bluuebunny/crossref_metadata_2025_split huggingface dataset:
Brief Report: Associations Between Self-Reported Substance Use Behaviors and PrEP Acceptance and Adherence Among Black MSM in the HPTN 073 Study
Authors: Okafor Chukwuemeka N. , Hucks-Ortiz Christopher , Hightow-Weidman Lisa B. , Magnus Manya , Emel Lynda , Beauchamp Geetha , Kuo Irene , Hendrix Craig , Mayer Kenneth H. , Shoptaw Steven J. 
Published: May 2020

Background:
Pre-exposure prophylaxis (PrEP) is efficacious for HIV prevention. Black men who have sex with men (MSM) accounted for the largest proportion of new HIV diagnoses in the United States relative to other racial/ethnic groups. Black MSM who use substances are at an increased risk for HIV infection and are ideal candidates for PrEP, but barriers to maintaining PrEP adherence remain a concern. We assessed whether substance use behaviors are associated with initiation and adherence to PrEP among a sample of black MSM in the United States.

Methods:
Data for this analysis come from the HIV Prevention Trails Network Study 073 (HPTN 073). Substance use behaviors—including alcohol, marijuana, poppers (ie, alkyl nitrites), and stimulants (ie, methamphetamine/cocaine use) including use of these substances before/during condomless anal intercourse (CAI)—were assessed longitudinally through self-report. PrEP adherence was assessed by pharmacological testing in blood. Generalized estimating equations were used to evaluate association between substance use behaviors and PrEP initiation and adherence.

Results:
Among 226 HIV-negative black MSM, the majority (60%) were 25+ years of age. Most of the substance use behaviors were not significantly associated with PrEP initiation or adherence. However, stimulant use before/during CAI was significantly associated with lower odds of PrEP adherence (adjusted odds ratio = 0.21, 95% confidence interval = 0.07 to 0.61; P = <0.01).

Conclusions:
These findings suggest that PrEP adherence is feasible among black MSM who use substances. However, black MSM who engage in stimulant use before/during CAI may present a unique group for additional study and support with enhanced behavioral health and support services.
Future of Diagnostic Computed Tomography
Authors: Shahid Imran , Lancelot Eric , Desché Pierre 
Published: May 2020

Abstract
Iodinated contrast media (CM) are utilized in approximately 40% of the 300 million computed tomography (CT) scans undertaken annually. This review focuses on the physicochemical properties and safety of iodinated CM, and the development of new x-ray CM, and it explores methods to optimize CT scanning parameters. It concludes that good x-ray CM should have high structural stability, hydrophilicity, and CT attenuation; low viscosity, osmolality, and protein binding; no metabolism and tissue accumulation; and a complete elimination.
Metastatic Parathyroid Hormone-Secreting Prostate Adenocarcinoma Mimicking Ectopic Parathyroid Adenoma Demonstrated on 99mTc-MIBI Image
Authors: Chen Yu-Hung , Hsu Yung-Hsiang , Chen Hwa-Tsung , Chang Bee-Song , Liu Shu-Hsin 
Published: May 2020

Abstract

99mTc-MIBI has long been used to localize hyperfunctioning parathyroid tissue in patients with hyperparathyroidism. This tracer can also concentrate in various neoplastic tissues including prostate adenocarcinoma. We herein report a case with parathyroid hormone-secreting metastatic prostate cancer mimicking an ectopic parathyroid adenoma on the 99mTc-MIBI scan. We conclude that metastatic prostate cancer should be included as one of the differential diagnoses when interpreting 99mTc-MIBI scan.
FDG PET/CT in a Patient With Mantle Cell Lymphoma and COVID-19
Authors: Playe Margot , Siavellis Justine , Braun Thorsten , Soussan Michaël 
Published: May 2020

Abstract
A 52-year-old woman with no medical history was admitted on March 18, 2020, presenting since 3 days asthenia, abdominal pain, and dry cough but no fever. Adenomegalies, splenomegaly, leukocytosis, and elevated LDH suggested mature lymphoproliferation. Considering the current health context, an RT-PCR testing for COVID-19 (coronavirus disease 2019) was performed and found to be positive. Early chest CT showed no sign of pulmonary infection but multiple adenomegalies. An 18F-FDG PET/CT performed 5 days later to assess the extent of the hemopathy revealed the apparition of FDG-avid bilateral ground glass and subpleural curvilinear opacities suggesting COVID-19–associated pneumopathy.
Solitary Breast Metastasis From Thyroid Papillary Carcinoma Revealed on Whole-Body Radioactive 131I Scan
Authors: Kharroubi Dris , Richa Carine , Saie Clotilde , Chami Linda , Lussey-Lepoutre Charlotte 
Published: May 2020

