Cuspal deflection and microleakage in premolar teeth restored with resin-based composites with and without an intermediary flowable layer

OBJECTIVES: To assess cuspal deflection and cervical enamel microleakage with and without an intermediary flowable RBC layer for the incremental restoration of mesio-occluso-distal (MOD) cavities with two resin-based composites (RBCs). METHODS: Forty sound upper premolar teeth had standardised MOD cavities prepared. Restoration of the teeth involved the placement of the RBCs (Filtek P60 or Filtek Supreme) in eight increments with the appropriate bonding system with and without an intermediary flowable RBC layer (Filtek Flow). Buccal and palatal cusp deflections were recorded post-irradiation using a twin channel deflection measuring gauge. Following restoration, the teeth were thermocycled, immersed in a 0.2% basic fuchsin dye for 24h, sagittally sectioned and examined for cervical enamel microleakage. RESULTS: A significant reduction in cuspal deflection was evident when both RBC materials were used to restore the cavity by employing an intermediary flowable (P<0.001) compared with when no intermediary flowable was utilised. No statistically significant differences were identified in microleakage between the teeth restored with Filtek P60 or Filtek Supreme when an intermediary flowable (Filtek Flow) was employed. CONCLUSIONS: The results of the current study suggest that there was a benefit to the operator in terms of a reduction in cuspal deflection but not from the maintenance of the synergism of the adhesive bond, namely microleakage at the cervical enamel cavosurface margin, when an intermediate layer of a flowable RBC was used under higher elastic modulus RBCs.     

Maternal red blood cell alloimmunisation in south western Uganda

Aims/Objectives: To identify the frequency and nature of maternal red blood cell (RBC) alloimmunisation in Uganda and to determine the prevalence of RhD negativity and the rate of RBC alloimmunisation in Ugandan pregnant women. Background: Haemolytic disease of the foetus and newborn (HDFN) results from maternal alloimmunisation following exposure to allogeneic RBCs during pregnancy or blood transfusion. The prevalence of maternal RBC alloimmunisation in Ugandans is not known. Materials and Methods: Pregnant women at Mbarara Hospital, South Western Uganda, were investigated in a cross‐sectional study. Demographics, transfusion and obstetric histories were recorded. Maternal RBC alloimmunisation was demonstrated using immunohaematological techniques. Results: A total of 2001 pregnant women were recruited; 3·6% of them being RhD negative. Forty‐five women (2·2%; 95% CI: 1·6–2·9) were found to be alloimmunised to RBC antigens. There were 38 RBC alloantibodies of known specificity including anti‐S, 12; anti‐M, 11; anti‐Le^a, 6; anti‐D, 4 and 1 each of anti‐K, anti‐Fy^b, anti‐Jk^a, anti‐Lu^a and anti‐Kp^a. In two women (4·4%), there were antibody combinations (anti‐M+S and anti‐K+Kp^a). Obstetric history, gestational age and previous immunising events were not significantly associated with the rate of alloimmunisation. Conclusions: This study revealed a maternal RBC alloimmunisation rate of 2·2% which was comparable with findings from a Zimbabwean study where the prevalence was 1·7%. Given the 6·0% prevalence of anti‐D among RhD‐negative women in our study and the high immunogenicity of the D antigen, programmes for preventing anti‐D alloimmunisation and HDFN in Uganda should be considered seriously.     

Clinical outcome of transfusions with extended red blood cell matching in β-thalassemia patients: A single-center experience

Background

The development of alloantibodies may complicate the management of patients with β-thalassemia. An extended antigenic matching may reduce the risk of alloimmunization. Our previous study showed that the introduction of molecular red blood cell (RBC) typing allows finding suitable blood units for multi-transfused patients. The aim of this study was to evaluate the benefit of RBC transfusion with extended antigenic match.

The Red Blood Cell Deformability in Patients Suffering from End Stage Renal Failure on Hemodialysis or Continuous Ambulatory Peritoneal Dialysis

