Molecular characterization and safety assessment of biofortified provitamin A rice

Part of the studies involved in safety assessment of genetically engineered crops includes characterizing the organization, integrity, and stability of the inserted DNA and evaluating the potential allergenicity and toxicity of newly-expressed proteins. Molecular characterization of the introduced DNA in provitamin A biofortified rice event GR2E confirmed insertion of a single copy of the transfer-DNA in the genome and its inheritance as a single locus. Nucleotide sequencing of the inserted DNA confirmed it was introduced without modifications. The phytoene synthase, and carotene desaturase proteins did not display sequence similarity with allergens or toxins. Both proteins were rapidly digested in simulated gastric fluid and their enzymatic activity was inhibited upon heat treatment. Acute oral toxicity testing of the protein in mice demonstrated lack of adverse effects. These evidences substantiated the lack of any identifiable hazards for both proteins and in combination with other existing comparative analyses provided assurance that food derived from this rice is safe. This conclusion is in line with those of the regulatory agencies of US Food and Drug Administration, Health Canada and Food Standard Australia and New Zealand.

Serum cardiac troponin I concentrations decrease following treatment of primary immune-mediated haemolytic anaemia

OBJECTIVES

The measurement of serum cardiac troponin I concentrations in dogs with a range of non-primary cardiac illnesses suggests that cardiac myocyte damage is commonplace. Dogs with primary immune-mediated haemolytic anaemia have increased serum cardiac troponin I concentrations at the time of diagnosis. However, it is unclear whether biochemical evidence of cardiac myocyte damage improves following successful treatment of anaemia.

METHODS

A haematology profile was performed and serum cardiac troponin I concentrations were measured in 19 dogs with primary immune-mediated haemolytic anaemia before and after treatment.

RESULTS

The haematocrit increased significantly (P = 0 · 0001) following treatment of primary IMHA (median pre: 0 · 13 L/L, median post: 0 · 33 L/L). The serum cardiac troponin I concentrations decreased significantly (P < 0 · 05) after treatment (median pre: 0 · 26 ng/mL, median post: 0 · 16 ng/mL).

CLINICAL SIGNIFICANCE

Serum cardiac troponin I concentration decreases following successful treatment of primary immune-mediated haemolytic anaemia. The clinical and prognostic significance of serum cardiac troponin I concentrations before and after treatment in dogs with primary immune-mediated haemolytic anaemia merits further investigation.

Development and assessment of national performance indicators for infection prevention and control and antimicrobial stewardship in European long-term care facilities

BACKGROUND

Healthcare-associated infections in long-term care facilities (LTCFs) are of increasing importance.

AIM

To develop consensus national performance indicators (NPIs) for infection control (ICPI) and antimicrobial stewardship (ASPI) in LTCFs, and assess the performance of 32 European countries against these NPIs.

METHODS

Previously established European standards were the basis for consensus and the same iterative approach with national representatives from the 32 countries. A World Health Organization scoring system recorded how close each country was to implementing each standard.

FINDINGS

The 42 agreed component indicators were grouped into six NPI categories: 'national programme', 'guidelines', 'expert advice', 'IC structure' (not present in the ASPI), 'surveillance' and 'composite'. 'Guidelines' scored the highest mean total possible score (60%, range 20-100%), followed by 'composite' (53%, range 30-100%), 'expert advice' (48%, range 20-100%), 'surveillance' (47%, range 20-83%), 'national programme' (42%, range 20-100%) and 'IC structure' (39%, range 20-100%). Although several scores were low, some countries were able to implement all NPIs, indicating that this was feasible. Most NPIs were very significantly related, indicating that they were considered to be important by the countries. 'Guidelines' and 'IC structure' were significantly related to European region (P ≤ 0.05). Accreditation/inspection was not evident in seven (22%) countries, nine (28%) countries had accreditation/inspection that included IC assessments, and seven (22%) countries had accreditation/inspection that included IC and antimicrobial stewardship assessments. Multi-variable analysis found that only the NPI and the ICPI 'expert advice' were associated with accreditation/inspection which included IC and antimicrobial stewardship.

