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1.
Infect Immun ; 92(6): e0005824, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38780215

ABSTRACT

Haemophilus ducreyi causes the genital ulcer disease chancroid and painful cutaneous ulcers in children who live in the tropics. To acquire heme from the host, H. ducreyi expresses a TonB-dependent hemoglobin receptor, HgbA, which is necessary and sufficient for H. ducreyi to progress to the pustular stage of disease in a controlled human infection model. HgbA transports hemoglobin across the outer membrane; how heme is transported across the cytoplasmic membrane is unclear. In previous studies, transcripts encoding the YfeABCD heme transporter were upregulated in experimental lesions caused by H. ducreyi in human volunteers, suggesting the latter may have a role in virulence. Here we constructed a double deletion mutant, 35000HPΔyfeABΔyfeCD, which exhibited growth defects relative to its parent 35000HP in media containing human hemoglobin as an iron source. Five human volunteers were inoculated at three sites on the skin overlying the deltoid with each strain. The results of the trial showed that papules formed at 100% (95% CI, 71.5, 100) at both 35000HP and 35000HPΔyfeABΔyfeCD-inoculated sites (P = 1.0). Pustules formed at 60% (95% CI, 25.9, 94.1) at parent-inoculated sites and 53% (95% CI, 18.3, 88.4) at mutant-inoculated sites (P = 0.79). Thus, the ABC transporter encoded by yfeAB and yfeCD was dispensable for H. ducreyi virulence in humans. In the absence of YfeABCD, H. ducreyi likely utilizes other periplasmic binding proteins and ABC-transporters such as HbpA, SapABCDF, and DppBCDF to shuttle heme from the periplasm into the cytoplasm, underscoring the importance of redundancy of such systems in gram-negative pathogens.


Subject(s)
Bacterial Proteins , Chancroid , Haemophilus ducreyi , Iron , Haemophilus ducreyi/genetics , Haemophilus ducreyi/pathogenicity , Haemophilus ducreyi/metabolism , Humans , Chancroid/microbiology , Chancroid/pathology , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Virulence , Iron/metabolism , Male , Adult , Heme/metabolism
2.
Infect Immun ; 91(9): e0017623, 2023 09 14.
Article in English | MEDLINE | ID: mdl-37594273

ABSTRACT

Haemophilus ducreyi is a causative agent of cutaneous ulcers in children who live in the tropics and of the genital ulcer disease chancroid in sexually active persons. In the anaerobic environment of abscesses and ulcers, anaerobic respiration and mixed acid fermentation (MAF) can be used to provide cellular energy. In Escherichia coli, MAF produces formate, acetate, lactate, succinate, and ethanol; however, MAF has not been studied in H. ducreyi. In human challenge experiments with H. ducreyi 35000HP, transcripts of the formate transporter FocA and pyruvate formate lyase (PflB) were upregulated in pustules compared to the inocula. We made single and double mutants of focA and pflB in 35000HP. Growth of 35000HPΔfocA was similar to 35000HP, but 35000HPΔpflB and 35000HPΔfocA-pflB had growth defects during both aerobic and anaerobic growth. Mutants lacking pflB did not secrete formate into the media. However, formate was secreted into the media by 35000HPΔfocA, indicating that H. ducreyi has alternative formate transporters. The pH of the media during anaerobic growth decreased for 35000HP and 35000HPΔfocA, but not for 35000HPΔpflB or 35000HPΔfocA-pflB, indicating that pflB is the main contributor to media acidification during anaerobic growth. We tested whether formate production and transport were required for virulence in seven human volunteers in a mutant versus parent trial between 35000HPΔfocA-pflB and 35000HP. The pustule formation rate was similar for 35000HP (42.9%)- and 35000HPΔfocA-pflB (62%)-inoculated sites. Although formate production occurs during in vitro growth and focA-pflB transcripts are upregulated during human infection, focA and pflB are not required for virulence in humans.


Subject(s)
Escherichia coli Proteins , Haemophilus ducreyi , Child , Humans , Haemophilus ducreyi/genetics , Virulence , Ulcer , Healthy Volunteers , Formates , Escherichia coli , Membrane Transport Proteins
3.
Neurology ; 100(14): e1510-e1519, 2023 04 04.
Article in English | MEDLINE | ID: mdl-36653178

