Sensory evaluations of a novel iron and zinc-enriched powder for the potential treatment and prevention of iron deficiency in women of reproductive age

Iron deficiency (ID) and ID with anaemia (IDA) are serious global health problems that disproportionately affect women aged 15-49 years. Although food fortification is one of the most effective and sustainable ways to combat nutritional deficiencies, iron remains one of the most difficult micronutrients to fortify, given its tendency to react strongly with food constituents. Therefore, it is important to assess the sensory properties of foods fortified with iron to determine the acceptability and palatability in target populations. We aimed to determine the palatability and acceptability of a novel iron and zinc-enriched powder fortified in tap water by conducting sensory evaluations in 35 women of reproductive age using a 9-point hedonic scale, where participants rated the sensory properties of six samples containing different amounts of the active or placebo powder. We found significant differences between samples reconstituted at 1, 2, and 3 g/L for sensory properties, including overall taste. Participants were found to be more willing to drink the mineral-enriched powder when prepared at the lowest concentration (1 g/L) compared to higher concentrations. Our results provide important insight into the sensory qualities of a novel formulation of an iron and zinc-enriched powder for at-home fortification and indicate consumer acceptability in reproductive-aged women, a key group at risk for ID/IDA. If found to improve iron status, novel treatments like this product will contribute to global efforts to develop safe, acceptable and sustainable interventions for ID and IDA.

Impact of trauma centre capacity and volume on the mortality risk of incoming new admissions

INTRODUCTION

Trauma centre capacity and surge volume may affect decisions on where to transport a critically injured patient and whether to bypass the closest facility. Our hypothesis was that overcrowding and high patient acuity would contribute to increase the mortality risk for incoming admissions.

METHODS

For a 6-year period, we merged and cross-correlated our institutional trauma registry with a database on Trauma Resuscitation Unit (TRU) patient admissions, movement and discharges, with average capacity of 12 trauma bays. The outcomes of overall hospital and 24 hours mortality for new trauma admissions (NEW) were assessed by multivariate logistic regression.

RESULTS

There were 42 003 (mean=7000/year) admissions having complete data sets, with 36 354 (87%) patients who were primary trauma admissions, age ≥18 and survival ≥15 min. In the logistic regression model for the entire cohort, NEW admission hospital mortality was only associated with NEW admission age and prehospital Glasgow Coma Scale (GCS) and Shock Index (SI) (all p<0.05). When TRU occupancy reached ≥16 patients, the factors associated with increased NEW admission hospital mortality were existing patients (TRU >1 hour) with SI ≥0.9, recent admissions (TRU ≤1 hour) with age ≥65, NEW admission age and prehospital GCS and SI (all p<0.05).

CONCLUSION

The mortality of incoming patients is not impacted by routine trauma centre overcapacity. In conditions of severe overcrowding, the number of admitted patients with shock physiology and a recent surge of elderly/debilitated patients may influence the mortality risk of a new trauma admission.

Mathematical model of thrombin generation and bleeding phenotype in Amish carriers of Factor IX:C deficiency vs. controls

INTRODUCTION

Factor IX:C (FIX:C) levels vary in hemophilia B carriers even in pedigrees with a unifying genetic defect. Analyzing the balance between pro-and anticoagulants might increase our understanding of carriers' bleeding potential.

AIM

In this research study, we evaluated bleeding scores (BS) and a novel mathematical model of thrombin generation (TG) in Amish FIX:C deficient carriers and controls.

METHODS

Blood samples and BS were obtained from post-menarchal females, including 59 carriers and 57 controls from the same extended pedigree. Factors II, V, VII, VIII, IX, X, antithrombin, tissue factor pathway inhibitor and protein C were assayed to generate mathematical models of TG in response to 5pM tissue factor (TF) and for TF + thrombomodulin. BS was based on a modification of the MCMDM-1VWD scoring system.

RESULTS

Carriers had a lower mean FIX:C (68% vs. 119%), von Willebrand factor antigen (108 vs.133) and Tissue activatable fibrinolysis inhibitor (103 vs. 111) compared to controls; both groups had a similar mean BS. Carriers demonstrated significantly lower TG parameters on both mathematical models compared to controls. Carriers with FIX:C ≤ 50% had lower TG curves than those >50% but similar BS.

CONCLUSION

Thrombin generation showed significant differences between carriers and controls, between low (≤50%) and high (>50%) FIX:C carriers, and specifically in the TF + thrombomodulin model, between high FIX:C carriers and controls, although the BS were not different.

Distinguishing lupus anticoagulants from factor VIII inhibitors in haemophilic and non-haemophilic patients

INTRODUCTION

Accurate diagnosis of an inhibitor, a neutralizing antibody to infused factor VIII (FVIII), is essential for appropriate management of haemophilia A (HA). Low-titre inhibitors may be difficult to diagnose due to high rates of false-positive inhibitor results in that range. Transient low-titre inhibitors and false-positive inhibitors may be due to the presence of a lupus anticoagulant (LA) or other non-specific antibodies. Fluorescence immunoassay (FLI) to detect antibodies to FVIII is a sensitive method to identify inhibitors in HA. Evaluations of antibody profiles by various groups have demonstrated that haemophilic inhibitors detected by Nijmegen-Bethesda (NBA) and chromogenic Bethesda (CBA) assays correlate with positivity for anti-FVIII immunoglobulin (Ig) G1 and G4.

AIM

This study sought to determine whether FLI could distinguish false-positive FVIII inhibitor results related to LAs from clinically relevant FVIII inhibitors in HA patients.

METHODS

Samples from haemophilic and non-haemophilic subjects were tested for LA, specific FVIII inhibitors by NBA and CBA, and anti-FVIII immunoglobulin profiles by FLI.

RESULTS

No samples from LA-positive non-haemophilic subjects were positive by FLI for anti-FVIII IgG4. Conversely, 91% of NBA-positive samples from haemophilia subjects were positive for anti-FVIII IgG4. Two of 11 haemophilia subjects had samples negative for anti-FVIII IgG4 and CBA, which likely represented LA rather than FVIII inhibitor presence.

CONCLUSIONS

Assessment of anti-FVIII profiles along with the CBA may be useful to distinguish a clinically relevant low-titre FVIII inhibitor from a transient LA in HA patients.

