Qualitative study exploring general dental practitioners' views of MIH and its management in the UK and Australia.

BACKGROUND: Molar-incisor hypomineralisation (MIH) is a prevalent condition, and how it is managed varies greatly between professional groups. AIM: To explore, and compare, the UK and Australian general dental practitioners' management of MIH in children. DESIGN: Face-to-face (remote) semistructured interviews were undertaken, using country-specific topic guides. Participants were purposively sampled and recruited through national conferences and research networks (eviDent Foundation and Northern Dental Practice Based Research Network). Interviews (from each country) were audio-recorded, transcribed verbatim and independently analysed using thematic analysis. RESULTS: Two major themes arose from the UK interviews: (i) decision-making complexities and understanding of treatment options and (ii) need for specialist input. The main Australian themes were (i) multidisciplinary approach to management supporting decision-making complexities and (ii) economic implications for care. Several difficulties, such as financial implications, multidisciplinary care and clinical decision-making, were identified as barriers to effectively managing MIH by GDPs in primary care. CONCLUSION: There are similarities and differences in the knowledge and management of MIH amongst UK and Australian nonspecialists. The different healthcare systems played a significant role in shaping how GDPs manage MIH with barriers relating to affordability, multidisciplinary care and clinical decision-making.

Fit for Purpose? The Suitability of Oral Health Outcome Measures to Inform Policy.

KNOWLEDGE TRANSFER STATEMENT: Oral health research and program evaluation should consider alternative outcome measures for population oral health other than the DMFT index.

Navigating the Dual Role of Clinician-Researcher in Qualitative Dental Research.

In qualitative research, the researcher is the research instrument. Therefore, a qualitative researcher who is also a clinician must consider how their dual position informs participant consent, data collection, and analysis. This reflexivity is essential in research design to effectively respond to ethical questions around role, authenticity, trust, and transparency around disclosing their clinician status to participants.

Best clinical practice guidance for clinicians dealing with children presenting with molar-incisor-hypomineralisation (MIH): an updated European Academy of Paediatric Dentistry policy document.

AIM: To update the existing European Academy of Paediatric Dentistry (EAPD) 2010 policy document on the 'Best Clinical Practice guidance for clinicians dealing with children presenting with Molar-Incisor-Hypomineralisation (MIH).' METHODS: Experts, assigned the EAPD, worked on two different topics: (A) Aetiological factors involved in MIH, and (B) Treatment options for the clinical management of MIH. The group prepared two detailed systematic reviews of the existing literature relevant to the topics and following a consensus process produced the updated EAPD policy document on the 'Best Clinical Practice guidance for clinicians dealing with children presenting with molar-incisor-hypomineralisation (MIH).' The GRADE system was used to assess the quality of evidence regarding aetiology and treatment which was judged as HIGH, MODERATE, LOW or VERY LOW, while the GRADE criteria were used to indicate the strength of recommendation regarding treatment options as STRONG or WEAK/CONDITIONAL. RESULTS: (A) Regarding aetiology, it is confirmed that MIH has a multifactorial aetiology with the duration, strength and timing of occurrence of the aetiological factors being responsible for the variable clinical characteristics of the defect. Perinatal hypoxia, prematurity and other hypoxia related perinatal problems, including caesarean section, appear to increase the risk of having MIH, while certain infant and childhood illnesses are also linked with MIH. In addition, genetic predisposition and the role of epigenetic influences are becoming clearer following twin studies and genome and single-nucleotide polymorphisms analyses in patients and families. Missing genetic information might be the final key to truly understand MIH aetiology. (B) Regarding treatment options, composite restorations, preformed metal crowns and laboratory indirect restorations provide high success rates for the posterior teeth in appropriate cases, while scheduled extractions provide an established alternative option in severe cases. There is great need for further clinical and laboratory studies evaluating new materials and non-invasive/micro-invasive techniques for anterior teeth, especially when aesthetic and oral health related quality of life (OHRQoL) issues are concerned. CONCLUSIONS: MIH has been studied more extensively in the last decade. Its aetiology follows the multifactorial model, involving systemic medical and genetic factors. Further focused laboratory research and prospective clinical studies are needed to elucidate any additional factors and refine the model. Successful preventive and treatment options have been studied and established. The appropriate choice depends on the severity of the defects and the age of the patient. EAPD encourages the use of all available treatment options, whilst in severe cases, scheduled extractions should be considered.