ABSTRACT

BACKGROUND AND OBJECTIVES: Some athletes experience a slow recovery after sport-related concussion (SRC). There is little agreement on what constitutes slow recovery, however, and minimal data on the prevalence, predictors, or prognosis for this group. The objectives of this study were to apply an operationalized definition of slow recovery and characterize predictors and long-term prognosis of these individuals. METHODS: This is a prospective multisite observational study of collegiate athletes. Participants underwent multimodal assessments preseason and 5 additional time points after SRC. Time from injury to initiation of return to play progression (asymptomatic timepoint) and from injury to return to play (RTP) were the primary markers of recovery. RESULTS: One thousand seven hundred fifty-one concussed male and female collegiate athletes were studied. Eighty percent of participants reached the asymptomatic and/or RTP time points by days 14 and 24, respectively. Slow recovery was thus defined as exceeding 1 or both of those intervals (n = 399). This group was statistically more likely to be female (41.1% vs 35.6%, p = 0.05), have higher initial postinjury SCAT symptom severity scores (mean [SD]: 36.6 [23.4] vs 25.4 [19.9], p < 0.001), lower postinjury Standardized Assessment of Concussion scores (mean [SD]:25.74 [2.98] vs 26.26 [2.85], p = 0.004), perform worse on the postinjury Balance Error Scoring System (mean [SD]: 17.8 [8.9] vs 15.9 [8.5], p < 0.01), have fewer assessments in the first 14 days after injury (mean [SD]: 48.8 [29.7] vs 67.9 [24.6], p < 0.01), and be injured in practice (70.7% vs 65.1%, p = 0.04). 77.6% of the slow recovery group returned to play within 60 days of injury, and 83.4% (n = 349) returned to play within 90 days of injury. Only 10.6% had not returned to play 6 months postinjury. DISCUSSION: This study suggests an overall favorable prognosis for slowly recovering athletes and provides data for athletes and medical teams to consider in calibrating RTP expectations and making decisions about medical disqualification vs ongoing engagement in their sport.


Subject(s)
Athletic Injuries , Brain Concussion , Humans , Male , Female , Athletic Injuries/diagnosis , Prospective Studies , Neuropsychological Tests , Brain Concussion/diagnosis , Brain Concussion/epidemiology , Brain Concussion/therapy , Athletes
4.
J Infect Dis ; 227(3): 317-321, 2023 02 01.
Article in English | MEDLINE | ID: mdl-35876728

ABSTRACT

Compared with wounded skin, ascorbic acid is enriched in pustules of humans experimentally infected with Haemophilus ducreyi. Compared with the broth-grown inocula, transcription of the H. ducreyi ulaABCD operon, which encodes genes for ascorbic acid uptake, is increased in pustules. We hypothesized that ascorbic acid uptake plays a role in H. ducreyi virulence. Five volunteers were infected with both H. ducreyi strain 35000HP and its isogenic ulaABCD deletion mutant at multiple sites; the papule and pustule formation rates of the mutant and parent strains were similar. Thus, ascorbic acid uptake is not essential for H. ducreyi virulence in humans.


Subject(s)
Chancroid , Haemophilus ducreyi , Humans , Haemophilus ducreyi/genetics , Virulence , Chancroid/genetics , Ascorbic Acid , Operon
5.
Radiat Res ; 198(3): 221-242, 2022 09 01.
Article in English | MEDLINE | ID: mdl-35834823

ABSTRACT

The hematopoietic system is highly sensitive to stress from both aging and radiation exposure, and the hematopoietic acute radiation syndrome (H-ARS) should be modeled in the geriatric context separately from young for development of age-appropriate medical countermeasures (MCMs). Here we developed aging murine H-ARS models, defining radiation dose response relationships (DRRs) in 12-month-old middle-aged and 24-month-old geriatric male and female C57BL/6J mice, and characterized diverse factors affecting geriatric MCM testing. Groups of approximately 20 mice were exposed to ∼10 different doses of radiation to establish radiation DRRs for estimation of the LD50/30. Radioresistance increased with age and diverged dramatically between sexes. The LD50/30 in young adult mice averaged 853 cGy and was similar between sexes, but increased in middle age to 1,005 cGy in males and 920 cGy in females, with further sex divergence in geriatric mice to 1,008 cGy in males but 842 cGy in females. Correspondingly, neutrophils, platelets, and functional hematopoietic progenitor cells were all increased with age and rebounded faster after irradiation. These effects were higher in aged males, and neutrophil dysfunction was observed in aged females. Upstream of blood production, hematopoietic stem cell (HSC) markers associated with age and myeloid bias (CD61 and CD150) were higher in geriatric males vs. females, and sex-divergent gene signatures were found in HSCs relating to cholesterol metabolism, interferon signaling, and GIMAP family members. Fluid intake per gram body weight decreased with age in males, and decreased after irradiation in all mice. Geriatric mice of substrain C57BL/6JN sourced from the National Institute on Aging were significantly more radiosensitive than C57BL/6J mice from Jackson Labs aged at our institution, indicating mouse source and substrain should be considered in geriatric radiation studies. This work highlights the importance of sex, vendor, and other considerations in studies relating to hematopoiesis and aging, identifies novel sex-specific functional and molecular changes in aging hematopoietic cells at steady state and after irradiation, and presents well-characterized aging mouse models poised for MCM efficacy testing for treatment of acute radiation effects in the elderly.


