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1.
Placenta ; 140: 11-19, 2023 09 07.
Article in English | MEDLINE | ID: mdl-37515848

ABSTRACT

INTRODUCTION: Transplacental transport of maternal IgG via the neonatal Fc receptor (FcRn) provides babies with passive immunity. Several factors are reported to influence transport, including the avidity of antibodies (Abs) for their cognate antigens. Unfortunately, information on the role of antibody (Ab) avidity is limited. This study investigated if i) antibodies (Abs) with high avidity for 6 Plasmodium falciparum antigens and tetanus toxoid (TTx) were preferentially transferred to premature and term Cameroonian babies and ii) if Ab avidity was increased in babies whose mothers had placental malaria (PM), implicating the involvement of immune complexes. METHODS: Total IgG (mg/ml) and Abs to malarial antigens (AMA1, EBA-175, MSP1-42, MSP2, MSP3, DBL5 of VAR2CSA) and TTx were measured in paired mother-cord samples obtained from premature and term deliveries in Cameroon. Half the women had PM at delivery. Avidity Indices (AIs) were determined by treating antigen-bound-Abs with different molar concentrations of NH4SCN and calculating 50% endpoints. RESULTS: Total IgG and antigen-specific Abs increased in cord blood with gestational age; however, AIs did not. AIs in paired maternal-cord blood samples were strongly associated for all antigens (r = 0.77-0.96). However, no significant different in AIs was found between paired mother-cord blood samples for any of the antigens (p values > 0.05). Similarly, Ab avidity was not increased in cord blood of babies whose mothers had PM or hypergammaglobulinemia. DISCUSSION: Overall, there was no evidence that higher avidity Abs to any of the malarial antigens or TTx were preferentially transferred to Cameroonian babies.


Subject(s)
Malaria, Falciparum , Premature Birth , Infant, Newborn , Infant , Humans , Female , Pregnancy , Placenta , Plasmodium falciparum , Antibodies, Protozoan , Antigens, Protozoan , Immunoglobulin G
2.
mBio ; 14(2): e0046423, 2023 04 25.
Article in English | MEDLINE | ID: mdl-37010413

ABSTRACT

Moraxella catarrhalis is found almost exclusively within the human respiratory tract. This pathobiont is associated with ear infections and the development of respiratory illnesses, including allergies and asthma. Given the limited ecological distribution of M. catarrhalis, we hypothesized that we could leverage the nasal microbiomes of healthy children without M. catarrhalis to identify bacteria that may represent potential sources of therapeutics. Rothia was more abundant in the noses of healthy children compared to children with cold symptoms and M. catarrhalis. We cultured Rothia from nasal samples and determined that most isolates of Rothia dentocariosa and "Rothia similmucilaginosa" were able to fully inhibit the growth of M. catarrhalis in vitro, whereas isolates of Rothia aeria varied in their ability to inhibit M. catarrhalis. Using comparative genomics and proteomics, we identified a putative peptidoglycan hydrolase called secreted antigen A (SagA). This protein was present at higher relative abundance in the secreted proteomes of R. dentocariosa and R. similmucilaginosa than in those from non-inhibitory R. aeria, suggesting that it may be involved in M. catarrhalis inhibition. We produced SagA from R. similmucilaginosa in Escherichia coli and confirmed its ability to degrade M. catarrhalis peptidoglycan and inhibit its growth. We then demonstrated that R. aeria and R. similmucilaginosa reduced M. catarrhalis levels in an air-liquid interface culture model of the respiratory epithelium. Together, our results suggest that Rothia restricts M. catarrhalis colonization of the human respiratory tract in vivo. IMPORTANCE Moraxella catarrhalis is a pathobiont of the respiratory tract, responsible for ear infections in children and wheezing illnesses in children and adults with chronic respiratory diseases. Detection of M. catarrhalis during wheezing episodes in early life is associated with the development of persistent asthma. There are currently no effective vaccines for M. catarrhalis, and most clinical isolates are resistant to the commonly prescribed antibiotics amoxicillin and penicillin. Given the limited niche of M. catarrhalis, we hypothesized that other nasal bacteria have evolved mechanisms to compete against M. catarrhalis. We found that Rothia are associated with the nasal microbiomes of healthy children without Moraxella. Next, we demonstrated that Rothia inhibit M. catarrhalis in vitro and on airway cells. We identified an enzyme produced by Rothia called SagA that degrades M. catarrhalis peptidoglycan and inhibits its growth. We suggest that Rothia or SagA could be developed as highly specific therapeutics against M. catarrhalis.


