with a mean valgus angulation of 17.3 degrees. In the axial plane, 98% of tongue pieces were in a position of adduction (64%) or neutral (34%), with an average angulation into adduction of 15.0 degrees. Sanders 2B fractures were more likely to be in a position of valgus and adduction than those of 2C fractures.

Discussion:
The tongue-type calcaneus fracture most often displaces into a position of plantarflexion, valgus, and adduction. Knowledge of this deformity may aid in achieving successful closed reduction when using the Essex-Lopresti maneuver or other less invasive techniques.
High Rate of Union for Aseptic Distal Tibial Nonunions in Adults Treated With Slow Gradual Compression via Circular External Fixation
Authors: Cunningham Bryce A. , O'Connor Daniel P. , Brinker Mark R. 
Published: February 2018

Objective:
To evaluate the healing rate of aseptic nonunions of the distal third of the tibia treated with Ilizarov slow gradual compression and deformity correction.

Design:
Retrospective cohort study.

Setting:
Tertiary referral center.

Patients/Participants:
Ninety-four consecutive adult patients with 94 distal third tibial aseptic nonunions.

Intervention:
Ilizarov external fixation and slow gradual compression; most patients also underwent bone grafting, deformity correction, or both before the initiation of compression.

Main Outcome Measurements:
Rate of bony union.

Results:
Eighty-seven of 94 cases (92.6%) healed after slow gradual compression across the nonunion site with a circular external fixator. Four of the 7 patients who failed treatment healed after additional operative treatment, and the remaining 3 refused further care.

Conclusions:
Circular external fixation with slow gradual compression was successful in treating aseptic nonunions of the distal third of the tibia in 92.6% of cases. Careful selection of patients for this treatment method can lead to a high success rate with a relatively low rate of major complications.

Level of Evidence:
Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Growth Friendly Surgery and Serial Cast Correction in the Treatment of Early-onset Scoliosis for Patients With Prader-Willi Syndrome
Authors: Oore Jonathan , Connell Braydon , Yaszay Burt , Samdani Amer , Hilaire Tricia St. , Flynn Tara , El-Hawary Ron 
Published: February 2018

Background:
Prader-Willi syndrome (PWS) patients can present with scoliosis which can be treated with serial cast correction (SCC) or with growth friendly surgery (GFS). This study’s purpose was to describe the results of SCC as well as GFS for PWS patients with early-onset scoliosis (EOS).

Methods:
PWS patients were identified from 2 international multicenter EOS databases. Scoliosis, kyphosis, spine height (T1-S1), right/left hemithoracic heights/widths (RHTH, LHTH, RHTW, LHTW) were measured pretreatment, postoperation, and at 2-year follow-up. Complications were recorded.

Results:
Overall, 23 patients with 2-year follow-up were identified. Pretreatment; patients treated with SCC (n=10) had mean age of 1.8±0.6 years; body mass index (BMI), 16±1.5 kg/m2; scoliosis, 45±18 degrees; kyphosis, 56±9 degrees; T1-S1, 22.4±2.4 cm; RHTH, 8.0±2.0 cm; LHTH, 8.5±1.7 cm; RHTW, 6.6±1.3 cm; and LHTW, 8.0±1.0 cm. Patients treated with GFS (n=13) had mean age of 5.8±2.6 years; BMI, 21±5.4 kg/m2; scoliosis, 76±14 degrees; kyphosis, 59±25 degrees; T1-S1, 24.1±3.6 cm; RHTH, 10.0±1.6 cm; LHTH, 10.6±1.6 cm; RHTW, 9.4±2.5 cm; and LHTW, 8.1±2.8 cm. At 2-year follow-up, patients treated with SCC had mean scoliosis 37±11 degrees (18% correction, P=0.06); kyphosis, 42±6 degrees (NS); T1-S1, 26.4±2.1 cm (P<0.01); RHTH, 9.0±1.1 cm (13%; P=0.30); LHTH, 10.0±1.5 cm (18%, P<0.01); RHTW, 7.4±1.1 cm (12%, P<0.01); and LHTW, 8.0±1.0 cm (0%, P=0.34). At 2-year follow-up, patients treated with GFS had mean scoliosis 42±13 degrees (45% correction, P<0.000001); kyphosis, 53±13 degrees (10%, P=0.19); T1-S1, 31.5±5.4 cm (P<0.00001); RHTH, 12.0±2.4 cm (20%; P<0.01); LHTH, 12.0±1.7 cm (13%; P<0.01); RHTW, 9.8±1.3 cm (4%; P=0.27); and LHTW, 7.9±2.3 cm (3%;P=0.11). As an entire group, patients with a BMI>17 kg/m² had more device-related than disease-related complications (P=0.09). Patients treated with SCC had 0.9 complications per patient. Patients treated with GFS had 2.2 complications per patient [≤5 y more often had ≥2 complications (P=0.05)].