Subject(s)
Acute Radiation Syndrome , Animals , Disease Models, Animal , Female , Hematopoiesis/radiation effects , Hematopoietic Stem Cells/radiation effects , Male , Mice , Mice, Inbred C57BL , Radiation Tolerance
6.
Microbiol Spectr ; 10(2): e0243021, 2022 04 27.
Article in English | MEDLINE | ID: mdl-35297652

ABSTRACT

CpxRA is an envelope stress response system that is highly conserved in the Enterobacteriaceae. CpxA has kinase activity for CpxR and phosphatase activity for phospho-CpxR (CpxR-P), a transcription factor. In response to membrane stress, CpxR-P is produced and upregulates genes involved in membrane repair and downregulates genes that encode virulence factors that are trafficked across the cell membrane. Mutants that constitutively activate CpxRA in Salmonella enterica serovar Typhimurium and in uropathogenic Escherichia coli (UPEC) are attenuated in murine models. We hypothesized that pharmacologic activation of CpxR could serve as an antimicrobial/antivirulence strategy and recently showed that 2,3,4,9-tetrahydro-1H-carbazol-1-amines activate the CpxRA system by inhibiting CpxA phosphatase activity. Here, we tested the ability of a series of three CpxRA-activating compounds with increasing potency to clear UPEC stain CFT073 in a murine urinary tract infection model. We show that these compounds are well tolerated and achieve sufficient levels to activate CpxR in the kidneys, bladder, and urine. Although the first two compounds were ineffective in promoting clearance of CFT073 in the murine model, the most potent derivative, compound 26, significantly reduced bacterial recovery in the urine and trended toward reducing bacterial recovery in the bladder and kidneys, with efficacy similar to ciprofloxacin. Treatment of CFT073 cultured in human urine with compound 26 fostered accumulation of CpxR-P and decreased the expression of proteins involved in siderophore biosynthesis and binding, heme degradation, and flagellar movement. These studies suggest that chemical activation of CpxRA may present a viable strategy for treating infections due to UPEC. IMPORTANCE The increasing prevalence of urinary tract infections (UTIs) due to antibiotic-resistant uropathogenic Escherichia coli (UPEC) is a major public health concern. Bacteria contain proteins that sense their environment and have no human homologs and, thus, are attractive drug targets. CpxRA is a conserved sensing system whose function is to reduce stress in the bacterial cell membrane; activation of CpxRA reduces the expression of virulence determinants, which must cross the cell membrane to reach the bacterial surface. We previously identified a class of compounds that activate CpxRA. We show in a mouse UTI model that our most potent compound significantly reduced recovery of UPEC in the urine, trended toward reducing bacterial recovery in the bladder and kidneys, did not kill UPEC, and downregulated multiple proteins involved in UPEC virulence. Since these compounds do not act by a killing mechanism, they have potential to treat UTIs caused by antibiotic-resistant bacteria.


Subject(s)
Escherichia coli Infections , Escherichia coli Proteins , Urinary Tract Infections , Uropathogenic Escherichia coli , Animals , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacterial Proteins/genetics , Disease Models, Animal , Escherichia coli Infections/drug therapy , Escherichia coli Infections/microbiology , Escherichia coli Proteins/metabolism , Female , Gene Expression Regulation, Bacterial , Humans , Male , Mice , Phosphoric Monoester Hydrolases/genetics , Phosphoric Monoester Hydrolases/metabolism , Protein Kinases/genetics , Protein Kinases/metabolism , Salmonella typhimurium/metabolism , Urinary Tract Infections/drug therapy , Urinary Tract Infections/microbiology , Virulence Factors/genetics
7.
Sports Med ; 52(2): 403-415, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34427877

ABSTRACT

BACKGROUND: Sport-related concussion is recognized as a significant injury with variable recovery rates. OBJECTIVE: This study defined the acute natural history of sport concussion in male and female collegiate athletes participating in a broad array of sports. METHODS: We conducted a prospective, longitudinal investigation among collegiate student athletes (n = 34,709) from 30 academic institutions. Primary outcomes included the time (days) from injury until initiation of a return to participation (RTP) protocol and time from injury until medical clearance for unrestricted RTP. RESULTS: Concussed athletes (n = 1751, 19.2 years, 63.2% male) participating in 22 different sports began the RTP protocol in a median 6.4 (IQR 3.7-11.8) days. Time to initiate the RTP protocol was lengthened by less frequent post-injury assessments, greater initial post-injury symptom severity, limited contact sports participation, practice/training injuries, and three or more prior concussions. The median total RTP duration was 12.8 (IQR 8.7-20.1) days. Total RTP duration was shorter with ADHD medication usage, males, and greater assessment frequency; while greater initial post-injury symptom severity, practice-/training-related injuries, and three or more prior concussions had longer recoveries. CONCLUSION: Although median recovery times are consistent with previous guidelines, it was not until 1 month post-injury that a preponderance of collegiate athletes were cleared to begin the RTP protocol (92%) or cleared for unrestricted sport participation (85%). Intrinsic and extrinsic factors had a small effect, altering recovery trajectories by up to 2 days, suggesting a largely unified approach to post-injury monitoring and management across all athletes. These data represent a shift from previous classification parameters of normal clinical recovery.


