Manipulating the diseased oral microbiome: the power of probiotics and prebiotics

Dental caries and periodontal disease are amongst the most prevalent global disorders. Their aetiology is rooted in microbial activity within the oral cavity, through the generation of detrimental metabolites and the instigation of potentially adverse host immune responses. Due to the increasing threat of antimicrobial resistance, alternative approaches to readdress the balance are necessary. Advances in sequencing technologies have established relationships between disease and oral dysbiosis, and commercial enterprises seek to identify probiotic and prebiotic formulations to tackle preventable oral disorders through colonisation with, or promotion of, beneficial microbes. It is the metabolic characteristics and immunomodulatory capabilities of resident species which underlie health status. Research emphasis on the metabolic environment of the oral cavity has elucidated relationships between commensal and pathogenic organisms, for example, the sequential metabolism of fermentable carbohydrates deemed central to acid production in cariogenicity. Therefore, a focus on the preservation of an ecological homeostasis in the oral environment may be the most appropriate approach to health conservation. In this review we discuss an ecological approach to the maintenance of a healthy oral environment and debate the potential use of probiotic and prebiotic supplementation, specifically targeted at sustaining oral niches to preserve the delicately balanced microbiome.

Dental Mitigation Strategies to Reduce Aerosolization of SARS-CoV-2

Limiting infection transmission is central to the safety of all in dentistry, particularly during the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Aerosol-generating procedures (AGPs) are crucial to the practice of dentistry; it is imperative to understand the inherent risks of viral dispersion associated with AGPs and the efficacy of available mitigation strategies. In a dental surgery setting, crown preparation and root canal access procedures were performed with an air turbine or high-speed contra-angle handpiece (HSCAH), with mitigation via rubber dam or high-volume aspiration and a no-mitigation control. A phantom head was used with a 1.5-mL min-1 flow of artificial saliva infected with Φ6-bacteriophage (a surrogate virus for SARS-CoV-2) at ~108 plaque-forming units mL-1, reflecting the upper limits of reported salivary SARS-CoV-2 levels. Bioaerosol dispersal was measured using agar settle plates lawned with the Φ6-bacteriophage host, Pseudomonas syringae. Viral air concentrations were assessed using MicroBio MB2 air sampling and particle quantities using Kanomax 3889 GEOα counters. Compared to an air turbine, the HSCAH reduced settled bioaerosols by 99.72%, 100.00%, and 100.00% for no mitigation, aspiration, and rubber dam, respectively. Bacteriophage concentrations in the air were reduced by 99.98%, 100.00%, and 100.00% with the same mitigations. Use of the HSCAH with high-volume aspiration resulted in no detectable bacteriophage, both on nonsplatter settle plates and in air samples taken 6 to 10 min postprocedure. To our knowledge, this study is the first to report the aerosolization in a dental clinic of active virus as a marker for risk determination. While this model represents a worst-case scenario for possible SARS-CoV-2 dispersal, these data showed that the use of HSCAHs can vastly reduce the risk of viral aerosolization and therefore remove the need for clinic fallow time. Furthermore, our findings indicate that the use of particle analysis alone cannot provide sufficient insight to understand bioaerosol infection risk.

SAT0045 DISTRIBUTION AND SEVERITY OF PERIODONTITIS PREDICTS PROGRESSION TO INFLAMMATORY ARTHRITIS IN ANTI-CCP POSITIVE AT-RISK INDIVIDUALS WITHOUT CLINICAL SYNOVITIS

Background:

The prevalence of periodontal disease and the citrullinating bacteriumPorphyromonas gingivalisare increased in anti-CCP positive individuals at-risk of rheumatoid arthritis (RA) (1). This suggests periodontal inflammation may have an important role in the initiation and development of RA. Despite significant interest in the role of the periodontium and other mucosal sites in the initiation of RA-related autoimmunity, the influence of mucosal inflammation on progression to inflammatory arthritis (IA) in at-risk individuals remains unclear.

Objectives:

To investigate the association between periodontitis and progression to inflammatory arthritis in anti-CCP+ at-risk individuals without synovitis.

Methods:

Anti-CCP positive individuals with musculoskeletal symptoms but no clinical synovitis (CCP+ at-risk) were recruited as part of a national prospective cohort study. Comprehensive periodontal examination was performed at baseline by a dentist; six sites per tooth were assessed for clinical attachment level (CAL), pocket depth (PD) and bleeding on probing (BOP). Periodontal disease sites (PDD) were defined as CAL ≥2mm and PD ≥4mm. The distribution of PDD was classified in line with recent guidelines (2). The severity i.e. total burden of periodontal inflammation, was quantified at patient level using the periodontal inflamed surface area (PISA) index(3). CCP+ at-risk were monitored for progression to IA. Multivariable Cox regression was used to assess the effect of PDD distribution and PISA on progression to IA.

