Biodentine™ as a temporary filling in deep carious lesions in permanent teeth: a prospective observational 33-month follow-up study.

PURPOSE: The study aimed to evaluate temporary fillings using Biodentine™ in asymptomatic deep carious lesions after 12, 24, and 36 months in school children from the remote village of Kerung, Nepal. METHODS: From November 2018 to November 2019, 91 temporary fillings were placed using Biodentine™ (a hydraulic calcium silicate cement) in permanent molars with deep carious lesions of schoolchildren in the remote district of Kerung, Nepal. These restorations were performed after selective caries removal in a non-dental setting with hand instruments and cotton roll isolation, as electric motors and saliva ejection systems were unavailable. In total, 78 single-surface and 13 multi-surface fillings were placed. Clinical and radiographic follow-up periods encompassed 12, 21, and 33 months, respectively. RESULTS: After 12 months, all single-surface fillings (100%) survived, whilst all multi-surface fillings were partially or entirely lost. The survival rate of single-surface restorations after 21 and 33 months was 67.6% and 50%, respectively. Radiographically, no pathology was observed. CONCLUSION: This study showed that Biodentine could be used in deep carious lesions as a temporary filling in single-surface lesions for at least up to 1 year and in a substantial number of cases for up to 21 and 33 months.

Multinational comparison study of aircraft pilot healthcare avoidance behaviour.

BACKGROUND: US and Canadian pilots are required to meet medical standards to secure their active flying status, but a subgroup exhibit healthcare avoidance behaviour due to fear of loss of that status. This phenomenon has the potential to impact pilot health, aeromedical screening and aviation safety. No international comparison study of pilot healthcare avoidance currently exists between US and Canadian pilots. AIMS: To compare the rate and subtypes of healthcare avoidance behaviour secondary to fear for loss of flying status between US and Canadian pilots. METHODS: A comparison analysis of data collected during two independent, non-probabilistic, cross-sectional internet surveys including any individual certified to perform flying duties in the USA (US survey) or Canada (Canadian survey). RESULTS: There were 4320 US pilots and 1415 Canadian pilots who completed informed consent and 3765 US pilots and 1405 Canadian pilots were included in the results. There were 56% of US pilots who reported a history of healthcare avoidance behaviour compared to 55% of Canadian pilots (P = 0.578). A multivariable logistic regression that included age, pilot type and gender showed that US pilots were slightly more likely than Canadian pilots to report this behaviour (odds ratio 1.22, 95% confidence interval 1.06-1.4). CONCLUSIONS: Healthcare avoidance behaviour due to fear of loss of flying status has a relatively high prevalence in both US and Canadian pilot populations.

Effect of cryopreservation on a rare McLeod donor red blood cell concentrate.

