Cerambycid Pheromones Attract Predators Temnoscheila virescens (Coleoptera: Trogossitidae), Chariessa pilosa (Coleoptera: Cleridae), and Apiomerus crassipes (Hemiptera: Reduviidae).

In 2011-2013, we determined the interactive effects of the cerambycid pheromones racemic syn-2,3-hexanediol, racemic 3-hydroxyhexan-2-one, and racemic 3-hydroxyoctan-2-one on trap catches of predators associated with bark and woodboring beetles in north Georgia and South Carolina. Temnoscheila virescens (F.) (Coleoptera: Trogossitidae) was attracted to traps baited with 3-hydroxyhexan-2-one; ethanol enhanced attraction. Traps baited with syn-2,3-hexanediol attracted Chariessa pilosa (Forster) (Coleoptera: Cleridae); attraction was interrupted by 3-hydroxyhexan-2-one. An assassin bug Apiomerus crassipes (F.) (Hemiptera: Reduviidae) was attracted to traps baited with 3-hydroxyhexan-2-one and/or 3-hydroxyoctan-2-one. Ethanol had no effect on trap catches of C. pilosa and A. crassipes. We compared response profiles of these predators to those of longhorn beetles captured in these same studies to provide insights on possible ecological interactions between these species.

Cerambycid Pheromones 3,2-Hydroxyketones Affect Catches of Some Bark and Ambrosia Beetles (Coleoptera: Curculionidae) in Ethanol-Baited Multiple-Funnel Traps in Southeastern United States.

In 2012-2013, we assessed the interactive effects of the cerambycid pheromones syn-2,3-hexanediol, 3-hydroxyhexan-2-one, and 3-hydroxyoctan-2-one on catches of bark and ambrosia beetles (Coleoptera: Curculionidae) in ethanol-baited multiple-funnel traps in north Georgia and South Carolina. We found that catches for nine of eleven species of ambrosia beetles in ethanol-baited traps were either unaffected or enhanced by the addition of 3,2-hydroxyketones. Similarly catches of five species of bark beetles were either unaffected or enhanced by the addition of 3,2-hydroxyketones. In particular, catches of Xylosandrus crassiusculus (Motschulsky), Cnestus mutilatus (Blandford), and Monarthrum fasciatum (Say) in ethanol-baited traps increased with the addition of 3-hydroxyhexan-2-one and/or 3-hydroxyoctan-2-one. Catches of the bark beetles Hylocurus rudis (LeConte) and Hypothenemus rotundicollis (Eichhoff) were enhanced by the addition of 3-hydroxyhexan-2-one and 3-hydroxyoctan-2-one, respectively. syn-2,3-Hexanediol had no effect on catches of bark and ambrosia beetles in ethanol-baited traps. Our data provide support for the use of ethanol + cerambycid pheromones for targeting non-native species of bark and ambrosia beetles as well as cerambycids in detection programs.

Interactions Between syn- and anti-2,3-Hexanediol Lures on Trap Catches of Woodboring Beetles and Associates in Southeastern United States.

In 2016, we conducted three experiments to clarify the effects of 2,3-hexanediols isomers on trap catches of Neoclytus acuminatus (F.) (Coleoptera: Cerambycidae). We also noted the effects of the isomers on trap catches of other cerambycids and associated species of predators and competitors. Catches of N. acuminatus in traps baited with ethanol + syn-2,3-hexanediol + racemic 3-hydroxyoctan-2-one were reduced with the addition of anti-2,3-hexanediol, an attractant for Curius dentatus Newman (Coleoptera: Cerambycidae). A fourth experiment conducted in 2017 verified that racemic 3-hydroxyoctan-2-one increases catches of N. acuminatus in traps baited with ethanol + syn-2,3-hexanediol. The addition of anti-2,3-hexanediol increased catches of Knulliana cincta (Drury) (Coleoptera: Cerambycidae) in traps baited with ethanol + racemic 3-hydroxyoctan-2-one, whereas attraction of Neoclytus scutellaris (Olivier) to traps baited with ethanol + racemic 3-hydroxyhexan-2-one was reduced by syn-2,3-hexanediol. Trap catches of the beetle predators Chariessa pilosa (Forster), Enoclerus ichneumonus (F.), and Madoniella dislocata (Say) (Coleoptera: Cleridae) were affected by 2,3-hexanediol isomers, whereas other common predators were unaffected by the isomers. Attraction of the bostrichid Xylobiops basilaris (Say) (Coleoptera: Bostrichidae) was increased by the 2,3-hexanediols; the relative effect of the two isomeric blends was dependent on trap co-baits of 3-hydroxy-2-ketones. The two enantiomeric blends of 2,3-hexanediol had minimal effects on catches of most species of ambrosia beetles, whereas the 3-hydroxy-2-ketones affected trap catches of some species.

Trap Height Affects Catches of Bark and Woodboring Beetles (Coleoptera: Curculionidae, Cerambycidae) in Baited Multiple-Funnel Traps in Southeastern United States.