Results:

126 CCP+ at-risk underwent full periodontal examination and were followed up for median 23.4 months (range 0.6 – 56.8 months). Mean age was 49 years, 86 (68%) were females. At baseline, 42(33%) subjects had no PDD, 51(40%) had localised PDD (<30% teeth with one or more PDD site) and 33 (26%) had generalised PDD (≥ 30% of teeth with one or more PDD site). Mean (SD) PISA for all subjects was 267(319)mm2. 31 subjects (25%) progressed to IA after median of 12.6 months (range 0.6 – 49.5 months). Progression to IA was significantly higher in subjects with localised PDD compared with those without PDD (33% vs 16%, HR (95% CI) 2.45 (1.02, 5.94) p=0.02), figure 1. Interestingly, this association was not seen in subjects with generalised PDD (19% progression, HR 0.68 (0.20, 2.32). In addition, severity (i.e. total burden) of periodontal inflammation (PISA) was not significantly predictive of progression to IA alone (HR 1.001 (0.999-1.002), p=0.08). However, when adjusting for distribution of PDD, PISA was significantly associated with progression to IA (HR 1.0016 (1.0003- 1.003), p=0.00163).

Conclusion:

Periodontal inflammation predicts progression to IA in CCP+ at-risk individuals without clinical synovitis. The severity (i.e. total burden) of periodontitis appears to be particularly predictive of progression to IA in patients with localised periodontitis. These data suggest periodontitis may be an important factor in the development of RA and provide rationale for periodontal intervention with the aim of arthritis prevention in at-risk individuals.

References:

[1] Mankia K et al, JAMA Network Open(2019)

[2] Caton J et al, J Clin Periodontol(2018)

[3] Nesse W et al, J Clin Periodontol(2008)

Disclosure of Interests :

Kulveer Mankia: None declared, Zhain Mustufvi: None declared, Jing Kang: None declared, Aradhna Tugnait: None declared, Robert Letton: None declared, Laurence Duquenne: None declared, Alastair Speirs: None declared, Val Clerehugh: None declared, Deirdre Devine: None declared, Paul Emery Grant/research support from: AbbVie, Bristol-Myers Squibb, Merck Sharp & Dohme, Pfizer, Roche (all paid to employer), Consultant of: AbbVie (consultant, clinical trials, advisor), Bristol-Myers Squibb (consultant, clinical trials, advisor), Lilly (clinical trials, advisor), Merck Sharp & Dohme (consultant, clinical trials, advisor), Novartis (consultant, clinical trials, advisor), Pfizer (consultant, clinical trials, advisor), Roche (consultant, clinical trials, advisor), Samsung (clinical trials, advisor), Sandoz (clinical trials, advisor), UCB (consultant, clinical trials, advisor)

The subgingival microbiomes in periodontitis and health of individuals with rheumatoid arthritis and at risk of developing rheumatoid arthritis

Serum anti-citrullinated protein antibodies (ACPAs), present in 70% of people with rheumatoid arthritis (RA), can be detected ≤10years before the onset of clinical disease. RA and periodontitis are epidemiologically associated and we have reported a high incidence of periodontitis in people who are ACPA+ and at risk of RA. Periodontal bacteria may contribute by multiple routes to the generation of RA-autoantibodies. This study aims to characterise the subgingival microbiomes from periodontitis and health in individuals with/without RA and at risk of RA.

Forty-five ACPA+ no RA (RA-at-risk; RAR), 31 healthy controls (HC) and 30 ACPA+ RA patients (RA) underwent a periodontal examination. DNA from subgingival plaque from healthy and deep pocket sites were paired-end sequenced using the Illumina HiSeq3000 and data analysed using MG-RAST + DESeq.

Metagenomes in RA samples had high proportions of Actinobacteria; RAR microbiomes contained higher proportions of Bacteroidetes than HC. The relative abundance of P. gingivalis was high in periodontitis and RAR; Aggregatibacter actinomycetemcomitans was detected with similar frequency in each group. Other bacteria implicated in periodontitis and/or autoantibody generation (Filifactor alocis, Prevotella spp, Leptotrichia spp.) were detected. Analyses are on-going to elucidate the diversity and functional potential of the subgingival microbiome associated with RA.