An update of treatment modalities in children and adolescents with teeth affected by molar incisor hypomineralisation (MIH): a systematic review.

PURPOSE: To systematically review the treatment modalities for molar-incisor hypomineralisation for children under the age of 18 years. The research question was, 'What are the treatment options for teeth in children affected by molar incisor hypomineralisation?' METHODS: An electronic search of the following electronic databases was completed MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, LILACS, Google Scholar and Open Grey identifying studies from 1980 to 2020. The PRISMA guidelines were followed. The studies were screened, data extracted and calibration was completed by two independent reviewers. RESULTS: Of 6220 potential articles, 34 studies were included. Twenty studies investigated management of molars with fissure sealants, glass ionomer cement, polyacid modified resin composite, composite resin, amalgam, preformed metal crowns, laboratory-manufactured crowns and extractions. In four articles management of incisors with microabrasion, resin-infiltration and a combination of approaches was reported. Eight studies looked at strategies to mineralise MIH-affected teeth and/or reduce hypersensitivity. Two studies investigated patient-centred outcomes following treatment. Due to the heterogeneity between the studies, meta-analysis was not performed. CONCLUSION: The use of resin-based fissure sealants, preformed metal crowns, direct composite resin restorations and laboratory-made restorations can be recommended for MIH-affected molars. There is insufficient evidence to support specific approaches for the management of affected incisors. Products containing CPP-ACP may be beneficial for MIH-affected teeth.

An update of the aetiological factors involved in molar incisor hypomineralisation (MIH): a systematic review and meta-analysis.

PURPOSE: To systematically review the aetiological factors associated with molar incisor hypomineralisation (MIH). To this day, the aetiology remains unknown. Determining risk factors would allow risk assessment and enhance early diagnosis of MIH in young patients. The aim was to assess, evaluate and summarise the relationship between MIH and reported aetiological hypotheses. METHODS: Electronic database searches of MEDLINE, EMBASE, EBSCO, LILACS and Cochrane Library were conducted. Authors conformed to PRISMA guidelines. Studies were screened, data extracted, assessment of risk of bias and calibration was completed by two independent reviewers. Meta-analyses with heterogeneity calculations were performed. RESULTS: Of the potential 8949 studies, 64 studies were included in the qualitative analysis whilst 45 were included in the quantitative analysis. Prenatal factors: results are inconclusive as only unspecified maternal illnesses appear to be linked to MIH. Perinatal factors: prematurity (OR 1.45; 95% CI 1.24-1.70; p = 0.0002) and caesarean delivery (OR 1.45; 95% CI 1.09, 1.93; p < 0.00001) are associated with an increased risk of developing MIH. Birth complications are also highlighted. These three factors can lead to hypoxia, and children with perinatal hypoxia are more likely to develop MIH (OR 2.76; 95% CI 2.09-3.64; p < 0.0001). Postnatal factors: measles, urinary tract infection, otitis media, gastric disorders, bronchitis, kidney diseases, pneumonia and asthma are associated with MIH. Fever and antibiotic use, which may be considered as consequences of childhood illnesses, are also associated with MIH. Genetic factors: an increasing number of studies highlight the genetic and epigenetic influences in the development of MIH. CONCLUSION: Several systemic and genetic and/or epigenetic factors acting synergistically or additively are associated with MIH, revealing a multifactorial aetiology model. Peri- and postnatal aetiological factors are more likely to increase the odds of causing MIH than prenatal factors.

The interaction and interference of preformed metal crowns on magnetic resonance imaging: a scoping review with a systematic methodology.