Effects of pre-analytical heat treatment in factor VIII (FVIII) inhibitor assays on FVIII antibody levels

INTRODUCTION

The use of pre-analytical heat treatment (PHT) with the Nijmegen-Bethesda assay (NBA) for inhibitors to factor VIII (FVIII) can remove/destroy infused or endogenous FVIII from patient plasma samples, allowing testing of recently infused patients with haemophilia. Two PHT methods have been described as follows: heating to 56°C for 30 minutes and heating to 58°C for 90 minutes. Data examining the effects of PHT on anti-FVIII IgG4 , the antibodies known to correlate most closely with the presence of FVIII inhibitors, are limited.

AIM

To assess the effect of PHT on the levels of detectable anti-FVIII IgG4 .

METHODS

Nijmegen-Bethesda assay-positive specimens were incubated at 56, 58 or 60°C for 90 minutes, and anti-FVIII IgG4 was measured by fluorescence immunoassay (FLI) at 30-minute intervals. The effects of PHT on the ability of recombinant FVIII (rFVIII) to inhibit detection of patient antibodies by FLI was also examined to assess the stability of rFVIII under the various PHT conditions tested.

RESULTS

Levels of anti-FVIII IgG4 showed little change following incubations at 56°C (mean 101% of original value at 30 minutes and 100% at 60 minutes) but decreased upon exposure to 58°C (mean 85% at 30 minutes and 66% at 60 minutes). In addition, heating to 56°C effectively decreased the ability of rFVIII to block antibody binding compared to unheated rFVIII.

CONCLUSION

The optimal temperature for PHT in the FVIII NBA is 56°C. Higher temperatures may lead to loss of inhibitory antibodies.

Laboratory testing for factor VIII and IX inhibitors in haemophilia: A review

Inhibitors are antibodies directed against haemophilia treatment products which interfere with their function. Factor VIII (FVIII) inhibitors in haemophilia A and factor IX (FIX) inhibitors in haemophilia B are significant clinically when they require a change in a patient's treatment regimen. Their persistence may increase morbidity and mortality. Multiple laboratory tests are now available for detecting and understanding inhibitors in haemophilia. Inhibitors are traditionally measured by their interference in clotting or chromogenic factor assays. They may also be detected using immunologic assays, such as enzyme-linked immunosorbent assay or fluorescence immunoassay. Anti-FVIII or anti-FIX antibodies of IgG4 subclass best correlate with the presence of functional inhibitors. Improvements in inhibitor measurement have been recently introduced. Preanalytical heat treatment of patient specimens allows testing of patients without delaying treatment. Use of chromogenic and immunologic assays may aid in identification of false-positive results, which are frequent among low-titre inhibitors. Validated reagent substitutions can be used to reduce assay cost. New methods for defining assay positivity and reporting low-titre inhibitors have been suggested. Challenges remain in the areas of quality control, assay standardization, monitoring of patients undergoing immune tolerance induction therapy and testing in the presence of modified and novel treatment products.

Survey of the anti-factor IX immunoglobulin profiles in patients with hemophilia B using a fluorescence-based immunoassay

Essentials Studies characterizing neutralizing antibodies (inhibitors) in hemophilia B (HB) are lacking. The current study describes anti-factor (F) IX antibody profiles in 37 patients who have HB. Anti-FIX IgG4 levels exhibited a strong positive correlation with Nijmegen-Bethesda results. These data will help to more clearly define, predict, and treat alloantibody formation in HB.

SUMMARY

Background Hemophilia B (HB) is an inherited bleeding disorder caused by the absence or dysfunction of coagulation factor IX (FIX). A subset of patients who have HB develop neutralizing alloantibodies (inhibitors) against FIX after infusion therapy. HB prevalence and the proportion of patients who develop inhibitors are much lower than those for hemophilia A (HA), which makes studies of inhibitors in patients with HB challenging due to the limited availability of samples. As a result, there is a knowledge gap regarding HB inhibitors. Objective Evaluate the largest group of patients with inhibitor-positive HB studied to date to assess the relationship between anti-FIX antibody profiles and inhibitor formation. Methods A fluorescence immunoassay was used to detect anti-FIX antibodies in plasma samples from 37 patients with HB. Results Assessments of antibody profiles showed that anti-FIX IgG1-4 , IgA, and IgE were detected significantly more often in patients with a positive Nijmegen-Bethesda assay (NBA). All NBA-positive samples were positive for IgG4 . Anti-FIX IgG4 demonstrated a strong correlation with the NBA, while correlations were significant, yet more moderate, for anti-FIX IgG1-2 and IgA. Conclusions The anti-FIX antibody profile in HB patients who develop inhibitors is diverse and correlates well with the NBA across immunoglobulin (sub)class, and anti-FIX IgG4 is particularly relevant to functional inhibition. The anti-FIX fluorescence immunoassay may serve as a useful tool to confirm the presence of antibodies in patients who have low positive NBA results and to more clearly define, predict, and treat alloantibody formation against FIX.

A study of prospective surveillance for inhibitors among persons with haemophilia in the United States

Inhibitors are a rare but serious complication of treatment of patients with haemophilia. Phase III clinical trials enrol too few patients to adequately assess new product inhibitor risk. This project explores the feasibility of using a public health surveillance system to conduct national surveillance for inhibitors. Staff at 17 U.S. haemophilia treatment centres (HTC) enrolled patients with haemophilia A and B into this prospective study. HTC staff provided detailed historic data on product use and inhibitors at baseline, and postenrolment patients provided monthly detailed infusion logs. A central laboratory performed inhibitor tests on blood specimens that were collected at baseline, annually, prior to any planned product switch or when clinically indicated. The central laboratory also performed genotyping of all enrolled patients. From January 2006 through June 2012, 1163 patients were enrolled and followed up for 3329 person-years. A total of 3048 inhibitor tests were performed and 23 new factor VIII inhibitors were identified, 61% of which were not clinically apparent. Infusion logs were submitted for 113,205 exposure days. Genotyping revealed 431 distinct mutations causing haemophilia, 151 of which had not previously been reported elsewhere in the world. This study provided critical information about the practical issues that must be addressed to successfully implement national inhibitor surveillance. Centralized testing with routine monitoring and confirmation of locally identified inhibitors will provide valid and representative data with which to evaluate inhibitor incidence and prevalence, monitor trends in occurrence rates and identify potential inhibitor outbreaks associated with products.

Comparison of clot-based, chromogenic and fluorescence assays for measurement of factor VIII inhibitors in the US Hemophilia Inhibitor Research Study

BACKGROUND

Detection and validation of inhibitors (antibodies) to hemophilia treatment products are important for clinical care, evaluation of product safety and assessment of population trends.