T Cell Costimulation by Derivatives of Benzoic Acid

A number of analogues of benzoic acid were evaluated in a T cell costimulation assay. One compound, the sodium salt of 2-chloro-5-nitrobenzoic acid (CNBA-Na) was chosen for further study and was found to be a potent costimulator of anti-CD3-induced proliferation of both H9 lymphoblastoid cells ( P<0.001) and human peripheral blood mononuclear cells ( P=0.001) in a dose-dependent manner. The costimulatory effect of CNBA-Na on CD3-triggered DNA synthesis did not enhance human immunodeficiency virus replication in infected cells. Studies with blocking monoclonal antibodies against B7-1 or B7-2 indicated that the immunopotentiatory effect of CNBA-Na required a macromolecular interaction between CD28 (a costimulatory receptor on T cells) and its counter receptor B7 expressed on antigen-presenting cells. The discovery that this low molecular weight compound causes T cell proliferation highlights a potentially novel therapeutic approach to immunodeficiency diseases.

Counting platelets at transfusion threshold levels: impact on the decision to transfuse. A BEST Collaborative - UK NEQAS(H) International Exercise

BACKGROUND AND OBJECTIVES

Obtaining accurate and precise platelet enumeration in automatic platelet analysers at low platelet counts is a challenge. To explore the performance of current haematology analysers in counting platelet concentrations usually used as platelet transfusion threshold.

MATERIAL AND METHODS

An international exercise where four blood samples with platelet levels near usual platelet transfusion thresholds was prepared and distributed.

RESULTS

The samples shipped had a platelet count of 6·3, 13·3, 21·6 and 53·0 × 10(9) /l according to the international reference method. We received 82 sets of results from nine countries. Instruments from six different manufacturers were represented. Although the mean count for each of the four samples was very similar to the values, according to the reference method (9·0, 16·2, 23·0 and 57·6 × 10(9) /l), significant variability in the results was found. Assuming that these were patient samples and the result of the count used to indicate a prophylactic platelet transfusion, undertransfusion would have occurred for 24·5% of the LP1 samples at a transfusion threshold of 10 × 10(9) /l and, at a threshold of 20 × 10(9) /l, undertransfusion would have occurred for 7·2% of the LP1 and 16·2% of the LP2 samples and overtransfusion would have occurred with 23·1% of the LP3 samples.

CONCLUSION

The results suggest that significant inaccuracy exists in counting low levels of platelets and that this inaccuracy might have a significant impact in under- and overtransfusion of platelet concentrates to patients.

Establishment of the first international repository for transfusion-relevant bacteria reference strains: ISBT working party transfusion-transmitted infectious diseases (WP-TTID), subgroup on bacteria

BACKGROUND

Bacterial contamination of platelet concentrates (PCs) still remains a significant problem in transfusion with potential important clinical consequences, including death. The International Society of Blood Transfusion Working Party on Transfusion-Transmitted Infectious Diseases, Subgroup on Bacteria, organised an international study on Transfusion-Relevant Bacteria References to be used as a tool for development, validation and comparison of both bacterial screening and pathogen reduction methods.

MATERIAL AND METHODS

Four Bacteria References (Staphylococcus epidermidis PEI-B-06, Streptococcus pyogenes PEI-B-20, Klebsiella pneumoniae PEI-B-08 and Escherichia coli PEI-B-19) were selected regarding their ability to proliferate to high counts in PCs and distributed anonymised to 14 laboratories in 10 countries for identification, enumeration and bacterial proliferation in PCs after low spiking (0·3 and 0·03 CFU/ml), to simulate contamination occurring during blood donation.

RESULTS

Bacteria References were correctly identified in 98% of all 52 identifications. S. pyogenes and E. coli grew in PCs in 11 out of 12 laboratories, and K. pneumoniae and S. epidermidis replicated in all participating laboratories. The results of bacterial counts were very consistent between laboratories: the 95% confidence intervals were for S. epidermidis: 1·19-1·32 × 10(7) CFU/ml, S. pyogenes: 0·58-0·69 × 10(7) CFU/ml, K. pneumoniae: 18·71-20·26 × 10(7) CFU/ml and E. coli: 1·78-2·10 × 10(7) CFU/ml.

CONCLUSION

The study was undertaken as a proof of principle with the aim to demonstrate (i) the quality, stability and suitability of the bacterial strains for low-titre spiking of blood components, (ii) the property of donor-independent proliferation in PCs, and (iii) their suitability for worldwide shipping of deep frozen, blinded pathogenic bacteria. These aims were successfully fulfilled. The WHO Expert Committee Biological Standardisation has approved the adoption of these four bacteria strains as the first Repository for Transfusion-Relevant Bacteria Reference Strains and, additionally, endorsed as a project the addition of six further bacteria strain preparations suitable for control of platelet contamination as the next step of enlargement of the repository.