Subject(s)
Athletic Injuries , Brain Concussion , Sports , Athletes , Athletic Injuries/diagnosis , Brain Concussion/diagnosis , Female , Humans , Male , Prospective Studies
8.
Pediatr Dent ; 43(4): 287-289, 2021 Jul 15.
Article in English | MEDLINE | ID: mdl-34467845

ABSTRACT

Purpose: The purpose of this study was to assess the relationship between the number of teeth present at 12 months and decayed, missing, or filled surfaces (dmfs) at 30 and 48 months. Methods: Data are from a longitudinal, multisite study with clinical dental examinations conducted at 12, 30, and 48 months of age. Spearman correlation and chi-square tests assessed relationships between teeth present at 12 months and dmfs at 30 (n equals 1,062) and 48 months (n equals 985). Results: Spearman correlations were weak but significant for both 30- and 48-month time points (R equals 0.066, P=0.032; R equals 0.093, P=0.004, respectively). Mantel-Haenszel chi-square analyses of categories of teeth present at 12 months (zero, one to four, five to eight, and greater than or equal to nine) and categories of dmfs at 30 and 48 months (zero, one to two, three to five, six to 15, and greater than or equal to 16) revealed nonsignificant (P=0.326) relationship with 30-month dmfs but a significant (P=0.013) relationship with 48-month dmfs. Conclusion: Results suggest that early tooth eruption is weakly associated with an occurrence of early childhood caries.


Subject(s)
Dental Caries , Tooth Eruption , Chi-Square Distribution , Child, Preschool , Dental Caries/epidemiology , Dental Caries Susceptibility , Humans , Longitudinal Studies
10.
Radiat Res ; 195(4): 307-323, 2021 04 01.
Article in English | MEDLINE | ID: mdl-33577641

ABSTRACT

Medical countermeasures (MCMs) for hematopoietic acute radiation syndrome (H-ARS) should be evaluated in well-characterized animal models, with consideration of at-risk populations such as pediatrics. We have developed pediatric mouse models of H-ARS and delayed effects of acute radiation exposure (DEARE) for efficacy testing of MCMs against radiation. Male and female C57BL/6J mice aged 3, 4, 5, 6, 7 and 8 weeks old (±1 day) were characterized for baseline hematopoietic and gastrointestinal parameters, radiation response, efficacy of a known MCM, and DEARE at six and 12 months after total-body irradiation (TBI). Weanlings (age 3 weeks) were the most radiosensitive age group with an estimated LD50/30 of 712 cGy, while mice aged 4 to 8 weeks were more radioresistant with an estimated LD50/30 of 767-787 cGy. Female weanlings were more radiosensitive than males at 3 and 4 weeks old but became significantly more radioresistant after the pubertal age of 5 weeks. The most dramatic increase in body weight, RBC counts and intestinal circumference length occurred from 3 to 5 weeks of age. The established radiomitigator Neulasta® (pegfilgrastim) significantly increased 30-day survival in all age groups, validating these models for MCM efficacy testing. Analyses of DEARE among pediatric survivors revealed depressed weight gain in males six months post-TBI, and increased blood urea nitrogen at 12 months post-TBI which was more severe in females. Hematopoietic DEARE at six months post-TBI appeared to be less severe in survivors from the 3- and 4-week-old groups but was equally severe in all age groups by 12 months of age. Similar to our other acute radiation mouse models, there was no appreciable effect of Neulasta used as an H-ARS MCM on the severity of DEARE. In summary, these data characterize a pediatric mouse model useful for assessing the efficacy of MCMs against ARS and DEARE in children.


Subject(s)
Acute Radiation Syndrome/drug therapy , Filgrastim/pharmacology , Hematopoietic System/drug effects , Polyethylene Glycols/pharmacology , Radiation Tolerance/drug effects , Acute Radiation Syndrome/etiology , Acute Radiation Syndrome/physiopathology , Animals , Disease Models, Animal , Hematopoietic System/physiopathology , Hematopoietic System/radiation effects , Humans , Mice , Pediatrics , Radiation Tolerance/radiation effects , Whole-Body Irradiation/adverse effects
11.
mBio ; 12(1)2021 01 12.
Article in English | MEDLINE | ID: mdl-33436440

