Knowledge, attitudes, and behaviors related to dietary salt intake and the acceptability of salt substitute among the Australian culturally and linguistically diverse community: An online survey

The Australian culturally and linguistically diverse (CALD) communities may be at higher risk of salt intake than recommended given the use of a combination of discretionary sources and exposure to processed foods within a western country. This survey aimed to understand the knowledge, attitudes, and behaviors toward dietary salt and the acceptability of salt substitutes in the CALD communities. An online cross-sectional survey was conducted among adults who self-reported being a part of a CALD community, which was defined as non-Indigenous cultural groups in Australia having cultural or linguistic connections with their overseas place of birth, ancestry or ethnic origin, religion, preferred language or language spoken at home. A total of 218 respondents opened the survey link. A total of 196 completed the entire survey. The majority of respondents (162, 83%) were aware that high salt intake causes serious health problems. Altogether 134 (69%) respondents were aware that there is a recommended amount for daily salt consumption although only 59 (44%) knew precise recommendations as <5 g salt per day. Around one quarter of the respondents rarely or never looked for ‟low in salt'' or ‟reduced salt'' messages on food labels when shopping. Over half specified they always or often added salt during cooking or preparing foods in the household. Almost 4 in 5 CALD respondents were willing to reduce their salt intake for health and 3 in 4 were open to trying a salt substitute. Further research into the utility of a salt substitute intervention in the Australian CALD community is warranted.

The Effect of Weight Loss Through Lifestyle Interventions in Patients With Heart Failure With Preserved Ejection Fraction-A Systematic Review and Meta-Analysis of Randomised Controlled Trials

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) accounts for >50% of heart failure cases and is associated with significant morbidity and health system burden. To date, there have been limited treatment options proven to improve outcomes in these patients, with sodium glucose co-transporter 2 (SGLT2) inhibitors the first class of drug to demonstrate significant clinical benefits, including reductions in heart failure hospitalisation. Obesity is associated with all forms of heart failure and has been linked with worse clinical outcomes. Numerous reviews support the benefits of weight loss in heart failure, more specifically in patients with heart failure with reduced ejection fraction. However, the evidence in HFpEF patients is less clear. With limited pharmacotherapy options and growing support for weight loss in patients with HFpEF, this systematic review and meta-analysis aims to examine the effects of lifestyle interventions on weight loss and other health outcomes in patients with HFpEF.

METHODS

Web of Science, Embase, Scopus, and PubMed databases were searched to identify relevant studies up to February 2023. Included studies were randomised controlled trials (with a duration of four weeks or more) of lifestyle interventions conducted in adults with HFpEF that reported weight loss. Outcomes of interest were body weight, body mass index (BMI), blood pressure (systolic and diastolic), aerobic capacity (6-minute walk distance), New York Heart Association (NYHA) Functional Classification, self-reported health quality of life (Minnesota Living with Heart Failure Questionnaire; MLHFQ), and N-terminal pro B-Type Natriuretic Peptide (NT-proBNP) levels. Review Manager software was used to conduct random effect meta-analyses, forest plots were generated for each outcome, and between-study heterogeneity was estimated using the I2 test statistic. Risk-of-bias assessment used the Cochrane risk-of-bias tool, and the certainty of the evidence was assessed using GRADE.

RESULTS

From 2,282 records identified, six studies with a total of 375 participants, between three to six months in duration, were included in this systematic review and meta-analysis. Lifestyle interventions consisted of diet only, exercise only, combination of diet and exercise, and education and exercise. Over a mean follow-up of 4.5 months, pooled effects of the interventions were associated with a reduction in body weight of >5kg (weight mean difference (WMD): -5.30 kg; 95% CI: -8.72 to -1.87; p=0.002), and a reduction in resting systolic (WMD: -2.98 mmHg; 95% CI: -4.20 to -1.76; p<0.001) and diastolic blood pressure (WMD: -4.51 mmHg; 95% CI: -8.39 to -0.64; p=0.02) compared with those who received usual care. Interventions also improved 6-minute walk distance (WMD: 43.63 m; 95% CI: 22.28 to 64.97; p<0.001), NYHA class (WMD: -0.54; 95% CI: -0.75 to -0.33; p<0.001), and MLHFQ score (WMD: -17.77; 95% CL: -19.00 to -16.53; p<0.001).

CONCLUSION

In patients with HFpEF, lifestyle intervention was associated with a significant reduction in body weight and had favourable effects on blood pressure, aerobic capacity, NYHA class, and health-related quality of life. Further research is needed in this population to examine the feasibility and durability of weight loss interventions and to examine the potential impact on hard clinical endpoints.

Exploring factors to interpretation of targeted nutrition messages for people living with multiple sclerosis

OBJECTIVES

Current dietary recommendations for MS suggest following national dietary guidelines developed for the general population. The aim of this study was to explore the interpretation of MS-targeted nutrition messages.

METHODS

Using the Elaboration Likelihood Model of persuasion, three nutrition messages were developed targeting the strongest evidence for MS: vitamin D, dietary fat, and dietary diversity. Semi-structured interviews including the cognitive 'thinking-aloud' technique were used to test the messages with adults living with MS. Data were transcribed and coded thematically.