Evaluation of noninvasive methods for the estimation of haemoglobin content in red blood cell concentrates

OBJECTIVES

Red blood cell concentrates (RCCs) are the major blood component transfused to patients. There is a great variability in patient response, depending on both the patient's blood volume and haemoglobin content in the RCC. Standardisation of transfusion practice is needed to improve the prediction of patient outcome.

AIM

We hypothesise that labelling of RCCs with haemoglobin content will add possibilities for the standardisation of transfusion practice.

METHODS

Data from multiple international transfusion services regarding haemoglobin content and weight or volume of RCC were collected and analysed.

RESULTS

We demonstrate a strong and highly significant correlation between haemoglobin content with both weight and volume of the RCCs. A linear regression model was used to assess these relationships, and it demonstrates how haemoglobin content can be estimated for different cell production processes.

CONCLUSIONS

We recommend the use of weight or volume of the RCCs as the basis of estimating haemoglobin in the RCC and postulate that this can be used in future studies to explore the effects of a haemoglobin dose-based transfusion system. As the weight - and sometimes the volume - of the blood bag is easily accessible, in contrast to direct haemoglobin measurements from each individual unit, this method is feasible and simple.

Long-term effects of pre-surgical stress management for men with early stage prostate cancer undergoing radical prostatectomy (RP)

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Background: We conducted a randomized trial to examine pre-surgical stress management for men undergoing RP. We previously reported on the short-term benefits in reducing mood disturbances before and after surgery. Methods: One hundred and fifty- eight men were randomly assigned to one of three conditions. Men in the stress management (SM) group discussed their fears and concerns about the upcoming surgery and were taught diaphragmatic breathing, guided imagery, an imaginal exposure to the day of surgery, and exposure to adaptive coping skills. Men in the supportive attention (SA) group discussed their fears and concerns about the upcoming surgery and then a semi-structured interview was conducted. Men in the SM and SA groups met with a clinical psychologist two times prior to surgery, a brief session just prior to surgery, and then again prior to discharge. Men in the usual care (UC) group had no meetings with a psychologist. Men completed psychosocial and quality of life (QOL) measures including distress (BSI-GSI), intrusive thoughts (IES), and QOL (SF-36), at baseline and 6 and 12 months later. Results: Men were primarily Caucasian (78%), married (85%) and highly educated (80% some college or higher). Mixed model analyses, controlling for ethnicity, age, martial status, stage, baseline PSA, Gleason score, and the respective baseline measure, indicated a significant group main effect for SF-36 Role Physical (SF-RP)(p=0.01). Post-hoc analyses revealed significantly higher SF-RP scores for the SM (86) vs. UC (63) group and marginally higher scores for the SM (86) vs. SA (73) group. There was a marginally significant group main effect for pain scores (SF-BP) (p=0.12) with the SM group reporting significantly better pain scores than the UC group (80 vs. 71), and neither group differed from the SA group (77). There was also a group by time effect for general health scores (SF-GH) revealing by 12 months after surgery that the SM (74) and SA (76) groups both reported higher SF-GH scores than the UC group (68). There were no group differences on any of the other outcomes. Conclusions: Results suggest that even a brief pre-surgical stress management intervention is beneficial in terms of improving aspects of QOL 6 and 12 months after RP. Funding: NIMH/NCI RO1MH59432

No significant financial relationships to disclose.

Chlorhexidine-modified glass ionomer for band cementation? An in vitro study

OBJECTIVE

To compare the mean retentive strength, predominant site of band failure, amount of cement remaining on the tooth at deband and survival time of orthodontic micro-etched bands cemented with chlorhexidine-modified (CHXGIC) or conventional glass ionomer cement (GIC).

DESIGN

In vitro study.

SETTING

Dental Materials Laboratory.

MATERIALS AND METHODS

One-hundred-and-twenty intact, caries-free third molars were collected from patients attending for third molar surgery. These were stored for 3 months in distilled water and decontaminated in 0.5% chloramine. To assess retentive strength, 80 teeth were randomly selected and 40 were banded with each cement. Testing was undertaken using a Nene M3000 testing machine at a cross-head speed of 1 mm/min. Following debanding, the predominant site of failure was recorded as cement-enamel or cement-band interface. The amount of cement remaining on the tooth surface following deband was assessed and coded. Survival time for another 40 banded specimens, 20 cemented with each cement, was assessed following application of mechanical stress in a ball mill.

MAIN OUTCOME MEASURES

Retentive strength, predominant site of failure, amount of cement remaining on the tooth surface, survival time.

