Publications by authors named "Larjava H"

Article Synopsis
  • Voiding cystourethrography (VCUG) is widely used to diagnose vesicoureteral reflux (VUR) but has high radiation exposure; direct radionuclide cystography (DRC) was created to address this issue.
  • A study involving 156 children assessed the effectiveness of DRC compared to VCUG and found that DRC identified VUR in 35.3% of patients, while VCUG found it in 61.5%.
  • Despite DRC being intended as a lower-radiation option, it actually resulted in higher radiation exposure and additional costs, raising questions about its use in screening for VUR.
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Article Synopsis
  • The study assesses how effective patient shielding is at reducing fetal radiation exposure during computed tomography pulmonary angiography, using a phantom model with a prosthetic pregnancy belly.
  • Different CT scanners were tested, and results showed that shielding can significantly reduce fetal absorbed radiation dose with some scanners, decreasing exposure by 3.9% to 39.4%.
  • However, in some cases, like with the GE Optima scanner, the shielding actually increased fetal dose by 100%, highlighting that the impact varies based on the specific scanner used.
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Objective: Calcified carotid artery atheroma (CCAA) can be identified incidentally on standard dental panoramic radiographs (DPRs). We sought to (1) determine the prevalence of CCAA on DPRs in a general dental population and (2) establish the proportion of patients in whom this would represent a new statin-indicated condition.

Methods: We identified patients aged ≥30 with DPRs from 2019 to 2021 from the University of British Columbia Dental Clinic.

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Objective: To investigate how delayed blood centrifugation affects the composition of the resultant platelet rich fibrin membrane (PRF, a concentrated growth factor preparation) and its biological effects towards gingival fibroblasts.

Materials And Methods: Blood samples were collected from 18 healthy individuals and centrifuged immediately (T-0), or after a 1-6-minute delay (T-1-6, respectively), to generate PRF. Each PRF membrane was weighed.

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Objectives: The aim of the patient out-of-plane shield is to reduce the patient radiation dose. Its effect on tube current modulation was evaluated with the out-of-plane shield visible in the localizer but absent in the scan range in chest CT with different CT scanners.

Methods: An anthropomorphic phantom was scanned with six different CT scanners from three different vendors.

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Periodontal disease (PD) can be prevented by local or systemic application of epidermal growth factor receptor inhibitors (EGFRIs) that stabilize αvβ6 integrin levels in the periodontal tissue, leading to an increase in the expression of anti-inflammatory cytokines, such as transforming growth factor-β1. Systemic EGFRIs have side effects and, therefore, local treatment of PD applied into the periodontal pockets would be preferrable. Thus, we have developed slow-release three-layered microparticles of gefitinib, a commercially available EGFRI.

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Objectives: Peri-implantitis (PI) is caused by bacteria in the peri-implant space but the consensus on microbial profile is still lacking. Current microbial sampling of PI lesions has largely focused on analyzing bacterial species that have been shed from the implant surface and captured in the pocket fluid. The purpose of the present study was to investigate the morphotypes of bacteria in biofilm covering the implant threads and explore whether certain morphotypes were associated with PI.

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Standard cell cultures are performed in aqueous media with a low macromolecule concentration compared to tissue microenvironment. In macromolecular crowding (MMC) experiments, synthetic polymeric crowders are added into cell culture media to better mimic macromolecule concentrations found in vivo. However, their effect on cultured cells is incompletely understood and appears context-dependent.

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Soft tissue calcification occurs in many parts of the body, including the gingival tissue. Epithelial cell-derived MVs can control many functions in fibroblasts but their role in regulating mineralization has not been explored. We hypothesized that microvesicles (MVs) derived from gingival epithelial cells could regulate calcification of gingival fibroblast cultures in osteogenic environment.

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In periodontal disease (PD), bacterial biofilms suppress β6 integrin expression transforming growth factor-β1 signaling, resulting in gingival inflammation and bone loss. β6 integrin-null ( ) mice develop spontaneous PD. The aim of this study was to unravel potential differences in oral microbiome in wild-type (WT) and FVB mice.

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Objectives: Decontamination of biofilm-colonized rough implant surfaces remains challenging. We investigated the effect of airflow with glycine powder (AFG) on decontamination of mature oral multispecies biofilm from a sandblasted and acid etched (SLA) titanium surface.

Materials And Methods: Subgingival dental plaque was cultured on SLA disks anaerobically for 21 days.

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Background: Decontamination of biofilm-infected rough implant surfaces is challenging. Platelet rich blood products have been shown to have anti-microbial properties against periodontal pathogens. Our aim was to investigate the effect of a potential biological implant surface disinfectant, leukocyte- and platelet-rich fibrin (L-PRF), on a mature oral multispecies biofilm on a rough titanium surface.