PURPOSE: Preformed metal crowns are widely used to restore primary and permanent teeth. Children may require magnetic resonance imaging (MRI) for diagnosis and monitoring of diseases in the head and neck region. Metallic objects, in the field of view, may compromise the diagnostic value of an MRI. The impact on the diagnostic quality of an MRI in children who have had preformed metal crowns placed has not been assessed. The aim of this systematic review was to evaluate the impact that PFMCs have on MRI imaging quality and thus the overall diagnostic value. METHODS: Electronic searches of the following databases were completed: MEDLINE, EMBASE, Cochrane Library, Web of Science and Open Grey. Primary in vivo studies on children who had at least one preformed metal crown placed and required an MRI investigation were to be included. PRISMA guidelines were followed and screening/data extraction was carried out by two independent calibrated reviewers. RESULTS: A total of 7665 articles were identified. After removing duplicates, 7062 were identified for title and abstract screening. Thirty-four articles underwent full-text review, of which none met the inclusion criteria. Most common reasons for exclusion were not placing preformed metal crowns (n = 16) or in vitro studies (n = 12). CONCLUSION: No in vivo studies were identified to establish the hypothetical impact preformed metal crowns would have on the diagnostic quality of an MRI in the head and neck region. Decision making needs to be guided on a case by case basis. Further high-quality clinical studies are required.

Microbial challenge-testing of treatment processes for quantifying stormwater recycling risks and management.

Pathogenic microorganisms have been identified as the main human health risks associated with the reuse of treated urban stormwater (runoff from paved and unpaved urban areas). As part of the Smart Water initiative (Victorian Government, Australia), a collaborative evaluation of three existing integrated stormwater recycling systems, and the risks involved in non-potable reuse of treated urban stormwater is being undertaken. Three stormwater recycling systems were selected at urban locations to provide a range of barriers including biofiltration, storage tanks, UV disinfection, a constructed wetland, and retention ponds. Recycled water from each of the systems is used for open space irrigation. In order to adequately undertake exposure assessments, it was necessary to quantify the efficacy of key barriers in each exposure pathway. Given that none of the selected treatment systems had previously been evaluated for their treatment efficiency, experimental work was carried out comprising dry and wet weather monitoring of each system (for a period of 12 months), as well as challenging the barriers with model microbes (for viruses, bacteria and parasitic protozoa) to provide input data for use in Quantitative Microbial Risk Assessment.

The multi-faceted dynamics of HIV-1 transmission in Northern Alberta: A combined analysis of virus genetic and public health data.

Molecular epidemiology has become a key tool for tracking infectious disease epidemics. Here, the spread of the most prevalent HIV-1 subtypes in Northern Alberta, Canada, was characterized with a Bayesian phylogenetic approach using 1146 HIV-1 pol sequences collected between 2007 and 2013 for routine clinical management purposes. Available patient metadata were qualitatively interpreted and correlated with onwards transmission using Fisher exact tests and logistic regression. Most infections were from subtypes A (n=36), B (n=815) and C (n=211). Africa is the dominant origin location for subtypes A and C while the subtype B epidemic was seeded from the USA and Middle America and, from the early 1990s onwards, mostly by interprovincial spread. Subtypes A (77.8%) and C (74.0%) were usually heterosexually transmitted and circulate predominantly among Blacks (61.1% and 85% respectively). Subtype B was mostly found among Caucasians (48.6%) and First Nations (36.8%), and its modes of transmission were stratified by ethnic origin. Compared to subtypes A (5.6%) and C (3.8-10.0%), a larger portion of subtype B patients were found within putative provincial transmission networks (20.3-29.5%), and this almost doubled when focusing on nationwide transmission clusters (37.9-57.5%). No clear association between cluster membership and particular patient characteristics was found. This study reveals complex and multi-faceted transmission dynamics of the HIV-1 epidemic in this otherwise low HIV prevalence population in Northern Alberta, Canada. These findings can aid public health planning.

Rat microglial interleukin-3.