RESULTS

Mean retentive strength for bands cemented with CHXGIC (0.32 MPa, SD 0.09) or GIC (0.28 MPa, SD 0.07) did not differ significantly (p=0.05). All bands failed at the enamel-cement interface. There was no significant difference in the amount of cement remaining on the tooth surface after deband for each cement type (p=0.23). The mean survival time of bands cemented with CHXGIC or GIC was 7.0 and 6.4 hours, respectively (p=0.23).

CONCLUSIONS

There was no significant difference in mean retentive strength, amount of cement remaining on the tooth after deband or mean survival time of bands cemented with CHXGIC or GIC. Bands cemented with either cement failed predominantly at the enamel-cement interface. The results suggest that CHXGIC may have comparable clinical performance to GIC for band cementation.

Endocrine levels at the start of treatment are associated with subsequent psychological adjustment in cancer patients with metastatic disease

OBJECTIVE

This study examined the association between hormonal profiles at the start of cancer treatment and subsequent psychological symptomatology.

METHODS

Twenty-seven patients with metastatic renal cell carcinoma and 18 patients with metastatic melanoma completed three assessments during the course of treatment: at the start of treatment (baseline), at the end of treatment (3 weeks after baseline), and at a follow-up appointment 1 month later. Cortisol, norepinephrine, and epinephrine levels were measured at baseline using 15-hour urine samples. At each assessment, patients completed the Impact of Event Scale (IES) and the Brief Symptom Inventory (BSI).

RESULTS

Patients reported moderate levels of distress throughout treatment as measured by the IES and BSI. Norepinephrine levels at the start of treatment were positively associated with IES total scores at the end of treatment and at follow-up, and cortisol levels were positively associated with IES total scores at follow-up after adjusting for baseline IES and overall distress scores. Norepinephrine levels were also positively associated with depression scores at follow-up, and cortisol levels were positively associated with depression scores at the end of treatment and at follow-up after adjusting for baseline depression and overall distress scores.

CONCLUSIONS

Hormonal profiles at the start of cancer treatment are associated with subsequent psychological adjustment.

Investigation to evaluate and validate the Leeds in situ device for the study of enamel remineralisation in vivo

OBJECTIVES

Recently, a novel device to generate dental plaque in situ on a removable human enamel surface was described. The device permitted the recovery of plaque intact and undisturbed on its enamel substrate. The aim of this investigation was to determine the utility and robustness of this model for analysis of the effects of therapeutics on both enamel remineralisation and on the overlying biofilm composition.

METHODS

Enamel slices were taken from extracted sound human teeth, sterilised and a 'flat' area ground on each slice. An artificial lesion was formed within this area using acidified gel and the hardness of the enamel within the area of the lesion was determined at five sites using a 'Vickers' indenter. A nylon ring was then attached over the area of the lesion with cyanoacrylate and the excess enamel removed to form the completed device. Two devices were attached to the upper molars of 22 volunteers. Each volunteer was randomly assigned to receive either a fluoride containing (1500 ppm) or a fluoride free dentifrice. The devices were retained for a 4 week period whilst undertaking normal oral hygiene. All procedures were conducted according to GCP. After a 2 week break, the volunteers were fitted with two further devices, given dentifrice of the alternate type and the procedure repeated. Plaque from each device was harvested for microbiological analyses and the enamel subject to microhardness measurement. Then for each device the change in microhardness of the enamel within the lesion over the 4 week period was calculated.

RESULTS

There were no significant differences in viable counts of total aerobic bacteria, mutans streptococci or lactobacilli, nor in acidic, aciduric or arginolytic populations in plaque from patients using the two different dentifrices. However, devices subjected to the fluoride containing dentifrice demonstrated a significantly greater increase in microhardness of the enamel (P<0.025).

CONCLUSIONS

These results suggest that the novel in situ device is capable of measuring the effect of 1500 ppm fluoride on remineralisation of carious enamel over a 4 week period and is also well suited to determining concomitant effects on plaque ecology.

Risk-resistance adaptation model for caregivers and their children with sickle cell syndromes

This investigation examined the risk-resistance adaptation model for children with sickle cell disease and their primary caregivers. Participants were 55 children, ranging in age from 5 to 16 years with a mean age of 9 years 2 months, diagnosed with sickle cell disease and their primary caregivers, recruited from a university medical center. Measures included adjustment (i.e. primary caregiver and child adjustment), risk factors (i.e. disease and disability, functional independence, and psychosocial stressors), resistance factors (i.e. intrapersonal health locus of control, social-ecological), and stress processing (coping). Primary caregivers' adjustment was associated with developmental coping, changeR2 = .08, and child adaptation was associated with an internal health locus of control, changeR2 = .22. An indirect effect of primary caregivers' coping on child adjustment was found through influence on primary caregivers' adjustment, changeR2 = .11. The findings support research among other chronically ill populations that suggests an association between coping and disease adjustment. The results were interpreted to support the use of theoretically driven models in predicting the adaptation of children with chronic illness and adjustment in their caregivers.

