Social Media and Black Maternal Health: The Role of Health Literacy and eHealth Literacy.

BACKGROUND: Black women experience greater maternal mortality and morbidity than White women. Although there are many causes of this disparity, providing more and better maternal health information to this population may be beneficial. Social media offers a way to easily and quickly disseminate information to empower and educate Black women about health during pregnancy. OBJECTIVE: This study sought to identify social media use patterns to determine what sources Black women used to obtain information about pregnancy and to explore whether health literacy/eHealth literacy influence those patterns. METHODS: This cross-sectional, nationally representative survey panel included 404 Black women. Health literacy was measured by the Single Item Literacy Screener, and eHEALS was used to measure eHealth literacy. We examined participants' social media activity, social media use, social media use for support, and sharing of pregnancy-related health information. Relationships between health literacy, eHealth literacy, and social media use were assessed. KEY RESULTS: Overall, 67.5% of participants had high health literacy, and the average eHealth literacy score was high (34.5). Most women (71.6%) reported using more than three social media accounts as a source for pregnancy information. Women with low health literacy searched social media for general and specific pregnancy health information, reported more social media use during pregnancy in general (p < .001), and more use of social media for giving and getting support (p = .003). Women with higher eHealth literacy were more likely to report more social media use (r = 0.107, p = .039) and often used social media to give and get support (r = 0.197, p = .0001). Women with high health literacy more often reported sharing the pregnancy information they found on social media with their nurse (χ2 = 7.068, p = .029), doula (χ2 = 6.878, p = .032), and childbirth educator (χ2 = 10.289, p = .006). Women who reported higher eHealth literacy also reported more often sharing the pregnancy information they found on social media with their doctor (r = 0.115, p = .030), nurse (r = 0.139, p = .001), coworkers (r = 0.160, p = .004), and family or friends (r = 0.201, p = .0001). CONCLUSION: Substantial numbers of Black women use social media to find pregnancy health information. Future studies should elicit more detailed information on why and how Black women use social media to obtain pregnancy information and support as well as what role health literacy and eHealth literacy may have on birth outcomes. [HLRP: Health Literacy Research and Practice. 2023;7(3):e119-e129.].

Streptolysin O Deficiency in Streptococcus pyogenes M1T1 covR/S Mutant Strain Attenuates Virulence in In Vitro and In Vivo Infection Models.

Mutation within the Streptococcus pyogenes (Streptococcus group A; Strep A) covR/S regulatory system has been associated with a hypervirulent phenotype resulting from the upregulation of several virulence factors, including the pore-forming toxin, streptolysin O (SLO). In this study, we utilized a range of covR/S mutants, including M1T1 clonal strains (5448 and a covS mutant generated through mouse passage designated 5448AP), to investigate the contribution of SLO to the pathogenesis of covR/S mutant Strep A disease. Up-regulation of slo in 5448AP resulted in increased SLO-mediated hemolysis, decreased dendritic cell (DC) viability post coculture with Strep A, and increased production of tumor necrosis factor (TNF) and monocyte chemoattractant protein 1 (MCP-1) by DCs. Mouse passage of an isogenic 5448 slo-deletion mutant resulted in recovery of several covR/S mutants within the 5448Δslo background. Passage also introduced mutations in non-covR/S genes, but these were considered to have no impact on virulence. Although slo-deficient mutants exhibited the characteristic covR/S-controlled virulence factor upregulation, these mutants caused increased DC viability with reduced inflammatory cytokine production by infected DCs. In vivo, slo expression correlated with decreased DC numbers in infected murine skin and significant bacteremia by 3 days postinfection, with severe pathology at the infection site. Conversely, the absence of slo in the infecting strain (covR/S mutant or wild-type) resulted in detection of DCs in the skin and attenuated virulence in a murine model of pyoderma. slo-sufficient and -deficient covR/S mutants were susceptible to immune clearance mediated by a combination vaccine consisting of a conserved M protein peptide and a peptide from the CXC chemokine protease SpyCEP. IMPORTANCE Streptococcus pyogenes is responsible for significant numbers of invasive and noninvasive infections which cause significant morbidity and mortality globally. Strep A isolates with mutations in the covR/S system display greater propensity to cause severe invasive diseases, which are responsible for more than 163,000 deaths each year. This is due to the upregulation of virulence factors, including the pore-forming toxin streptolysin O. Utilizing covR/S and slo-knockout mutants, we investigated the role of SLO in virulence. We found that SLO alters interactions with host cell populations and increases Strep A viability at sterile sites of the host, such as the blood, and that its absence results in significantly less virulence. This work underscores the importance of SLO in Strep A virulence while highlighting the complex nature of Strep A pathogenesis. This improved insight into host-pathogen interactions will enable a better understanding of host immune evasion mechanisms and inform streptococcal vaccine development programs.