Anemia is the main problem for patients suffering from end stage renal disease (ESRD). This study aimed to determine whether the index of rigidity (IR), that shows red blood cells (RBCs) deformability and the possible IR disturbances can provide an explanation about the cause of anemia, in patients undergoing maintenance hemodialysis (HD) or on peritoneal dialysis. The IR was determined in 39 hemodialyzed patients, who were already in dialysis for a period of time ranging from 16 to 120 months (mean ± SD = 41.8 ± 24.1) (Group A). Furthermore, the IR was measured in 32 patients on continuous ambulatory peritoneal dialysis (CAPD), who were in CAPD for a period of time ranging from 6 to 60 months (mean ± SD = 10.7 ± 9.9) (Group B). Finally, the IR was determined in 17 normal individuals (group C). The RBCs IR was measured twice in group A (before and after the end of a hemodialysis session) and once in groups B and C. The IR was determined by hemorrheometry (method of filtration), using special equipment. In group A the IR was increased in comparison to the control group (C) (17.9 ± 6.2 vs. 10.2 ± 1.8, p < 0.0001). This increase was even higher in the measurement at the end of the hemodialysis session (paired t‐test, p < 0.0001). The RBCs IR in CAPD patients was significantly lower than that of HD patients (12 ± 3.8 vs. 17.9 ± 6.2, p < 0.0001) and was not statistically different from the control group (12 ± 3.8 vs. 10.2 ± 1.8, p = 0.068). It is concluded from the study that: 1) in HD patients occur disturbances in the deformability of the RBCs, that are worsened by the hemodialysis session; 2) the index of rigidity of RBCs is significantly higher in the HD patients than in CAPD patients; 3) in patients on CAPD, the disturbance of deformability of the RBCs was less in comparison to the control group, which however does not reach the statistically significant levels.     

Serology of antibodies to second- and third-generation cephalosporins associated with immune hemolytic anemia and/or positive direct antiglobulin tests

BACKGROUND: First-generation cephalosporins rarely caused immune hemolytic anemia (IHA). Second- and third-generation cephalosporins, especially cefotetan and ceftriaxone, are increasingly associated with severe, sometimes fatal IHA. STUDY DESIGN AND METHODS: Samples from 53 patients with drug-induced IHA and/or positive direct antiglobulin test (DAT) were tested. Patients' sera were tested against drug-treated red cells (RBCs) and untreated or enzyme-treated RBCs, with and without the addition of drug solution. Eluates from patients' RBCs were tested against drug-treated and untreated RBCs. RESULTS: Forty-three patients had antibodies to cefotetan, 8 to ceftriaxone, 1 to cefoxitin, and 1 to cefotaxime. All patients had a positive DAT; only anticefoxitin and anti-cefotetan were demonstrable in RBC eluates. Sera containing anti-cefoxitin, anti-cefotaxime, and anti-cefotetan reacted with drug-treated RBCs (100%) and untreated or enzyme-treated RBCs in the presence of drug (98% or 100%, respectively). All of the ceftriaxone antibodies reacted with untreated or enzyme-treated RBCs in the presence of drug, but those tested did not react with ceftriaxone-treated RBCs. In addition to cefotetan-dependent antibodies, 19 (44%) and 14 (33%) of 43 sera contained drug-independent antibodies when tested with and without the presence of a polyethylene glycol potentiator, respectively. CONCLUSION: Cefotetan is by far the most common cause of drug-induced IHA. All cefotetan antibodies and the single examples of cefoxitin and cefotaxime antibodies reacted with drug-coated RBCs, and most, in contrast to the reactions of antibodies to first-generation cephalosporins (e.g., cephalothin), also reacted with RBCs (not treated with drug) in the presence of the drug. Ceftriaxone antibodies reacted only by the latter mechanism. Drug-independent antibodies (i.e., those reacting without any drug being present) were detected in 33 to 44 percent of patients' sera containing cefotetan antibodies, depending on the sensitivity of the method used.     

Establishing RHD zygosity in India: a step into the future of foetal and neonatal haemolytic disease prevention

Background: Determination of RHD zygosity is important for the prevention of haemolytic disease of foetus and neonate. There is no data from India regarding the prevalence of RHD genotypes. Objectives: We conducted this study to investigate RHD zygosity in phenotypically RhD positive (RhD+) Indians. We have also investigated the utility and concordance of two different genotyping techniques. Methods: Hundred serologically RhD+ Indians were genotyped at the RHD gene using polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) and polymerase chain reaction–sequence‐specific primer (PCR–SSP) techniques. Results : Of the 100 RhD+ individuals, 26 (25%) were D heterozygous by both methods and 74 (71·2%) were D homozygous. There was no discordance in the results from the two techniques. Conclusion: At least 25% of RhD+ Indians are heterozygous at the RHD gene. Both the genotyping techniques were equally robust and their complete concordance indicates RHD deletion as the main mechanism underlying RhD negativity in Indians.     