Conclusions:
At 2-year follow-up, SCC and GFS were both effective in treating EOS in PWS patients. Patients treated with SCC had significant improvements in spine height and LHTH. Patients treated with GFS had significant improvements in scoliosis magnitude, spine height, RHTH, and LHTH.

Level of Evidence:
Level IV—therapeutic study.
The Association Between Acute Respiratory Distress Syndrome Hospital Case Volume and Mortality in a U.S. Cohort, 2002–2011*
Authors: Ike John D. , Kempker Jordan A. , Kramer Michael R. , Martin Greg S. 
Published: February 2018

Objectives:
This study examines the relationships between hospitals’ annual acute respiratory distress syndrome case volume with hospitals’ acute respiratory distress syndrome case fatality rates and individuals’ odds of acute respiratory distress syndrome hospital mortality.

Design:
Retrospective cohort study.

Setting:
The U.S. Healthcare Cost and Utilization Project’s Nationwide Inpatient Sample, 2002–2011.

Patients:
Acute respiratory distress syndrome discharges defined by the presence of an acute respiratory distress syndrome International Classification of Diseases, 9th revision, Clinical Modification diagnosis code (518.82 or 518.5) and a mechanical ventilation procedure code (96.70, 96.71 or 96.72) on the discharge diagnosis and procedure lists. If the procedure code 96.71 was on the discharge record (mechanical ventilation < 96 hr duration), the patient also needed to be classified as deceased.

Interventions:
None.

Measurements and Main Results:
We analyzed 2,686 hospitals and 117,204 cases of acute respiratory distress syndrome. Average annual hospital acute respiratory distress syndrome in-hospital mortality was 47%. Acute respiratory distress syndrome case volume was categorized as low (1–9), medium (10–49), and high (50–423 cases per year). In a hospital-level Poisson regression adjusting for hospital characteristics, when compared with low-volume acute respiratory distress syndrome hospitals, high- and medium-volume acute respiratory distress syndrome hospitals had lower annual acute respiratory distress syndrome case fatality (rate ratio, 0.75; 99% CI, 0.71–0.79 and rate ratio, 0.86; 99% CI, 0.82–0.90, respectively; p ≤ 0.001 for both). In an individual-level, multivariable model adjusting for hospital and individual characteristics, high and medium acute respiratory distress syndrome volume hospitals were associated with lower odds of acute respiratory distress syndrome mortality compared with low-volume hospitals (odds ratio, 0.85 [99% CI, 0.74–0.99]; p = 0.006 and odds ratio, 0.89 [99% CI 0.79–1.00]; p = 0.01, respectively).

Conclusions:
In this cohort, at both an individual- and hospital-level, higher acute respiratory distress syndrome hospital case volume is associated with lower acute respiratory distress syndrome hospital mortality.
Cerebral Autoregulation in the Prediction of Delayed Cerebral Ischemia and Clinical Outcome in Poor-Grade Aneurysmal Subarachnoid Hemorrhage Patients*
Authors: Gaasch Max , Schiefecker Alois J. , Kofler Mario , Beer Ronny , Rass Verena , Pfausler Bettina , Thomé Claudius , Schmutzhard Erich , Helbok Raimund 
Published: February 2018

Objectives:
Pressure reactivity index and oxygen reactivity index are used to assess cerebral autoregulation after acute brain injury. The value of autoregulation indices in the prediction of delayed cerebral ischemia and outcome in patients with subarachnoid hemorrhage is still inconclusive. In this study, we aimed to focus on the predictive value of the first 72 hours commonly referred to as “early brain injury” in comparison to the overall monitoring period.