Subject(s)
Asthma , Moraxella catarrhalis , Child , Adult , Humans , Peptidoglycan/metabolism , Respiratory Sounds
3.
Malar J ; 21(1): 346, 2022 Nov 19.
Article in English | MEDLINE | ID: mdl-36403045

ABSTRACT

BACKGROUND: The primary antibody (Ab) response to Plasmodium falciparum is a critical step in developing immunity to malaria. Information on the initial Ab responses of babies in malaria-endemic areas is incomplete, in part, because babies receive maternal IgG via transplacental-transfer and usually become infected before maternal IgG wanes. The study aimed to identify the primary IgM and IgG Ab responses to malarial antigens in Cameroonian babies. METHODS: Infants (n = 70) living in a high malaria transmission area were followed from birth throughout the first year of life (mean 341 ± 42 days, an average of 8.5 time points per infant). Malaria infection was assessed by microscopy and PCR, and IgM and IgG antibodies (Abs) were measured using a multiplex immunoassay to AMA1, EBA-175, MSP1-42, MSP2, MSP3, RESA, LSA1, and CSP. RESULTS: The half-life of maternal IgG varied among the antigens, ranging from 0.7 to 2.5 months. The first infection of 41% of the babies was sub-microscopic and only 11 to 44% of the babies produced IgM to the above antigens; however, when the first infection was detected by microscopy, 59-82% of the infants made IgM Abs to the antigens. Infants were able to produce IgM even when maternal IgG was present, suggesting maternal Abs did not suppress the baby's initial Ab response. Using longitudinal regression models that incorporated time-varying covariates, infants were found to produce IgG Ab to only AMA-1 when the first infection was sub-microscopic, but they produced IgG Abs to MSP1-42 (3D7, FVO), AMA1 (3D7, FVO) MSP2-FC27, MSP3, RESA, and LSA1, but not MSP 2-3D7, EBA-175, and CSP during their first slide-positive infection. Notably, the primary and secondary IgG responses were short-lived with little evidence of boosting. CONCLUSIONS: The primary Ab response of babies who had maternal IgG was similar to that reported for primary infections in malaria-naïve adults.


Subject(s)
Malaria, Falciparum , Malaria , Humans , Infant , Adult , Plasmodium falciparum , Malaria, Falciparum/epidemiology , Antibodies, Protozoan , Merozoite Surface Protein 1 , Antibody Formation , Antigens, Protozoan , Immunoglobulin M , Immunoglobulin G
4.
Clin Breast Cancer ; 22(5): e674-e679, 2022 07.
Article in English | MEDLINE | ID: mdl-35279407

ABSTRACT

BACKGROUND: Sentinel Lymph Node Biopsy (SLNB) is used to stage the axilla, but there is limited data in patients with prior ipsilateral breast cancer. This study compares redo-SLNB (reSLNB) and Axillary node sample (ANS) in this sub-cohort of patients. MATERIALS AND METHODS: This is a retrospective study looking at patients with a new ipsilateral primary or recurrence with history of breast-conserving surgery. Planned and performed surgery, patient demographics and previous treatments were recorded. Node positivity and success rate of reSLNB was analyzed. RESULTS: A total of 86 patients were identified that had mastectomy for ipsilateral recurrent disease with radiologically negative axilla. Out of the 48 that had reSLNB, 35(72.9%) were successful. Nineteen percent of the reSLNB had positive axillae and 20% of the ANS patients. reSLNB success rate was significantly lower amongst patients with previous axillary surgery (P = .014) and previous positive nodes(P = .001). CONCLUSION: reSLNB should be considered to restage the axilla in patients with previous history of ipsilateral cancer especially that there is growing evidence showing good identification rate.


Subject(s)
Breast Neoplasms , Sentinel Lymph Node Biopsy , Axilla/pathology , Axilla/surgery , Breast Neoplasms/pathology , Breast Neoplasms/surgery , Female , Humans , Lymph Nodes/pathology , Mastectomy , Neoplasm Recurrence, Local/surgery , Retrospective Studies
5.
AIDS Behav ; 26(8): 2723-2737, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35167038

ABSTRACT

Inequities in pre-exposure prophylaxis (PrEP) experiences will impede HIV epidemic elimination among gay and bisexual men (GBM). Ethnicity is a strong marker of inequity in the United States, but evidence from other countries is lacking. We investigated experiences on-PrEP to 12 months follow-up in a prospective cohort of 150 GBM in Auckland, New Zealand with an equity quota of 50% non-Europeans. Retention at 12 months was 85.9%, lower among Maori/Pacific (75.6%) than non-Maori/Pacific participants (90.1%). Missed pills increased over time and were higher among Maori/Pacific. PrEP breaks increased, by 12 months 35.7% of Maori/Pacific and 15.7% of non-Maori/Pacific participants had done so. Condomless receptive anal intercourse partners were stable over time. STIs were common but chlamydia declined; 12-month incidence was 8.7% for syphilis, 36.0% gonorrhoea, 46.0% chlamydia, 44.7% rectal STI, 64.0% any STI. Structural interventions and delivery innovations are needed to ensure ethnic minority GBM gain equal benefit from PrEP.Clinical trial number ACTRN12616001387415.