Units of red blood cell (RBC) concentrates with rare phenotypes are typically not included in method validation studies for cryopreservation processes; rather, they are reserved for patients with rare blood needs. Some rare RBC phenotypes may demonstrate membrane abnormalities, like acanthocytosis as observed for RBCs with the McLeod phenotype, and are specifically banked for these rare attributes; however, the impact that rare RBC phenotypes have on post-thaw quality has not been well studied. To evaluate how a rare RBC phenotype is affected by the cryopreservation process, 4 RBC units, cryopreserved in 1993 using manual methods, were selected for evaluation. These RBCs included one with the McLeod phenotype and three with phenotypes not known to cause significant membrane changes. Post-thaw, an altered deglycerolization protocol, implemented to reduce supernatant glycerol after cryopreservation, was used before processing RBCs on an automated closed system (ACP 215; Haemonetics, Boston, MA) to accommodate the use of a closed system cell processor not available when the RBC units were previously cryopreserved. RBC quality was tested at 24 hours, 7 days, and 14 days post-deglycerolization. Before deglycerolization, an extracted sample from the thawed glycerolized RBC unit was used to obtain genetic material for phenotype confirmation. Genotyping confirmed the McLeod phenotype. When comparing McLeod with non-McLeod units, RBCs from the McLeod donor exhibited acanthocytosis, higher rigidity, and lower morphology scores than RBCs from the non-McLeod units post-deglycerolization. Hemolysis, however, was comparable across all 4 units, meeting regulatory standards. Therefore, McLeod RBCs can withstand cryopreservation, suggesting that units from these donors, glycerolized using older methods, can be deglycerolized using the ACP 215 and stored hypothermically for 14 days. It was also determined that genotyping can be performed on non-leukocyte-reduced cryopreserved RBCs, allowing for confirmation of genetic profiles of donor units banked before the implementation of molecular methods.Units of red blood cell (RBC) concentrates with rare phenotypes are typically not included in method validation studies for cryopreservation processes; rather, they are reserved for patients with rare blood needs. Some rare RBC phenotypes may demonstrate membrane abnormalities, like acanthocytosis as observed for RBCs with the McLeod phenotype, and are specifically banked for these rare attributes; however, the impact that rare RBC phenotypes have on post-thaw quality has not been well studied. To evaluate how a rare RBC phenotype is affected by the cryopreservation process, 4 RBC units, cryopreserved in 1993 using manual methods, were selected for evaluation. These RBCs included one with the McLeod phenotype and three with phenotypes not known to cause significant membrane changes. Post-thaw, an altered deglycerolization protocol, implemented to reduce supernatant glycerol after cryopreservation, was used before processing RBCs on an automated closed system (ACP 215; Haemonetics, Boston, MA) to accommodate the use of a closed system cell processor not available when the RBC units were previously cryopreserved. RBC quality was tested at 24 hours, 7 days, and 14 days post-deglycerolization. Before deglycerolization, an extracted sample from the thawed glycerolized RBC unit was used to obtain genetic material for phenotype confirmation. Genotyping confirmed the McLeod phenotype. When comparing McLeod with non-McLeod units, RBCs from the McLeod donor exhibited acanthocytosis, higher rigidity, and lower morphology scores than RBCs from the non-McLeod units post-deglycerolization. Hemolysis, however, was comparable across all 4 units, meeting regulatory standards. Therefore, McLeod RBCs can withstand cryopreservation, suggesting that units from these donors, glycerolized using older methods, can be deglycerolized using the ACP 215 and stored hypothermically for 14 days. It was also determined that genotyping can be performed on non-leukocyte­reduced cryopreserved RBCs, allowing for confirmation of genetic profiles of donor units banked before the implementation of molecular methods.

Outcomes of different radioprotective precautions in children undergoing dental radiography: a systematic review.

PURPOSE: To evaluate the effectiveness of all radioprotective measures in underage patients who undergo a dental radiodiagnostic examination. METHODS: A systematic review was performed including randomised controlled trials (RCTs), or cluster trials, cohort studies, cross-sectional studies, case-control studies and comparative in vitro research. These studies examined the healthy underage human population (below 18 years) undergoing a dental radiodiagnostic examination. All radioprotective measures were included except for justification as an intervention. The primary outcomes were in vivo mortality and morbidity. Some surrogate or indirect outcomes such as in vitro effective dose and organ absorbed doses were also accepted. Secondary outcomes with regards to image quality and therapeutic value were also analysed. RESULTS: Eighteen papers were eligible for implementation. Fifteen studies underwent narrative synthesis. Regression analysis was performed on three studies. CONCLUSION: The following radioprotective measures can reduce the exposure dose. For lateral cephalometry: collimation, filtration, the fastest receptor type and circumstantial thyroid shielding. For oblique lateral radiographs: the shortest exposure time, a smaller horizontal angulation, a longer focus to skin distance. For intraoral radiography: rectangular collimation, the fastest image receptor speed and thyroid shielding when the thyroid gland is in line of or very close to the primary beam. For panoramic radiographs: collimation, the fastest receptor type and the use of automatic exposure control (AEC) or manual adjustment of intensity. For cone-beam computed tomography: collimation, the largest voxels size in relation to the treatment need, change in image settings such as ultra-low dose settings, shorter exposure time, a lower amount of projections, lower beam intensity, reduction of the potential, use of a thyroid shield except in two situations and the use of AEC. All of the changes in exposure parameters should be performed while maintaining a sufficient therapeutic value on an individual and indication-based level.

In vivo correlation of near-infrared transillumination and visual inspection with bitewing radiography for the detection of interproximal caries in permanent and primary teeth.