Interleukin-3 (IL-3, multi-CSF) is a growth factor for a variety of hematopoietic progenitor cells. Recently, microglial cells, the resident macrophages of the central nervous system (CNS) have been shown to proliferate in the presence of IL-3 both in vivo and in culture. Data obtained from cultured astrocytes gave rise to the hypothesis that astrocytes synthesize the microglial growth factor. This is the first report identifying rat microglial cells themselves as a source of IL-3. Culture media conditioned by isolated microglia enhanced microglial proliferation above fresh media controls. IL-3 polypeptide was detected in both conditioned media (CM) and in microglial cells by Western blotting and immunoprecipitation. Furthermore, anti-IL-3 antibodies were able to inhibit microglial proliferation induced by conditioned media. mRNAIL-3 was present in single microglial cells as revealed by in situ hybridization. Total RNA prepared from purified microglia yielded a single PCR amplification product. Identity of the PCR product was confirmed by Southern blot hybridization using a cDNAIL-3 probe and by DNA sequencing. Expression of mRNAIL-3 was observed in both absence and presence of lipopolysaccharide, a bacterial endotoxin, that commonly induces expression of inflammatory cytokines and inhibits microglial proliferation. It is concluded that IL-3 expression in ensuring the recruitment of enhanced numbers of immunocompetent cells at sites of lesion. In the light of weak immune reactions in the brain, it is hypothesized that the expression of a characteristic T cell feature in monocyte-derived microglia may be a partial compensation of T cell functions in brain lesions.

Bacteremic nosocomial pneumonia. A 7-year experience in one institution.

STUDY OBJECT: To describe the epidemiology, microbiology, and outcome of nosocomial pneumonia with secondary bloodstream infection. DESIGN: Prospective cohort study. SETTING: Tertiary care Canadian teaching hospital. PATIENTS: Inpatients. MEASUREMENT: All inpatient blood cultures were concurrently monitored over an 89 month period. Following chart review, patients experiencing nosocomial bloodstream infection due to pneumonia were identified. A standardized definition of pneumonia was used. RESULTS: One hundred forty-nine episodes occurred in 145 patients, 0.66/1,000 hospital admissions, 8.4% of all nosocomial bloodstream infections. No change in rate occurred in the study period. Fifty-four percent of episodes developed in one of seven ICUs. Staphylococcus aureus was the most frequently identified etiologic organism (27%). The ICU and non-ICU cases did not differ in etiology. No organism became more prevalent during the study period. Twenty percent of patients died within 1 week of first positive culture; episodes associated with Pseudomonas species had a much higher mortality rate (45%) than other infections (14%) (p = 0.002). The ICU and non-ICU infections had a similar mortality rate. CONCLUSION: Pneumonia is an important cause of nosocomial bloodstream infection, but it is not increasing in frequency or changing in etiology in our institution. The ICUs are a major contributor to this problem but have the same case short-term mortality rate and microbial etiology as non-ICU cases. Cases associated with Pseudomonas have a much higher mortality rate.

Central venous catheters as a source of hemodialysis-related bacteremia.

OBJECTIVE: To describe investigations into an increase in hemodialysis-related bacteremia that occurred in our hospital in the first 6 months of 1996. SETTING: Hemodialysis unit in a tertiary-care medical center. METHODS: Prospective surveillance for hemodialysis bacteremia has been performed for several years. Cases that occurred in 1995 were compared to cases in the first 6 months of 1996. Unit data on dialysis runs and method of dialysis access were used to calculate rates. Nested polymerase chain reaction (PCR) was used to type 18 Staphylococcus aureus isolates from 1996. A case-control study comparing 80 randomly selected hemodialysis patients from 1995 and 1996 was performed to examine infection risk factors. RESULTS: The hemodialysis bacteremia rate was 1.2 per 1,000 runs in 1995 and 2.8 per 1,000 in the first 6 months of 1996 (P=.0009). The 25 cases in 1995 and 32 in the first half of 1996 were similar in age, gender, means of vascular access, and microbial etiology. Central venous catheter (CVC) access accounted for >90% of cases in both time periods. S aureus was the most common microbial etiology (53% of the 1996 cases). PCR typing of S aureus isolates from 1996 demonstrated five different strains, the most common having six isolates. The use of CVCs as a means of vascular access abruptly increased in the unit in January 1996, from <30% of dialysis runs in 1995 to >40% in 1996 (P<.001), associated with structural changes in healthcare delivery in the region resulting in delays in performing surgical procedures, such as creation of vascular grafts and fistulae. CONCLUSION: A marked increase in hemodialysis bacteremia occurred in 1996, associated with increased reliance on CVCs for vascular access in hemodialysis patients during a period of healthcare restructuring.