Subject(s)
HIV Infections , Pre-Exposure Prophylaxis , Sexual and Gender Minorities , Sexually Transmitted Diseases , Ethnicity , Follow-Up Studies , HIV Infections/drug therapy , HIV Infections/epidemiology , HIV Infections/prevention & control , Homosexuality, Male , Humans , Male , Minority Groups , New Zealand/epidemiology , Prospective Studies , Sexual Behavior , Sexually Transmitted Diseases/epidemiology , Sexually Transmitted Diseases/prevention & control
6.
Semin Thorac Cardiovasc Surg ; 34(2): 763-770, 2022.
Article in English | MEDLINE | ID: mdl-34023526

ABSTRACT

Prior coronary artery bypass grafting (CABG) has been considered a relative contraindication to lung transplantation due to the atherosclerotic disease burden and technical challenges. We hypothesized that lung transplant recipients with prior CABG have increased mortality compared to recipients without prior CABG. Further, the causes of death are different for lung transplant recipients with prior CABG vs without CABG. The Scientific Registry of Transplant Recipients database was queried to define the survival and causes of death of lung transplant recipients with or without CABG during the Lung Allocation Score era from May 5, 2005 to December 31, 2015. The primary end-points were all-cause mortality at 1 year and 5 years, as well as mortality due to major causes of death. This retrospective study cohort included a total of 13,064 lung transplant recipients, of whom 319 patients had previously undergone CABG, representing 2.4% of all transplants. Patients without prior CABG were more likely to have undergone bilateral lung transplantation compared to those with prior CABG (61.2 % vs 15.7%, P < 0.001). Among patients with prior CABG, single right lung transplant was most common. Overall patient survival at 1 year was 76.8% for lung transplant recipients with prior CABG and 85.4% for patients without prior CABG. Freedom from death due to graft failure at 1 and 5 years in patients with a prior CABG was 93.1% and 76.2% respectively, cardiac and/or cerebrovascular disease 96.2% and 88.5% respectively, and hemorrhage 97.9% and 97.5% respectively. In a multivariate Cox regression model utilizing time-dependent coefficients for recipient age, prior CABG, among several other risk factors, was associated with increased mortality within 1 year. Prior CABG is associated with short- and long-term mortality in lung transplant recipients with history of CABG despite the majority of these patients undergoing single lung transplantation vs bilateral lung transplantation. Graft failure and/or pulmonary causes are the most common cause of death regardless of whether or not the lung transplant recipient had prior CABG, but patients with prior CABG are at increased risk of death due to graft failure, cardiac or cerebrovascular disease, and hemorrhage.


Subject(s)
Coronary Artery Disease , Transplant Recipients , Coronary Artery Bypass/adverse effects , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/surgery , Hemorrhage , Humans , Lung , Retrospective Studies , Treatment Outcome
8.
Case Rep Gastrointest Med ; 2021: 5555961, 2021.
Article in English | MEDLINE | ID: mdl-33791134

ABSTRACT

Pemphigus vulgaris (PV) is an autoimmune blistering disorder of the skin and mucosal surfaces characterized by acantholysis (loss of adhesion between epidermal cells). Esophageal involvement of PV is an underdiagnosed entity as routine diagnostic endoscopy is not recommended in asymptomatic patients. Dysphagia and odynophagia are common presenting symptoms; however, upper gastrointestinal bleeding (UGIB) associated with esophageal involvement of PV without a history of mucosal blistering is extremely uncommon. We present a case of esophageal involvement of PV associated with active UGIB that was diagnosed on endoscopic evaluation. This case illustrated the importance of early endoscopy to identify the esophageal involvement of PV especially in patients with preexisting disease who present with gastrointestinal symptoms such as dysphagia, odynophagia, and hematemesis. Early recognition of esophageal involvement of PV and initiation of corticosteroid and/or immunosuppressant therapy may improve the outcome of the disease.

9.
Infect Immun ; 89(6)2021 05 17.
Article in English | MEDLINE | ID: mdl-33722929

ABSTRACT

High-avidity antibodies (Abs) are acquired after a few Plasmodium falciparum infections in low transmission areas, but it remains unclear if Ab avidity to different merozoite antigens increases with age in individuals with persistent antigenemia and, if so, when a fully mature Ab response occurs. The study used plasma samples collected between 1996 and 1998 from 566 individuals aged 4 to 84 years in Simbok, Cameroon, where residents received an estimated 1.6 infectious mosquito bites/person/night. Plasma samples were examined for Ab levels (median fluorescence intensity [MFI]) and Ab avidity index (AI) (where AI = [MFI after treatment with 2 M NH4SCN/MFI without salt] × 100) using a bead-based multiplex immunoassay for recombinant AMA1, EBA-175, MSP1-42 (3D7, FVO), MSP2 (3D7, Fc27), and MSP3. Blood-smear positivity for P. falciparum declined with age from 54.3% at 4 to 5 years to 18% at 16 to 40 years and <11% at >40 years of age, although most individuals had submicroscopic parasitemia. Ab affinity maturation, based on age-related patterns of median AI, percentage of individuals with AI of ≥50, and strength of association between MFI and AI, occurred at different rates among the antigens; they developed rapidly before age 4 years for AMA1, increased gradually with age for EBA-175 and MSP1 until ∼16 to 25 years, but occurred negligibly for MSP2 and MSP3. In a hyperendemic area with perennial transmission, affinity maturation resulting in an increase in the proportion of high-avidity Abs occurred for some merozoite antigens, in parallel with a decline in malaria slide passivity, but not for others.