PURPOSE: To evaluate near-infrared light transillumination (NILT) for interproximal caries detection in children by comparing the correlation between both NILT and visual inspection (ICDAS) with bitewing (BW) radiography and by investigating possible differences in caries detection with NILT between primary and permanent teeth. METHODS: From 35 patients, 121 and 63 interproximal surfaces in, respectively, primary and permanent teeth were included. NILT images were obtained using DIAGNOcam™ (KaVo) and scored by two calibrated raters. A consensus diagnosis was reached for BW radiography; whereas, the ICDAS scores were obtained by one calibrated rater. Weighted Kappa (wκ) was used to evaluate inter- and intra-rater reliability of NILT and to evaluate the correlation between NILT, ICDAS and BW radiography. RESULTS: The correlation between NILT and BW radiography was moderate to substantial for primary teeth [Rater 1: wκ = 0.61 (95% CI = 0.49-0.75), Rater 2: wκ = 0.55 (95% CI = 0.41-0.69)] and fair for permanent teeth [Rater 1: wκ = 0.34 (95% CI = 0.15-0.53), Rater 2: wκ = 0.33 (95% CI = 0.08-0.58)]. The correlation between ICDAS and BW radiography was moderate for primary teeth [wκ = 0.49 (95% CI = 0.35-0.63)] and substantial for permanent teeth [wκ = 0.62 (95% CI = 0.32-0.92)]. No significant differences were found between primary and permanent teeth. CONCLUSION: NILT cannot be recommended as a single diagnostic tool for interproximal caries detection in primary teeth. The number of false negatives for dentine caries, especially in first primary molars, was too high. For the use in permanent teeth, NILT could be more accurate than BW radiography.

Best clinical practice guidance for prescribing dental radiographs in children and adolescents: an EAPD policy document.

BACKGROUND: The European Academy of Paediatric Dentistry (EAPD) proposes this best clinical practice guidance to help practitioners decide when and how to prescribe dental radiographs in children and adolescents. METHODS: Four expert working groups conducted each a systematic review of the literature. The main subjects were radiation protection, intraoral dental radiography (bitewing and periapical radiographs), panoramic radiography (PR) and cone-beam computed tomography (CBCT). In addition, three workshops were held during the corresponding EAPD Interim Seminar in Chania (Crete, Greece) in 2019. On the basis of the identified evidence, all invited experts presented their findings and during the workshops aspects of clinical relevance were discussed. RESULTS: Several clinical-based recommendations and statements were agreed upon. CONCLUSION: There is no or low-grade evidence about the efficacy of dental radiographic examinations in young populations. The given recommendations and rationales should be understood as best clinical practice guidance. It is essential to respect the radiological principles of an individualized and patient-specific justification. When a dental radiograph is required, its application needs to be optimized, aiming at limiting the patient's exposure to ionising radiation according to the ALADAIP principle (As Low As Diagnostically Achievable being Indication-oriented and Patient-specific).

[Prevalence of sleep-related breathing disorders of inpatients with psychiatric disorders]. / Prävalenz schlafbezogener Atmungsstörungen bei stationären Patienten mit psychischen Erkrankungen.

BACKGROUND: Sleep-related breathing disorders seriously impair well-being and increase the risk for relevant somatic and psychiatric disorders. Moreover, risk factors for sleep-related breathing disorders are highly prevalent in psychiatric patients. The aim of this study was for the first time in Germany to study the prevalence of obstructive sleep apnea syndrome (OSAS) as the most common form of sleep-related breathing disorder in patients with psychiatric disorders. METHODS: In 10 psychiatric hospitals in Germany and 1 hospital in Switzerland, a total of 249 inpatients underwent an 8­channel sleep polygraphy to investigate the prevalence of sleep apnea in this group of patients. RESULTS: With a conspicuous screening result of 23.7% of the subjects, a high prevalence of sleep-related breathing disorders was found to occur among this group of patients. Male gender, higher age and high body mass index (BMI) were identified as positive risk factors for the detection of OSAS. DISCUSSION: The high prevalence indicates that sleep apnea is a common sleep disorder among psychiatric patients. Although OSAS can lead to substantial disorders of the mental state and when untreated is accompanied by serious somatic health problems, screening procedures are not part of the routine work-up in psychiatric hospitals; therefore, sleep apnea is presumably underdiagnosed in psychiatric patients. In view of the results of this and previous studies, this topic complex should be the subject of further research studies.

Paediatric dental emergencies: a retrospective study and a proposal for definition and guidelines including pain management.

AIM: This was primarily to perform a retrospective analysis of 1000 emergency dental visits in order to characterize the nature of the dental emergency and the treatment provided and secondly to define a guideline for dental emergency treatment in children including pain management. MATERIALS AND METHODS: A retrospective review was conducted of 1000 patients (aged 0-16 years) who visited the dental emergency service of the paediatric dental clinic at the Ghent University Hospital, Belgium over a period of 3 years. Data regarding age, gender, reason for visit, year of visit, consequent appointments and treatment provided were collected. Statistical analysis was carried out using descriptive statistics (frequency distribution) and Chi-square test, with significance level set as P < 0.05. RESULTS: The number of patients visiting with a dental emergency increased annually. Approximately half (50.2%) of all paediatric dental emergency consultations were based on pain due to caries and its consequences. More than a quartile (26.7%) of emergency patients suffered from dental trauma of either primar or permanent teeth. The majority (96.7%) of the patients reported pain, 16.3% of the patients did not necessarily need immediate attention. CONCLUSION: Dental emergencies in a university hospital based setting were predominantly related to caries and trauma. A precise definition of dental emergencies is recommended in order to prevent abuse of paediatric emergency services.