Abstract
Breast metastasis from thyroid papillary carcinoma is an exceptional situation. Here, we present the diagnostic approach and the management of a 19-year-old woman with single breast metastasis from thyroid carcinoma. There was no extra thyroidal extension, neoplastic emboli, or lymph node invasion. The metastasis was revealed by whole-body radioactive 131I scan, explored by a fine-needle aspiration, and confirmed by elevated thyroglobulin in situ.
Four-dimensional Flow Magnetic Resonance Imaging Quantification of Blood Flow in Bicuspid Aortic Valve
Authors: Gordon Daniel Z. , Abbasi Muhannad A. , Lee Jeesoo , Sarnari Roberto , Sojoudi Alireza , Wei Qiao , Scott Michael B. , Collins Jeremy D. , Allen Bradley D. , Blaisdell Julie A. , Carr James C. , Markl Michael 
Published: May 2020

Background:
Four-dimensional (D) flow magnetic resonance imaging (MRI) is limited by time-consuming and nonstandardized data analysis. We aimed to test the efficiency and interobserver reproducibility of a dedicated 4D flow MRI analysis workflow.

Materials and Methods:
Thirty retrospectively identified patients with bicuspid aortic valve (BAV, age=47.8±11.8 y, 9 male) and 30 healthy controls (age=48.8±12.5 y, 21 male) underwent Aortic 4D flow MRI using 1.5 and 3 T MRI systems. Two independent readers performed 4D flow analysis on a dedicated workstation including preprocessing, aorta segmentation, and placement of four 2D planes throughout the aorta for quantification of net flow, peak velocity, and regurgitant fraction. 3D flow visualization using streamlines was used to grade aortic valve outflow jets and extent of helical flow.

Results:
4D flow analysis workflow time for both observers: 5.0±1.4 minutes per case (range=3 to 10 min). Valve outflow jets and flow derangement was visible in all 30 BAV patients (both observers). Net flow, peak velocity, and regurgitant fraction was significantly elevated in BAV patients compared with controls except for regurgitant fraction in plane 4 (91.1±29.7 vs. 62.6±19.6 mL/s, 37.1% difference; 121.7±49.7 vs. 90.9±26.4 cm/s, 28.9% difference; 9.3±10.1% vs. 2.0±3.4%, 128.0% difference, respectively; P<0.001). Excellent intraclass correlation coefficient agreement for net flow: 0.979, peak velocity: 0.931, and regurgitant fraction: 0.928.

Conclusion:
Our study demonstrates the potential of an efficient data analysis workflow to perform standardized 4D flow MRI processing in under 10 minutes and with good-to-excellent reproducibility for flow and velocity quantification in the thoracic aorta.
Brown Adipose Tissue: A Potential Site for Islet Transplantation
Authors: Xu Kang , Xie Raoying , Lin Xiaolin , Jia Junshuang , Zeng Nan , Li Wangen , Xiao Dong , Du Tao 
Published: May 2020

Background.
Islet transplantation is a promising treatment in patients with complicated diabetes. The ideal transplant site that can extend islet graft survival and reduce the required number of engrafted islets remains to be established.

Methods.
Donor islets were isolated from red fluorescent protein (RFP+) mice and transplanted into interscapular brown adipose tissue (BAT) or unilateral inguinal white adipose tissue of age-matched diabetic RFP− mice. Blood glucose and body weight of the mice were monitored, and vitality and function of ectopic RFP+ islets were detected by fluorescence imaging, histological examination, and intraperitoneal glucose tolerance test (GTT).

Results.
BAT enabled the marginal number of grafted islets (80 islets) to restore blood glucose, insulin level, and GTT to normal values in all diabetic recipient mice in the short term after graft, and maintained these values for 1 year at the end of the experiment. Importantly, in the short term after transplantation, abundant extra- and intraislet neovasculatures were observed in BAT, but not in white adipose tissue, which allowed the ectopic islets to retain typical architecture and morphology and contributed to the normal GTT. Moreover, the islet-engrafted BAT displayed normal structure and morphology without significant immunocyte infiltration, and the recipient mice also showed normal lipid levels in the blood.