METHODS

Centralized monitoring for factor VIII (FVIII) inhibitors was conducted for patients in the Hemophilia Inhibitor Research Study using a previously reported modified Nijmegen-Bethesda clotting assay (NBA), a chromogenic Bethesda assay (CBA) and a novel fluorescence immunoassay (FLI).

RESULTS

NBA and CBA were performed on 1005 specimens and FLI on 272 specimens. CBA was negative on 880/883 specimens (99.7%) with Nijmegen-Bethesda units (NBU) < 0.5 and positive on 42/42 specimens (100%) with NBU ≥ 2.0 and 43/80 specimens (53.8%) with NBU 0.5-1.9. Among specimens with positive NBA and negative CBA, 58.1% were FLI negative, 12.9% had evidence of lupus anticoagulant, and 35.5% had non-time-dependent inhibition. CBA and FLI were positive on 72.4% and 100% of 1.0-1.9 NBU specimens and 43.1% and 50.0% of 0.5-0.9 NBU specimens. FLI detected antibodies in 98.0% of CBA-positive and 81.6% of NBA-positive specimens (P = 0.004). Among 21 new inhibitors detected by NBA, five (23.8%) with 0.7-1.3 NBU did not react in CBA or FLI. Among previously positive patients with 0.5-1.9 NBU, 7/25 (28%) were not CBA or FLI positive. FLI was positive on 36/169 NBU-negative specimens (21.3%).

CONCLUSIONS

FVIII specificity could not be demonstrated by CBA or FLI for 26% of inhibitors of 0.5-1.9 NBU; such results must be interpreted with caution. Low titer inhibitors detected in clot-based assays should always be repeated, with consideration given to evaluating their reactivity with FVIII using more specific assays.

Validation of Nijmegen-Bethesda assay modifications to allow inhibitor measurement during replacement therapy and facilitate inhibitor surveillance

BACKGROUND

As part of a pilot U.S. inhibitor surveillance project initiated at the Centers for Disease Control and Prevention (CDC) in 2006, a centralized inhibitor measurement was instituted.

OBJECTIVE

To validate a modified method for inhibitor measurement suitable for surveillance of treated and untreated patients.

METHODS/RESULTS

In all, 710 subjects with hemophilia A were enrolled; 122 had a history of inhibitor (HI). Nijmegen-Bethesda assay (NBA) results on 50 split specimens shipped on cold packs and frozen were equivalent (r=0.998). Because 55% of 228 initial specimens had factor (F)VIII activity (VIII:C) present, a heat treatment step was added. Heating specimens to 56°C for 30 min and centrifuging removed FVIII, as demonstrated by a reduction of VIII:C and FVIII antigen to <1 U dL(-1) in recently treated patients. Among specimens inhibitor-negative before heating, one of 159 with negative HI and five of 30 with positive HI rose to ≥ 0.5 Nijmegen-Bethesda units (NBU) after heating. Correlation of heated and unheated inhibitor-positive specimens was 0.94 (P=0.0001). The modified method had a coefficient of variation (CV) for a 1 NBU positive control of 10.3% and for the negative control of 9.8%. Based on results on 710 enrollment specimens, a positive CDC inhibitor was defined as ≥ 0.5 NBU. Results were similar when 643 post-enrollment specimens were included. Of 160 enrolled hemophilia B patients, two had HI. All others had NBU ≤ 0.2 at enrollment.

CONCLUSION

The CDC experience demonstrates that this modified NBA can be standardized to be within acceptable limits for clinical tests and can be used for national surveillance.

F8 and F9 mutations in US haemophilia patients: correlation with history of inhibitor and race/ethnicity

Both genetic and treatment-related risk factors contribute to the development of inhibitors in haemophilia. An inhibitor surveillance system piloted at 12 US sites has the goal of assessing risk factors through prospective data collection. This report examines the relationship of genotype and race/ethnicity to history of inhibitor in a large cohort of US haemophilia patients. Mutation analysis was performed on 676 haemophilia A (HA) and 153 haemophilia B (HB) patients by sequencing, Multiplex Ligation-dependent Probe Amplification, and PCR for inversions in F8 introns 22 (inv22) and 1 (inv1). Two HB patients with deletions had history of inhibitor. In severe HA, frequency of history of inhibitor was: large deletion 57.1%, splice site 35.7%, inv22 26.8%, nonsense 24.5%, frameshift 12.9%, inv1 11.1% and missense 9.5%. In HA, 19.6% of 321 White non-Hispanics (Whites), 37.1% of 35 Black non-Hispanics (Blacks) and 46.9% of 32 Hispanics had history of inhibitor (P = 0.0003). Mutation types and novel mutation rates were similar across ethnicities. When F8 haplotypes were constructed, Whites and Hispanics showed only H1 and H2. Within H1, history of inhibitor was 12.4% in Whites, 40.0% in Blacks (P = 0.009) and 32.4% in Hispanics (P = 0.002). Inhibitor frequency is confirmed to vary by mutation type and race in a large US population. White patients with history of inhibitor did not exhibit rare F8 haplotypes. F8 gene analysis did not reveal a cause for the higher inhibitor frequencies in Black and Hispanic patients.

In non-severe hemophilia A the risk of inhibitor after intensive factor treatment is greater in older patients: a case-control study

BACKGROUND

 Twenty-five percent of new anti-factor VIII (FVIII) antibodies (inhibitors) that complicate hemophilia A occur in those with mild and moderate disease. Although intensive FVIII treatment has long been considered a risk factor for inhibitor development in those with non-severe disease, its strength of association and the influence of other factors have remained undefined.

OBJECTIVE

 To evaluate risk factors for inhibitor development in patients with non-severe hemophilia A.

METHODS

 Information on clinical and demographic variables and FVIII genotype was collected on 36 subjects with mild or moderate hemophilia A and an inhibitor and 62 controls also with mild or moderate hemophilia A but without an inhibitor.

RESULTS

 Treatment with FVIII for six or more consecutive days during the prior year was more strongly associated with inhibitor development in those ≥30years of age compared with those <30years of age [adjusted odds ratio (OR) 12.62; 95% confidence interval (CI), 2.76-57.81 vs. OR 2.54; 95% CI, 0.61-10.68]. Having previously received <50days of FVIII was also not statistically associated with inhibitor development on univariate or multivariate analysis.

CONCLUSIONS

 These findings suggest that inhibitor development in mild and moderate hemophilia A varies with age, but does not vary significantly with lifetime FVIII exposure days: two features distinct from severe hemophilia A.