Streptococcus pyogenes vaccine candidates do not induce autoimmune responses in a rheumatic heart disease model.

We have developed a candidate vaccine to protect against multiple strains of Streptococcus pyogenes infections. The candidate vaccine contains two synthetic peptides derived from S. pyogenes proteins: the M-protein epitope, p*17 and the IL-8 degrading S. pyogenes Cell-Envelope Proteinase (SpyCEP) epitope, K4S2. In this study we utilise a rat autoimmune valvulitis model that displays both the cardiac and neurobehavioural pathology associated with post-streptococcal sequelae, to assess if the vaccine candidate antigens induce autoimmune complications and inflammatory pathology. Each antigen was conjugated to carrier protein diphtheria toxoid (DT) and independently assessed for potential to induce autoimmune pathology in female Lewis rats. Rats were administered three subcutaneous doses, and one intranasal dose over a four-week study with a two-week recovery period. A positive control group received recombinant S. pyogenes M5 (rM5) protein, and the negative control group received PBS. Rats that received rM5 developed significant cardiac and neurological pathologies. There was no evidence of these pathologies in the PBS control group, or the rats administered either P*17-DT or K4S2-DT. This study provides further preclinical evidence of the safety of the vaccine candidates p*17 and K4S2 and their appropriateness as candidates in human clinical trials.

Utilization of Maternal Health Care Among Immigrant Mothers in New York City, 2016-2018.

Immigrant women represent half of New York City (NYC) births, and some immigrant groups have elevated risk for poor maternal health outcomes. Disparities in health care utilization across the maternity care spectrum may contribute to differential maternal health outcomes. Data on immigrant maternal health utilization are under-explored in the literature. We conducted a cross-sectional analysis of the population-based NYC Pregnancy Risk Assessment Monitoring System survey, using 2016-2018 data linked to birth certificate variables, to explore self-reported utilization of preconception, prenatal, and postpartum health care and potential explanatory pathways. We stratified results by maternal nativity and, for immigrants, by years living in the US; geographic region of origin; and country of origin income grouping. Among immigrant women, 43% did not visit a health care provider in the year before pregnancy, compared to 27% of US-born women (risk difference [RD] = 0.16, 95% CI [0.13, 0.20]), 64% had no dental cleaning during pregnancy compared to 49% of US-born women (RD = 0.15, 95% CI [0.11, 0.18]), and 11% lost health insurance postpartum compared to 1% of US-born women (RD = 0.10, 95% CI [0.08, 0.11]). The largest disparities were among recent arrivals to the US and immigrants from countries in Central America, South America, South Asia, and sub-Saharan Africa. Utilization differences were partially explained by insurance type, paternal nativity, maternal education, and race and ethnicity. Disparities may be reduced by collaborating with community-based organizations in immigrant communities on strategies to improve utilization and by expanding health care access and eligibility for public health insurance coverage before and after pregnancy.

Prime-Pull Immunization with a Bivalent M-Protein and Spy-CEP Peptide Vaccine Adjuvanted with CAF®01 Liposomes Induces Both Mucosal and Peripheral Protection from covR/S Mutant Streptococcus pyogenes.