ABSTRACT

Exudative cutaneous ulcers (CU) in yaws-endemic areas are associated with Treponema pallidum subsp. pertenue (TP) and Haemophilus ducreyi (HD), but one-third of CU cases are idiopathic (IU). Using mass drug administration (MDA) of azithromycin, a yaws eradication campaign on Lihir Island in Papua New Guinea reduced but failed to eradicate yaws; IU rates remained constant throughout the campaign. To identify potential etiologies of IU, we obtained swabs of CU lesions (n = 279) and of the skin of asymptomatic controls (AC; n = 233) from the Lihir Island cohort and characterized their microbiomes using a metagenomics approach. CU bacterial communities were less diverse than those of the AC. Using real-time multiplex PCR with pathogen-specific primers, we separated CU specimens into HD-positive (HD+), TP+, HD+TP+, and IU groups. Each CU subgroup formed a distinct bacterial community, defined by the species detected and/or the relative abundances of species within each group. Streptococcus pyogenes was the most abundant organism in IU (22.65%) and was enriched in IU compared to other ulcer groups. Follow-up samples (n = 31) were obtained from nonhealed ulcers; the average relative abundance of S. pyogenes was 30.11% in not improved ulcers and 0.88% in improved ulcers, suggesting that S. pyogenes in the not improved ulcers may be azithromycin resistant. Catonella morbi was enriched in IU that lacked S. pyogenes As some S. pyogenes and TP strains are macrolide resistant, penicillin may be the drug of choice for CU azithromycin treatment failures. Our study will aid in the design of diagnostic tests and selective therapies for CU.IMPORTANCE Cutaneous ulcers (CU) affect approximately 100,000 children in the tropics each year. While two-thirds of CU are caused by Treponema pallidum subspecies pertenue and Haemophilus ducreyi, the cause(s) of the remaining one-third is unknown. Given the failure of mass drug administration of azithromycin to eradicate CU, the World Health Organization recently proposed an integrated disease management strategy to control CU. Success of this strategy requires determining the unknown cause(s) of CU. By using 16S rRNA gene sequencing of swabs obtained from CU and the skin of asymptomatic children, we identified another possible cause of skin ulcers, Streptococcus pyogenes Although S. pyogenes is known to cause impetigo and cellulitis, this is the first report implicating the organism as a causal agent of CU. Inclusion of S. pyogenes into the integrated disease management plan will improve diagnostic testing and treatment of this painful and debilitating disease of children and strengthen elimination efforts.


Subject(s)
Skin Ulcer/complications , Skin Ulcer/microbiology , Streptococcus pyogenes/isolation & purification , Yaws/complications , Yaws/microbiology , Anti-Bacterial Agents/therapeutic use , Azithromycin/therapeutic use , Child , Clostridiales , Haemophilus ducreyi , Humans , Metagenomics , Microbiota , Papua New Guinea/epidemiology , Polymerase Chain Reaction , Prospective Studies , RNA, Ribosomal, 16S , Skin Ulcer/drug therapy , Skin Ulcer/epidemiology , Streptococcus pyogenes/genetics , Treponema , Ulcer , Yaws/drug therapy , Yaws/epidemiology
12.
Br J Sports Med ; 55(24): 1387-1394, 2021 Dec.
Article in English | MEDLINE | ID: mdl-33355211

ABSTRACT

OBJECTIVES: To examine sex differences in sport-related concussion (SRC) across comparable sports. METHODS: Prospective cohort of collegiate athletes enrolled between 2014 and 2017 in the Concussion Assessment, Research and Education Consortium study. RESULTS: Among 1071 concussions (females=615; 57.4%), there was no difference in recovery (median days to full return to play) (females=13.5 (IQR 9.0, 23.1) vs males=11.8 (IQR 8.1, 19.0), p=0.96). In subgroup analyses, female recovery was longer in contact (females=12.7 days (IQR 8.8, 21.4) vs males=11.0 days (IQR 7.9, 16.2), p=0.0021), while male recovery was longer in limited contact sports (males=16.9 days (IQR 9.7, 101.7) vs females=13.8 days (IQR 9.1, 22.0), p<0.0001). There was no overall difference in recovery among Division I schools (females=13.7 (IQR 9.0, 23.1) vs males=12.2 (IQR 8.2 19.7), p=0.5), but females had longer recovery at the Division II/III levels (females=13.0 (IQR 9.2, 22.7) vs males=10.6 (IQR 8.1, 13.9), p=0.0048). CONCLUSION: Overall, no difference in recovery between sexes across comparable women's and men's sports in this collegiate cohort was found. However, females in contact and males in limited contact sports experienced longer recovery times, while females had longer recovery times at the Division II/III level. These disparate outcomes indicate that, while intrinsic biological sex differences in concussion recovery may exist, important, modifiable extrinsic factors may play a role in concussion outcomes.


Subject(s)
Athletic Injuries , Brain Concussion , Athletes , Athletic Injuries/diagnosis , Athletic Injuries/epidemiology , Brain Concussion/diagnosis , Female , Humans , Male , Prospective Studies , Students , Universities
13.
Health Phys ; 119(5): 633-646, 2020 11.
Article in English | MEDLINE | ID: mdl-32932286