RESULTS

Theoretical saturation was reached by 15 interviews. The data corpus indicated three themes and seven subthemes. The data revealed that people living with MS changed their diet after MS diagnosis. Dietary change was due to uncertainty, fear of disease progression and risk of relapse. The admiration and scepticism of extremist MS diets depended on personal vulnerability and support from health care professionals. The unique MS journey appeared influential to message interpretation; driven by engagement, practicality, and credibility.

CONCLUSION

The interpretation of targeted nutrition messages revealed that dietary changes made after diagnosis are a coping mechanism to improve sense of control and self-management.

PRACTICAL IMPLICATIONS

The potential psychological benefit of dietary change for MS management must be prioritised using person-centred care.

The effects of canagliflozin in type 2 diabetes in subgroups defined by population-specific body mass index: Insights from the CANVAS Program and CREDENCE trial

AIM

To assess the effects of canagliflozin on clinical outcomes and intermediate markers across population-specific body mass index (BMI) categories in the CANVAS Program and CREDENCE trial.

METHODS

Individual participant data were pooled and analysed in subgroups according to population-specific BMI. The main outcomes of interest were: major adverse cardiovascular events (MACE, a composite of nonfatal myocardial infarction, nonfatal stroke or cardiovascular death); composite renal outcome; and changes in systolic blood pressure (SBP), body weight, albuminuria and estimated glomerular filtration rate (eGFR) slope. Cox proportional hazards models and mixed-effect models were used.

RESULTS

A total of 14 520 participants were included, of whom 9378 (65%) had obesity. Overall, canagliflozin reduced the risk of MACE (hazard ratio [HR] 0.83, 95% confidence interval [CI] 0.75 to 0.93) with no heterogeneity of treatment effect across BMI subgroups (Pheterogeneity  = 0.76). Similarly, canagliflozin reduced composite renal outcomes (HR 0.75, 95% CI 0.66 to 0.84) with no heterogeneity across subgroups observed (Pheterogeneity  = 0.72). The effects of canagliflozin on body weight and SBP differed across BMI subgroups (Pheterogeneity  <0.01 and 0.04, respectively) but were consistent for albuminuria (Pheterogeneity  = 0.60). Chronic eGFR slope with canagliflozin treatment was consistent across subgroups (Pheterogeneity  >0.95).

CONCLUSIONS

The cardiovascular and renal benefits of canagliflozin and its safety profile were consistent across population-specific BMI subgroups for adults in the CANVAS Program and CREDENCE trial.

Tree Nut and Peanut Consumption and Risk of Cardiovascular Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Cardiovascular disease (CVD) is the leading cause of death globally. Habitual consumption of tree nuts and peanuts is associated with cardioprotective benefits. Food-based dietary guidelines globally recommend nuts as a key component of a healthy diet. This systematic review and meta-analysis were conducted to examine the relationship between tree nut and peanut consumption and risk factors for CVD in randomized controlled trials (RCTs) (PROSPERO: CRD42022309156). MEDLINE, PubMed, CINAHL, and Cochrane Central databases were searched up to 26 September, 2021. All RCT studies that assessed the effects of tree nut or peanut consumption of any dose on CVD risk factors were included. Review Manager software was used to conduct a random effect meta-analysis for CVD outcomes from RCTs. Forest plots were generated for each outcome, between-study heterogeneity was estimated using the I2 test statistic and funnel plots and Egger's test for outcomes with ≥10 strata. The quality assessment used the Health Canada Quality Appraisal Tool, and the certainty of the evidence was assessed using grading of recommendations assessment, development, and evaluation (GRADE). A total of 153 articles describing 139 studies (81 parallel design and 58 cross-over design) were included in the systematic review, with 129 studies in the meta-analysis. The meta-analysis showed a significant decrease for low-density lipoprotein (LDL) cholesterol, total cholesterol (TC), triglycerides (TG), TC:high-density lipoprotein (HDL) cholesterol, LDL cholesterol:HDL cholesterol, and apolipoprotein B (apoB) following nut consumption. However, the quality of evidence was "low" for only 18 intervention studies. The certainty of the body of evidence for TC:HDL cholesterol, LDL cholesterol:HDL cholesterol, and apoB were "moderate" because of inconsistency, for TG were "low," and for LDL cholesterol and TC were "very low" because of inconsistency and the likelihood of publication bias. The findings of this review provide evidence of a combined effect of tree nuts and peanuts on a range of biomarkers to create an overall CVD risk reduction.

Canagliflozin and atrial fibrillation in type 2 diabetes mellitus: A secondary analysis from the CANVAS Program and CREDENCE trial and meta-analysis

AIM

To assess the effects of canagliflozin on the incidence of atrial fibrillation/atrial flutter (AF/AFL) and other key cardiorenal outcomes in a pooled analysis of the CANVAS and CREDENCE trials.

MATERIALS AND METHODS

Participants with type 2 diabetes and high risk of cardiovascular disease or chronic kidney disease were included and randomly assigned to canagliflozin or placebo. We explored the effects of canagliflozin on the incidence of first AF/AFL events and AF/AFL-related complications (ischaemic stroke/transient ischaemic attack/hospitalization for heart failure). Major adverse cardiovascular events and a renal-specific outcome by baseline AF/AFL status were analysed using Cox regression models.