Subject(s)
Antibodies, Protozoan/immunology , Antibody Affinity/immunology , Antigens, Protozoan/immunology , Malaria, Falciparum/epidemiology , Malaria, Falciparum/immunology , Merozoites/immunology , Plasmodium falciparum/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Cameroon , Child , Child, Preschool , Female , Humans , Malaria, Falciparum/parasitology , Male , Middle Aged , Young Adult
10.
Front Immunol ; 12: 610108, 2021.
Article in English | MEDLINE | ID: mdl-33717094

ABSTRACT

Pregnant women infected with Plasmodium falciparum often produce antibodies (Abs) to VAR2CSA, a ligand that binds to placental chondroitin sulfate A causing placental malaria (PM). Antibodies to VAR2CSA are associated with improved pregnancy outcomes. Antibody avidity is a surrogate marker for the extent of maturation of the humoral immune response. Little is known about high avidity Abs to VAR2CSA for women living in urban African cities. Therefore, this study sought to determine: i) if high avidity Abs to full-length VAR2CSA (FV2) increase with gravidity in women in Yaoundé, Cameroon exposed to ~ 0.3-1.1 infectious mosquito bites per month, ii) if high avidity Abs to FV2 are directed against a specific region of VAR2CSA, and iii) if having high avidity Abs to FV2 improve pregnancy outcomes. Plasma samples collected at delivery from 695 women who had Abs to FV2 were evaluated. Ab levels and the Avidity Index (AI), defined as the percent Abs remaining bound to FV2 after incubation with 3M NH4SCN, were determined. Similar Ab levels to FV2 were present in women of all gravidities (G1 through 6+; p=0.80), except significantly lower levels were detected in PM-negative (PM-) primigravidae (p <0.001). Median Ab avidities increased between gravidity 1 and 2 (p<0.001) and remained stable thereafter (G3-G6+: p=0.51). These results suggest that B cell clonal expansion began during the first pregnancy, with clonal selection primarily occurring during the second. However, the majority of women (84%) had AI <35, a level of high avidity Abs previously reported to be associated with improved pregnancy outcomes. When plasma from 107 Cameroonian women was tested against 8 different regions of FV2, high avidity Abs were predominately restricted to DBL5 with median AI of 50 compared to AI <25 for the other domains. The only significance influence of high avidity Abs on pregnancy outcome was that babies born to mothers with AI above the median were 104 g heavier than babies born to women with AI below the median (p=0.045). These results suggest that a vaccine that boosts maturation of the immune response to VAR2CSA may be beneficial for women residing in urban areas.


Subject(s)
Antibodies, Protozoan/immunology , Antigens, Protozoan/immunology , Malaria, Falciparum/epidemiology , Malaria, Falciparum/immunology , Plasmodium falciparum/immunology , Pregnancy Complications, Parasitic/epidemiology , Pregnancy Complications, Parasitic/immunology , Antibodies, Protozoan/blood , Antibody Affinity/immunology , Antigens, Protozoan/blood , Antigens, Protozoan/chemistry , Cameroon/epidemiology , Cities , Female , Humans , Malaria, Falciparum/blood , Pregnancy , Pregnancy Complications, Parasitic/blood , Pregnancy Outcome , Protein Interaction Domains and Motifs/immunology , Public Health Surveillance
11.
Int J STD AIDS ; 32(1): 67-74, 2021 01.
Article in English | MEDLINE | ID: mdl-33198606

ABSTRACT

Antimicrobial resistance of Neisseria gonorrhoeae (NG) is of global public health concern. The aim of this study was to explore demographic and behavioural factors associated with antimicrobial susceptibility of NG to ceftriaxone and azithromycin. Gonococcal isolates (n = 391) from clients attending the Auckland Sexual Health Service, New Zealand, from July 2014 - June 2015 (n = 206), and July 2017 - June 2018 (n = 185), were tested for susceptibility to ceftriaxone and azithromycin. Laboratory data were linked with behavioural and demographic data. Geometric mean azithromycin MICs increased across the two time periods (0.239 mg/L in 2014/15 to 0.347 mg/L in 2017/18, p < 0.001), and ceftriaxone MICs decreased (0.007 mg/L in 2014/15 to 0.005 mg/L in 2017/18, p < 0.001). Demographic and behavioural factors were not associated with differences in ceftriaxone MICs; however azithromycin MICs were higher in men who have sex with men (0.356 mg/L) compared with the heterosexual study population (0.192 mg/L, p < 0.001) and were lower in Pacific peoples (0.201 mg/L, p < 0.001) and Maori (0.244 mg/L, p = 0.05) compared with those of European ethnicity (0.321 mg/L). Our findings show that azithromycin MICs increased in our region between 2014 and 2018; associations were seen with sexual orientation and ethnicity.