Laboratory response to intranasal desmopressin in women with menorrhagia and platelet dysfunction

Intranasal desmopressin (IN-DDAVP) is used for home treatment of menorrhagia in women with inherited bleeding disorders. The effect of IN-DDAVP on laboratory haemostatic parameters in women with menorrhagia related to platelet dysfunction is unknown. We evaluated the effects of IN-DDAVP on haemostatic parameters in women with menorrhagia and platelet dysfunction and correlated them with menstrual flow. Eleven women (aged 18-45) with menorrhagia and haemostatic abnormalities had determination of von Willebrand factor antigen (VWF:Ag), von Willebrand factor ristocetin cofactor (VWF:RCo) activity, factor VIII coagulant activity (FVIII:C), platelet aggregation and platelet adenosine tri-phosphate (ATP) release pre-IN-DDAVP and 60-min post-IN-DDAVP. Eight of eleven women underwent platelet function analyzer (PFA-100) closure time determination with collagen/adrenaline and collagen/adenosine diphosphate cartridges pretreatment and post-treatment. IN-DDAVP was administered during two consecutive menstrual cycles. Menstrual flow was assessed during each cycle using a pictorial blood assessment chart. Treatment with IN-DDAVP resulted in elevated VWF levels and shortened PFA-100 closure time with significant inverse correlation between shortening of PFA-100 closure times and increases in VWF levels. There were also significant inverse correlations between changes in menstrual flow and changes in VWF:Ag (P = 0.02), VWF:RCo (P = 0.04) and FVIII:C (P = 0.006), following treatment. In vitro platelet aggregation and platelet ATP release response did not correct and did not correlate with changes in menstrual flow. Our results demonstrate a correlation between haemostatic parameters and menstrual flow following IN-DDAVP in women with menorrhagia and platelet dysfunction.

Screening women with menorrhagia for underlying bleeding disorders: the utility of the platelet function analyser and bleeding time

Menorrhagia is a very common clinical problem among women of reproductive age and recent studies have suggested that underlying bleeding disorders, particularly von Willebrand's deficiency and platelet function defects, are prevalent in women presenting with menorrhagia. The objective of this study was to determine the utility of the platelet function analyser (PFA-100) and bleeding time (BT) as initial screening tests for underlying bleeding disorders in women with menorrhagia. In this study, 81 women with a physician diagnosis of menorrhagia underwent PFA-100 testing, BT and comprehensive haemostatic testing. The effectiveness of the PFA-100 and BT as screening tools in women with menorrhagia was assessed using results of haemostatic testing for von Willebrand's disease (VWD) and platelet dysfunction. In women presenting with menorrhagia, the PFA-100 had a sensitivity 80%, specificity 89%, positive predictive value (PPV) 33%, negative predictive value (NPV) 98% and efficiency 88% for VWD. For platelet aggregation defects, the PFA-100 closure time had a sensitivity 23%, specificity 92%, PPV of 75%, NPV of 52% and efficiency 55%. The data suggest that the PFA-100 may be useful in stratifying women with menorrhagia for further von Willebrand testing; however, neither the PFA-100 nor the BT tests are effective for purposes of classifying women for standard platelet aggregometry testing in women presenting with menorrhagia.

Antimicrobial activity of ultrasonic cleaners

This study assessed the antimicrobial activity of two cleaning solutions and tap water after varying periods of use in one ultrasonic cleaner. Testing involved filling the cleaner's tank and a centred glass beaker with the same test solution. An aluminium foil strip test first determined that no significant differences in cavitational activity existed inside the beaker compared with outside. Standardized solutions of Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella choleraesuis were left at room temperature for 10 min. Aliquots were exposed to both cleaning solution and ultrasonic action. Unused test solution was removed from the tank, filter-sterilized, mixed with bacterial suspension and placed into a sterile beaker. Cleaning was allowed for 10 min. The beaker was removed and its contents examined. The tank was allowed to cool for 30 min and the process was repeated four times. The entire experimental set was repeated once. Exposure to test solution alone in all but one case produced reductions in bacterial numbers from initial >/=2 x 10(9) by 19.9-52.6%. Application of both chemical exposure and ultrasonic cleaning produced greater bacterial kill (46.4-99.7% reductions). However, kill became less effective on repeated use of a commercial cleaning solution. Reduction was highest when fresh ultrasonic cleaning solutions were used. In no case did complete sterilization occur. As well as removing adherent material, ultrasonic cleaning may also markedly reduce the number of viable organisms present.

Measurement of von Willebrand factor activity: relative effects of ABO blood type and race

Tests based on three different principles are reported to measure the activity of von Willebrand factor (VWF): ristocetin cofactor (VWF:RCo), collagen binding (VWF:CB), and the so-called "activity ELISA" (VWF:MoAb). We measured these and other diagnostic parameters in a population of 123 randomly selected female study controls, age 18-45 years. Type O subjects had significantly lower levels than non-O subjects in each test. Race differences were seen in all tests except VWF:RCo, with Caucasians having significantly lower levels than African-Americans. ABO differences accounted for 19% of the total variance in VWF:Ag (P < 0.0001) and race for 7% (P < 0.0001), for a total of 26%. Both effects were mediated through VWF:Ag and were independent. VWF:Ag level was the primary determinant of VWF function, accounting for approximately 60% of the variance in VWF:RCo and VWF:CB and 54% of the variance in factor VIII. The ratio VWF:RCo/VWF:Ag differed significantly by race within blood group. The median ratios were 0.97 for type O Caucasians vs. 0.79 for type O African-Americans and 0.94 for non-O Caucasians vs. 0.76 for non-O African-Americans. The ratio VWF:CB/VWF:Ag did not vary. This suggests racial differences in the interaction of VWF with GP1b but not with subendothelium. Alternatively, VWF:RCo may be regulated to maintain a relatively constant plasma level in the presence of excessive VWF:Ag. This heterogeneity within the normal population is partially responsible for the difficulty in defining diagnostic limits for von Willebrand disease.