ABSTRACT

Development of medical countermeasures against radiation relies on robust animal models for efficacy testing. Mouse models have advantages over larger species due to economics, ease of conducting aging studies, existence of historical databases, and research tools allowing for sophisticated mechanistic studies. However, the radiation dose-response relationship of inbred strains is inherently steep and sensitive to experimental variables, and inbred models have been criticized for lacking genetic diversity. Jackson Diversity Outbred (JDO) mice are the most genetically diverse strain available, developed by the Collaborative Cross Consortium using eight founder strains, and may represent a more accurate model of humans than inbred strains. Herein, models of the Hematopoietic-Acute Radiation Syndrome and the Delayed Effects of Acute Radiation Exposure were developed in JDO mice and compared to inbred C57BL/6. The dose response relationship curve in JDO mice mirrored the more shallow curves of primates and humans, characteristic of genetic diversity. JDO mice were more radioresistant than C57BL/6 and differed in sensitivity to antibiotic countermeasures. The model was validated with pegylated-G-CSF, which provided significantly enhanced 30-d survival and accelerated blood recovery. Long-term JDO survivors exhibited increased recovery of blood cells and functional bone marrow hematopoietic progenitors compared to C57BL/6. While JDO hematopoietic stem cells declined more in number, they maintained a greater degree of quiescence compared to C57BL/6, which is essential for maintaining function. These JDO radiation models offer many of the advantages of small animals with the genetic diversity of large animals, providing an attractive alternative to currently available radiation animal models.


Subject(s)
Acute Radiation Syndrome/pathology , Bone Marrow/pathology , Hematopoietic Stem Cells/pathology , Radiation Exposure/adverse effects , Radiation Injuries, Experimental/pathology , Acute Radiation Syndrome/etiology , Animals , Bone Marrow/radiation effects , Collaborative Cross Mice , Disease Models, Animal , Hematopoietic Stem Cells/radiation effects , Male , Mice , Mice, Inbred C57BL , Radiation Dosage , Radiation Injuries, Experimental/etiology
15.
JAMA Netw Open ; 3(1): e1919771, 2020 01 03.
Article in English | MEDLINE | ID: mdl-31977061

ABSTRACT

Importance: There is potential scientific and clinical value in validation of objective biomarkers for sport-related concussion (SRC). Objective: To investigate the association of acute-phase blood biomarker levels with SRC in collegiate athletes. Design, Setting, and Participants: This multicenter, prospective, case-control study was conducted by the National Collegiate Athletic Association (NCAA) and the US Department of Defense Concussion Assessment, Research, and Education (CARE) Consortium from February 20, 2015, to May 31, 2018, at 6 CARE Advanced Research Core sites. A total of 504 collegiate athletes with concussion, contact sport control athletes, and non-contact sport control athletes completed clinical testing and blood collection at preseason baseline, the acute postinjury period, 24 to 48 hours after injury, the point of reporting being asymptomatic, and 7 days after return to play. Data analysis was conducted from March 1 to November 30, 2019. Main Outcomes and Measures: Glial fibrillary acidic protein (GFAP), ubiquitin C-terminal hydrolase-L1 (UCH-L1), neurofilament light chain, and tau were quantified using the Quanterix Simoa multiplex assay. Clinical outcome measures included the Sport Concussion Assessment Tool-Third Edition (SCAT-3) symptom evaluation, Standardized Assessment of Concussion, Balance Error Scoring System, and Brief Symptom Inventory 18. Results: A total of 264 athletes with concussion (mean [SD] age, 19.08 [1.24] years; 211 [79.9%] male), 138 contact sport controls (mean [SD] age, 19.03 [1.27] years; 107 [77.5%] male), and 102 non-contact sport controls (mean [SD] age, 19.39 [1.25] years; 82 [80.4%] male) were included in the study. Athletes with concussion had significant elevation in GFAP (mean difference, 0.430 pg/mL; 95% CI, 0.339-0.521 pg/mL; P < .001), UCH-L1 (mean difference, 0.449 pg/mL; 95% CI, 0.167-0.732 pg/mL; P < .001), and tau levels (mean difference, 0.221 pg/mL; 95% CI, 0.046-0.396 pg/mL; P = .004) at the acute postinjury time point compared with preseason baseline. Longitudinally, a significant interaction (group × visit) was found for GFAP (F7,1507.36 = 16.18, P < .001), UCH-L1 (F7,1153.09 = 5.71, P < .001), and tau (F7,1480.55 = 6.81, P < .001); the interaction for neurofilament light chain was not significant (F7,1506.90 = 1.33, P = .23). The area under the curve for the combination of GFAP and UCH-L1 in differentiating athletes with concussion from contact sport controls at the acute postinjury period was 0.71 (95% CI, 0.64-0.78; P < .001); the acute postinjury area under the curve for all 4 biomarkers combined was 0.72 (95% CI, 0.65-0.79; P < .001). Beyond SCAT-3 symptom score, GFAP at the acute postinjury time point was associated with the classification of athletes with concussion from contact controls (ß = 12.298; 95% CI, 2.776-54.481; P = .001) and non-contact sport controls (ß = 5.438; 95% CI, 1.676-17.645; P = .005). Athletes with concussion with loss of consciousness or posttraumatic amnesia had significantly higher levels of GFAP than athletes with concussion with neither loss of consciousness nor posttraumatic amnesia at the acute postinjury time point (mean difference, 0.583 pg/mL; 95% CI, 0.369-0.797 pg/mL; P < .001). Conclusions and Relevance: The results suggest that blood biomarkers can be used as research tools to inform the underlying pathophysiological mechanism of concussion and provide additional support for future studies to optimize and validate biomarkers for potential clinical use in SRC.