RESULTS

Overall, 354 participants experienced a first AF/AFL event. Canagliflozin had no detectable effect on AF/AFL (hazard ratio [HR] 0.82, 95% confidence interval [CI] 0.67-1.02) compared with placebo. Subgroup analysis, however, suggested a possible reduction in AF/AFL in those with no AF/AFL history (HR 0.78, 95% CI 0.62-0.99). Canagliflozin was also associated with a reduction in AF/AFL-related complications (HR 0.74, 95% CI 0.65-0.86). There was no evidence of treatment heterogeneity by baseline AF/AFL history for other key cardiorenal outcomes (all P_interaction  > 0.14). Meta-analysis of five sodium-glucose cotransporter-2 (SGLT2) inhibitor trials demonstrated a 19% reduction in AF/AFL events with active treatment (HR 0.81, 95% CI 0.72-0.92).

CONCLUSIONS

Overall, a significant effect of canagliflozin on the incidence of AF/AFL events could not be shown, however, a possible reduction in AF/AFL events in those with no prior history requires further investigation. Meta-analysis suggests SGLT2 inhibition reduces AF/AFL incidence.

Clinical researchers' lived experiences with data quality monitoring in clinical trials: a qualitative study

BACKGROUND

Fundamental to the success of clinical research that involves human participants is the quality of the data that is generated. To ensure data quality, clinical trials must comply with the Good Clinical Practice guideline which recommends data monitoring. To date, the guideline is broad, requires technology for enforcement, follows strict industry standards, mostly designed for drug-registration trials and based on informal consensus. It is also unknown what challenges clinical trials and researchers face in implementing data monitoring procedures. Thus, this study aimed to describe researcher experiences with data quality monitoring in clinical trials.

METHODS

We conducted semi-structured telephone interviews following a guided-phenomenological approach. Participants were recruited from the Australian and New Zealand Clinical Trials Registry and were researchers affiliated with a listed clinical study. Each transcript was analysed with inductive thematic analysis before thematic categorisation of themes from all transcripts. Primary, secondary and subthemes were categorised according to the emerging relationships.

RESULTS

Data saturation were reached after interviewing seven participants. Five primary themes, two secondary themes and 21 subthemes in relation to data quality monitoring emerged from the data. The five primary themes included: education and training, ways of working, working with technology, working with data, and working within regulatory requirements. The primary theme 'education and training' influenced the other four primary themes. While 'working with technology' influenced the 'way of working'. All other themes had reciprocal relationships. There was no relationship reported between 'working within regulatory requirements' and 'working with technology'. The researchers experienced challenges in meeting regulatory requirements, using technology and fostering working relationships for data quality monitoring.

CONCLUSION

Clinical trials implemented a variety of data quality monitoring procedures tailored to their situation and study context. Standardised frameworks that are accessible to all types of clinical trials are needed with an emphasis on education and training.

A Clinician-Led, Experience-Based Co-Design Approach for Developing mHealth Services to Support the Patient Self-management of Chronic Conditions: Development Study and Design Case

BACKGROUND

Despite the increasing use of mobile health (mHealth) services, such as mHealth apps or SMS text messaging services, that support the patient self-management of chronic conditions, many existing mHealth services lack theoretical guidance. In addition, although often the target audience for requirement acquisition at the initial mHealth app design stage, it is a common challenge for them to fully conceptualize their needs for mHealth services that help self-manage chronic conditions.

OBJECTIVE

This study proposes a novel co-design approach with the initial requirements for mHealth services proposed by clinicians based on their experiences in guiding patients to self-manage chronic conditions. A design case is presented to illustrate our innovative approach to designing an mHealth app that supports the self-management of patients with obesity in their preparation for elective surgery.

METHODS

We adopted a clinician-led co-design approach. The co-design approach consisted of the following four cyclic phases: understanding user needs, identifying an applicable underlying theory, integrating the theory into the prototype design, and evaluating and refining the prototype mHealth services with patients. Expert panel discussions, a literature review, intervention mapping, and patient focus group discussions were conducted in these four phases.

RESULTS

In stage 1, the expert panel proposed the following three common user needs: motivational, educational, and supportive needs. In stage 2, the team selected the Social Cognitive Theory to guide the app design. In stage 3, the team designed and developed the key functions of the mHealth app, including automatic push notifications; web-based resources; goal setting and monitoring; and interactive health-related exchanges that encourage physical activity, healthy eating, psychological preparation, and a positive outlook for elective surgery. Push notifications were designed in response to a patient's risk level, as informed by the person's response to a baseline health survey. In stage 4, the prototype mHealth app was used to capture further requirements from patients in the two focus group discussions. Focus group participants affirmed the potential benefits of the app and suggested more requirements for the function, presentation, and personalization needs. The app was improved based on these suggestions.

CONCLUSIONS

This study reports an innovative co-design approach that was used to leverage the clinical experiences of clinicians to produce the initial prototype app and the approach taken to allow patients to effectively voice their needs and expectations for the mHealth app in a focus group discussion. This approach can be generalized to the design of any mHealth service that aims to support the patient self-management of chronic conditions.