Platelet functional defects in women with unexplained menorrhagia

Menorrhagia is a common clinical problem and is unexplained in more than 50% of women. Although studies suggest that von Willebrand's Disease (VWD) is found in a substantial number of women with unexplained menorrhagia, the prevalence of platelet defects in women with menorrhagia is unknown. To determine the prevalence of platelet and other hemostatic defects, we evaluated women ages 17-55 diagnosed with unexplained menorrhagia. Seventy-four women (52 white, 16 black, six other) were studied. Bleeding time was prolonged in 23 women (31.5%). Maximal percent platelet aggregation was decreased with one or more agonists in 35 (47.3%) women. The most commonly found platelet function defects were reduced aggregation responses to ristocetin in 22 women and to epinephrine in 16 women. Sixteen of 22 women with reduced ristocetin aggregation had von Willebrand ristocetin cofactor (VWF:RCo) and von Willebrand factor antigen (VWF:Ag) > 60%. Platelet ATP release was decreased with one or more agonists in 43 (58.1%) women. Of the black women studied, 11/16 (69%) had abnormal platelet aggregation studies compared with 20/52 white women (39%) (P = 0.06). Black women with menorrhagia had a higher prevalence of decreased platelet aggregation in response to ristocetin and epinephrine than did white women (P = 0.0075, P = 0.02). Ten women (13.5%) had VWF:RCo and/or VWF:Ag < 60%. Using race and blood group specific ranges, 5 (6.8%) women had decreased VWF:RCo, VWF:Ag and/or collagen binding (VWF:CB). Mild factor XI deficiency was found in two women and one woman with mild factor V deficiency and one hemophilia A carrier were identified. We conclude that the prevalence of platelet function defects and other inherited bleeding disorders is substantial in a multiracial US population of women with unexplained menorrhagia.

Factor V Leiden and factor V R2 allele: high-throughput analysis and association with venous thromboembolism

Thrombophilia is a multigenic disease in which the combination of genetic polymorphisms increases the risk of deep vein thrombosis (DVT). The rapid identification of these genetic combinations requires high-throughput analysis of single nucleotide polymorphisms (SNPs). The TaqMan fluorogenic 5'-->*3' nuclease assay (PE/Applied Biosystems, Foster City, CA) with custom-designed primers, probes and controls has provided a highly efficient platform for high throughput. This assay was used to rapidly detect two SNPs, FV Leiden (G1691A) and FV A4070G (R2 allele), in a study of 6295 subjects. With one thermal cycler, we completed sample set-up, PCR and analysis on 84 samples in 3 h with an additional 12 wells containing 4 "no template controls" (NTC), 4 "allele-1 controls", and 4 "allele-2 controls" in a 96-well plate. When additional thermal cyclers were used and more assays were set up while the initial sets of reactions were in the PCR machines, the output could correspondingly be increased. The TaqMan assay was extremely accurate, avoided contamination by using uracil-N-glycolase (UNG) in a single, closed tube, and offered the possibility for additional automation with robotic equipment to implement the PCR. This TaqMan assay facilitates high throughput to screen large populations quickly and economically while utilizing a simple protocol that requires minimal expenditure of personnel time. Our results demonstrated a prevalence of the R2 allele of 11.9% in U.S. Caucasians, 5.6% in African-Americans, 13.4% in Asian or Pacific Islanders and 11.3% in Hispanics. No association between venous thromboembolism and the R2 allele was noted, and furthermore no interaction with FV Leiden was observed.

Population differences in von Willebrand factor levels affect the diagnosis of von Willebrand disease in African-American women

Diagnosis of von Willebrand disease (vWD) is based on a panel of laboratory tests that measure the amount and function of von Willebrand factor (vWF). In population studies, vWF is higher in African Americans than Caucasians. Bleeding time, factor VIII activity (FVIII), vWF antigen (vWF:Ag), "vWF activity" ELISA (vWF:Act), ristocetin cofactor (vWF:RCof), and ristocetin-induced platelet aggregation (RIPA) were measured on 123 women with menorrhagia and 123 randomly selected control women; 70 cases and 76 controls were African American. Among controls, African Americans had significantly higher levels of vWF:Ag (mean 120 vs. 102 U/dl, P = 0.017). Among all subjects, African Americans had higher levels of vWF:Ag (mean 123 vs. 103, P = 0.001), vWF:Act (mean 101 vs. 89, P = 0.006), and FVIII (mean 118 vs. 104, P = 0.008). VWF:RCof did not differ between races (93 vs. 94 U/dl). RIPA was reduced in African Americans (P < 0.0001). In both races, women with type O blood differed significantly from those with other ABO types in vWF:Ag, vWF:Act, FVIII, and vWF:RCof. Based on criteria of two or more tests below race- and ABO-specific reference ranges, 6.5% of menorrhagia cases and 0.8% of controls were classified as having vWD, or its phenocopy. Among Caucasians, no controls and 7 cases (15.6%) were classified as affected, and in African Americans, 1 control (1.3%) and 1 case (1.4%) were so classified. Racial differences in vWF further complicate the issues surrounding diagnosis of vWD. The finding of increased vWF:Ag not accompanied by increased vWF:RCof has implications for understanding the structure-function relationships of vWF. Published 2001 Wiley-Liss, Inc.

Dexamethasone and stress-induced analgesia

Analgesia induced in rats by cold-water swim stress and measured by the tail-flick and hot-plate methods was significantly antagonized after IP pretreatment for 3 days with 8 mg/kg dexamethasone. The analgesia developed by the cold-water swim stressor was also attenuated by 1 mg/kg naloxone. These results suggest that the corticosteroids may have a role in modulating stress-induced analgesia and that the adrenal-pituitary axis modulates the endogenous opiate system. These conclusions are based on recent reports that indicate the release of the opiate-like peptide beta-endorphin and adrenocorticotropin (ACTH) from the pituitary are increased by acute stress and inhibited by administration of the synthetic glucocorticoid dexamethasone.

In vitro quantitative chemical analysis of tattoo pigments

BACKGROUND

The composition of cosmetic tattoos might prove relevant to their treatment by high-powered lasers.

OBJECTIVES

To test the accuracy and completeness of information supplied by the tattoo ink manufacturers and to perform an elemental assay of tattoo pigments using scanning electron microscopy with energy-dispersive x-ray analysis.

DESIGN

Samples of 30 tattoo inks were examined using "standardless" energy-dispersive spectrometry. This technique uses quantitative electron x-ray microanalysis. The technique reliably identifies all elements with the exception of those elements with atomic numbers less than 11.

SETTING

A major national referral laboratory for microscopic examination and biochemical analysis of tissue. These results were compared with ink compositions compiled from manufacturer-supplied material safety data sheets.

MAIN OUTCOME MEASURES

(1) The percentage of any given element in whole tattoo pigments. (2) The presence or absence of elements and/or compounds as recorded in material safety data sheets supplied by the tattoo ink manufacturers.