Subject(s)
Anti-Bacterial Agents/pharmacology , Azithromycin/pharmacokinetics , Ceftriaxone/pharmacology , Gonorrhea/drug therapy , Neisseria gonorrhoeae/drug effects , Adolescent , Adult , Anti-Bacterial Agents/therapeutic use , Azithromycin/pharmacology , Azithromycin/therapeutic use , Ceftriaxone/therapeutic use , Drug Resistance, Bacterial , Female , Gonorrhea/epidemiology , Humans , Male , Microbial Sensitivity Tests , Neisseria gonorrhoeae/isolation & purification , New Zealand/epidemiology , Sexual Behavior , Young Adult
12.
Malar J ; 19(1): 171, 2020 May 01.
Article in English | MEDLINE | ID: mdl-32357882

ABSTRACT

BACKGROUND: Antibodies (Ab) play a significant role in immunity to Plasmodium falciparum malaria. Usually, following repeated exposure to pathogens, affinity maturation and clonal selection take place, resulting in increased antibody avidity. However, some studies suggest affinity maturation may not occur to malaria antigens in endemic areas. Information on development of antibody avidity is confusing and conflicting, in part, because different techniques have been used to measure avidity. Today, bead-based multiplex immunoassays (MIA) are routinely used to simultaneously quantitate antibody levels to multiple antigens. This study evaluated the feasibility of developing an avidity MIA with 5 merozoite antigens (AMA1, EBA-175, MSP1-42, MSP2, MSP3) that uses a single chaotropic concentration. METHODS: The most common ELISA protocols that used the chaotropic reagents guanidine HCl (GdHCl), urea, and ammonium thiocyanate (NH4SCN) were adapted to a multiplex MIA format. Then, different concentrations of chaotropes and incubation times were compared and results were expressed as an Avidity Index (AI), i.e., percentage of antibody remaining bound in the presence of chaotrope. Experiments were conducted to (i) identify the assay with the widest range of AI (discriminatory power), (ii) determine the amount of chaotrope needed to release 50% of bound Ab using plasma from adults and infants, and (iii) evaluate assay repeatability. RESULTS: Overall, 4 M GdHCl and 8 M urea were weaker chaotropes than 3 M NH4SCN. For example, they failed to release significant amounts of Ab bound to MSP1-42 in adult plasma samples; whereas, a range of AI values was obtained with NH4SCN. Titration of NH4SCN revealed that 2 M NH4SCN gave the widest range of AI for the 5 antigens. Binding studies using plasma from 40 adults and 57 1-year old infants in Cameroon showed that 2.1 M ± 0.32 (mean ± SD) NH4SCN (adults) and 1.8 M ± 0.23 M (infants) released 50% of bound Ab from the merozoite antigens. CONCLUSIONS: An avidity MIA is feasible for the 5 merozoite antigens that uses a single concentration (2 M) of NH4SCN. The assay provides a simple method to quickly obtain information about Ab quantity and quality in the acquisition of immunity to malaria in endemic populations.


Subject(s)
Antibodies, Protozoan/immunology , Antibody Affinity/immunology , Antigens, Protozoan/immunology , Plasmodium falciparum/immunology , Adolescent , Adult , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoassay , Infant , Malaria, Falciparum/immunology , Male , Merozoites/immunology , Middle Aged , Young Adult
13.
Nucl Med Commun ; 41(7): 666-673, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32404647

ABSTRACT

OBJECTIVES: This study investigated the subcentimetre lesion detection gains of a Bayesian penalised likelihood reconstruction (BPLR) (Q.Clear, GE Healthcare, Milwaukee, USA) in PET/computed tomography (CT) phantom images and compares observer performance with ordered subset expectation maximisation (OSEM) reconstruction images (VUE Point HD, GE Healthcare). METHODS: Images were presented to three blinded experienced observers to identify lesions and assign confidence ratings. Responses were analysed using jackknife alternative free receiver operator characteristic (JAFROC) software. Phantom lesions (active and nonactive) were constructed using putty. Seventy nonactive and 93 (F) active lesions, with diameters of 3, 5 or 7 mm were suspended in active backgrounds at varying contrast ratios (2:1-32:1) within an National Electrical Manufacturers Association 2012 phantom. PET/CT images were acquired with a GE Discovery 710 and reconstructed using both BPLR (penalisation coefficient 400) and high-definition attenuation corrected (HDAC) OSEM (2 iterations, 24 subsets). RESULTS: Small but significant (P = 0.009) visual detection gains were seen for active lesions with BPLR [weighted JAFROC figure of merit (wJAFROC FOM) = 0.77] over OSEM (FOM = 0.74). When split by subset, these improvements were significant for 5 mm and lesion to background ratio of 8:1. No significant (P = 0.514) differences were seen for the identification of nonactive lesions of any size (BPLR FOM = 0.74 and OSEM FOM = 0.73). CONCLUSIONS: Significant detection gains were demonstrated for small active lesions with BPLR over OSEM. Coupled with the significant increase in contrast-to-noise ratio, these results support the use of BPLR in the imaging of small active (≤7 mm) lesions but show no improvement with BPLR in the identification of true negative lesions.