Design:
Retrospective observational cohort study.

Setting:
Neurocritical care unit at a tertiary academic medical center.

Patients:
Forty-three consecutive poor-grade patients with nontraumatic subarachnoid hemorrhage admitted between 2012 and 2016 undergoing continuous high-frequency monitoring.

Interventions:
High-frequency monitoring includes arterial blood pressure, intracranial pressure, and brain tissue oxygen tension. Pressure reactivity index and oxygen reactivity index were evaluated as moving correlation coefficient between mean arterial pressure/intracranial pressure and cerebral perfusion pressure/brain tissue oxygen tension, respectively.

Measurements and Main Results:
Median autoregulation monitoring time was 188 ± 91 hours per patient. Initial pressure reactivity index was 0.31 ± 0.02 and decreased significantly to 0.01 ± 0.01 (p < 0.001) 3 days after admission with a second peak 10 days after admission (0.18 ± 0.14; p = 0.001). Admission oxygen reactivity index was high, 0.25 ± 0.03, and decreased to a minimum of 0.11 ± 0.02 eight days after admission (p = 0.008). Patients with delayed cerebral ischemia had significantly higher overall mean pressure reactivity index values (p < 0.04), which were more pronounced during the first 72 hours, reflecting early brain injury (p < 0.02). High pressure reactivity index during the first 72 hours was associated with poor functional outcome (p < 0.001). No association between oxygen reactivity index and delayed cerebral ischemia or clinical outcome was observed (p = 0.8/0.78).

Conclusions:
High initial pressure reactivity index, presumably reflecting early brain injury, but not oxygen reactivity index, was associated with delayed cerebral ischemia and worse clinical outcome in poor-grade subarachnoid hemorrhage patients. Our data indicate that autoregulation indices should be interpreted cautiously when used in these patients and that timing is crucial when autoregulation indices are evaluated as predictor for delayed cerebral ischemia and outcome.
“Meniscus Sign” to Identify the Lenticule Edge in Small-Incision Lenticule Extraction
Authors: Titiyal Jeewan S. , Kaur Manpreet , Brar Anand S. , Falera Ruchita 
Published: February 2018

Purpose:
To describe our technique of lenticule edge identification in small-incision lenticule extraction using the “meniscus sign” to prevent lenticule misdissection.

Methods:
Femtosecond laser application for small-incision lenticule extraction was performed. A “double ring” was visible, signifying the edge of the cap cut (outer ring) and lenticule cut (inner ring). The anterior and posterior lamellar planes were delineated in 2 different directions. During creation of the posterior lamellar channel, the lenticule edge was slightly pushed away from the surgeon to create a gap between the inner ring (diameter of the lenticule cut) and the lenticule edge. The lenticule edge assumed a frilled wavy appearance, and the meniscus sign was observed as a gap between the lenticule edge and the inner ring. The meniscus-shaped gap served as a landmark to identify the lenticule edge, and the relationship between the frilled lenticule edge and surgical instruments further acted as a guide to identify the correct plane of dissection.

Results:
This technique was successfully undertaken in 50 eyes of 25 patients. The meniscus sign was observed in all cases, and no case had cap lenticular adhesions.

Conclusions:
The meniscus sign helps to identify the lenticule edge and correct dissection planes and provides a visual landmark during the entire surgical procedure.
The Relationship Between Difficulties in Daily Living and Suicidal Ideation Among Older Adults
Authors: Zhang Li , Sun Long , Zhou Chengchao , Ge Dandan , Qian Yangyang 
Published: February 2018

Abstract
To date, few studies have examined the association between difficulties in activities of daily living (ADL) and suicidal ideation (SI) among the seniors in China. This study aims to explore this association among older adults in China. A total of 3313 older people (60+) were included in this study, and questionnaires were administered by face-to-face interview. In total, 4.2% of the participants reported SI. The mean score of ADL among older adults with SI (21.06 ± 10.92) was much higher than that in those without SI (16.13 ± 5.60). Multivariate analyses showed that some specific domains of ADL including using transport, medical care, and household activities were associated with SI even after we controlled the psychological conditions. An association was observed between difficulties in daily living and SI among older adults in China. Psychological interventions should be taken to prevent potential risk of suicide targeting the seniors with certain disabilities.
Beneficial Effects of Adrenal Androgen Supplement in Bleeding Cirrhotic Rats
Authors: Huang Hui-Chun , Hsu Shao-Jung , Chang Ching-Chih , Tsai Ming-Hung , Lee Fa-Yauh , Hou Ming-Chih , Lee Shou-Dong 
Published: February 2018