CONCLUSION

The identified gaps represent significant potential patient safety issues. The NPIs should serve as a basis for monitoring improvements over the coming years.

Regulation of cathelicidin antimicrobial peptide expression by an endoplasmic reticulum (ER) stress signaling, vitamin D receptor-independent pathway

Vitamin D receptor (VDR)-dependent mechanisms regulate human cathelicidin antimicrobial peptide (CAMP)/LL-37 in various cell types, but CAMP expression also increases after external perturbations (such as infection, injuries, UV irradiation, and permeability barrier disruption) in parallel with induction of endoplasmic reticulum (ER) stress. We demonstrate that CAMP mRNA and protein expression increase in epithelial cells (human primary keratinocytes, HaCaT keratinocytes, and HeLa cells), but not in myeloid (U937 and HL-60) cells, following ER stress generated by two mechanistically different, pharmacological stressors, thapsigargin or tunicamycin. The mechanism for increased CAMP following exposure to ER stress involves NF-κB activation leading to CCAAT/enhancer-binding protein α (C/EBPα) activation via MAP kinase-mediated phosphorylation. Furthermore, both increased CAMP secretion and its proteolytic processing to LL-37 are required for antimicrobial activities occur following ER stress. In addition, topical thapsigargin also increases production of the murine homologue of CAMP in mouse epidermis. Finally and paradoxically, ER stress instead suppresses the 1,25(OH)(2) vitamin D(3)-induced activation of VDR, but blockade of VDR activity does not alter ER stress-induced CAMP up-regulation. Hence, ER stress increases CAMP expression via NF-κB-C/EBPα activation, independent of VDR, illuminating a novel VDR-independent role for ER stress in stimulating innate immunity.

A topical Chinese herbal mixture improves epidermal permeability barrier function in normal murine skin

Chinese herbal medicine (CHM) has been shown to have beneficial effects for both skin disorders with barrier abnormality and as skin care ingredients. Yet, how CHM exerts their benefits is unclear. As most, if not all, inflammatory dermatoses are accompanied by abnormal permeability barrier function, we assessed the effects of topical CHM extracts on epidermal permeability barrier function and their potential mechanisms. Topical CHM accelerated barrier recovery following acute barrier disruption. Epidermal lipid content and mRNA expression of fatty acid and ceramide synthetic enzymes increased following topical CHM treatment in addition to mRNA levels for the epidermal glucosylceramide transport protein, ATP-binding cassette A12. Likewise, CHM extract increased mRNA expression of antimicrobial peptides both in vivo and in vitro. These results demonstrate that the topical CHM extract enhances epidermal permeability barrier function, suggesting that topical CHM could provide an alternative regimen for the prevention/treatment of inflammatory dermatoses accompanied by barrier abnormalities.

Detection of bacteraemias during non-surgicalroot canal treatment

Some dental procedures initiate a bacteraemia. In certain compromised patients, this bacteraemia may lead to distant site infections, most notably infective endocarditis.

OBJECTIVE

To investigate whether a detectable bacteraemia was produced during non-surgical root canal therapy.

METHODS

Thirty patients receiving non-surgical root canal therapy were studied. Three blood samples were taken per patient: pre-operatively, peri-operatively and post-operatively. In addition, a paper point sample was collected from the root canal. The blood samples were cultured by pour plate and blood bottle methods. The isolated organisms were identified by standard techniques. Blood samples were analysed for the presence of bacterial DNA by the polymerase chain reaction (PCR). In two cases where the same species of organism was identified in the root canal and the bloodstream, the isolates were typed by pulsed field gel electrophoresis (PFGE).

RESULTS

By conventional culturing, a detectable bacteraemia was present in 9 (30%) of the 30 patients who had no positive pre-operative control blood sample. In 7 (23.3%) patients, the same species of organism was identified in both the bloodstream and in the paper point sample from the root canal system. Overall, PCR gave lower detection rates compared with conventional culture, with 10 of 90 (11%) of the blood samples displaying bacterial DNA. PFGE typing was undertaken for two pairs of culture isolates from blood and paper points; these were found to be genetically identical.