Time-consuming and expensive data quality monitoring procedures persist in clinical trials: A national survey

INTRODUCTION

The Good Clinical Practice guideline identifies that data monitoring is an essential research activity. However, limited evidence exists on how to perform monitoring including the amount or frequency that is needed to ensure data quality. This study aims to explore the monitoring procedures that are implemented to ensure data quality in Australian clinical research studies.

MATERIAL AND METHODS

Clinical studies listed on the Australian and New Zealand Clinical Trials Registry were invited to participate in a national cross-sectional, mixed-mode, multi-contact (postal letter and e-mail) web-based survey. Information was gathered about the types of data quality monitoring procedures being implemented.

RESULTS

Of the 3689 clinical studies contacted, 589 (16.0%) responded, of which 441 (77.4%) completed the survey. Over half (55%) of the studies applied source data verification (SDV) compared to risk-based targeted and triggered monitoring (10-11%). Conducting 100% on-site monitoring was most common for those who implemented the traditional approach. Respondents who did not conduct 100% monitoring, included 1-25% of data points for SDV, centralized or on-site monitoring. The incidence of adverse events and protocol deviations were the most likely factors to trigger a site visit for risk-based triggered (63% and 44%) and centralized monitoring (48% and 44%), respectively.

CONCLUSION

Instead of using more optimal risk-based approaches, small single-site clinical studies are conducting traditional monitoring procedures which are time consuming and expensive. Formal guidelines need to be improved and provided to all researchers for 'new' risk-based monitoring approaches.

Using e-cigarettes for smoking cessation: evaluation of a pilot project in the North West of England

AIMS

E-cigarettes have been advocated as an effective smoking cessation intervention, with evidence indicating that they are substantially less harmful than conventional cigarettes. As a result, a pilot to encourage people to swap from conventional cigarettes to e-cigarettes was conducted in 2018 in a socially deprived area in the North West of England. This evaluation highlights the key findings from the pilot.

METHODS

An analysis of secondary data at 4 weeks (n = 1022) was undertaken to predict those who used solely used e-cigarettes (i.e. had quit tobacco, as confirmed by a carbon monoxide test, CO < 10 ppm) from baseline characteristics, using chi-square tests and logistic regression. Baseline data were demographics, smoking levels and service provider type.

RESULTS

Of the 1022 participants who engaged with the pilot 614 were still engaged at 4 weeks, of whom 62% had quit; quitting was more likely in younger participants (aged 18-24) and less likely in those who were sick and disabled. Of those who still smoked tobacco at week 4 (n = 226), smoking had reduced from a baseline of 19.1 cigarettes/day to 8.7. Overall, 37% (381) of those initially enrolled were confirmed to be using an e-cigarette on its own at follow-up. Successful quit was associated with occupation (unemployed, 33% vs intermediate, 47%, p = .023) and residing in the less deprived quintiles of deprivation (50% vs 34% in the most deprived quintile, p = .016).

CONCLUSIONS

Making the conservative assumption that all those not in contact at 4 weeks were still smoking tobacco, for every five people entering the scheme, three people stayed on the programme and reduced their cigarette smoking and one person cut out tobacco altogether. E-cigarettes appear to be an effective nicotine replacement therapy; however, further research is required to determine whether e-cigarette users are more likely to reduce their overall nicotine consumption in the longer term.

Exploring perceptions, barriers and use of systematic reviews amongst nutrition professionals and nutrition students

AIM

Systematic reviews (SRs) are a core component of evidence-based practice and are widely used in developing nutrition policy. This study aimed to examine nutrition professionals and students' perceptions, barriers and use of SRs. A secondary aim was to examine confidence using and conducting SRs.

METHODS

A self-administered online survey was developed, pilot-tested and implemented via SurveyMonkey. The survey consisted of 29 items separated into demographics, perceptions, use, and knowledge of SRs, confidence in using and conducting SRs, and barriers to use and conduct of SRs. The survey was disseminated via professional newsletters and social media.

RESULTS

Ninety-four nutrition professionals/students completed the survey. Survey results indicated respondents valued SRs, with SRs used most commonly to update knowledge. While most respondents (67%) were confident in using SRs, many (59%) expressed a lack of confidence in conducting a SR. In particular, few respondents (12%) reported confidence in conducting meta-analyses. The majority of respondents were aware that SRs underpinned guidelines and nutrition resources, however, few (21%) respondents identified that self-substantiation of health claims were based on SRs. Time, access to scientific database, lack of workplace support and confidence were the main barriers to SRs use.

CONCLUSIONS

SRs were reported as being valued by nutrition professionals and students, though time constraints, a lack of confidence and organisations which did not prioritise research were barriers to conducting SRs. The findings of this survey highlight a need for training and education as potential strategies to promote SR engagement in nutrition professionals and students.

Exploring Data Quality Management within Clinical Trials

BACKGROUND

Clinical trials are an important research method for improving medical knowledge and patient care. Multiple international and national guidelines stipulate the need for data quality and assurance. Many strategies and interventions are developed to reduce error in trials, including standard operating procedures, personnel training, data monitoring, and design of case report forms. However, guidelines are nonspecific in the nature and extent of necessary methods.

OBJECTIVE

This article gathers information about current data quality tools and procedures used within Australian clinical trial sites, with the aim to develop standard data quality monitoring procedures to ensure data integrity.