Conclusions.
BAT remarkably enhances the viability and biological function of the transplanted ectopic islets. Moreover, the anatomical location of BAT lends itself to biopsy, removal, and islet retransplantation, which strongly suggests the BAT as a potential desirable site for islet transplantation in basic and clinical research.
Kratom (Mitragyna speciosa): worldwide issues
Authors: Ramanathan Surash , McCurdy Christopher R. 
Published: May 2020

Purpose of review
To inform readers about the increasingly popular Western dietary supplement, kratom (Mitragyna speciosa) and how the products are available in the Western world compared with traditional Southeast Asian use. Kratom has been traditionally used for increasing stamina of outdoor laborers (farmers), mood enhancement, pain, and opium addiction. Interestingly, kratom has been reported to have a paradoxical effect in that stimulant feelings, and sedative feelings can be obtained depending on the amount utilized. There are several biologically active alkaloids present in kratom.

Recent findings
Recent studies have been focused on the interactions of mitragynine, the most abundant alkaloid, and opioid-like effects. This has been driven by the harm that kratom products have produced in the Western world, in stark contrast to the lack of harm in Southeast Asian traditional use over centuries. Many users in the Western world ingest kratom for mood enhancement and/or to ween themselves from prescription or illicit opioids. Highly concentrated products and recreational use and misuse have resulted in individuals pushing doses to levels that have not been imagined or ever studied in animal, let alone humans.

Summary
Kratom, as a preparation and how it is utilized is different around the world.
Explanation of the onset of bouncing cycles in isotropic rotor dynamics; a grazing bifurcation analysis
Authors: Mora Karin , Champneys Alan R. , Shaw Alexander D. , Friswell Michael I. 
Published: May 2020

The dynamics associated with bouncing-type partial contact cycles are considered for a 2 degree-of-freedom unbalanced rotor in the rigid-stator limit. Specifically, analytical explanation is provided for a previously proposed criterion for the onset upon increasing the rotor speed
Ω
of single-bounce-per-period periodic motion, namely internal resonance between forward and backward whirling modes. Focusing on the cases of 2 : 1 and 3 : 2 resonances, detailed numerical results for small rotor damping reveal that stable bouncing periodic orbits, which coexist with non-contacting motion, arise just beyond the resonance speed
Ω

p
:
q

. The theory of discontinuity maps is used to analyse the problem as a codimension-two degenerate grazing bifurcation in the limit of zero rotor damping and
Ω
=
Ω

p
:
q

. An analytic unfolding of the map explains all the features of the bouncing orbits locally. In particular, for non-zero damping
ζ
, stable bouncing motion bifurcates in the direction of increasing
Ω
speed in a smooth fold bifurcation point that is at rotor speed

O

(
ζ
)

beyond
Ω

p
:
q

. The results provide the first analytic explanation of partial-contact bouncing orbits and has implications for prediction and avoidance of unwanted machine vibrations in a number of different industrial settings.
SARS-CoV-2 infection, clinical features and outcome of COVID-19 in United Kingdom nursing homes
Authors: Graham NSN , Junghans C , Downes R , Sendall C , Lai H , McKirdy A , Elliott P , Howard R , Wingfield D , Priestman M , Ciechonska M , Cameron L , Storch M , Crone MA , Freemont PS , Randell P , McLaren R , Lang N , Ladhani S , Sanderson F , Sharp DJ 
Published: May 2020

ABSTRACTObjectivesTo understand SARS-Co-V-2 infection and transmission in UK nursing homes in order to develop preventive strategies for protecting the frail elderly residents.DesignAn outbreak investigation.Setting4 nursing homes affected by COVID-19 outbreaks in central London.Participants394 residents and 70 staff in nursing homes.InterventionsTwo point-prevalence surveys one week apart where residents underwent SARS-CoV-2 testing and had relevant symptoms documented. Asymptomatic staff from three of the four homes were also offered SARS-CoV-2 testing.Main outcome measuresAll-cause mortality, and mortality attributed to COVID-19 on death certificates. Prevalence of SARS-CoV-2 infection and symptoms in residents and staff.ResultsOverall, 26% (95% confidence interval 22 to 31) of residents died over the two-month period. All-cause mortality increased by 203% (95% CI 70 to 336). Systematic testing identified 40% (95% CI 35 to 46) of residents, of whom 43% (95% CI 34 to 52) were asymptomatic and 18% (95% CI 11 to 24) had atypical symptoms, as well as 4% (95% CI -1 to 9) of asymptomatic staff who tested positive for SARS-CoV-2.ConclusionsThe SARS-CoV-2 outbreak was associated with a very high mortality rate in residents of nursing homes. Systematic testing of all residents and a representative sample of staff identified high rates of SARS-CoV-2 positivity across the four nursing homes, highlighting a potential for regular screening to prevent future outbreaks.
European lockdowns and the consequences of relaxation during the COVID-19 pandemic
Authors: Glass David H. 
Published: May 2020