Infections with Streptococcus pyogenes and their sequelae are responsible for an estimated 18 million cases of serious disease with >700 million new primary cases and 500,000 deaths per year. Despite the burden of disease, there is currently no vaccine available for this organism. Here, we define a combination vaccine P*17/K4S2 comprising of 20-mer B-cell peptide epitopes, p*17 (a mutant derived from the highly conserved C3-repeat region of the M-protein), and K4S2 (derived from the streptococcal anti-neutrophil factor, Spy-CEP). The peptides are chemically conjugated to either diphtheria toxoid (DT) or a nontoxic mutant form of diphtheria toxin, CRM197. We demonstrate that a prime-pull immunization regimen involving two intramuscular inoculations with P*17/K4S2 adjuvanted with a two-component liposomal adjuvant system (CAF01; developed by Statens Serum Institut [SSI], Denmark), followed by an intranasal inoculation of unadjuvanted vaccine (in Tris) induces peptide- and S. pyogenes-binding antibodies and protects from mucosal and skin infection with hypervirulent covR/S mutant organisms. Prior vaccination with DT does not diminish the response to the conjugate peptide vaccines. Detailed Good Laboratory Practice (GLP) toxicological evaluation in male and female rats did not reveal any gross or histopathological adverse effects.IMPORTANCE A vaccine to control S. pyogenes infection is desperately warranted. S. pyogenes colonizes the upper respiratory tract (URT) and skin, from where it can progress to invasive and immune-mediated diseases. Global mortality estimates for S. pyogenes-associated diseases exceeds 500,000 deaths per year. S. pyogenes utilizes antigenic variation as a defense mechanism to circumvent host immune responses and thus a successful vaccine needs to provide strain-transcending and multicompartment (mucosal and skin) immunity. By defining highly conserved and protective epitopes from two critical virulence factors (M-protein and Spy-CEP) and combining them with a potent immunostimulant, CAF®01, we are addressing an unmet clinical need for a mucosally and skin-active subunit vaccine. We demonstrate that prime-pull immunization (2× intramuscular injections followed by intranasal immunization) promotes high sustained antibody levels in the airway mucosa and serum and protects against URT and invasive disease.

Preclinical safety and immunogenicity of Streptococcus pyogenes (Strep A) peptide vaccines.

We have developed two candidate vaccines to protect against multiple strains of Strep A infections. The candidates are combinatorial synthetic peptide vaccines composed of a M protein epitope (J8 or p*17) and a non-M protein epitope (K4S2). To enhance immunogenicity, each peptide is conjugated to the carrier protein CRM197 (CRM) and formulated with aluminium hydroxide adjuvant Alhydrogel (Alum) to make the final vaccines, J8-CRM + K4S2-CRM/Alum and p*17-CRM + K4S2-CRM/Alum. The safety and toxicity of each vaccine was assessed. Sprague Dawley rats were administered three intramuscular doses, over a six-week study with a 4-week recovery period. A control group received CRM only formulated with Alum (CRM/Alum). There was no evidence of systemic toxicity in the rats administered either vaccine. There was an associated increase in white blood cell, lymphocyte and monocyte counts, increased adrenal gland weights, adrenocortical hypertrophy, and increased severity of granulomatous inflammation at the sites of injection and the associated inguinal lymph nodes. These changes were considered non-adverse. All rats administered vaccine developed a robust and sustained immunological response. The absence of clinical toxicity and the development of an immunological response in the rats suggests that the vaccines are safe for use in a phase 1 clinical trial in healthy humans.

A unique group of scabies mite pseudoproteases promotes cutaneous blood coagulation and delays plasmin-induced fibrinolysis.

BACKGROUND: Scabies, a highly contagious skin disease affecting more than 200 million people worldwide at any time, is caused by the parasitic mite Sarcoptes scabiei. In the absence of molecular markers, diagnosis requires experience making surveillance and control challenging. Superficial microthrombi in the absence of vasculitis in scabies-affected skin are a recognised, yet unexplained histopathological differential of scabies infection. This study demonstrates that a family of Scabies Mite Inactivated Cysteine Protease Paralogues (SMIPP-Cs) excreted by the mites plays a role in formation of scabies-induced superficial microthrombi. METHODOLOGY/PRINCIPAL FINDINGS: A series of in vitro and ex vivo experiments involving two representative recombinant SMIPP-Cs was carried out. In the presence of SMIPP-Cs, the thrombin clotting time (TCT), fibrin formation and plasmin induced fibrinolysis were monitored in vitro. The ultrastructure of the SMIPP-C-modulated fibrin was analysed by Scanning Electron Microscopy (SEM). Immuno-histological analyses were performed ex vivo, to localise the SMIPP-C proteins within scabies infected skin biopsies. SMIPP-Cs displayed pro-coagulant properties. They bound calcium ions, reduced the thrombin clotting time, enhanced the fibrin formation rate and delayed plasmin-induced fibrinolysis. The SMIPP-Cs associated with fibrin clots during fibrinogen polymerisation and did not bind to preformed fibrin. Scanning electron microscopy revealed that the fibrin clots formed in the presence of SMIPP-Cs were aberrant and denser than normal fibrin clots. SMIPP-Cs were detected in microthrombi which are commonly seen in scabietic skin. CONCLUSIONS/SIGNIFICANCE: The SMIPP-Cs are the first scabies mite proteins found in sub-epidermal skin layers and their pro-coagulant properties promote superficial microthrombi formation in scabetic skin. Further research is needed to evaluate their potential as diagnostic or therapeutic target.