CONCLUSIONS

Non-surgical root canal treatment may invoke a detectable bacteraemia.

Reversal of Delayed Union of Anterior Cervical Fusion Treated with Pulsed Electromagnetic Field Stimulation: Case Report

We present a case report of anterior cervical fusion non-union that was successfully treated with pulsed electromagnetic field (PEMF) stimulation. In this case, a C6-C7 nonunion was identified clinically and radiographically 1 year after surgery. Imaging revealed nonunion with partial resorption of the bone graft compared with imaging studies performed 8 months earlier. The patient wore a PEMF stimulation device for 3 h/d for 10 months. After 3 months of treatment, the patient's symptoms were resolved. X-rays obtained after 15 weeks of stimulation showed improvement in bone fusion, and x-rays obtained at 31 weeks after stimulation showed even bone density around the C7 screws. The patient remained symptom-free 13 months after the termination of PEMF stimulation at last assessment. PEMF stimulation demonstrated its clinical potential in healing established nonunion of anterior cervical spine fusion. Its use is noninvasive and can be considered an alternative to surgical intervention in selected patients.

The effectiveness of various disinfectants used as endodontic intracanal medications: an in vitro study

The purpose of this study was to compare in vitro the suitability of four disinfectants as intracanal medications: calcium hydroxide, chlorhexidine gel, chlorhexidine in the form of a controlled-release delivery system (PerioChip), and the combination of chlorhexidine gel with calcium hydroxide. Saline was used as the control. The disinfectants were tested at three different time periods (3, 8, and 14 days) by using human tooth specimens that had been previously contaminated with Enterococcus faecalis. Calcium hydroxide worked very efficiently in killing E. faecalis in the 3-day group and 8-day group. It was not as effective in the 14-day group. The different chlorhexidine formulations were also found to be effective for all time periods. More specifically, the combination of chlorhexidine gel with calcium hydroxide and the chlorhexidine gel worked slightly better than the PerioChip, but there was no significant difference among the medications.

Taking the Measure of the Wildest Dance on Earth

By exploiting the symmetry of randomness, three mathematicians have revealed the geometric underpinnings of the frenetic random dance called Brownian motion. The methods they used seem likely to apply to other random processes, some as familiar as the flow of water through a filter. The proof was presented at the recent Current Developments in Mathematics 2000 conference sponsored by Harvard University and the Massachusetts Institute of Technology.

Pursestring closure of radial forearm fasciocutaneous donor sites

BACKGROUND

The radial forearm fasciocutaneous free flap has become one of the most common methods of reconstructing defects after head and neck ablative surgery. The fasciocutaneous flap is an excellent replacement for the tissue that has been removed. Unfortunately, donor site morbidity remains a problem. Donor site morbidity is primarily related to poor skin graft take, cosmesis, and neural dysfunction. Decreasing the size of the donor site defect may allow for improved cosmesis with decreased morbidity.

MATERIAL AND METHODS

Prospective evaluation of a pursestring closure of radial forearm fasciocutaneous donor sites over a 16-month period.

RESULTS

Seventy-one radial forearm free flaps were used. Sixty-seven had a pursestring closure of the donor site. After flap elevation the mean size of the defect was 61 cm2 (range, 28-140 cm2). Pursestring closure decreased the mean of the defect to 34 cm2 (range, 10-104 cm2) (P <.0001). Defect size was decreased by a mean of 44.5% (range, 24.5%-66.7%) (P <.0001).

COMPLICATIONS

The rate of skin graft loss (>25%) (9% of patients) was less than that reported in the literature. No patient required a second surgical procedure. Neural morbidity was equal in both groups. Cosmesis was much improved.

CONCLUSIONS

Pursestring closure allowed for a significantly decreased donor defect, associated with better cosmesis and less skin graft loss.