METHODS

Relevant information about data quality management methods and procedures, error levels, data monitoring, staff training, and development were collected. Staff members from 142 clinical trials listed on the National Health and Medical Research Council (NHMRC) clinical trials Web site were invited to complete a short self-reported semiquantitative anonymous online survey.

RESULTS

Twenty (14%) clinical trials completed the survey. Results from the survey indicate that procedures to ensure data quality varies among clinical trial sites. Centralized monitoring (65%) was the most common procedure to ensure high-quality data. Ten (50%) trials reported having a data management plan in place and two sites utilized an error acceptance level to minimize discrepancy, set at <5% and 5 to 10%, respectively. The quantity of data variables checked (10-100%), the frequency of visits (once-a-month to annually), and types of variables (100%, critical data or critical and noncritical data audits) for data monitoring varied among respondents. The average time spent on staff training per person was 11.58 hours over a 12-month period and the type of training was diverse.

CONCLUSION

Clinical trial sites are implementing ad hoc methods pragmatically to ensure data quality. Findings highlight the necessity for further research into "standard practice" focusing on developing and implementing publically available data quality monitoring procedures.

Marfan syndrome and vascular dissections during pregnancy

Pregnancy in a patient with Marfan syndrome may pose significant maternal and fetal risks, and pregnancy outcome is most impacted by the extent of cardiovascular involvement present at conception. This review addresses principles to guide preconception counseling of a Marfan patient, in addition to antepartum and intrapartum management considerations. Multidisciplinary care is recommended during pregnancy, given the potential for multiorgan involvement and various complications which may occur. Mode of delivery planning is guided by the degree of aortic root dilatation. Dissection of a dilated aortic root can present a surgical emergency during pregnancy, and principles for cardiopulmonary bypass in a pregnant patient are reviewed.

The treatment of run-off from a fertiliser plant for nitrification, denitrification and phosphorus removal by use of constructed wetlands: a demonstration study

The paper describes an evaluation carried out on demonstration scale to show that it was possible to use a Hybrid Reed Bed System comprising a Horizontal flow and a Vertical Flow Bed for treating the high strength run-off from a fertiliser packaging plant. The site is located close to an estuary which is sensitive to nutrients. The environmental regulators were therefore concerned that excessive mass flows of nitrate, ammoniacal nitrogen and phosphate, potentially arising from the site run-off, were not discharged into the estuary. The fertiliser manufacturing company required a simple, low maintenance system for removing nitrogen and phosphorus. A series of experimental runs were carried out to characterise the performance of the Hybrid System, establishing the effluent quality that could be achieved and the mass removal rate which was appropriate for acceptable treatment. These tests showed that it was possible to achieve a reduction of 79% in Total N whilst using molasses as a carbon source for denitrification. When using a 4:1 recycle ratio this produced an effluent with concentrations of 14 mg NH(4)-N/litre and 18 mg NO(3)-N/litre from treating site run-off containing concentrations in the order of 75 mg/litre of both NH(3)N and NO(3)-N. Chemical dosing with an iron salt brought the P concentration down to around 0.5 mg PO(4)-P/litre.

Immunization of Macaca fascicularis against experimental periodontitis using a vaccine containing cysteine proteases purified from Porphyromonas gingivalis

INTRODUCTION

Periodontitis is a common infectious disease to which Porphyromonas gingivalis has been closely linked, in which the attachment tissues of the teeth and their alveolar bone housing are destroyed. We conducted a study to determine if immunization using a purified antigen could alter the onset and progression of the disease.

METHODS

Using the ligature-induced model of periodontitis in Macaca fascicularis, we immunized five animals with cysteine protease purified from P. gingivalis and used an additional five animals as controls. Alveolar bone loss was measured by digital subtraction radiography.

RESULTS

Immunization induced high titers of specific immunoglobuin G serum antibodies that were opsonic. Total bacterial load, levels of P. gingivalis in subgingival plaque and levels of prostaglandin E(2) in gingival crevicular fluid were significantly reduced. Onset and progression of alveolar bone loss was inhibited by approximately 50%. No manifestations of toxicity were observed.

CONCLUSIONS

Immunization using a purified protein antigen from P. gingivalis inhibits alveolar bone destruction in a ligature-induced periodontitis model in M. fascicularis.

Functional characteristics of antibodies induced by Arg-gingipain (HRgpA) and Lys-gingipain (Kgp) from Porphyromonas gingivalis