Long-term ethanol consumption and macrocytosis: diagnostic and pathogenic implications

Although excessive alcohol consumption is known to elevate the mean cell volume (MCV) of erythrocytes, the relationships among the intensity of ethanol exposure, the generation of abnormal red blood cell indices, and the underlying pathogenic mechanisms have remained unclear. The authors examined 105 alcoholics with a wide range of ethanol consumption (40-500 g of ethanol/day), 62 moderate drinkers (mean consumption 1-40 g/day), and 24 abstainers, who underwent detailed interviews, measurements of blood cell counts, markers of liver status, and circulating antibodies against ethanol-derived protein modifications. Follow-up information was collected from healthy volunteers with detailed records on drinking habits. Data from the NORIP project for laboratory parameters in apparently healthy moderate drinkers or abstainers (n = 845) were used for reference interval comparisons. The highest MCV (P < 0.001) and mean cell hemoglobin (MCH) (P < 0.01) occurred in the alcoholics. However, the values in the moderate drinkers also responded to ethanol intake such that the upper normal limit for MCV based on the data from moderate drinkers was 98 fl, as compared with 96 fl from abstainers. Follow-up cases with carefully registered drinking habits showed parallel changes in MCV and ethanol intake. Anti-adduct IgA and IgM against acetaldehyde-induced protein modifications were elevated in 94% and 64% of patients with high MCV, respectively, the former being significantly less frequent in the alcoholics with normal MCV (63%) (P < 0.05). The data indicate dose-related responses in red blood indices upon chronic ethanol consumption, which may also be reflected in reference intervals for hematological parameters in health care. Generation of immune responses against acetaldehyde-modified erythrocyte proteins may be associated with the appearance of such abnormalities.     

Toxicology of 3-epi-deoxynivalenol,a deoxynivalenol-transformation product by Devosia mutans 17-2-E-8

Microbial detoxification of deoxynivalenol (DON) represents a new approach to treating DON-contaminated grains. A bacterium Devosia mutans 17-2-E-8 was capable of completely transforming DON into a major product 3-epi-DON and a minor product 3-keto-DON. Evaluation of toxicities of these DON-transformation products is an important part of hazard characterization prior to commercialization of the biotransformation application. Cytotoxicities of the products were demonstrated by two assays: a MTT bioassay assessing cell viability and a BrdU assay assessing DNA synthesis. Compared with DON, the IC₅₀ values of 3-epi-DON and 3-keto-DON were respectively 357 and 3.03 times higher in the MTT bioassay, and were respectively 1181 and 4.54 times higher in the BrdU bioassay. Toxicological effects of 14-day oral exposure of the B6C3F₁ mouse to DON and 3-epi-DON were also investigated. Overall, there were no differences between the control (free of toxin) and the 25 mg/kg bw/day or 100 mg/kg bw/day 3-epi-DON treatments in body and organ weights, hematology and organ histopathology. However, in mice exposed to DON (2 mg/kg bw/day), white blood cell numbers and serum immunoglobulin levels were altered relative to controls, and lesions were observed in adrenals, thymus, stomach, spleen and colon. Taken together, in vitro and in vivo studies indicate that 3-epi-DON is substantially less toxic than DON.     

血细胞计数影响因素分析

本文分析血细胞计数的影响因素,发现血细胞检测结果受环境温度、放置时间、采血方式等因素的影响,检验人员在采血和检测过程中应尽可能排除各种影响因素,为临床提供真实可靠的检验结果。     

Influence of calcium permeabilization and membrane-attached hemoglobin on erythrocyte deformability.

The present study was designed to evaluate the influence of intracellular calcium [Ca]i regulated membrane attached hemoglobin (Hbm) on the deformability of human RBC and ghosts. [Ca]i of RBC was elevated via the ionophore A23187 (10 microM); the deformability of RBC and resealed ghosts was determined via measuring RBC and ghost transit times through 5 microns diameter pores with the Cell Transit Analyzer (CTA). Salient results included: (1) significantly increased RBC levels of Hbm following ionophore treatment; (2) elevated Hbm with increasing lysing medium calcium concentration (0-5 mM); (3) decreased deformability of both intact RBC and ghosts with increasing Hbm and significant (P less than 0.02 or better) linear relationships between Hbm and RBC or ghost transit times; and (4) an increased sensitivity to ionophore treatment/membrane attached hemoglobin for the higher percentiles of the CTA transit time distribution (i.e., for more rigid subpopulations). Our results thus indicate that calcium-induced interaction of hemoglobin with the RBC membrane produces cellular rheological changes; in addition, they demonstrate the usefulness of the CTA system in measuring both average RBC rheologic behavior and the distribution of cellular rheologic properties within an erythrocyte population.