The AtCAO gene, encoding chlorophyll a oxygenase, is required for chlorophyll b synthesis in Arabidopsis thaliana

Chlorophyll b is synthesized from chlorophyll a and is found in the light-harvesting complexes of prochlorophytes, green algae, and both nonvascular and vascular plants. We have used conserved motifs from the chlorophyll a oxygenase (CAO) gene from Chlamydomonas reinhardtii to isolate a homologue from Arabidopsis thaliana. This gene, AtCAO, is mutated in both leaky and null chlorina1 alleles, and DNA sequence changes cosegregate with the mutant phenotype. AtCAO mRNA levels are higher in three different mutants that have reduced levels of chlorophyll b, suggesting that plants that do not have sufficient chlorophyll b up-regulate AtCAO gene expression. Additionally, AtCAO mRNA levels decrease in plants that are grown under dim-light conditions. We have also found that the six major Lhcb proteins do not accumulate in the null ch1-3 allele.

Women who are HIV infected: the role of religious activity in psychosocial adjustment

The role of religious activity in the psychosocial adjustment of 205 inner-city African-American women, one-half of whom are HIV infected, was examined. Those who were HIV infected reported praying more but viewed prayer as less effective in coping with a chronic illness. Frequency of prayer predicted optimism about the future, whereas religious activity was not related to current depressive symptoms.

Purification and functional analysis of the DnaK homologue from Prevotella intermedia OMZ 326

This study examined heat shock proteins (hsps) of the periodontal pathogen Prevotella intermedia and the closely related species, Prevotella nigrescens and Prevotella corporis. After heat shock at 45 degrees C for 5 min, cell-free extracts were analysed by SDS-PAGE and Western blotting with polyclonal antibodies against Escherichia coli hsps. P. intermedia, P. nigrescens and P. corporis all expressed a DnaK homologue. The P. nigrescens DnaK was of a similar molecular mass to E. coli DnaK (70 kDa), whilst those of P. intermedia and P. corporis were approximately 69 kDa. DnaJ homologues were expressed in each species; however, no homologue of GrpE was detected. P. intermedia DnaK was purified to homogeneity by ion-exchange and affinity-chromatography, and was shown to restore activity of denatured luciferase. This molecular chaperone activity was enhanced by E. coli DnaJ and GrpE which are components of the Hsp70 molecular chaperone machine.

Prospective evaluation of neutrophil autoantibodies in 500 consecutive patients with inflammatory bowel disease

Previous studies have shown antineutrophil cytoplasmic autoantibodies (ANCA) in patients with inflammatory bowel disease (IBD). A particular subclass, the so-called 'atypical' (perinuclear) p-ANCA type, occurs in the majority of patients with ulcerative colitis. The purpose of this prospective study was to assess, in a blinded fashion, this 'subclinical' serological marker in a consecutive series of IBD patients. Five hundred patients were evaluated, including 247 patients with ulcerative colitis and 253 with Crohn's disease involving the small and/or large intestine. Overall, 194 (38.8%) of all patients with IBD were positive, including 164 (66.3%) with ulcerative colitis and 30 (11.9%) with Crohn's disease. Except for coexistent sclerosing cholangitis, no other clinical or laboratory variable had an effect on the rate of ANCA detection. This is the largest single study of ANCA in patients with IBD and the only study to provide data solely from a single Canadian centre. Results emphasize the immunopathological differences between ulcerative colitis and Crohn's disease, and indicate that both disorders are heterogeneous inflammatory disease processes.

Cascading toward divorce: the roles of marital and child factors

This longitudinal study examined the role of marital and child factors in predicting divorce potential and actual divorce occurrence. Participants included 140 young adolescents (73 girls, 67 boys; mean age = 13 years 2 months) and their parents. Child-related (number of children in the family, the presence of a male child in the family, and the adolescent's level of anxiety-withdrawal and conduct disorder problems) and intramarital (marital satisfaction and, for some analyses, divorce potential) factors served as predictors. For both wife and husband data, lower levels of marital satisfaction predicted higher current levels of divorce potential, and, in turn, divorce potential predicted greater likelihood for divorce up to 7 years later. No child-related variables predicted divorce potential or divorce occurrence.