Association between Urinary Triclosan and Serum Testosterone Levels in U.S. Adult Males from NHANES, 2011-2012.

Triclosan was introduced into the market in the 1970s and has since been used as an antimicrobial agent in a diverse array of consumer and personal care products. Although it has been widely used over a number of years, there is growing concern and debate over its safety and efficacy and its potential as an endocrine disruptor. Although prior animal toxicology studies have shown an association between triclosan and decreased testosterone levels, human studies have been limited, particularly for adult men. Using the National Health and Nutrition Examination Survey data (NHANES, 2011-2012), we examined the association of urinary triclosan on testosterone levels in adult men 18-65 years of age. Multivariable linear regression analysis failed to show an association between triclosan and serum testosterone (ß = 0.0003, p = 0.98, 95% CI = -0.024, 0.025). The results suggest there is no association or that triclosan concentrations are too low to cause a significant impact on testosterone levels. Additionally, longitudinal studies would provide a more comprehensive understanding of the direction of change and magnitude of causal relationships over time.

High-quality nuclear genome for Sarcoptes scabiei-A critical resource for a neglected parasite.

The parasitic mite Sarcoptes scabiei is an economically highly significant parasite of the skin of humans and animals worldwide. In humans, this mite causes a neglected tropical disease (NTD), called scabies. This disease results in major morbidity, disability, stigma and poverty globally and is often associated with secondary bacterial infections. Currently, anti-scabies treatments are not sufficiently effective, resistance to them is emerging and no vaccine is available. Here, we report the first high-quality genome and transcriptomic data for S. scabiei. The genome is 56.6 Mb in size, has a a repeat content of 10.6% and codes for 9,174 proteins. We explored key molecules involved in development, reproduction, host-parasite interactions, immunity and disease. The enhanced 'omic data sets for S. scabiei represent comprehensive and critical resources for genetic, functional genomic, metabolomic, phylogenetic, ecological and/or epidemiological investigations, and will underpin the design and development of new treatments, vaccines and/or diagnostic tests.

Erratum: Author Correction: M-protein based vaccine induces immunogenicity and protection from Streptococcus pyogenes when delivered on a high-density microarray patch (HD-MAP).

[This corrects the article DOI: 10.1038/s41541-020-00222-2.].

M-protein based vaccine induces immunogenicity and protection from Streptococcus pyogenes when delivered on a high-density microarray patch (HD-MAP).

We evaluated vaccination against Streptococcus pyogenes with the candidate vaccine, J8-DT, delivered by a high-density microarray patch (HD-MAP). We showed that vaccination with J8-DT eluted from a coated HD-MAP (J8-DT/HD-MAP), induced similar total IgG responses to that generated by vaccination with J8-DT adjuvanted with Alum (J8-DT/Alum). We evaluated the effect of dose reduction and the number of vaccinations on the antibody response profile of vaccinated mice. A reduction in the number of vaccinations (from three to two) with J8-DT/HD-MAP induced comparable antibody responses to three vaccinations with intramuscular J8-DT/Alum. Vaccine-induced protection against an S. pyogenes skin challenge was assessed. J8-DT/HD-MAP vaccination led to a significant reduction in the number of S. pyogenes colony forming units in skin (92.9%) and blood (100%) compared to intramuscular vaccination with unadjuvanted J8-DT. The protection profile was comparable to that of intramuscular J8-DT/Alum. J8-DT/HD-MAP induced a shift in the antibody isotype profile, with a bias towards Th1-related isotypes, compared to J8-DT/Alum (Th2 bias). Based on the results of this study, the use of J8-DT/HD-MAP should be considered in future clinical development and control programs against S. pyogenes. Furthermore, the innate characteristics of the technology, such as vaccine stability and increased coverage, ease of use, reduction of sharp waste and the potential reduction of dose may be advantageous compared to current vaccination methods.

Phylogenetic relationships, stage-specific expression and localisation of a unique family of inactive cysteine proteases in Sarcoptes scabiei.