Arginine-specific gingipain (HRgpA) and lysine-specific gingipain (Kgp), enzymes produced by Porphyromonas gingivalis, may be candidates for an anti-P. gingivalis vaccine. The purpose of our study was to determine whether HRgpA and Kgp have opsonic target sites and whether these sites are available and accessible on intact P. gingivalis cells. Rabbits were used to generate polyclonal antibodies to both proteins. Animals were immunized and immunoglobulin G (IgG) fractions were isolated from preimmune and immune sera. Functional characteristics of the antibodies were assessed by determining antibody titers by enzyme-linked immunosorbent assay (ELISA), generating Western immunoblots, and measuring antibody enhancement of P. gingivalis opsonization, phagocytosis and killing by polymorphonuclear leukocytes (PMN) of intact cells of strains of P. gingivalis representative of the four serotypes. Strains studied included 33277 (serotype A), A7A1-28 (serotype B), W50 (serotype C) and 381 (serotype D). Both HRgpA and Kgp induced high titers of IgG antibody. Anti-HRgpA and anti-Kgp bound to both HRgpA and Kgp demonstrating a large proportion of shared antigenic epitopes. The two antibodies bound equally well to all four P. gingivalis serotypes with titers ranging from 77 to 205 ELISA units when compared to preimmune IgG set at 1 ELISA unit. The immunoblot patterns of binding of the two antibodies to HRgpA and Kgp and to sonicates of the four P. gingivalis serotypes were virtually identical. Both antibodies detected components in HRgpA at 27, 35 and 45 kDa and in Kgp at 27, 32, 35, 40 and 55 kDa. The antibodies also detected components at or near these same positions in addition to multiple high molecular mass components in the cell sonicates of P. gingivalis. Both proteins induced antibodies that significantly enhanced opsonization as assessed by chemiluminescence, with values ranging from 130 mV to 375 mV for anti-HRgpA IgG and from 240 mV to 475 mV for anti-Kgp IgG. Both antibodies significantly enhanced PMN-mediated bacterial killing of the four P. gingivalis serotypes, although the percentage of killing varied among the serotypes (24-81% for anti-HRgpA and 37-89% for anti-Kgp). Thus, both HRgpA and Kgp express opsonic target sites and induce high titers of antibodies that opsonize and enhance killing of all four serotypes of P. gingivalis. These two proteins appear to be potential candidate antigens for an anti-P. gingivalis vaccine.

Humoral immunity host factors in subjects with failing or successful titanium dental implants

BACKGROUND

Treatment with titanium dental implants is in general successful. However, an unknown number of implants do not integrate and are removed either by exfoliation or at the time of second stage surgery. It would be of importance to identify subjects at risk and predict early implant failure.

METHODS

In a retrospective study serum IgG antibody titers and avidity in sera from 40 subjects who had experienced titanium dental implant treatments with non-osseo-integration as the outcome (NOTI) and in sera from 40 age and gender matched control subjects who had received successful titanium dental implants (SOTI) were studied. Serum IgG titers to whole cell Actinomyces viscosus, Bacteroides forsythus, Porphyromonas gingivalis, Staphylococcus aureus, and Streptococcus intermedius sonicated antigen preparations were studied by ELISA.

RESULTS

Serum IgG antibody titers to S. aureus were significantly higher in subjects with SOTI than in NOTI (p<0.001) suggesting that higher titers indicate protection against implant failure as a result of S. aureus infection. Statistically significant higher serum IgG antibody avidity to P. gingivalis and B. forsythus were found in subjects with SOTI than in subjects with NOTI (p<0.01 and p<0.001, respectively). Statistical analysis failed to demonstrate antibody titer or avidity differences to the other pathogens studied. The likelihood that SOTI was associated with a high OD reading for S. aureus was 13.1:1 (p<0.001). Whether subjects were edentulous or not, or if they had lost teeth because of periodontitis or caries did not seem to matter.

CONCLUSION

Serum IgG antibodies relative to B. forsythus, P. gingivalis and S. aureus may be associated with the outcome of implant procedures and explain why early implant failures occur.

Serum antibody titers to Bacteroides forsythus in elderly subjects with gingivitis or periodontitis

BACKGROUND

The risks for periodontal disease appear to increase with age.

STUDY PURPOSE

To determine associations between clinical findings, the presence of specific bacteria in periodontal pockets, and serum antibody titers. 10 older subjects (mean age=73.0 years SD+/-4.9) with confirmed gingivitis only (gingivitis group) and 10 subjects with periodontitis (mean age: 76.1 years, SD+/-10.4) (periodontitis group) were studied.

RESULTS

The mean group differences for probing depth and clinical attachment levels were 4.1 mm and 5.6 mm, respectively, and were significantly different (p<0.001). Both groups had high plaque scores (>60% surfaces with plaque). DNA probes demonstrated that B. forsythus was present in 8/10 samples from the periodontitis group and in 7/10 samples from the gingivitis group. The B. forsythus isolates studied were found in four of the subjects with periodontitis and from 2 of the subjects with gingivitis. Serum antibody titers to 6 ribotypes of B. forsythus were studied. Western blots, gradient gels, and pulsed field gel electrophoresis concurrently demonstrated that the B. forsythus isolates were genotypically, and phenotypically unique for each subject. Antibody titers to two selected B. forsythus isolates were significantly higher in the periodontitis group (p<0.01, Mann-Whitney test). The study confirmed that antibody serum titers to the six different ribotypes of B. forsythus varied greatly between older individuals with gingivitis or periodontitis. Not all strains of B. forsythus elicited higher titers in periodontitis affected subjects.

CONCLUSIONS

The results of the present study suggest genotype variation of B. forsythus that is unique to the individual and that serotype variation can be expected. It is possible that B. forsythus under specific host conditions can modulate surface antigen factors to evade the host immune response.