Subject(s)
Athletes/statistics & numerical data , Biomarkers/blood , Brain Concussion/blood , Brain Concussion/diagnosis , Brain Concussion/physiopathology , Students/statistics & numerical data , Adolescent , Adult , Case-Control Studies , Female , Glial Fibrillary Acidic Protein/blood , Humans , Male , Neurofilament Proteins/blood , Prospective Studies , Ubiquitin Thiolesterase/blood , United States , Young Adult , tau Proteins/blood
16.
Sex Transm Infect ; 96(4): 306-311, 2020 06.
Article in English | MEDLINE | ID: mdl-31515293

ABSTRACT

OBJECTIVES: Chlamydia trachomatis (CT) and Mycoplasma genitalium (MG) cause the majority of non-gonococcal urethritis (NGU). The role of Ureaplasma urealyticum (UU) in NGU is unclear. Prior case-control studies that examined the association of UU and NGU may have been confounded by mixed infections and less stringent criteria for controls. The objective of this case-control study was to determine the prevalence and aetiology of mixed infections in men and assess if UU monoinfection is associated with NGU. METHODS: We identified 155 men with NGU and 103 controls. Behavioural and clinical information was obtained and men were tested for Neisseria gonorrhoeae and CT, MG, UU and Trichomonas vaginalis (TV). Men who were five-pathogen negative were classified as idiopathic urethritis (IU). RESULTS: Twelve per cent of NGU cases in which a pathogen was identified had mixed infections, mostly UU coinfections with MG or CT; 27% had IU. In monoinfected NGU cases, 34% had CT, 17% had MG, 11% had UU and 2% had TV. In controls, pathogens were rarely identified, except for UU, which was present in 20%. Comparing cases and controls, NGU was associated with CT and MG monoinfections and mixed infections. UU monoinfection was not associated with NGU and was almost twice as prevalent in controls. Men in both the case and control groups who were younger and who reported no prior NGU diagnosis were more likely to have UU (OR 0.97 per year of age, 95% CI 0.94 to 0.998 and OR 6.3, 95% CI 1.4 to 28.5, respectively). CONCLUSIONS: Mixed infections are common in men with NGU and most of these are UU coinfections with other pathogens that are well-established causes of NGU. UU monoinfections are not associated with NGU and are common in younger men and men who have never previously had NGU. Almost half of NGU cases are idiopathic.


Subject(s)
Chlamydia trachomatis/isolation & purification , Coinfection/epidemiology , Mycoplasma genitalium/isolation & purification , Trichomonas vaginalis/isolation & purification , Ureaplasma urealyticum/isolation & purification , Urethritis/epidemiology , Adolescent , Adult , Case-Control Studies , Coinfection/etiology , Humans , Male , Middle Aged , Neisseria gonorrhoeae/isolation & purification , Prevalence , Urethritis/etiology , Young Adult
17.
Infect Immun ; 87(7)2019 07.
Article in English | MEDLINE | ID: mdl-31036601

ABSTRACT

Haemophilus ducreyi causes chancroid and is a major cause of cutaneous ulcers in children. Due to environmental reservoirs, both class I and class II H. ducreyi strains persist in cutaneous ulcer regions of endemicity following mass drug administration of azithromycin, suggesting the need for a vaccine. The hemoglobin receptor (HgbA) is a leading vaccine candidate, but its efficacy in animal models is class specific. Controlled human infection models can be used to evaluate vaccines, but only a class I strain (35000HP) has been characterized in this model. As a prelude to evaluating HgbA vaccines in the human model, we tested here whether a derivative of 35000HP containing a class II hgbA allele (FX548) is as virulent as 35000HP in humans. In eight volunteers infected at three sites with each strain, the papule formation rate was 95.8% for 35000HP versus 62.5% for FX548 (P = 0.021). Excluding doses of FX548 that were ≥2-fold higher than those of 35000HP, the pustule formation rate was 25% for 35000HP versus 11.7% for FX548 (P = 0.0053). By Western blot analysis, FX548 and 35000HP expressed equivalent amounts of HgbA in whole-cell lysates and outer membranes. The growth of FX548 and 35000HP was similar in media containing hemoglobin or hemin. By whole-genome sequencing and single-nucleotide polymorphism analysis, FX548 contained no mutations in open reading frames other than hgbA We conclude that by an unknown mechanism, FX548 is partially attenuated in humans and is not a suitable strain for HgbA vaccine efficacy trials in the model.