X-ray computed microtomography characterizes the wound effect that causes sap flow underestimation by thermal dissipation sensors.

Insertion of thermal dissipation (TD) sap flow sensors in living tree stems causes damage of the wood tissue, as is the case with other invasive methods. The subsequent wound formation is one of the main causes of underestimation of tree water-use measured by TD sensors. However, the specific alterations in wood anatomy in response to inserted sensors have not yet been characterized, and the linked dysfunctions in xylem conductance and sensor accuracy are still unknown. In this study, we investigate the anatomical mechanisms prompting sap flow underestimation and the dynamic process of wound formation. Successive sets of TD sensors were installed in the early, mid and end stage of the growing season in diffuse- and ring-porous trees, Fagus sylvatica (Linnaeus) and Quercus petraea ((Mattuschka) Lieblein), respectively. The trees were cut in autumn and additional sensors were installed in the cut stem segments as controls without wound formation. The wounded area and volume surrounding each sensor was then visually determined by X-ray computed microtomography (X-ray microCT). This technique allowed the characterization of vessel anatomical transformations such as tyloses formation, their spatial distribution and quantification of reduction in conductive area. MicroCT scans showed considerable formation of tyloses that reduced the conductive area of vessels surrounding the inserted TD probes, thus causing an underestimation in sap flux density (SFD) in both beech and oak. Discolored wood tissue was ellipsoidal, larger in the radial plane, more extensive in beech than in oak, and also for sensors installed for longer times. However, the severity of anatomical transformations did not always follow this pattern. Increased wound size with time, for example, did not result in larger SFD underestimation. This information helps us to better understand the mechanisms involved in wound effects with TD sensors and allows the provision of practical recommendations to reduce biases associated with wounding in field sap flow measurements.

Comparison of species classification models of mass spectrometry data: Kernel Discriminant Analysis vs Random Forest; A case study of Afrormosia (Pericopsis elata (Harms) Meeuwen).

RATIONALE: The genus Pericopsis includes four tree species of which only Pericopsis elata (Harms) Meeuwen is of commercial interest. Enforcement officers might have difficulties discerning this CITES-listed species from some other tropical African timber species. Therefore, we tested several methods to separate and identify these species rapidly in order to enable customs officials to uncover illegal trade. In this study, two classification methods using Direct Analysis in Real Time (DART™) ionization coupled with Time-of-Flight Mass Spectrometry (DART-TOFMS) data to discern between several species are presented. METHODS: Metabolome profiles were collected using DART™ ionization coupled with TOFMS analysis of heartwood specimens of all four Pericopsis species and Haplormosia monophylla (Harms) Harms, Dalbergia melanoxylon Guill. & Perr. Harms, and Milicia excelsa (Welw.) C.C. Berg. In total, 95 specimens were analysed and the spectra evaluated. Kernel Discriminant Analysis (KDA) and Random Forest classification were used to discern the species. RESULTS: DART-TOFMS spectra obtained from wood slivers and post-processing analysis using KDA and Random Forest classification separated Pericopsis elata from the other Pericopsis taxa and its lookalike timbers Haplormosia monophylla, Milicia excelsa, and Dalbergia melanoxylon. Only 50 ions were needed to achieve the highest accuracy. CONCLUSIONS: DART-TOFMS spectra of the taxa were reproducible and the results of the chemometric analysis provided comparable accuracy. Haplormosia monophylla was visually distinguished based on the heatmap and was excluded from further analysis. Both classification methods, KDA and Random Forest, were capable of distinguishing Pericopsis elata from the other Pericopsis taxa, Milicia excelsa, and Dalbergia melanoxylon, timbers that are commonly traded.

Quality control of apheresis platelets: a multicentre study to evaluate factors that can influence pH measurement.