AbstractThis paper investigates the lockdowns introduced in France, Germany, Italy, Spain, and the UK and also explores the potential consequences of different degrees of relaxation. The analysis employs a two-stage SEIR model with different reproductive numbers pre-and post-lockdown. These parameters are estimated from data on the daily number of confirmed cases in a process that automatically detects the time at which the lockdown became effective. The model is evaluated by considering its predictive accuracy on current data and it is then deployed to explore partial relaxations. The results indicate that the different countries have been successful in reducing the reproductive number to values ranging from 0.67 (95% CI: 0.64 - 0.70) to 0.92 (95% CI: 0.89 - 0.95). Results also suggest that a relaxation of 25% could halt the decline incases in all five countries, while a 50% relaxation could lead to second peaks that are higher and last longer than the earlier peaks in each country. Even though the relaxations so far may have preserved the success of the lockdowns, vigilance is still needed. A relaxation of around 10-15% is recommended if COVID-19 is to continue to decline in all five countries.
Investigation on the interaction between nifedipine and ritonavir containing antivirus regimens: a physiologically-based pharmacokinetic/pharmacodynamic analysis
Authors: Niu Wan-jie , Li Si-ze , Jin Sha-sha , Lin Xi-ying , Zhang Meng-wan , Cai Wei-min , Zhong Ming-kang , Xiang Xiao-qiang , Jiao Zheng 
Published: May 2020

AbstractBackground and ObjectiveHypertension is a common comorbidity of patients with COVID-19, SARS or HIV infection. Those patients are often treated with commonly used antiviral and antihypertensive agents concomitantly, such as ritonavir-containing regimens and nifedipine. Since ritonavir is a strong inhibitor of CYP3A, when nifedipine is combined with ritonavir-containing antiviral drugs, there is a potential risk of drug-drug interaction. This study aimed to provide guidance on nifedipine treatment during and after co-administration with ritonavir-containing regimens using a physiologically-based pharmacokinetic/pharmacodynamic (PBPK/PD) analysis.MethodsA PBPK/PD model was developed for nifedipine by the software of Simcyp®, and the model was verified using published data. The effects of ritonavir on nifedipine exposures and systolic blood pressure were assessed for instant-release, sustained-release and controlled-release formulations. Moreover, various nifedipine regimens were investigated when co-administrated with and withdrawing ritonavir.ResultsPBPK/PD models for three formulations of nifedipine were successfully established. The model predicted pharmacokinetic profiles of nifedipine were comparable to the published data. Ratios of predicted versus observed AUCDDI/AUCNifedipineof nifedipine were within 0.70- to 1.83-fold. Model simulations showed that the inhibitory effect of ritonavir on CYP3A4 increased the Cmaxof nifedipine by 9.82-34.35 times and the AUC24hby 44.94-50.77 times at steady state. Moreover, nifedipine dose reduced to 1/16 of the regular dose during ritonavir co-administration could lead to severe hypotension.ConclusionsRitonavir had a pronounced influence on the pharmacokinetics and antihypertensive effect of nifedipine. It is not recommended for patients to take nifedipine and ritonavir-containing regimens simultaneously.
Computational simulation to assess patient safety of uncompensated COVID-19 two-patient ventilator sharing using the Pulse Physiology Engine
Authors: Webb Jeffrey B. , Bray Aaron , Asare Philip K. , Clipp Rachel B. , Mehta Yatin B. , Penupolu Sudheer , Patel Aalpen A. , Poler S. Mark 
Published: May 2020