Cascading toward divorce: the roles of marital and child factors

This longitudinal study examined the role of marital and child factors in predicting divorce potential and actual divorce occurrence. Participants included 140 young adolescents (73 girls, 67 boys; mean age = 13 years 2 months) and their parents. Child-related (number of children in the family, the presence of a male child in the family, and the adolescent's level of anxiety-withdrawal and conduct disorder problems) and intramarital (marital satisfaction and, for some analyses, divorce potential) factors served as predictors. For both wife and husband data, lower levels of marital satisfaction predicted higher current levels of divorce potential, and, in turn, divorce potential predicted greater likelihood for divorce up to 7 years later. No child-related variables predicted divorce potential or divorce occurrence.

Quartz inactivates alpha 1-antiproteinase: possible role in mineral dust-induced emphysema

Occupational exposure to some types of mineral particles has been shown to be associated with the development of emphysema, but the mechanism of this process is unknown. Because many mineral particles are known to catalyze the formation of active oxygen species in aqueous solution, we hypothesized that mineral particles could oxidatively inactive antiproteinases, leading to an imbalance between protease and antiprotease activities, events similar to those believed to occur with cigarette smoke. To test this hypothesis, human alpha 1-antiproteinase (alpha 1-AP) was incubated with suspensions of freshly ground or aged quartz, and antiproteolytic activity was determined by using porcine pancreatic elastase. Increasing concentrations of quartz were associated with increasing losses of antiproteolytic activity; this effect could be prevented by catalase. Freshly ground quartz was more active than aged quartz. Western blot analysis for alpha 1-AP showed abnormal banding, suggesting that porcine pancreatic elastase-alpha 1-AP complex formation was impaired by silica exposure. Chemical assay of aqueous quartz suspensions demonstrated production of hydrogen peroxide; incubation of alpha 1-AP with hydrogen peroxide caused a dose-dependent loss of antiproteolytic activity, and this also could be prevented by catalase. We conclude that, at least in vitro, quartz can inactivate alpha 1-AP through a hydrogen peroxide-mediated mechanism and that oxidative loss of antiproteinase activity could play a role in mineral dust-induced emphysema.

Adolescent depressed mood and young adult functioning: a longitudinal study

The present study examined two aspects of depressed mood in adolescence: (1) stability across the adolescent years and (2) ability to predict functioning in young adulthood. Participants included 82 Caucasian individuals (46 females and 36 males) who were assessed one time per year for 4 consecutive years during adolescence (mean age at initial assessment = 13.5 years) and again during young adulthood (mean age = 19). The results indicated that depressed mood, as measured by the Children's Depression Inventory (CDI), remained relatively stable across at least 3 consecutive years of data collection during adolescence. In addition, adolescent CDI scores predicted young adult functioning in each of four areas: prosocial competence, self-esteem, externalizing problems, and internalizing problems.

Analysis of immunoglobulin class, IgG subclass and titre of HPA-1a antibodies in alloimmunized mothers giving birth to babies with or without neonatal alloimmune thrombocytopenia

We analysed the titre and isotype composition of antibodies produced by mothers giving birth to babies with or without neonatal alloimmune thrombocytopenic purpura (NAITP) and patients with post-transfusion purpura (PTP). All these individuals produced an antibody specific for the HPA-1a allotype present on the platelet glycoprotein IIb-IIIa (GPIIb-IIIa). Sera from mothers who gave birth to thrombocytopenic babies (group 1, n = 36), non-thrombocytopenic babies (group 2, n = 4) or from PTP patients (group 3, n = 3) were tested by an indirect-ELISA. Results indicated no evident differences in the isotype composition or titre of the antibodies from the three groups of sera. The antibody titre ranged from 1:120 to 1:3500. Antibodies with the IgG1 subclass were present in all sera. Most sera contained IgG1 alone (24/43 sera tested) or in combination with IgG3 (10/43). IgG2 was never present and only three sera showed intermediate reactivity with anti-IgG4 MAb. Few sera (nine sera from groups 1 and 2) were weakly positive when tested with the anti-IgM antibodies. These results suggest that neither the titre nor the isotype composition can be used to predict the severity or the occurrence of thrombocytopenia in newborns.

Pathophysiology of thrombocytopenia associated with HIV infection in homosexual men. A preliminary report

The pathophysiology of HIV associated immune thrombocytopenia (HIV-ITP) and its response to AZT was investigated. Using autologous 111Indium-labelled platelets, platelet kinetic were analysed in two patient groups. Group 1 (untreated) was comprised of 13 patients with HIV-ITP. Group 2 (AZT) was comprised of 6 patients with a history of HIV-ITP prior to starting AZT. These patients were studied following a rise in their platelet count on AZT. Platelet survivals in both groups were shortened compared to controls, however there was no significant difference between the 2 groups. However platelet turnover rates were significantly depressed in Group 1 compared to Group 2 (P less than 0.05) and control values (P less than 0.05). The platelet count correlated with platelet turnover in Group 1 but not in AZT treated patients. Thus patients with HIV-ITP appear to have both shortened survivals and suppressed platelet production. The mechanism of the latter is unknown, but the increased turnover rate seen with AZT suggests it is a direct or indirect effect of the HIV virus.