Subject(s)
Bayes Theorem , Image Processing, Computer-Assisted/methods , Phantoms, Imaging , Positron Emission Tomography Computed Tomography/instrumentation , Humans , Likelihood Functions , Signal-To-Noise Ratio
14.
Biomater Sci ; 8(9): 2611-2626, 2020 May 06.
Article in English | MEDLINE | ID: mdl-32239020

ABSTRACT

Current cell expansion methods for tissue engineering and regenerative medicine applications rely on the use of enzymatic digestion passaging and 2D platforms. However, this enzymatic treatment significantly reduces cell quality, due to the destruction of important cell-surface proteins. In addition, culture in 2D results in undesired de-differentiation of the cells caused by the lack of 3D similarity to the natural extracellular matrix (ECM) environment. Research has led to the development of thermo-responsive surfaces for the continuous culture of cells. These thermo-responsive materials properties can be used to passage cells from the surface when the cell culture temperature is reduced. Here we report the development of a PLA/thermo-responsive (PDEGMA) blend 3D electrospun fibre-based scaffold to create an enzymatic-free 3D cell culture platform for the expansion of mammalian cells with the desired phenotype for clinical use. Human corneal stromal cells (hCSCs) were used as an exemplar as they have been observed to de-differentiate to an undesirable myo-fibroblastic phenotype when cultured by conventional 2D cell culture methods. Scaffolds were functionalised with a cell adherence peptide sequence GGG-YIGSR by thiol-ene chemistry to improve cell adherence and phenotype support. This was obtained by functionalising the thermo-responsive polymer with a thiol (PDEGMA/PDEGSH) by co-polymerisation. These incorporated thiols react with the norbornene acid functionalised peptide (Nor-GGG-YIGSR) under UV exposure. Presence of the thiol in the scaffold and subsequent peptide attachment on the scaffolds were confirmed by fluorescence labelling, ToF-SIMS and XPS analysis. The biocompatibility of the peptide containing scaffolds was assessed by the adhesion, proliferation and immuno-staining of hCSCs. Significant increase in hCSC adherence and proliferation was observed on the peptide containing scaffolds. Immuno-staining showed maintained expression of the desired phenotypic markers ALDH, CD34 and CD105, while showing no or low expression of the undesired phenotype marker α-SMA. This desired expression was observed to be maintained after thermo-responsive passaging and higher when cells were cultured on PLA scaffolds with 10 wt% PDEGMA/4 mol% PDEGS-Nor-GGG-YIGSR. This paper describes the fabrication and application of a first generation, biocompatible peptide conjugated thermo-responsive fibrous scaffold. The ease of fabrication, successful adherence and expansion of a therapeutically relevant cell type makes these scaffolds a promising new class of materials for the application of cell culture expansion platforms in the biomaterials and tissue engineering field.


Subject(s)
Cell Culture Techniques , Tissue Engineering , Tissue Scaffolds , Cell Adhesion , Cell Proliferation , Cell Survival , Cells, Cultured , Cornea/cytology , Extracellular Matrix , Humans , Peptides , Phenotype , Polymers , Stromal Cells
15.
Crit Rev Oncol Hematol ; 148: 102894, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32062314

ABSTRACT

Oncogene-driven non small cell lung cancer (NSCLC) is a distinct entity in thoracic oncology. The availability of effective target therapies, like EGFR inhibitors or ALK inhibitors, have revolutionized the prognosis of these patients. However, despite an initial response in the majority of patients, drug resistance ultimately occurs. In some cases, this resistance develops in few clonal cells (oligoprogression), so that a local ablation of these resistant deposits could allow to maintain the same systemic therapy and possibly to prolong patients' survival. For these purposes, stereotactic body radiation therapy (SBRT) is an ideal local ablative treatment, because it is effective, non invasive and with limited side effects. In this review, we aim to analyze available clinical data to verify whether SBRT can allow these patients to continue with existing target therapy longer, delay the switch to other systemic therapies and improve their outcome modifying the natural history of the disease.