Microbial factors and gingival crevicular fluid aspartate aminotransferase levels. A cross-sectional study

The aim of this cross-sectional study was to investigate the clinical application of chairside tests for gingival crevicular fluid (GCF) aspartate aminotransferase (AST) levels and plaque BANA hydrolysis activity with the presence of the periodontal pathogens Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans. The study comprised 100 periodontitis sites (pocket depths > or =4 mm, GI=3) from 10 patients with chronic adult periodontitis and 100 control sites (pocket depths <4 mm, GI<3) from 10 periodontally healthy patients comprising 55 healthy sites (pocket depths <4 mm, GI=0) and 45 gingivitis sites (pocket depths <4 mm, GI=1 or 2). The values for both BANA hydrolysis and AST levels were significantly higher in samples from periodontitis compared with gingivitis and healthy sites (p<0.001). A. actinomycetemcomitans was identified in 45% and P. gingivalis in 17% of periodontitis sites but neither pathogen was recovered from control sites and there was no significant correlation with the clinical parameters measured. There was no significant relationship between the presence of P. gingivalis and/or A. actinomycetemcomitans with BANA hydrolysis or AST levels. A significant correlation (p=0.0017) was observed between BANA hydrolysis and pocket depth and between AST hydrolysis and the GI (p=0.01). This study failed to demonstrate a positive association between chairside analysis of GCF metabolites for AST levels and/or BANA hydrolysis with P. gingivalis and A. actinomycetemcomitans. However, the GCF metabolites had a significant correlation with periodontally diseased sites in patients with chronic adult periodontitis and may help confirm clinical observations.

An assessment of microbial coronal leakage in teeth root filled with gutta-percha and three different sealers

The aim of this in vitro study was to determine the effect of three different root canal sealers on the bacterial penetration of obturated root canals. Eighty extracted human teeth with straight, single root canals were prepared using the modified double-flared technique with balanced force under copious irrigation until the master apical file was size 40. The teeth were divided randomly into experimental groups (60 teeth) and control groups (20 teeth). Twenty experimental teeth each were obturated by lateral condensation of cold gutta-percha with AH26, Apexit or Tubliseal EWT sealer. In the control groups, 10 teeth were obturated using the same technique with AH26, Apexit or Tubliseal EWT sealer. These teeth were completely sealed to serve as negative controls. The remaining 10 teeth were not obturated and served as positive controls. The root surface of each tooth, except the apical 2 mm, was sealed with nail varnish. The coronal part of each root canal was sealed with the cut end of a polypropylene tube and placed in a glass bottle containing sterile Todd-Hewitt Broth (THB). Aliquots of 0.5 ml of THB were injected into the polypropylene tube and the model system was centrifuged at 168 g. An innoculum of Streptococcus sanguis in THB was added to the tube at 5-day intervals and daily observations were made for bacterial growth in the apical reservoir for 90 days. All positive control teeth showed bacterial penetration within 24 h and negative control teeth remained uncontaminated throughout the test period. Leakage through the experimental teeth varied from 7 to 86 days. There was no statistically significant difference (P > 0.05) in leakage of the obturated canals between AH26, Apexit and Tubliseal EWT sealers.

Comparison of polymerase chain reaction and culture methods for detection of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in subgingival plaque samples

In this study, the major periodontal pathogens Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were detected in subgingival plaque samples from patients with periodontal disease by polymerase chain reaction (PCR) and conventional culture methods. 170 plaque samples from 43 patients were analysed; A. actinomycetemcomitans and P. gingivalis were each detected in 40 (24%) of samples by PCR, whereas conventional culture methods detected A. actinomycetemcomitans and P. gingivalis in 25 (15%) and 18 (11%) of samples, respectively. The proportion of patients carrying A. actinomycetemcomitans in at least 1 sampled periodontal site was 17/43 (40%) by PCR and 13/43 (30%) by culture; for P. gingivalis this was 12/43 (28%) by PCR and 9/43 (21%) by culture. Only 5 samples, from 3 patients, harboured both A. actinomycetemcomitans and P. gingivalis. It is concluded that PCR is more accurate than conventional culture methods for identification of these periodontal pathogens in subgingival plaque samples and has a higher frequency of detection.