Demystifying acid-base regulation

Acid-base imbalances may have serious clinical implications for all patients. The maintenance of homeostasis within the body is intimately linked to the balance of acids and bases within the body. Any disturbance in this balance will adversely effect all cellular metabolism and ultimately the functioning of vital body systems. Figure 3 may help you to understand the integration of the mechanisms which regulate acid-base balance in the body.

Shared antigens of Porphyromonas gingivalis and Bacteroides forsythus

Periodontitis in humans is caused by a group of predominantly gram-negative, anaerobic bacteria among which Porphyromonas gingivalis and Bacteroides forsythus are prominent. A similar group is present and presumably plays a similar role in experimental periodontitis in the primate Macaca fascicularis. Nevertheless, immunization using a vaccine containing only killed P. gingivalis suppresses the progress of experimental periodontitis in M. fascicularis. We investigated the hypothesis that gram-negative periodontopathic bacterial may share antigens, and immunization with one species may induce antibodies reactive with other gram-negative species. Using enzyme-linked immunosorbent assay (ELISA), Western and dot immunoblots with nonabsorbed and absorbed and immune and preimmune sera we show that monkeys immunized with P. gingivalis produce antibodies reactive not only with antigens of P. gingivalis but also with those of B. forsythus. Similarly, rabbits immunized with P. gingivalis or with B. forsythus produce antibodies that react with antigens of both bacteria. Cross-reactive antibodies bind to epitopes in lipid A and possibly in core carbohydrate of lipopolysaccharide. Using complexes of lipopolysaccharide with polymyxin B, bovine serum albumin and apolipoprotein A1 specificity of binding was documented. Using sera from monkeys immunized with P. gingivalis, cross-reactivity with Actinobacillus actinomycetemcomitans could not be demonstrated by ELI-SA, although binding to lipopolysaccharide but not to lipid A was demonstrated by Western and dot immunoblots. Antibodies to shared lipopolysaccharide epitopes of periodontopathic bacteria may account, at least in part, for the immune protection observed in immunized monkeys, and shared epitopes may have potential as a vaccine for periodontitis in humans.

Response of guinea pigs to a vaccine containing a new adjuvant (SAF) and gram-negative bacteria

Porphyromonas gingivalis is a gram-negative pathogen associated with severe periodontitis in man and other animals. A vaccine against P. gingivalis infection may improve resistance to such infection and disease progression in susceptible individuals. A vaccine composed of formalin-killed P. gingivalis and Syntex adjuvant formulation or saline was tested in guinea pigs. Blood was drawn before and at 2, 4, 6, 8, 24, and 27 weeks after immunization. There was no morbidity or mortality as a result of vaccination, and necropsy revealed no organ abnormalities or residual injection site granulomas. Serum immunoglobulin G (IgG) antibody titer and avidity were measured by enzyme-linked immunosorbent assay, and Western blots were done to determine the immunodominant antigens. The IgG titer increased more rapidly and reached higher values in the animals receiving SAF plus P. gingivalis vaccine than in those receiving saline plus P. gingivalis. Antibody titer decreased by 27 weeks, but avidity was twofold greater at 27 than at 8 weeks. Western blots indicated that protein and carbohydrate antigens are recognized.

Macaca fascicularis as a model in which to assess the safety and efficacy of a vaccine for periodontitis

We have assessed Macaca fascicularis as a potential model in which to test the efficacy and safety of a vaccine for periodontitis. Twenty-eight animals were surveyed and 20 studied in more detail. Clinical periodontal status was assessed, the subgingival microflora analyzed especially for the presence and proportions of Porphyromonas gingivalis and titers and avidities of serum antibodies reactive with P. gingivalis measured. Probing depths ranged from 0.90 mm to 3.80 mm, Gingival Index scores from 0.00 to 4.00 and Plaque Index scores from 0.00 to 3.00. About 40% of sites bled on probing. The animals manifested a subgingival flora characteristic of the anaerobic gram-negative bacteria found in human periodontal pockets, including Actinobacillus actinomycetemcomitans, P. gingivalis, Bacteroides forsythus, Campylobacter rectus, Prevotella intermedia and Fusobacterium nucleatum. P. gingivalis was detected in 70 of 80 samples studied, ranging from 0.01% to 20% of the total flora. Serum antibody reactive with antigens of P. gingivalis was observed in all animals, with titers ranging from 1.0 enzyme-linked immunosorbent assay (ELISA) unit to 25 ELISA units and avidities from 0.10 M to 2.20 M. Antibody titer and maximum percentage of P. gingivalis were inversely correlated, indicating that a humoral immune response may be effective in reducing P. gingivalis overgrowth. M. fascicularis appears to be an excellent model for use in vaccine development.