Regionalization of infection prevention and control services in a publicly funded health care system.

In 1994 health services in the Edmonton region were consolidated into an integrated network called Capital Health. Infection control professionals in the region met to develop a vision for the future of infection control; the tasks were to prepare a proposal for a regional program, develop indicators for outcome measurements, and standardize guidelines and products. Although regionalization of infection control is a complex process, we have had success with a proactive approach led by infection control professionals.

Bacteremia due to transplantation of contaminated cryopreserved pancreatic islets.

OBJECTIVE: To report two cases of pancreatic islet transplantation-related septicemia, and the results of an investigative protocol to identify potential sources of contamination. DESIGN: Case series. SETTING: University hospital clinical investigational islet transplantation program. RESULTS: The last two of our first seven islet transplantation recipients developed Enterobacter cloacae septicemia within hours of islet infusion. Both had received thawed cryopreserved islet infusions. No source of infection apart from islets could be identified. Pancreas harvesting and islet isolation protocols provided multiple opportunities for contamination. Environmental cultures during a mock islet isolation procedure failed to identify a source of Enterobacter. Previously cryopreserved islet lots were thawed and submitted for culture, 14/47 grew micro-organisms including E. cloacae in four instances. Following revision of protocols for aseptic handling of islets during processing and cryopreservation 55 consecutive pancreata undergoing processing were evaluated; 7 grew micro-organisms on arrival and in 3 cases these persisted through to cryopreservation. CONCLUSION: Two of seven islet transplantation recipients developed septicemia, likely related to infusion of contaminated cryopreserved islets. Using existing technology, for isolating islets from donor pancreata, recipients will remain at risk for this complication. Prevention should entail strict adherence to aseptic technique, and, possibly, use of surveillance microbial cultures during the islet isolation process.

Rhinofacial zygomycosis caused by Conidiobolus coronatus: a case report including in vitro sensitivity to antimycotic agents.

A case of zygomycosis caused by Conidiobolus coronatus, occurring in a 31-year-old priest from the Ivory Coast, is reported. Lesions eventually resolved after 2 1/2 years, during which the patient was variously treated with intravenous amphotericin B and miconazole as well as surgical resection. It is difficult to be certain which, if any, of these treatments contributed to resolution of lesions. A report of in vitro sensitivity data to a variety of antifungal agents is included.

Intensive chemotherapy and radical resections for primary nonseminomatous mediastinal germ cell tumors.

BACKGROUND: Primary nonseminomatous germ cell tumors of the mediastinum (PNSGM), unlike malignancies of gonadal origin, have a poor prognosis. We report a single institutional experience over a 5-year period of PNSGM treated with intensive chemotherapy, followed by radical operation in those who responded to this neoadjuvant regimen. METHODS: From 1993 to 1998, 20 patients were referred for the management of PNSGM. All were male, with a median age of 30.5 years (range 18 to 48). Eighteen of 20 (90%) presented with symptoms. Most tumors were large, with a median diameter of 10 cm (range 3 to 20 cm). Thirteen patients (65%) had metastatic disease at the time of presentation. Eleven patients had received no prior treatment (initial group) and 9 were referred for salvage therapy after progression of their tumors, following treatment at other facilities (salvage group). All had elevated serum tumor markers (beta hCG and alpha-fetoprotein). Preoperative chemotherapy included alternating cycles of combinations of 3 or more drugs, including cisplatin, bleomycin, etoposide, vincristine, methotrexate, actinomycin, cyclophosphamide, and doxorubicin. An average of 10 cycles of chemotherapy was given to each patient in the initial group, and six to those in the salvage group. Five patients (25%) developed transient renal insufficiency, and 35% developed pulmonary infiltrates related to bleomycin. There were 3 chemotherapy related deaths. RESULTS: After chemotherapy, 11 patients underwent operation, with 10 complete resections of the residual mediastinal tumors. There were no perioperative deaths. The 2-year survival in the initial group is 72%, and 42% for the salvage group. CONCLUSIONS: An aggressive, multidisciplinary approach of alternating cycles of chemotherapy, followed by complete surgical resection of all remaining disease in patients whose markers normalize, can be associated with prolonged survival in patients with PNSGM.