AbstractBackgroundThe COVID-19 pandemic is stretching medical resources internationally, sometimes creating ventilator shortages that complicate clinical and ethical situations. The possibility of needing to ventilate multiple patients with a single ventilator raises patient health and safety concerns in addition to clinical conditions needing treatment.Wherever ventilators are employed, additional tubing and splitting adaptors may be available. Adjustable flow-compensating resistance for differences in lung compliance on individual limbs may not be readily implementable.By exploring a number and range of possible contributing factors using computational simulation without risk of patient harm, this paper attempts to define useful bounds for ventilation parameters when compensatory resistance in limbs of a shared breathing circuit is not possible. This desperate approach to shared ventilation support would be a last resort when alternatives have been exhausted.MethodsA whole-body computational physiology model (using lumped parameters) was used to simulate each patient being ventilated. The primary model of a single patient with a dedicated ventilator was augmented to model two patients sharing a single ventilator. In addition to lung mechanics or estimation of CO2 and pH expected for set ventilation parameters (considerations of lung physiology alone), full physiological simulation provides estimates of additional values for oxyhemoglobin saturation, arterial oxygen tension, and other patient parameters. A range of ventilator settings and patient characteristics were simulated for paired patients.FindingsTo be useful for clinicians, attention has been directed to clinically available parameters. These simulations show patient outcome during multi-patient ventilation is most closely correlated to lung compliance, oxygenation index, oxygen saturation index, and end-tidal carbon dioxide of individual patients. The simulated patient outcome metrics were satisfactory when the lung compliance difference between two patients was less than 12 mL/cmH2O, and the oxygen saturation index difference was less than 2 mmHg.InterpretationIn resource-limited regions of the world, the COVID-19 pandemic will result in equipment shortages. While single-patient ventilation is preferable, if that option is unavailable and ventilator sharing using limbs without flow resistance compensation is the only available alternative, these simulations provide a conceptual framework and guidelines for clinical patient selection.
Time-varying reproduction numbers of COVID-19 in Georgia, USA, March 2-June 14, 2020
Authors: Muniz-Rodriguez Kamalich , Chowell Gerardo , Schwind Jessica S. , Ford Randall , Ofori Sylvia K. , Ogwara Chigozie A. , Davies Margaret R. , Jacobs Terrence , Cheung Chi-Hin , Cowan Logan T. , Hansen Andrew R. , Fung Isaac Chun-Hai 
Published: May 2020

ABSTRACTIn 2020, SARS-CoV-2 impacted Georgia, USA. Georgia announced state-wide shelter-in-place on April 2 and partially lifted restrictions on April 27. We analyzed daily incidence of confirmed COVID-19 cases by reporting date, March 2-June 14, in Georgia, Metro Atlanta, and Dougherty County and estimate the time-varying reproduction number, Rt, using R package EpiEstim. The median Rt estimate in Georgia dropped from between 2 and 4 in mid-March, to <2 in late March, and around 1 from mid-April to mid-June. Regarding Metro Atlanta, Rt fluctuated above 1.5 in March and around 1 since April. In Dougherty County, the median Rt declined from around 2 in late March to 0.32 on April 26. In Spring 2020, SARS-CoV-2 transmission in Georgia declined likely because of social distancing measures. However, as restrictions were relaxed in late April, community transmission continued with Rt fluctuating around 1 across Georgia, Metro Atlanta, and Dougherty County as of mid-June.
Deep immune profiling of COVID-19 patients reveals patient heterogeneity and distinct immunotypes with implications for therapeutic interventions
Authors: Mathew Divij , Giles Josephine R. , Baxter Amy E. , Greenplate Allison R. , Wu Jennifer E. , Alanio Cécile , Oldridge Derek A. , Kuri-Cervantes Leticia , Pampena M. Betina , D’Andrea Kurt , Manne Sasikanth , Chen Zeyu , Huang Yinghui Jane , Reilly John P. , Weisman Ariel R , Ittner Caroline A.G. , Kuthuru Oliva , Dougherty Jeanette , Nzingha Kito , Han Nicholas , Kim Justin , Pattekar Ajinkya , Goodwin Eileen C. , Anderson Elizabeth M. , Weirick Madison E. , Gouma Sigrid , Arevalo Claudia P. , Bolton Marcus J. , Chen Fang , Lacey Simon F. , Hensley Scott E. , Apostolidis Sokratis , Huang Alexander C. , Vella Laura A. ,   The UPenn COVID Processing Unit, Betts Michael R. , Meyer Nuala J. , Wherry E. John 
Published: May 2020

AbstractCOVID-19 has become a global pandemic. Immune dysregulation has been implicated, but immune responses remain poorly understood. We analyzed 71 COVID-19 patients compared to recovered and healthy subjects using high dimensional cytometry. Integrated analysis of ∼200 immune and >30 clinical features revealed activation of T cell and B cell subsets, but only in some patients. A subgroup of patients had T cell activation characteristic of acute viral infection and plasmablast responses could reach >30% of circulating B cells. However, another subgroup had lymphocyte activation comparable to uninfected subjects. Stable versus dynamic immunological signatures were identified and linked to trajectories of disease severity change. These analyses identified three “immunotypes” associated with poor clinical trajectories versus improving health. These immunotypes may have implications for therapeutics and vaccines.