RESULTS

Of the 30 tattoo inks studied, the most commonly identified elements were aluminum (87% of the pigments), oxygen (73% of the pigments), titanium (67% of the pigments), and carbon (67% of the pigments). The relative contribution of elements to the tattoo ink compositions was highly variable between different compounds. Overall, the manufacturer-supplied data sheets were consistent with the elemental analysis, but there were important exceptions.

CONCLUSION

The composition of elements in tattoo inks varies greatly, even among like-colored pigments. Knowledge of the chemical composition of popular tattoo inks might aid the clinician in effective laser removal.

TC-2559: a novel orally active ligand selective at neuronal acetylcholine receptors

TC-2559 [(E)-N-Methyl-4-[3-(5-ethoxypyridin)yl]-3-buten-1-amine] is a novel nicotinic agonist markedly more selective than recently reported novel nicotinic receptor ligands (selectivity ratio for central nervous system (CNS) to peripheral nervous system (PNS)>4000). TC-2559 competes effectively with [3H]-nicotine binding (K(i)=5 nM) but not with [125I]-bungarotoxin (>50,000 nM). Dopamine release from striatal synaptosomes and ion flux from thalamic synaptosomes indicate that TC-2559 is potent and efficacious in the activation of CNS receptors and significantly reduced glutamate-induced neurotoxicity in vitro. TC-2559 has no detectable effects on muscle and ganglion-type nicotinic acetylcholine receptors at concentrations up to 1 mM. TC-2559 significantly attenuates scopolamine-induced cognitive deficits in a step-through passive avoidance task. Acute and repeated oral dosing of TC-2559 enhances performance in a radial arm maze task. In contrast to the effects of equimolar concentrations of (-) nicotine, TC-2559 does not induce hypothermia and locomotor activity is not enhanced following repeated daily administration of 14 days. TC-2559 has a markedly enhanced CNS-PNS selectivity ratio and an intra-CNS selectivity as evidenced by the improved cognition without increased locomotor activity. The in vitro and in vivo studies in the present study suggest that TC-2559 has the desired profile to be further evaluated as a potential therapeutic agent for neurodegenerative diseases.

Intravenous versus oral administration of amitriptyline in patients with major depression

Antidepressants can be administered by different routes. Advantages for either the oral or the intravenous administration have been suggested from pharmacokinetic as well as from clinical points of view. Controlled comparison studies of the two routes do not provide unequivocal recommendations. In this investigation, amitriptyline was studied over a 4-week period consisting of a 2-week, double-blind/double-dummy phase with either oral (150 mg/day), high-dose intravenous (150 mg/day), or medium-dose intravenous (100 mg/day) treatment and a 2-week phase of open oral treatment in 80 patients with major depression. A psychopathologic assessment was made using the Hamilton Rating Scale for Depression, the Clinical Global Impressions Scale, the von Zerssen's "Befindlichkeitsskala," an adjective checklist, and a Visual Analog Scale. No significant differences were found concerning the mean scores of the rating scales or time of onset of action in the physicians' ratings. In the patients' self-ratings, there was an earlier therapeutic effect in the high-dose intravenous group. The number of improvers after 7 days was significantly higher in the high-dose intravenous group compared with both other groups. After 14 days, no significant differences in the numbers of improvers and responders between groups were detected. The results of this study do not clearly favor one of the tested options. The main differences found in this study seem to be dose-related rather than differentiating between oral and intravenous routes of administration.

Effect of leukocyte-endothelial adhesion antagonism on neutrophil migration and neurologic outcome after cortical trauma

BACKGROUND

Administration of anti-CD11B, a monoclonal antibody directed against the leukocyte adhesion molecule CD11B, results in decreased neutrophil infiltration into injured tissue after experimental ischemia. We determined the effect of anti-CD11B administration on neutrophil migration and neurologic functioning after experimental cortical trauma.

METHODS

Injuries were produced by a pneumatic impactor. Treatment animals received anti-CD11B after injury. Neurologic functioning was quantitated at 1, 12, and 24 hours after injury. Neutrophil migration was assessed with the myeloperoxidase assay.

RESULTS

Neutrophil influx was increased in injured cortex after trauma. Anti-CD11B significantly reduced neutrophil influx. There was no significant improvement in neurologic functioning after MAb administration.

CONCLUSIONS

These results show there is marked neutrophil response to injury as produced with the pneumatic contusion model. This migration may be significantly attenuated by administration of a anti-CD11B.

Pilot study of local autologous tumor infiltrating lymphocytes for the treatment of recurrent malignant gliomas

A prospective pilot study was performed in order to assess the safety of treating recurrent malignant gliomas (MGs) with locally infused autologous tumor infiltrating lymphocytes (TILs) and recombinant interleukin-2 (rIL-2). Six patients were entered between June 27, 1994 and June 2, 1995 and followed until July 1, 1998. At surgery an Ommaya reservoir was placed for later infusion of TILs and rIL-2. Following surgery, autologous TILs were expanded in vitro in the presence of rIL-2 and infused on treatment days 1 and 14, with concurrent rIL-2 infusions performed three times each week for one month. Following completion of immunotherapy all patients were offered chemotherapy. Phenotypic analysis demonstrated TILs to be T-lymphocytes (87-99% CD3+). Of these, 4 of 6 cases (67%) phenotyped as cytotoxic/suppressor T-lymphocytes (CD8+) and 2 of 6 cases (33%) phenotyped as helper/inducer T-lymphocytes (CD4+). TILs demonstrated limited selective cytotoxicity, with dose dependent cytotoxicity against autologous tumor, allogenic tumor and long term MG cell lines. There were no significant (Grade 3 or 4) complications. One patient developed transient low grade fevers, and 2 developed asymptomatic hydrocephalus. All patients developed transient and asymptomatic cerebral swelling, noted on the immediate post-treatment imaging studies. At three and six month follow-up, 3 patients responded with partial response, 2 demonstrated stable disease and 1 patient progressed. At long term follow-up, 1 patient had a complete response (45 month follow-up), 2 had a partial response (48 and 47 month follow-up) and 3 patients expired as a result of progressive disease (at 12, 12 and 18 months following immunotherapy). A relationship between subsequent chemotherapy or extent of resection to outcome was not apparent but could not be excluded. This pilot study demonstrated that locally infused autologous TILs and rIL-2 could be delivered without serious toxicity. Further studies are indicated to determine the safety and long term efficacy of TIL immunotherapy.