BACKGROUND: Scabies is worldwide one of the most common, yet neglected, parasitic skin infections, affecting a wide range of mammals including humans. Limited treatment options and evidence of emerging mite resistance against the currently used drugs drive our research to explore new therapeutic candidates. Previously, we discovered a multicopy family of genes encoding cysteine proteases with their catalytic sites inactivated by mutation (SMIPP-Cs). This protein family is unique in parasitic scabies mites and is absent in related non-burrowing mites. We postulated that the SMIPP-Cs have evolved as an adaptation to the parasitic lifestyle of the scabies mite. To formulate testable hypotheses for their functions and to propose possible strategies for translational research we investigated whether the SMIPP-Cs are common to all scabies mite varieties and where within the mite body as well as when throughout the parasitic life-cycle they are expressed. RESULTS: SMIPP-C sequences from human, pig and dog mites were analysed bioinformatically and the phylogenetic relationships between the SMIPP-C multi-copy gene families of human, pig and dog mites were established. Results suggest that amplification of the SMIPP-C genes occurred in a common ancestor and individual genes evolved independently in the different mite varieties. Recombinant human mite SMIPP-C proteins were produced and used for murine polyclonal antibody production. Immunohistology on skin sections from human patients localised the SMIPP-Cs in the mite gut and in mite faeces within in the epidermal skin burrows. SMIPP-C transcription into mRNA in different life stages was assessed in human and pig mites by reverse transcription followed by droplet digital PCR (ddPCR). High transcription levels of SMIPP-C genes were detected in the adult female life stage in comparison to all other life stages. CONCLUSIONS: The fact that the SMIPP-Cs are unique to three Sarcoptes varieties, present in all burrowing life stages and highly expressed in the digestive system of the infective adult female life stage may highlight an essential role in parasitism. As they are excreted from the gut in scybala they presumably are able to interact or interfere with host proteins present in the epidermis.

Patterns of Orofacial Clefting in New York City From 1983 to 2010: Trends by Racial Background, Birthplace, and Public Health Strategies.

OBJECTIVE: To determine the role of racial background, public health initiatives, and residence on the prevalence of orofacial clefts (OFCs) in New York City (NYC). DESIGN/METHODS: Retrospective review of OFC cases from the New York State Congenital Malformations Registry. PATIENTS/PARTICIPANTS: Patients born with an OFC and all live births to mothers residing in NYC between 1983 and 2010. MAIN OUTCOME MEASURES: Orofacial cleft birth prevalence by cleft type, race, and borough of maternal residence for each year and by time period around the implementation of public health interventions including folate supplementation. RESULTS: A total of 3557 cases were reviewed. The prevalence remained stable for cleft palate and cleft lip with or without cleft palate (CL ± P) in sequential time periods of the study. Among CL ± P cases, cleft lip prevalence decreased early in the study compared to increases in cleft lip and palate prevalence. For most years, the prevalence of OFCs was lower among African Americans than whites. A total of 12% to 26% of mothers in 4 of the NYC boroughs deliver outside of their borough of residence, choosing to give birth in Manhattan most often. No difference in OFC prevalence was shown in any of the 5 NYC boroughs. CONCLUSIONS: The period prevalence remained relatively stable during the time periods before and after the implementation of folate supplementation for OFCs in NYC. Prevalence of OFC subtypes was lower for most time periods during this study among African Americans compared to whites. Several factors may explain the choice of birthplace outside of the mother's borough of residence.

Stress, Socializing, and Other Motivations for Smoking Among the Lesbian, Gay, Bisexual, Transgender, and Queer Community in New York City.

PURPOSE: This study contributes to the emerging literature on lesbian, gay, bisexual, transgendered, and queer (LGBTQ) health disparities and tobacco use by examining the motivations for smoking among the New York City (NYC) LGBTQ population. APPROACH: We used grounded theory and blended methods from 3 grounded theorists-Strauss, Corbin, and Charmaz-for data collection, coding, and analysis. SETTING: NYC has extensive legislation to prevent smoking; however, the current smoking prevalence of homosexuals is double that of heterosexuals. PARTICIPANTS: Study participants were leaders from 23 NYC LGBTQ organizations. Leaders were chosen to establish a relationship with community and to ensure cultural sensitivity. Eligibility criteria required holding a leadership position in an organization serving the NYC LGBTQ community. METHODS: Interviews were transcribed verbatim and uploaded into Dedoose for analysis. An initial code list was developed from the interview guide. Key themes were identified as the themes with the most number of quotes. RESULTS: Three key themes emerged from our interviews: image, socializing, and stress. Smoking was reported to be a socialization aid and a maladaptive coping technique for stress arising from interactions of conflicting identities. CONCLUSION: Future smoking cessation interventions among the LGBTQ community should equip smokers with healthy coping mechanisms that address the stressors that arise from the intersections of smokers' many identities.