Molested as children: a hidden contribution to substance abuse?

A history of child sexual victimization may be much more prevalent among substance abusers than previously suspected and may be commonly missed if not assessed directly in every patient. The rates of reporting child sexual abuse among inpatient substance abusers were compared before and after the question was routinely asked in a treatment program. Before routine inquiry, 4% of men and 20% of women disclosed such abuse but after routine inquiries began the rates for adult men quadrupled, up to 42% of the teenaged boys reported such abuse, about 75% of adult women admitted such abuse, and 71 to 90% of teenaged girls disclosed histories of child sexual abuse. Unresolved issues from childhood sexual abuse may be a hidden factor underlying much substance abuse and if not treated may lead to rapid relapse.

Aggressive combination therapy in the successful management of life-threatening intracranial hemorrhage in a patient with idiopathic thrombocytopenic purpura

We describe acute therapy for a 13-year-old female from Panama with chronic idiopathic thrombocytopenia purpura (ITP) refractory to steroids, splenectomy, vinca alkaloids, and azathioprine. She presented with neurologic deterioration from a posterior fossa intracranial hemorrhage (ICH). This followed a 3-month history of severe dysfunctional uterine bleeding, progressive from menarche, which had required multiple red cell transfusions. Steroid and vinblastine therapy and transfusion of 40 U of platelets failed to increase the platelet count above 10,000/microliter. Development of a second larger ICH (frontal) produced morbid increase in intracranial pressure that necessitated neurosurgical decompression. Plasma exchange and colloid repletion with intravenous gamma globulin (1 g/kg) and an infusion of 20 U of platelets resulted in a transient rise in platelet count to 160,000/microliter, permitting surgery without bleeding. Danazol (800 mg/day) and conjugated estrogen (Premarin 25 mg/day) were begun to control the uterine bleeding. Intensive plasma exchange and i.v. IgG infusions were continued daily for 24 days, then twice weekly for several weeks. Platelet-bound IgG decreased almost 500% over the first 10 days of therapy, and platelets increased dramatically to 600,000/microliter after 3 weeks of therapy. The patient has remained amenorrheic with a normal platelet count for more than 24 months on daily danazol therapy and monthly infusions of i.v. IgG (0.4 g/kg/dose).

Antibodies as specific renin inhibitors: studies with polyclonal and monoclonal antibodies and Fab fragments

The use of antirenin antibody and Fab may provide a more specific physiologic tool and potential therapeutic agent than the existing pharmacologic inhibitors. The antibody combining site, by virtue of its larger size than organic compounds, has the capacity for a larger number of intramolecular contacts with its ligands, thus allowing increased selectivity and affinity. Renin-specific Fab obtained through immunization with purified dog renal renin has been studied. Fab had no effect on blood pressure in the sodium replete conscious dog but induced systemic hypotensive responses in the sodium deplete animal or during acute renovascular hypertension. These responses were accompanied with complete suppression of plasma renin and angiotensin II levels. The vasodepressor responses of Fab were comparable to the converting enzyme inhibitor, teprotide. However, the latter induced a greater renal vasodilator effect. Since antibodies and their fragments derived from immune sera are limited in their application to physiologic study with respect to lack of homogeneity, reproducibility and limitation of quantity, we obtained monoclonal antibodies to purified human renal renin. Fusion HR3 yielded 14 renin-antibody secreting clones. Six clones have been isolated and characterized. Isotypes include IgG1 and IgM. Kd's range from 6 X 10(-9) to 7.5 X 10(-10)M renin concentration. Five clones produce antibodies with antienzymatic activity. IC50's of these antibodies range from 1 X 10(-6) to 6 X 10(-8)M. All antibodies are renin-specific and do not bind several nonrenin enzymes and proteins examined. They are also highly species specific, i.e., do not crossreact with mouse, dog, bovine or rat renins but recognize hog renin. These catalytic-site directed antibodies may be highly potent and specific tools for physiologic studies in subhuman primates and man.

Noninvasive measurement of cardiac pressures by induced ventricular wall resonance: preliminary results in the dog

Experiments in the excised dog heart and in live dogs are presented wherein a method of induced right ventricular wall resonance has been utlized to estimate the pressure in the right ventricle of the heart. Externally induced cardiac wall vibrations produced low frequency signals which, when subjected to spectrum analysis and coherent signal processing, permitted close approximation of static pressures and wave forms in the right ventricle at normal and hypertensive levels.