ABSTRACT
Critical illness is accompanied by hypothalamic-pituitary-adrenal axis activation, but adrenal insufficiency characterized by inadequate glucocorticoid synthesis is common in critically ill cirrhotic patients, the “hepato-adrenal syndrome.” Adrenal cortex also synthesizes androgen (dehydroepiandrosterone, DHEA). DHEA maintains microcirculation by enhancing vascular endothelial nitric oxide synthase (eNOS) activity. In critical patients of other disease entities, a shift of adrenal steroidogenesis away from androgens toward glucocorticoid has been noted, arousing interests in androgen replacement in critical settings. Nevertheless, this has not been surveyed in cirrhosis with hemorrhage. In this study, liver cirrhosis was induced with common bile duct ligation (BDL) in Spraque-Dawley rats. Sham rats were controls. DHEA or vehicle was injected at the beginning of hemorrhage-transfused procedure, followed by terlipressin injection. Hemodynamic parameters were measured. Then abdominal aorta, superior mesenteric arteries (SMA) and splenorenal shunt (prominent portosystemic collateral vessel in rodents) eNOS and inducible NOS protein expressions were evaluated. In bleeding BDL groups without terlipressin injection, adrenocorticotropic hormone (ACTH) stimulation test was performed to evaluate the DHEA response. The results showed that DHEA significantly elevated mean arterial pressure, cardiac output, and stroke volume of bleeding cirrhotic rats treated with terlipressin and reduced systemic vascular resistance without affecting SMA flow, resistance, and portal pressure. DHEA upregulated abdominal aorta and SMA eNOS expressions. ACTH did not stimulate DHEA synthesis in bleeding BDL rats. In conclusion, androgen deficiency exists in bleeding cirrhotic rats. DHEA augments terlipressin-induced amelioration of shock without influencing splanchnic hemodynamics, possibly rendering it a feasible adjunct to vasoconstrictors in variceal hemorrhage.
Plasmodium–Salmonella Coinfection Induces Intense Inflammatory Response, Oxidative Stress, and Liver Damage: A Mice Model Study for Therapeutic Strategy
Authors: Patel Dinesh K. , Mittal Sandeep , Tiwari Nimisha , Maurya Anil K. , Singh Dhirendra , Pandey Alok K. , Pal Anirban 
Published: February 2018

ABSTRACT
Impairment of host immune response in malaria favors bacteremia caused by typhoidal or nontyphoidal serovars of Salmonella enterica. Ofloxacin and Artesunate are the drugs that are clinically proven for treating typhoid and malaria, respectively. The study evaluates the host responses upon treatment with antibiotic (Ofloxacin) and antimalarial (Artesunate) in a standardized mice model harboring coinfection. BALB/c mice (18–22 g) were simultaneously coinfected with Plasmodium yoelii nigeriensis (Pyn) and S. enterica serovar Typhimurium (STm) and then treated with Ofloxacin or/and Artesunate from day 4 to day 7. The bacterial burden, liver function enzymes, oxidative stress, m-RNA expression of Toll-like receptors (TLR-2 and TLR-4), Th1/Th2 cytokines, hemeoxygenase-1, and NFкB were assessed. Ofloxacin treatment failed to counter the bacterial proliferation in Pyn-STm coinfected mice. However, upon controlling parasitemia with antimalarial, the efficacy of Ofloxacin could be regained. Elevated bacterial burden with malaria induces the expression of TLR-2 and TLR-4 triggering intense inflammatory response (NFκB, Th1/Th2 cytokines) in coinfected mice. This results in critical liver damage (ALT, AST, and ALP), oxidative stress (lipid peroxidation, total GSH, catalase, and super oxide dismutase), and hemeoxygenase-1 (HO-1). The study concludes that malaria infection aggravates the secondary infection of Salmonella serovars and the control of septicemia is critical in recovery of the coinfected subject.