Transepidermal migration of external cardiac pacing wire presenting as a cutaneous nodule

Temporary epicardial pacing wires are used to control postoperative arrhythmias in patients who have undergone open heart surgery. We present an interesting case of a foreign body granuloma resulting from a retained epicardial pacing wire.

Nonablative skin remodeling: selective dermal heating with a mid-infrared laser and contact cooling combination

BACKGROUND AND OBJECTIVE

Many of the microscopic changes associated with photodamage reside in the dermis. It follows that subsurface heating of the skin might allow for cosmetic enhancement without loss of the epidermis. Accordingly, we investigated the clinical and microscopic changes produced by a mid-infrared laser coupled with a contact cooling device.

STUDY DESIGN/MATERIALS AND METHODS

Nine patients were treated with an erbium glass laser and sapphire cooling handpiece in contact with the skin. Postauricular sites were irradiated with pulse energies varying from 400-1,200 mJ and numbers of pulses from 4 to 40. Outcome measures included pain, edema, and erythema at predetermined postoperative intervals. Biopsies were performed just after treatment and 2 months postoperatively for selected pulse energy-pulse number combinations.

RESULTS

Erythema, edema, and pain increased with pulse energy and number of pulses. Likewise, immediate epidermal necrosis and subsequent scarring were observed for larger pulse energy-pulse number combinations. At sites with epidermal preservation, on biopsy, immediate dermal thermal damage was observed in a band-like pattern. The deep boundaries of this band were dependent on pulse energy and pulse number. After 8 weeks, biopsies showed dermal fibroplasia roughly correlating to the band of immediate dermal thermal damage.

CONCLUSION

Selective dermal heating can be achieved with a mid-infrared laser coupled to a contact surface cooling device. In this study, the range of fibroplasia and lack of clinically substantial cosmetic enhancement suggest that the dermal thermal damage achieved may be too deep and that the injury should be confined to more superficial levels to alter the most severely photodamaged dermis. Lasers Surg. Med. 26:186-195, 2000. Published 2000 Wiley-Liss, Inc.

Cleaning dental instruments: measuring the effectiveness of an instrument washer/disinfector

PURPOSE

To analyze the cleaning effectiveness of one type of instrument washer available for use in a dental office.

MATERIALS AND METHODS

Dental instruments were heavily contaminated with blood and specific test bacteria. They were placed in cleaning baskets or within instrument cassettes, processed through the instrument washer, and analyzed for remaining blood and viable bacteria.

RESULTS

Information obtained indicated that the washer is an effective cleaning system for dental instruments.

Strategies for dental clinic infection control

The application of proper infection control procedures helps to protect practitioners, patients and the community. The goal is to minimize the spread of potentially pathogenic micro-organisms and to remove and/or kill organisms that have contaminated objects and surfaces. Dental practitioners are aided in this process by the generation of rules, guidelines and recommendations by regulatory agencies and professional organizations. Ideally, each office/clinic would generate and maintain a written set of infection control procedures.

Managing antipsychotic-induced acute and chronic akathisia

Akathisia is a frequent and common adverse effect of treatment with antipsychotic (neuroleptic) drugs. This syndrome consists of subjective (feeling of inner restlessness and the urge to move) as well as objective components (rocking while standing or sitting, lifting feet as if marching on the spot and crossing and uncrossing the legs while sitting). Antipsychotic-induced akathisia can be classified according to the time of onset in the course of antipsychotic treatment (acute, tardive, withdrawal and chronic akathisia). Reported prevalence rates vary widely between 5 and 36.8%. Numerous risk factors for acute akathisia have been described and the exact pathophysiology of akathisia is still unknown. Since akathisia is a drug-induced adverse effect, optimal management involves its prevention rather than treatment. Standardised titration and the use of novel antipsychotics are successful measures of prevention. This paper reviews different forms of therapeutic approaches for the treatment of akathisia. Based on the available literature, propranolol or other lipophilic beta-blockers seem to be the most consistently effective treatment for acute akathisia. There is nothing in the literature to guide a clinician when treatment with beta-blockers fails. Addition of benzodiazepines would appear to be a sensible next choice, especially if subjective distress persists. If all of these drugs are unsuccessful, amantadine or clonidine can be tried. Other agents that have been investigated include ritanserin, piracetam, valproic acid (sodium valproate) and tricyclic antidepressants. Evidence on the treatment of tardive akathisia is unsatisfactory.

Moving towards a latex-free environment: advice from experiences in US dentistry

Most dental practitioners now routinely wear gloves while treating patients. The most commonly used types of gloves contain latex. Latex is also present in other personal protective equipment, such as masks, eyewear and clinic gowns. Increased use of such items, unfortunately, has been linked to adverse skin and mucous membrane reactions. Latex proteins and chemicals associated with the material's production have been implicated. Exposure to such chemicals has also resulted in allergic responses in dental patients. There is a strong movement in the USA to limit exposure to latex in healthcare environments, including dentistry. The aim of this article is to describe past, present and future efforts to create low-latex or latex-free environments.

Evaluation of an illuminated mirror

The viewing of oral structures with an adequate level of illumination is necessary to make accurate diagnoses of normalities and abnormalities in the oral cavity. The purpose of this study is to determine if a device with an illuminated mirror is heat sterilizable, easy to use, and compares in illumination potential to a traditional overhead dental operating light. We sterilized the Denlite in both chemical vapor and autoclave units (including a group that was cleaned ultrasonically prior to autoclave), testing the illuminance level every 10 cycles, for 100 cycles. We installed devices in the Graduate Operative Dentistry Clinic and requested those operators assigned to the units to rate the devices. Their acceptance rate was high in visibility, ease of use, acceptable temperature of handle, and lack of problems with the device. The device had an illuminance level of 14,200 lux, which is just below the maximum level of illuminance required by the American Dental Association's Specification on Dental Operating Lights.

Antimicrobial activities of dental impression materials

OBJECTIVE

The aim of this study was to measure the in vitro killing effects five commercial alginate impression materials had on five test microorganisms.

METHODS

Two alginates with no added disinfectant, one supplemented with chlorhexidine and two others containing quaternary ammonium compounds were tested. Challenge microbes included two gram-positive cocci, two gram-negative bacilli and a yeast. Saline solutions containing standardized concentrations of test microbes were used to mix the alginates. Some set specimens were immediately homogenized and the resulting fluids diluted and spread plated. Other specimens were processed 30 or 60 min after setting. After culturing, the numbers of colonies were counted and the levels of microbial reductions determined.