Monitoring the axilla in patients with silicone gel implants

Migration of silicone beyond the breast implant capsule may occur as a result of silicone bleed, leak, or rupture, and it may indicate failure of implant envelope integrity. We report a series of 23 patients with silicone implants who had axillary lymph node biopsies for palpable masses. Group 1 (n = 15) had biopsies performed an average of 6 years following aesthetic augmentation, and Group 2 (n = 8) had biopsies performed an average of 5 years after mastectomy reconstruction. All biopsies demonstrated foreign body reaction consistent with silicone migration. Five patients in Group 1 and two in Group 2 also had breast cancer detected by the axillary biopsy. Evaluation of the axilla utilized a combination of one or more techniques, including mammography, ultrasonography, magnetic resonance imaging, and fine-needle aspiration. We conclude that (1) routine evaluation of the axilla is mandatory in all patients with silicone breast implants; (2) an algorithmic approach in diagnosing axillary masses may be helpful, especially in augmentation patients; and (3) axillary masses detected by clinical examination or other means must be biopsied, even in the face of negative screening studies, because breast cancer may be coincidental with a silicone granuloma.

Isolation and preliminary characterization of the 14- to 18-kilodalton Candida albicans antigen as a phospholipomannan containing beta-1,2-linked oligomannosides

Western blot (immunoblot) analysis of Candida albicans germ tube extracts has demonstrated the probable presence of beta-1,2-linked oligomannosides acting as epitopes distributed over a 14- to 18-kDa antigen unreactive to concanavalin A. These conclusions about the existence of these non-mannan-associated oligomannoside species were reinforced in the present study by the demonstration of reactivity of factor serum 5 (Iatron Laboratories) with the same antigen. A monoclonal antibody which reacted in an enzyme immunoassay with beta-1,2-linked oligomannosides converted into neoglycolipids and in Western blotting with the 14- to 18-kDa antigen from yeast and germ tubes, through metaperiodate-sensitive epitopes, was used for further characterization of the molecule. Reducing agents and strong protease digestion, which have deleterious effects on C. albicans proteins and mannoproteins, affected neither the antigenicity nor the relative molecular weight of the molecule. Western blots performed after migration of protease-treated extracts in polyacrylamide gels without sodium dodecyl sulfate (SDS) showed that the 14- to 18-kDa antigen could be negatively charged, whereas metabolic radiolabeling demonstrated that these charges could originate, at least in part, from the presence of phosphorus within the molecule. Chloroform-methanol-water extraction of protease-resistant material led to purification of the 14- to 18-kDa antigen, as determined by SDS-polyacrylamide gel electrophoresis and Western blotting. Metabolic radiolabeling with mannose confirmed the presence of these sugar residues within the purified 14- to 18-kDa antigen (despite its nonreactivity to concanavalin A), whereas radiolabeling with palmitic acid demonstrated its lipopolysaccharidic nature. Together, these results led to the conclusion that the 14- to 18-kDa antigen is a phospholipomannan.

Factors determining the passage of drugs from blood into saliva

1. Following single oral dosing of ampicillin, cephalexin, tetracycline, erythromycin estolate, clindamycin and rifampicin to six normal volunteers, antibacterial activity was measured at 1, 3 and 6 h in serum, gingival fluid and minor gland saliva from all subjects and in parotid and submandiabular saliva from three. 2. pH values of all gingival fluid and saliva specimens were noted. 3. Partition coefficients between n-octanol and water were measured for erythromycin, clindamycin and rifampicin. Published data were used for ampicillin, cephalexin and tetracycline. 4. All antibiotics, but particularly rifampicin, were detected in gingival fluid. Only rifampicin and to a lesser degree, clindamycin were present in the other salivary constituents. 5. In studies of secretion of drugs in saliva, both the physico-chemical characteristics of the drugs and the physiological differences between individual salivary components should be considered. 6. Parotid saliva samples are likely to be of greatest value.