Gene silencing by RNA interference in Sarcoptes scabiei: a molecular tool to identify novel therapeutic targets.

BACKGROUND: Scabies is one of the most common and widespread parasitic skin infections globally, affecting a large range of mammals including humans, yet the molecular biology of Sarcoptes scabiei is astonishingly understudied. Research has been hampered primarily due to the difficulty of sampling or culturing these obligatory parasitic mites. A further and major impediment to identify and functionally analyse potential therapeutic targets from the recently emerging molecular databases is the lack of appropriate molecular tools. METHODS: We performed standard BLAST based searches of the existing S. scabiei genome databases using sequences of genes described to be involved in RNA interference in Drosophila and the mite model organism Tetranychus urticae. Experimenting with the S. scabiei mu-class glutathione S-transferase (SsGST-mu1) as a candidate gene we explored the feasibility of gene knockdown in S. scabiei by double-stranded RNA-interference (dsRNAi). RESULTS: We provide here an analysis of the existing S. scabiei draft genomes, confirming the presence of a double stranded RNA (dsRNA) - mediated silencing machinery. We report for the first time experimental gene silencing by RNA interference (RNAi) in S. scabiei. Non-invasive immersion of S. scabiei in dsRNA encoding an S. scabiei glutathione S-transferase mu-class 1 enzyme (SsGST-mu1) resulted in a 35% reduction in the transcription of the target gene compared to controls. CONCLUSIONS: A series of experiments identified the optimal conditions allowing systemic experimental RNAi without detrimental side effects on mite viability. This technique can now be used to address the key questions on the fundamental aspects of mite biology and pathogenesis, and to assess the potential therapeutic benefits of silencing S. scabiei target genes.

A Comparison of Alternative Tobacco Product Usage, Knowledge and Beliefs Between the New York City Lesbian, Gay, Bisexual, and Transgendered Community and Heterosexuals.

Within the United States, alternative tobacco product (ATP) and varies by geographic region, gender and age. Few articles have been published on the usage of these products among the lesbian, gay, bisexual, transgender or queer (LGBTQ) population. A web-based anonymous survey administered through Google Forms, was used to collect data on current tobacco usage, knowledge and beliefs from adult heterosexuals, homosexuals, bisexuals and transgendered persons residing in New York City from May 2014 to July 2014. Sixty-four individuals completed the survey; 30 were heterosexual and 32 identified as either lesbian, gay, bisexual, transgender or queer. Heterosexuals were found to have tried cigarettes, on average, almost a year before the LGBTQ respondents. Social networks were influential to LGBTQ respondents for an introduction to smoking; 48.00% were introduced by friends, 28.00% by family, 12.00% by a significant other and 9.09% by someone else. For heterosexuals, 73.68% reported that friends introduced them to smoking. More heterosexuals reported trying hookah (N = 10), snus (N = 4) and roll your own cigarettes (N = 5). On average respondents knew of eight different tobacco products, regardless of sexual identity. To our knowledge, we present for the first time a comparison of people who tried, current and former users of ATPs, beliefs and knowledge about ATPs, and sources of knowledge of ATPs by sexual identity from NYC. More research is needed to examine the impact of social networks and the upcoming FDA regulations on ATPs have on the overall prevalence of usage among the LGBTQ community.

The National Children's Study: Recruitment Outcomes Using the Provider-Based Recruitment Approach.