Legionella pneumophila htpAB heat shock operon: nucleotide sequence and expression of the 60-kilodalton antigen in L. pneumophila-infected HeLa cells

A 60-kilodalton (kDa) immunodominant antigen of Legionella pneumophila is a heat shock protein (HSP) of the GroEL class of HSPs. The gene (htpB) coding the 60-kDa protein was localized to a 3.2-kilobase DNA fragment of L. pneumophila cloned into pUC19 (pSH16) (P. S. Hoffman, C. A. Butler, and F. D. Quinn, Infect. Immun. 57:1731-1739, 1989). The nucleotide sequence of the DNA fragment cloned into M13 confirmed two open reading frames, htpA and htpB, that code for proteins of 96 and 548 amino acids, respectively. A consensus heat shock promoter sequence upstream of the start of htpA was identified, and no obvious promoter sequences were detected upstream of htpB. Amino acid sequence comparison studies revealed that the L. pneumophila HtpB protein exhibited 76% homology with the 65-kDa protein of Mycobacterium tuberculosis and 85% homology with both GroEL of Escherichia coli and HtpB of Coxiella burnetii. A comparison of the amino acid sequences among these proteins revealed several regions of nearly absolute sequence conservation, with the variable regions occurring in common areas. The purified L. pneumophila 60-kDa protein was antigenic for human T lymphocytes. Indirect fluorescent antibody studies indicated that the 60-kDa protein may be located in the periplasm or expressed on the surface by intracellular bacteria, suggesting that a stress-related mechanism may be involved in the expression of this immunodominant antigen.

Clinical and experimental sodium magnetic resonance imaging

In conclusion, sodium MR imaging has potential for providing physiologic information relevant to cell mitosis, cell energy state, rCBV, and seizures. Considerable technical and experimental development is necessary, however, before sodium MRI becomes a routine examination in the clinical setting.

Variations in human corpus callosum do not predict gender: a study using magnetic resonance imaging

Controversy exists in the neuropsychological literature concerning the existence of gender-associated differences in cognitive functioning and in hemispheric lateralization of cognitive functions. A recent study, based on 14 brains obtained at autopsy, reported sex differences in the splenium of the human corpus callosum and suggested that the larger splenium in females reflects less hemispheric lateralization, or "specialization," than the male brain for visuospatial functions. Our measurements of the human corpus callosum using magnetic resonance images of 37 living subjects failed to confirm reported sex differences in the splenium. A marginally significant sex-related difference in minimum body width and an age-related decrease in anteroposterior distance were found. Most striking were the large variations in callosal size and shape among individuals regardless of age or gender. Existing knowledge of the functions of the corpus callosum does not permit correlations between variations in callosal size and shape and variations in cognitive functions.

Variations in human corpus callosum do not predict gender: A study using magnetic resonance imaging

Controversy exists in the neuropsychological literature concerning the existence of gender-associated differences in cognitive functioning and in hemispheric lateralization of cognitive functions. A recent study, based on 14 brains obtained at autopsy, reported sex differences in the splenium of the human corpus callosum and suggested that the larger splenium in females reflects less hemispheric lateralization, or "specialization," than the male brain for visuospatial functions. Our measurements of the human corpus callosum using magnetic resonance images of 37 living subjects failed to confirm reported sex differences in the splenium. A marginally significant sex-related difference in minimum body width and an age-related decrease in anteroposterior distance were found. Most striking were the large variations in callosal size and shape among individuals regardless of age or gender. Existing knowledge of the functions of the corpus callosum does not permit correlations between variations in callosal size and shape and variations in cognitive functions.

Recurrent scintillating scotoma and homonymous hemianopia due to metastatic melanoma

Acute left homonymous hemianopia and recurrent scintillating scotoma occurred in a 43-year-old woman due to metastases from a cutaneous malignant melanoma that had been resected 5 years previously. Computed tomography initially demonstrated small, probably embolic, areas of occipital lobe infarction. Five months after the onset of her visual symptoms, massive cerebral hemorrhage occurred from a large right occipital lobe tumor that had not been present initially. Autopsy demonstrated malignant melanoma. Visual symptoms related to tumor embolization and/or cerebral hemorrhage may be the presenting features of metastatic cutaneous malignant melanoma.

Maintenance and stability of introduced genotypes in groundwater aquifer material

Three indigenous groundwater bacterial strains and Pseudomonas putida harboring plasmids TOL (pWWO) and RK2 were introduced into experimentally contaminated groundwater aquifer microcosms. Maintenance of the introduced genotypes was measured over time by colony hybridization with gene probes of various specificity. On the basis of the results of colony hybridization quantitation of the introduced organisms and genes, all introduced genotypes were stably maintained at approximately 10(5) positive hybrid colonies g-1 of aquifer microcosm material throughout an 8-week incubation period. Concomitant removal of the environmental contaminants, viz., toluene, chlorobenzene, and styrene, in both natural (uninoculated) and inoculated aquifer microcosms was also demonstrated. The results indicate that introduced catabolic plasmids, as well as indigenous organisms, can be stably maintained in groundwater aquifer material without specific selective pressure for the introduced genotypes. These results have positive implications for in situ treatment and biodegradation in contaminated aerobic groundwater aquifers.

Visual and kinesthetic components of pursuit-tracking performance

Ss (N=75) were trained on a pursuit rotor for 10 trials with ambient illumination from a strobe light flashing at frequencies of either 2, 5, 10, 15, or 20/sec. A transfer trial followed, with a strobe flashing frequency of 10/sec for all Ss. Results supported hypotheses derived from Adams' (1971) closed-loop theory of motor learning that (a) performance would improve during training as a function of amount of visual feedback available, and that (b) if after training visual feedback was reduced, performance would be maintained to the extent that reliance upon kinesthetic feedback had been learned as an alternate compensatory feedback loop.