RESULTS

Unsupplemented alginates had no antimicrobial effects. The quaternary-ammonium-containing alginates were completely effective against all five test microorganisms. The alginate with chlorhexidine killed all the gram-negative bacilli and the majority (95-99%) of the gram-positive cocci and yeast.

SIGNIFICANCE

Results indicated that disinfectant-containing alginate impression materials could reduce the number of soiling microorganisms present on and within test specimens.

Diagnosis of von Willebrand disease type 2N: a simplified method for measurement of factor VIII binding to von Willebrand factor

Diagnosis of von Willebrand disease Type 2N (vWD 2N), which mimics hemophilia A and its carrier state, is important for accurate genetic counseling and appropriate therapy. To make testing for the disorder more clinically applicable, we developed a simplified method for measurement of factor VIII (FVIII) binding to von Willebrand factor (vWF) using commercially available reagents and standard clinical assays. FVIII binding to vWF was measured by capture of patient vWF by polyclonal antibodies on cyanogen bromide-activated Sepharose beads, reaction with recombinant FVIII, and assay of unbound FVIII by clotting methods. Unbound vWF was measured in patient plasma after capture by the Laurell method. The ratio of bound FVIII/bound vWF was normal in hemophilia A, vWD Type 1, and vWD Type 3 patients, and abnormal in 5 subjects from two families, all of whom had vWD 2N mutations. Patient 1, with FVIII 8 U/dl, vWF: Ag 61 U/dl, vWF:RC 74 U/dl, and FVIII binding nil, was homozygous for the Arg91 Gln mutation. She was followed during pregnancy and delivered an unaffected heterozygous son. Patient 2 had FVIII 8 U/dl, vWF:Ag 73 U/dl, and vWF:RC 71 U/dl, and very low FVIII binding. She was heterozygous for Arg91Gln, as were her mother and sister; no second vWD 2N mutation was found. Her brother, with FVIII 14 U/dl, vWF:Ag 113 U/dl, and vWF:RC 72 U/dl, has no evidence of vWD 2N. With an X-linked inheritance pattern of bleeding tendency, this family is the first reported with combined hemophilia A and vWD 2N.

Effect of ultrasonic cleaning on microorganisms

PURPOSE

To establish a method to measure microbial kill caused by ultrasonic cleaning. Secondarily, to estimate the escape of bacteria from the ultrasonic cleaning solutions during operation of the unit.

MATERIALS AND METHODS

Three commercial enzymatic detergents and saline were used as cleaners. Depending on detergent, initial operational temperature was 21 degrees C, 37 degrees C or 60 degrees C. Streptococcus mutans ATCC 25175 (S. mutans suspensions) was adjusted to a final concentration of 1.0 x 10(3) cells/mL in saline. Suspensions (2000 mL) at the desired temperatures were added to the cleaner. Aliquots were removed, serially diluted in letheen broth and spread plated over mitis salivarius agar. Appropriate amounts of detergent solutions were added to S. mutans suspensions and the cleaner operated for 20 minutes. Aliquots were then removed and plated. The process was repeated twice. Plates were aerobically incubated at 37 degrees C for 7 days and the colonies counted. The procedure was repeated using three temperatures of S. mutans suspensions (21 degrees C, 37 degrees C or 60 degrees C), but without detergent or ultrasound. Also, detergents were added to 21 degrees C S. mutans suspensions and allowed to sit for 20 minutes without ultrasonic cleaning. Microbial sampling was done as previously described.

RESULTS

Results when ultrasound was used indicated that little kill (5-15%) occurred in 21 degrees C or 37 degrees C detergent solutions. Greater kill (25-35%) was noted with 21 degrees C and 37 degrees C saline. Complete kill was accomplished with 60 degrees C saline or the 60 degrees C detergent solution. When ultrasound and detergent were not used, there was no kill in 21 degrees C and 37 degrees C saline, but complete kill in 60 degrees C saline. In the absence of ultrasound no kill was noted in 21 degrees C S. mutans suspensions to which detergent had been added. Total kill of S. mutans was observed in 60 degrees C saline or 60 degrees C detergent with ultrasound or after a 20-minute exposure in 60 degrees C saline without ultrasonic cleaning. Very few bacteria escaped from the ultrasonic cleaning solutions into the air during the cleaning process. Placement of the unit lid effectively reduced emissions to zero.

Bacterial leakage of mineral trioxide aggregate as compared with zinc-free amalgam, intermediate restorative material, and Super-EBA as a root-end filling material

Several dye leakage studies have demonstrated the fact that mineral trioxide aggregate (MTA) leaks significantly less than other root-end filling materials. The purpose of this study was to determine the time needed for Serratia marcescens to penetrate a 3 mm thickness of zinc-free amalgam, Intermediate Restorative Material (IRM), Super-EBA, and MTA when these materials were used as root-end filling materials. Fifty-six, single-rooted extracted human teeth were cleaned and shaped with a series of .04 Taper rotary instruments (Pro-series 29 files). Once the canals were prepared in a crown down approach, the ends were resected and 48 root-end cavities were ultrasonically prepared to a 3 mm depth. The teeth were then steam sterilized. Using an aseptic technique, under a laminar air flow hood, the root-end cavities were filled with amalgam, IRM, Super-EBA, and MTA. Four root-end cavities were filled with thermoplasticized gutta-percha without a root canal sealer and served as positive controls. Another four root-end cavities were filled with sticky wax covered with two layers of nail polish and served as negative controls. The teeth were attached to presterilized (ethylene oxide gas) plastic caps, and the root ends were placed into 12-ml vials of phenol red broth. Using a micropipette, a tenth of a milliliter of S. marcescens was placed into the root canal of each tooth. To test the sterility of the apparatus set-up, the root canals of two teeth with test root-end filling materials and one tooth from the positive and negative control groups were filled with sterile saline. The number of days required for S. marcescens to penetrate the four root-end filling materials and grow in the phenol red broth was recorded and analyzed. Most of the samples filled with zinc-free amalgam leaked bacteria in 10 to 63 days. IRM began leaking 28 to 91 days. Super-EBA began leaking 42 to 101 days. MTA did not begin leaking until day 49. At the end of the study, four of the MTA samples had not exhibited any leakage. Statistical analysis of the data indicated Mineral Trioxide Aggregate to be a most effective root-end filling material against penetration of S. marcescens.