Subject(s)
Bacterial Proteins/genetics , Bacterial Proteins/immunology , Carrier Proteins/genetics , Carrier Proteins/immunology , Chancroid/prevention & control , Haemophilus Vaccines/immunology , Haemophilus ducreyi/immunology , Adult , Alleles , Bacterial Proteins/administration & dosage , Carrier Proteins/administration & dosage , Chancroid/immunology , Chancroid/microbiology , Female , Haemophilus Vaccines/administration & dosage , Haemophilus Vaccines/genetics , Haemophilus ducreyi/genetics , Humans , Male , Middle Aged , Young Adult
18.
Sports Med ; 48(7): 1761, 2018 07.
Article in English | MEDLINE | ID: mdl-29582378

ABSTRACT

The article Test-Retest Reliability and Interpretation of Common Concussion Assessment Tools.

19.
Sports Med ; 48(8): 1971-1985, 2018 08.
Article in English | MEDLINE | ID: mdl-29498030

ABSTRACT

BACKGROUND: Sport-related concussion and repetitive head impact exposure in contact sports continue to receive increased attention in public and medical spheres. The Concussion Assessment, Research and Education (CARE) Consortium, a multicenter cooperative, was established to study the natural history of concussion in National Collegiate Athletic Association (NCAA) collegiate student-athletes across 29 colleges and universities in the United States. The purpose of this investigation is to provide normative data from the CARE Consortium and evaluate for differences between sport categories. METHODS: NCAA student-athletes were evaluated annually for general demographics and sport-specific characteristics before the start of the competitive season. We collected demographic and medical history information and evaluated each student-athlete's neurocognitive function, neurological status, postural stability, and self-reported symptoms. Sports were categorized by the amount of contact typically associated with the sport (i.e., contact, limited contact, non-contact). Comparisons between the three sport categories for the evaluated variables were made using linear or zero inflated negative binomial regression models adjusted for gender, concussion history, and household income. RESULTS: Over a 2-year period (August 2014-July 2016), 15,681 NCAA athletes completed preseason evaluations. Overall, 53% of the athletes were in the contact sport group, 31% were in the limited contact group and 17% were in the non-contact group. After adjusting for covariates, there were statistically significant differences found between athlete groups, although the differences and effect sizes were small and not clinically significant. The contact sport group had better scores on Immediate Post-Concussion Assessment Testing (ImPACT®) visual and verbal memory, Sport Concussion Assessment Tool (SCAT) symptom checklist, and Brief Symptom Inventory-18 (BSI-18), but slower ImPACT reaction time and worse scores on Standardized Assessment of Concussion (SAC). Further, the data indicate that some ImPACT score distributions were noticeably different from those presented in the technical manual. CONCLUSIONS: In this large, racially and socio-economically diverse cohort of male and female college athletes, we found no evidence that student-athletes participating in contact sports have clinically meaningful deficits in pre-season cognitive and balance testing. They also did not report significantly more symptoms of psychological distress when compared with student-athletes in non-contact or limited contact sports. In addition, the data suggest potential limitations when using published ImPACT norms when evaluating injured athletes.


Subject(s)
Athletes , Athletic Injuries/prevention & control , Brain Concussion/prevention & control , Female , Health Promotion/methods , Humans , Male , Neuropsychological Tests , Students , Universities
20.
Hepatol Commun ; 2(1): 29-34, 2018 01.
Article in English | MEDLINE | ID: mdl-29404510

ABSTRACT

Only a subset of subjects with excessive alcohol consumption develops alcoholic liver disease (ALD). One of the major risk factors for ALD is the genetic variant of the patatin-like phospholipase domain-containing protein 3 (PNPLA3) gene. Coffee is one of the most commonly consumed beverages, and coffee consumption has been associated with lower levels of serum alanine aminotransferase. The aim of this study was to investigate the role of coffee drinking and PNPLA3 rs738409 and their association with alcoholic hepatitis (AH) in a well-characterized cohort of subjects from the Translational Research and Evolving Alcoholic Hepatitis Treatment consortium. AH subjects and heavy drinking controls without a history of liver disease who were enrolled between May 2013 and May 2016 were included (n = 339), and the details of alcohol and coffee consumption were assessed. The PNPLA3 variant was determined among participants of European ancestry (n = 183). Relationships between baseline data and AH status were determined, and multivariable logistic regression modeling was performed. During the study period, 189 cases with AH and 150 heavy drinking controls were prospectively enrolled. The prevalence of regular coffee consumption was significantly lower in patients with AH compared to controls (20% versus 43%; P < 0.0001). The overall minor allele frequency of the PNPLA3 variant was higher in AH cases. Multivariable logistic regression revealed that coffee consumption and PNPLA3 were significantly associated with AH status at baseline after adjusting for relevant patient characteristics. Conclusion: We found a higher prevalence of AH among heavy drinkers with PNPLA3 G/G and G/C genotypes regardless of coffee consumption status and a higher prevalence of AH among heavy drinkers who were not regular coffee drinkers. These findings remained after considering relevant baseline patient characteristics. Further studies are needed to confirm our observation. (Hepatology Communications 2018;2:29-34).

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