BACKGROUND AND OBJECTIVES: Blood operators routinely monitor the pH of apheresis platelets as a marker of the so-called storage lesion, which can result from manufacturing problems. It is also suspected that some donor characteristics can increase the risk of poor platelet storage. To explore this hypothesis, we analysed a large, multinational data set of quality control (QC) pH test results on apheresis platelets. MATERIALS AND METHODS: For the period between September 2011 and August 2014, seven blood operators in Canada, the USA, the Netherlands, the United Kingdom, France and Australia provided pH QC test results and donor characteristics on a total of 21,671 apheresis platelets. RESULTS: Some variations in pH distribution between blood operators were in part explained by differences in collection, processing and testing methods. Younger age and female gender were significantly associated with a pH value below the 10th percentile. Among donors who had two or more pH measurements (n = 3672), there was a strong correlation between pH results (r = 0·726; P < 0·0001). CONCLUSION: The strong intradonor correlation of pH measurements and the association between donor characteristics and pH results suggest that donor factors play a role in the quality of platelets.

Assessing the influence of component processing and donor characteristics on quality of red cell concentrates using quality control data.

BACKGROUND AND OBJECTIVES: Quality control (QC) data collected by blood services are used to monitor production and to ensure compliance with regulatory standards. We demonstrate how analysis of quality control data can be used to highlight the sources of variability within red cell concentrates (RCCs). MATERIALS AND METHODS: We merged Canadian Blood Services QC data with manufacturing and donor records for 28 227 RCC between June 2011 and October 2014. Units were categorized based on processing method, bag manufacturer, donor age and donor sex, then assessed based on product characteristics: haemolysis and haemoglobin levels, unit volume, leucocyte count and haematocrit. RESULTS: Buffy-coat method (top/bottom)-processed units exhibited lower haemolysis than units processed using the whole-blood filtration method (top/top). Units from female donors exhibited lower haemolysis than male donations. Processing method influenced unit volume and the ratio of additive solution to residual plasma. CONCLUSIONS: Stored red blood cell characteristics are influenced by prestorage processing and donor factors. Understanding the relationship between processing, donors and RCC quality will help blood services to ensure the safety of transfused products.

Manufacturing method affects mitochondrial DNA release and extracellular vesicle composition in stored red blood cells.

BACKGROUND AND OBJECTIVES: Damage-associated molecular patterns (DAMPs) are found in transfusion products, but their potential impacts are not fully understood. We examined the influence of manufacturing method on levels of mitochondrial (mt) DNA and extracellular vesicle (EV) DAMPs in red cell concentrates (RCCs). MATERIALS AND METHODS: Eighty-seven RCCs were prepared using nine different methods (6-15 units/method), including three apheresis, five whole blood (WB)-derived leucoreduced (LR) and one WB-derived non-LR method. On storage days 5 and 42, levels of mtDNA (by PCR) and number and cell of origin of EVs (by flow cytometry) were assessed in RCC supernatants. RESULTS: There was a 100-fold difference in mtDNA levels among methods, with highest levels in non-LR, followed by MCS+ and Trima apheresis RCCs. There was a 10-fold difference in EV levels among methods. RBC-derived CD235a+ EVs were found in fresh RCCs and increased in most during storage. Platelet-derived CD41a+ EVs were highest in non-LR and Trima RCCs and did not change during storage. WBC-derived EVs were low in most RCCs; CD14+ EVs increased in several RCCs during storage. CONCLUSION: DAMPs in RCCs vary by manufacturing method. MtDNA and EV could be informative quality markers that may be relevant to RCC immunomodulatory potential.

Plasmodium falciparum malaria occurring four years after leaving an endemic area.

We present a case of a 52-year-old woman of Ghanaian origin who developed Plasmodium falciparum malaria 4 years after leaving Africa. She had not returned to an endemic area since. We hypothesize several possible scenarios to explain this infection, of which we believe recrudescence of P. falciparum is the most plausible. This occurred most likely as a consequence of waning immunity several years after leaving a high-transmission area. She recovered after a 3-day treatment with atovaquone/proguanil.

An investigation of red blood cell concentrate quality during storage in paediatric-sized polyvinylchloride bags plasticized with alternatives to di-2-ethylhexyl phthalate (DEHP).