Subject(s)
Carcinoma, Non-Small-Cell Lung/radiotherapy , Lung Neoplasms/radiotherapy , Radiosurgery , Carcinoma, Non-Small-Cell Lung/pathology , Catheter Ablation , Disease Progression , Humans , Lung Neoplasms/pathology , Neoplasm Metastasis , Neoplasm Recurrence, Local , Neoplasm Staging , Oncogenes , Protein Kinase Inhibitors , Treatment Outcome
17.
Clin Oncol (R Coll Radiol) ; 32(1): 26-34, 2020 01.
Article in English | MEDLINE | ID: mdl-31377082

ABSTRACT

AIMS: To investigate the role of intensity-modulated proton therapy (IMPT) for regional nodal irradiation in patients with breast carcinoma in comparison with volumetric-modulated arc therapy (VMAT). MATERIALS AND METHODS: A cohort of 20 patients (10 in the breast-conserving surgery group and 10 post-mastectomy patients with tissue expander implants) was investigated. Proton plans were also computed using robust optimisation methods. Plan quality was assessed by means of dose-volume histograms and scored with conventional metrics. Estimates of the risk of secondary cancer induction (excess absolute risk, EAR) were carried out, taking into account fractionation, repopulation and repair. RESULTS: Concerning target coverage, the data proved a substantial equivalence of VMAT and IMPT: for example, coverage for the 50 Gy target, expressed in terms of V98%, was 47.8 ± 0.4, 47.6 ± 0.4, 47.3 ± 0.8, consistent with the objective of 47.5 Gy, for post-mastectomy patients for the three groups of patients. Also, the conformality of the dose distributions was similar for the two techniques, about 1.1, without statistically significant differences. Organ at risk planning aims were achieved for all structures for both techniques. The mean dose to the ipsilateral lung was 10.8 ± 1.1, 6.2 ± 0.8, 7.2 ± 1.0; for the contralateral lung was 3.2 ± 0.7, 0.3 ± 0.2, 0.4 ± 0.2; for the contralateral breast was: 3.1 ± 0.7, 0.3 ± 0.3 and 0.3 ± 0.3, whereas it was 3.9 ± 0.9, 0.4 ± 0.3 and 0.5 ± 0.5, respectively, for the heart for VMAT, IMPT and robust IMPT plans over the whole group of patients. Robust optimisation affected the near-to-maximum dose values for contralateral lung and breast, the mean dose for the heart and ipsilateral lung, with a deterioration ranging from 20 to 40% of the nominal value of IMPT plans (e.g. from 8.1 ± 6.4 to 11.4 ± 8.8 for the heart compared with 16.2 ± 5.2 for the VMAT plans). The numerical values of EAR per 10 000 patient-years were about one order of magnitude higher for VMAT than for IMPT for contralateral structures: 11.66 ± 2.01, 0.89 ± 0.80, 0.98 ± 0.77 for the contralateral breast and the three groups of plans, respectively; 14.31 ± 2.75, 1.42 ± 0.80, 1.78 ± 0.87 for the contralateral lung; and 34.86 ± 2.64, 18.85 ± 2.15, 20.98 ± 2.35 for the ipsilateral lung. CONCLUSION: IMPT with or without robust optimisation seems to be a potentially promising approach for the radiation treatment of breast cancer when nodal volumes should be irradiated. This was measured in terms of dosimetric advantage and predicted clinical benefit. In fact, the significant reduction in estimated EAR could add further clinical value to the dosimetric sparing of the organs at risk achievable with IMPT.


Subject(s)
Breast Neoplasms/radiotherapy , Proton Therapy/methods , Breast Neoplasms/pathology , Female , Humans , Radiotherapy Planning, Computer-Assisted/methods
18.
Niger Med J ; 60(4): 211-218, 2019.
Article in English | MEDLINE | ID: mdl-31831942

ABSTRACT

BACKGROUND: Too many artemisinin-based combination therapies (ACTs) are available, thus creating a dilemma on the most preferred for the treatment of malaria. AIM: We compared the effect of six ACTs in mitigating Plasmodium-induced hepatorenal toxicity in experimental malaria. MATERIALS AND METHODS: Forty adult male Swiss mice allotted into eight groups: Group 1 (normal control [NC] uninfected and untreated), Group 2 (parasitized nontreated - [PNT]), and Groups 3-8 received Plasmodium berghei inoculum. After 72 h, the initial parasitemia was established. Groups 3-8 were administered oral therapeutic doses of artesunate-amodiaquine (AA), artesunate-mefloquine (AM), artesunate-sulfadoxine-pyrimethamine (ASP), artemisinin-piperaquine (AP), dihydroartemisinin-piperaquine (DP), and artemether-lumefantrine (AL) per kg bodyweight, respectively, as standard regimen, and final parasitemia determined. Animals were euthanized via chloroform inhalation and blood collected for hepatorenal analysis. Liver and kidney were dissected out for histology. RESULTS: Parasitemia was significantly (P < 0.05) decreased in tests compared to PNT, except in ASP group. Liver enzymes were significantly (P < 0.05) increased in PNT compared to tests and NC. Hyperplastic cells and portal tract inflammation were prominent in ASP group, but mild to moderate in other treated groups. Urea-creatinine were significantly (P < 0.05) increased in PNT compared to treated groups. The Na+ and Cl- were significantly (P < 0.05) reduced in PNT, with significantly (P < 0.05) increased K+ compared to NC and treated groups. Glomerulonephritis and glomerulus splitting was observed in PNT, while moderate distortions were observed in treated groups. The AA and AM groups had good kidney histoarchitecture. CONCLUSION: Parasitemia decreased in all the treatment groups except in PNT and ASP groups which had severe hepatorenal distortions. Hepatorenal histoarchitecture were mildly distorted in the AA, AM and AL-administered groups with lower hepatorenal indices comparable to NC. The least elevated liver enzymes were in AA and AM. In decreasing order ASP > DP > AL > AP > AM > AA.