Computer simulation of the probability of detecting low volume carcinoma of the prostate with six random systematic core biopsies.

OBJECTIVES: Six random systematic core biopsies (SRSCB) of the prostate (biopsies from apex, middle, and base of each lobe) have been commonly used in detection of prostate carcinoma. The objective of this study was to verify the validity of the SRSCB technique in detecting cancer in prostates with low-volume tumor (less than 6 cc). METHODS: We developed a computer model of the prostate to simulate the SRSCB technique. The data for development of this model were taken from 159 radical prostatectomy specimens in which 112 patients had tumor volumes measured and in which 91 prostates had tumors with volumes less than 6 cc (by whole-mount sectioning). RESULTS: The simulation shows that only 20.3% of the simulated prostates, with total aggregate tumor volume between 0.034 and 5.1 cc, had a tumor distribution for which the SRSCB technique has a 95% probability of detecting the tumor. In fact, 26.8% had a tumor distribution that was completely disjointed from the six recommended biopsy regions. To compare these results with other possible occurrence, various biases for the angle of biopsy and the distribution of cancer foci were incorporated into the model. Study results should be viewed with the understanding that any simulated model has its limitations. In our simulated model, the shape of the simulated tumor foci (spherical) does not represent all the possible shapes of prostate cancer. However, these results indicate that detection of cancer with biopsies taken from the apex, middle, and base of each lobe of a prostate with tumor volumes of less than 6 cc may not be as effective as it is in prostates with larger tumor volumes or patients with an abnormal digital rectal examination. The study of bias models suggests that the distributional pattern of cancerous foci can have a significant impact on the effectiveness of a given biopsy strategy. CONCLUSIONS: We concluded that future attempts to improve systematic biopsy strategies for detection of low-volume cancer should include biomechanical characteristics of prostate cancer, including gland volume and tumor distribution. Driven by the conclusions from this idealized model, we have developed a three-dimensional model of the prostate gland from its whole-mount histologic maps. It is anticipated that this continuing investigation will lead to realistic guidelines for improving biopsy techniques.

A 3-D reconstruction algorithm for interpolation and extrapolation of planar cross sectional data.

A three dimensional (3-D) reconstruction algorithm utilizing both linear interpolation and linear extrapolation was developed for the study of human prostatic cancer. The algorithm was validated by comparing the volumes and shapes of original to reconstructed objects. Synthetic objects of known geometry and wax models with shapes characteristic of prostatic carcinomas were assessed with standard planimetry and by the digital interpolation-extrapolation method. Volume and multifocality measurements obtained by reconstructing excised prostate glands using histologic maps obtained from whole-mount sections were tested. The new algorithm provided greater accuracy in determining tumor volumes than conventional methods. This model provides a basis for mathematical analysis of prostate cancer lesions.

Predominance of staphylococcal organisms in infections occurring in a burns intensive care unit.

To assess the sites, incidence, and bacteriology of infections in intensive care burn patients, a prospective survey of all admissions to a tertiary care institution burn unit was carried out over a 12-month period. One hundred and sixteen patients were admitted, 106 with a diagnosis of thermal burns. Forty patients developed 90 infections. Only two deaths occurred, one in a patient with sepsis. In order of frequency, pneumonia, burn infection, UTI and primary bacteraemia were most common. Staphylococcal species accounted for a majority of infections at all body sites except UTI (47 per cent of all infections, including 11 of 14 bacteraemic infections). Staph. aureus sepsis was more common in those carrying the organism on admission. Strain typing of paired admission and subsequent clinical isolates in 19 patients with Staph. aureus sepsis indicated that eight (42 per cent) became infected with a strain they carried on admission. Further reductions in septic complications of burns in our center would be best directed at staphylococcal species, particularly Staph. aureus. Both eradication of carrier state, and prevention of acquisition of Staph. aureus strains could be explored.