OBJECTIVE: In 2009, the National Children's Study (NCS) Vanguard Study tested the feasibility of household-based recruitment and participant enrollment using a birth-rate probability sample. In 2010, the NCS Program Office launched 3 additional recruitment approaches. We tested whether provider-based recruitment could improve recruitment outcomes compared with household-based recruitment. METHODS: The NCS aimed to recruit 18- to 49-year-old women who were pregnant or at risk for becoming pregnant who lived in designated geographic segments within primary sampling units, generally counties. Using provider-based recruitment, 10 study centers engaged providers to enroll eligible participants at their practice. Recruitment models used different levels of provider engagement (full, intermediate, information-only). RESULTS: The percentage of eligible women per county ranged from 1.5% to 57.3%. Across the centers, 3371 potential participants were approached for screening, 3459 (92%) were screened and 1479 were eligible (43%). Of those 1181 (80.0%) gave consent and 1008 (94%) were retained until delivery. Recruited participants were generally representative of the county population. CONCLUSIONS: Provider-based recruitment was successful in recruiting NCS participants. Challenges included time-intensity of engaging the clinical practices, differential willingness of providers to participate, and necessary reliance on providers for participant identification. The vast majority of practices cooperated to some degree. Recruitment from obstetric practices is an effective means of obtaining a representative sample.

Pseudoproteases: mechanisms and function.

Catalytically inactive enzymes (also known as pseudoproteases, protease homologues or paralogues, non-peptidase homologues, non-enzymes and pseudoenzymes) have traditionally been hypothesized to act as regulators of their active homologues. However, those that have been characterized demonstrate that inactive enzymes have an extensive and expanding role in biological processes, including regulation, inhibition and immune modulation. With the emergence of each new genome, more inactive enzymes are being identified, and their abundance and potential as therapeutic targets has been realized. In the light of the growing interest in this emerging field the present review focuses on the classification, structure, function and mechanism of inactive enzymes. Examples of how inactivity is defined, how this is reflected in the structure, functions of inactive enzymes in biological processes and their mode of action are discussed.

Fetal sex and race modify the predictors of fetal growth.

The objective of this study is unknown if fetal sex and race modify the impact of maternal pre-pregnancy body mass index (BMI), and smoking on fetal growth. The authors studied markers of fetal growth in singleton offspring of 8,801 primiparous, normotensive women, enrolled in the Collaborative Perinatal Project. The authors tested for departures from additivity between sex/race and each predictor. The head-to-chest circumference ratio (HCC) decreased more, while birthweight and ponderal index (PI) increased more for each 1 kg/m(2) increase in pre-pregnancy BMI among term females versus males (P = 0.07, P < 0.01 and P = 0.08, interaction respectively). For term offspring of White compared with Black women, smoking independent of "dose" was associated with larger reductions in growth (165 g vs. 68 g reduction in birthweight, P < 0.01, interaction), greater reduction in fetal placental ratio (P < 0.01, interaction), PI (P < 0.01, interaction), and greater increase in HCC (P = 0.02), respectively. The association of BMI and smoking with fetal size appeared to be reversed in term versus preterm infants. Our study provides evidence that the associations of pre-pregnancy BMI and smoking are not constant across sex and race. This finding may be relevant to sex and race differences in neonatal and long term health outcomes.

Scabies mite inactive serine proteases are potent inhibitors of the human complement lectin pathway.

Scabies is an infectious skin disease caused by the mite Sarcoptes scabiei and has been classified as one of the six most prevalent epidermal parasitic skin diseases infecting populations living in poverty by the World Health Organisation. The role of the complement system, a pivotal component of human innate immunity, as an important defence against invading pathogens has been well documented and many parasites have an arsenal of anti-complement defences. We previously reported on a family of scabies mite proteolytically inactive serine protease paralogues (SMIPP-Ss) thought to be implicated in host defence evasion. We have since shown that two family members, SMIPP-S D1 and I1 have the ability to bind the human complement components C1q, mannose binding lectin (MBL) and properdin and are capable of inhibiting all three human complement pathways. This investigation focused on inhibition of the lectin pathway of complement activation as it is likely to be the primary pathway affecting scabies mites. Activation of the lectin pathway relies on the activation of MBL, and as SMIPP-S D1 and I1 have previously been shown to bind MBL, the nature of this interaction was examined using binding and mutagenesis studies. SMIPP-S D1 bound MBL in complex with MBL-associated serine proteases (MASPs) and released the MASP-2 enzyme from the complex. SMIPP-S I1 was also able to bind MBL in complex with MASPs, but MASP-1 and MASP-2 remained in the complex. Despite these differences in mechanism, both molecules inhibited activation of complement components downstream of MBL. Mutagenesis studies revealed that both SMIPP-Ss used an alternative site of the molecule from the residual active site region to inhibit the lectin pathway. We propose that SMIPP-Ss are potent lectin pathway inhibitors and that this mechanism represents an important tool in the immune evasion repertoire of the parasitic mite and a potential target for therapeutics.