19.
J Clin Microbiol ; 57(12)2019 12.
Article in English | MEDLINE | ID: mdl-31578264

ABSTRACT

Azithromycin is a component of empirical treatment regimens for Neisseria gonorrhoeae infections, but antimicrobial susceptibility testing for this agent is technically challenging. We compared the intertest variability, MIC values, and CLSI/EUCAST categorization of clinical and reference isolates of N. gonorrhoeae treated with azithromycin by testing 107 clinical isolates and nine reference isolates by agar dilution and in duplicates using MIC test strips (Liofilchem, Italy) and Etests (bioMérieux, France). Replicate isolate agreement within 1 log2 between duplicate tests was 87% for MIC test strips and 100% for Etests (P < 0.001). Essential agreement with the agar dilution method was higher for Etests (91%) than for MIC test strips (44%, P < 0.001). The geometric mean MIC was highest for MIC test strips (0.8 mg/liter) and significantly higher than both Etest (0.47 mg/liter, P < 0.001) and agar dilution (0.26 mg/liter, P < 0.001) methods. Etest MICs were higher than those obtained with agar dilution (P < 0.001). Agar dilution, MIC test strip, and Etest methods categorized 96%, 85%, and 95% (P = 0.003) of clinical isolates, respectively, as susceptible/wild type according to CLSI/EUCAST criteria. Our results illustrate the difficulties underlying azithromycin susceptibility testing for N. gonorrhoeae and demonstrate that results can vary using different methods. This variability could influence antimicrobial resistance reporting between laboratories involved in N. gonorrhoeae surveillance programs.


Subject(s)
Anti-Bacterial Agents/pharmacology , Azithromycin/pharmacology , Microbial Sensitivity Tests/methods , Neisseria gonorrhoeae/drug effects , Reproducibility of Results , France , Gonorrhea/microbiology , Humans , Italy , Neisseria gonorrhoeae/isolation & purification
20.
Sex Health ; 16(1): 47-55, 2019 02.
Article in English | MEDLINE | ID: mdl-30274568

ABSTRACT

Background In New Zealand, pre-exposure prophylaxis (PrEP) should target gay and bisexual men (GBM), and equity is an important principle. Baseline characteristics of GBM offered PrEP in a demonstration project with an enrolment quota of 50% non-Europeans are described. METHODS: An open-label, single-arm treatment evaluation study design ('NZPrEP') was used. The settings were four publicly funded sexual health clinics in Auckland in 2017. The study population was 150 GBM recruited from clinics, community sources and social media. Participants self-completed an online questionnaire about PrEP awareness, attitudes and sexual risk behaviour in the last 3 months. Baseline characteristics are described and examined to determine whether these were associated with PrEP initiation status (self-referral vs doctor/nurse recommendation). RESULTS: In total, 150 GBM of whom half (52%) were non-European, including 21.3% Maori, 19.3% Asian and 8.7% Pacific, were enrolled into the study. Two-thirds (65.3%) self-referred for PrEP and one-third (34.7%) were recommended PrEP by the doctor/nurse. Participants reported a high number of male condomless receptive anal intercourse partners (MenAICLR) (median 3, range 0-50), with 10% reporting 10 or more MenAICLR and 45.3% reporting group sex. In the previous year, 65.3% had a sexually transmissible infection (STI); 18% had rectal chlamydia or gonorrhoea at enrolment. Almost half (47.7%) had recently used drugs with sex, including 8.1% who used methamphetamine. Participants recommended PrEP had lower education, lived less centrally and had a higher STI prevalence than PrEP self-referrers, but their risk behaviour was similar. CONCLUSIONS: Early PrEP adopters in New Zealand have high HIV risk. Demonstration projects should consider equity mechanisms so that minorities can participate meaningfully.


Subject(s)
HIV Infections/prevention & control , Health Knowledge, Attitudes, Practice , Health Risk Behaviors , Homosexuality, Male/ethnology , Homosexuality, Male/statistics & numerical data , Pre-Exposure Prophylaxis , Adolescent , Adult , Ethnicity , Humans , Male , Middle Aged , Minority Groups , New Zealand/epidemiology , Sexual Behavior , Sexual and Gender Minorities/statistics & numerical data , State Medicine , Surveys and Questionnaires , White People , Young Adult
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