BACKGROUND AND OBJECTIVES: Di-2-ethylhexyl phthalate (DEHP) is a blood bag plasticizer. It is also a toxin, raising concerns for vulnerable populations, for example, neonates and infants. Here, the in vitro quality of red cell concentrates (RCC) stored in paediatric bags formulated with alternative plasticizers to DEHP was compared. MATERIALS AND METHODS: RCC were pooled and split into polyvinylchloride (PVC)/DEHP, PVC/1,2-cyclohexanedicarboxylic acid diisononyl ester (DINCH) or PVC/butyryl trihexyl citrate (BTHC) bags. Quality was assessed on storage days 5, 21, 35 and 43. RESULTS: Metabolism differed among the bags: pCO2 levels were lowest and pO2 were highest in BTHC bags. Glucose consumption and lactate production suggested higher metabolic rates in BTHC bags. ATP levels were best maintained in DINCH bags (day 43 mean level: 2·86 ± 0·29 µmol/g Hb). RCC in BTHC bags had the greatest potassium release (54·6 ± 3·0 mm on day 43). From day 21, haemolysis was higher in BTHC bags (P < 0·01) and by day 43 had exceeded 0·8% (0·85 ± 0·10%). RCC in BTHC bags showed more microparticle formation than RCC in DEHP or DINCH bags. CONCLUSION: The results suggest that the BTHC formulation used was detrimental to RBC quality. DINCH bags could be a viable alternative to DEHP: they outperformed DEHP bags energetically, with better maintenance of ATP levels.

Buffy coat (top/bottom)- and whole-blood filtration (top/top)-produced red cell concentrates differ in size of extracellular vesicles.

BACKGROUND AND OBJECTIVES: The influence that blood component separation methods have on changes to the red blood cell membrane during storage is not well understood. In Canada, red cell concentrates (RCCs) are produced using the buffy coat (BC, top/bottom) and the whole-blood filtration (WBF, top/top) methods, and this study aimed at comparing their influence on the characteristics of the extracellular vesicles (EV) which accumulated in the respective products during storage. MATERIALS AND METHODS: Using flow cytometry, dynamic light scattering and mass spectrometry, we assessed RCC EVs for concentration, size, lipid composition and correlation with supernatant haemoglobin (Hb). RESULTS: Accumulation of RBC EVs (CD235a(+) ) with storage time was similar in WBF and BC RCCs. The size of the EVs changed from <100 nm at d5 to near 200 nm by d42, with the EVs from WBF being smaller (P < 0·001) than BC RCCs at all storage times. The amount of EV-bound Hb in the WBF and BC units was similar (about 10% of total supernatant Hb). WBF EVs and BC EVs displayed similar lipid composition. CONCLUSION: Haemolysis and EVs increase in BC and WBF RCCs during storage. Differences in the size characteristics of the EVs in WBF and BC RCCs suggest that non-RBC EVs are more prevalent in WBF products. Understanding the impact that manufacturing has on the characteristics of the different populations of EVs in RCCs will aid quality improvement efforts.

The effect of processing method on the in vitro characteristics of red blood cell products.

BACKGROUND AND OBJECTIVES: While the clinical impact of differences in red blood cell (RBC) component processing methods is unknown, there are concerns they may be confounding variables in studies such as the ongoing 'age of blood' investigations. Here, we compare the in vitro characteristics of red cell concentrates (RCCs) produced by several different processing methods. MATERIALS AND METHODS: Nine processing methods were examined: three apheresis methods (Alyx, MCS+ and Trima), as well as leucoreduced whole blood-derived RCCs produced by buffy coat and whole blood filtration and non-leucoreduced RCCs. RCCs were stored in saline-adenine-glucose-mannitol or additive solutions (AS) 1 or 3 for 42 days, with quality tested on day 5 and day 42. RESULTS: Many significant product differences were observed both early in and at the end of storage. Mean haemoglobin (Hb) ranged from 52 to 71 g/unit and mean Hct from 59·5 to 64·8%. Most RCC passed regulated quality control criteria according to Canadian Standards Association guidelines, although there were some failures relating to Hb content and residual WBC counts. CONCLUSION: Processing method impacts RCC characteristics throughout storage; better understanding of these differences and reporting of processing method details is critical.

The effect of timing of gamma-irradiation on hemolysis and potassium release in leukoreduced red cell concentrates stored in SAGM.

While irradiation of red cell concentrates (RCC) prevents graft-versus-host disease in susceptible transfusion recipients, it also damages red blood cells (RBC). To understand the ability of irradiation regulations to prevent transfusion of inferior units, we irradiated 980 RCC in saline-adenine-glucose-mannitol (SAGM) using various combinations of pre-irradiation age and post-irradiation storage times, and measured hemolysis and extracellular potassium levels. We observed unacceptably high hemolysis (>0·8%) in some RCC and elevated extracellular potassium levels in all gamma-irradiated RCC. This suggests that more restrictive storage times should be considered for RCC in SAGM.