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Background: Leucocyte- and platelet-rich fibrin (L-PRF) is a blood-derived biomaterial rich in leucocytes and platelets embedded in a high-density fibrin network that can be compressed into a membrane and used in surgical applications to stimulate tissue regeneration and wound healing, especially in oral cavity. This study aimed to determine the combined effects of the growth factors and cells present in L-PRF on fibroblasts that directly face the L-PRF membranes placed during surgical procedures.

Methods: The effect of L-PRF from six donors on the expression of 84 key wound healing genes in normal human gingival fibroblasts was tested by RT-qPCR.

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In contemporary interventional cardiology, for typical elderly patients, the most severe radiation-related harm to patients can be considered to come from skin exposures. In this paper, maximum local skin doses in cardiological procedures are explored with Gafchromic film dosimetry. Film and reader calibrations and reading were performed at the Secondary Standards Dosimetry Laboratory of the Radiation and Nuclear Safety Authority (STUK), and data were gathered from seven hospitals in Finland.

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This study aimed to determine the exposure to radiation delivered to the patient during routine intraoperative cholangiography (IOC) in cholecystectomy and examine the factors affecting radiation dose and fluoroscopy time (FT). From January 2016 to December 2017, 598 IOC examinations were performed. This study included 324 intraoperative cholangiographies performed with c-arm equipment not exceeding 10 years of age.

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In periodontal disease (PD), bacterial biofilms cause gingival inflammation, leading to bone loss. In healthy individuals, αvβ6 integrin in junctional epithelium maintains anti-inflammatory transforming growth factor-β1 (TGF-β1) signaling, whereas its expression is lost in individuals with PD. Bacterial biofilms suppress β6 integrin expression in cultured gingival epithelial cells (GECs) by attenuating TGF-β1 signaling, leading to an enhanced pro-inflammatory response.

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The amount of interventional procedures such as percutaneous coronary intervention (PCI), transcatheter aortic valve implantation (TAVI), pacemaker implantation (PI) and ablations has increased within the previous decade. Simultaneously, novel fluoroscopy mainframes enable lower radiation doses for patients and operators. Therefore, there is a need to update the existing diagnostic reference levels (DRLs) and propose new ones for common or recently introduced procedures.

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Epithelial αvβ6 integrin participates in immune surveillance in many organs, including the gastrointestinal track. Expression of αvβ6 integrin is reduced in the junctional epithelium of the gingiva in periodontal diseases, and mutations in the ITGB6 gene are associated with these diseases in humans and mice. The aim of this study was to unravel potential differences in the inflammatory responses in the periodontal tissues of FVB wild-type (WT) and β6 integrin-null (Itgb6) mice, using a ligature-induced periodontitis model and assessing inflammation, bone loss and expression profiles of 34 genes associated with periodontal disease.

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Aims: Abundance of connexin 43 (Cx43), a transmembrane protein that forms hemichannels (HCs) and gap junctions (GJs), is dynamically regulated in human gingival fibroblasts (GFBLs) during wound healing. This may be important for fast and scarless gingival wound healing as Cx43 is involved in key cell functions important during this process. Our aim was to uncover the factors that regulate Cx43 expression and abundance in GFBLs.

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Integrins are cell surface receptors that traditionally mediate cell-to-extracellular matrix and cell-to-cell adhesion. They can, however, also bind a large repertoire of other molecules. Integrin αvβ6 is exclusively expressed in epithelial cells where it can, for example, serve as a fibronectin receptor.

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Fibroblasts are the most abundant connective tissue cells and play an important role in wound healing. It is possible that faster and scarless wound healing in oral mucosal gingiva relative to skin may relate to the distinct phenotype of the fibroblasts residing in these tissues. Connexin 43 (Cx43) is the most ubiquitous Cx in skin (SFBLs) and gingival fibroblasts (GFBLs), and assembles into hemichannels (HCs) and gap junctions (GJs) on the cell membrane.

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Traditionally, periodontal hand instruments are honed or sharpened during patient care as they dull easily during contact with enamel, calculus and cementum. This approach is taught in dental and hygiene schools around the world and remains the standard of care. Recently, some professional organizations have questioned whether this practice should be abandoned because of safety issues.

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Introduction: To evaluate risk indicators associated with implant failure and relationship between bone levels and soft-tissue health of anodized implants placed in private practice.

Material And Methods: Partially or completely edentulous patients who received an anodized implant between 2003 and 2013 were included. Univariate and multivariate analysis was used to identify the relationship between study variables and implant failure.

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Bone is a composite material composed of collagen and calcium phosphate (CaP) mineral. The collagen gives bone its flexibility while the inorganic material gives bone its resilience. The CaP in bone is similar in composition and structure to the mineral hydroxyapatite (HA) and is bioactive, osteoinductive and osteoconductive.

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