In north-central Georgia, trap height affected catches of some species of bark and woodboring beetles (Coleoptera) in traps baited with lures used in surveillance programs to detect non-native forest insects. Traps were placed within the canopy and understory of mature oak trees (Quercus spp.) with collection cups placed 18-23 m above ground level (AGL), and 0.3-0.5 m AGL, respectively. Traps were baited with ethanol to target ambrosia beetles (Curculionidae: Scolytinae) in one experiment, ethanol + syn-2,3-hexanediol + racemic 3-hydroxyhexan-2-one + racemic 3-hydroxyoctan-2-one to target hardwood woodborers (Cerambycidae) in a second experiment, and α-pinene + racemic ipsenol + racemic ipsdienol to target pine bark beetles (Curculionidae) and woodborers (Cerambycidae) in a third experiment. Canopy traps were more effective than understory traps for detecting Cnestus mutilatus (Blandford) (Curculionidae), Neoclytus scutellaris (Olivier), and Monochamus titillator (F.) (Cerambycidae). The reverse was true for Xylosandrus crassiusculus (Motschulsky), Dendroctonus terebrans (Olivier) (Curculionidae), and Neoclytus acuminatus (F.) (Cerambycidae). Catches of a third group which included Hylobius pales (Herbst), Ips grandicollis (Eichhoff) (Curculionidae), Neoclytus mucronatus (F.), and Anelaphus pumilus (Newman) (Cerambycidae) were largely unaffected by trap height. Similar patterns were noted for species of Cleridae, Scarabaeidae, Trogossitidae, and Zopheridae but not Histeridae or Tenebrionidae (Coleoptera). Catches of the bee assassin Apiomerus crassipes (F.) (Hemiptera: Reduviidae) in traps baited with the hardwood borer blend were greater in canopy traps than in understory traps.

Interactions between Ethanol, syn-2,3-Hexanediol, 3-Hydroxyhexan-2-one, and 3-Hydroxyoctan-2-one Lures on Trap Catches of Hardwood Longhorn Beetles in Southeastern United States.

The effectiveness of a four-component "super lure" consisting of ethanol (E) and the cerambycid pheromones syn-2,3-hexanediol (D6), racemic 3-hydroxyhexan-2-one (K6), and racemic 3-hydroxyoctan-2-one (K8) on trap catches of Cerambycidae (Coleoptera) was determined in southeast United States with seven trapping experiments in 2011-2013. We captured 74 species of longhorn beetles in our three-year study. Ethanol significantly increased the mean catches of seven species and increased the number of cerambycid species detected. Traps with the "super lure" were effective for 8 of 13 species of Cerambycidae previously shown to be attracted to binary combinations of ethanol plus one of the three pheromones. However, the "super lure" was less effective for the remaining five species with catch reductions of 40-90% compared with combinations of ethanol and one or two of the pheromones. For example, K6 + K8 lures reduced catches of Anelaphus villosus (F.) in traps with E + D6 by 90%. Similarly, catches of Anelaphus pumilus (Newman) in traps with E + K6 + D6 were reduced by 50% with the addition of K8. Catches of Knulliana cincta (Drury) in traps with K6 + K8 lures were interrupted by D6, an effect negated by the addition of ethanol. Given the interruptive effects on trap catches of some species when lures are combined in a single trap, developing optimal lure blends to maximize detection efficacy will be a challenge for managers of detection programs for non-native invasive species of longhorn beetles.

Pine Sawyers (Coleoptera: Cerambycidae) Attracted to α-Pinene, Monochamol, and Ipsenol in North America.

Detection tools are needed for Monochamus species (Coleoptera: Cerambycidae) because they are known to introduce pine wilt disease by vectoring nematodes in Asia, Europe, and North America. In 2012-2014, we examined the effects of the semiochemicals monochamol and ipsenol on the flight responses of the sawyer beetles Monochamus carolinensis (Olivier), Monochamus clamator (LeConte), Monochamus mutator LeConte, Monochamus notatus (Drury), Monochamus obtusus Casey, Monochamus scutellatus (Say), and Monochamus titillator (F.) complex (Coleoptera: Cerambycidae) to traps baited with α-pinene. Experiments were set in pine forests in New Brunswick and Ontario (Canada), and Arizona, Georgia, Michigan, Montana, Oregon, South Carolina, Utah, and Washington (United States). In brief, 40 traps were placed in 10 blocks of 4 traps per block per location. Traps were baited with: 1) α-pinene; 2) α-pinene + monochamol; 3) α-pinene + ipsenol; and 4) α-pinene + monochamol + ipsenol. Monochamol increased catches of six species and one species complex of Monochamus with an additive effect of ipsenol for five species and one species complex. There was no evidence of synergy between monochamol and ipsenol on beetle catches. Monochamol had no effect on catches of other Cerambycidae or on any associated species of bark beetles, weevils, or bark beetle predators. We present a robust data set suggesting that the combination of α-pinene, ipsenol, and monochamol may be a useful lure for detecting Monochamus species.

Ipsenol, Ipsdienol, Ethanol, and α-Pinene: Trap Lure Blend for Cerambycidae and Buprestidae (Coleoptera) in Pine Forests of Eastern North America.

In 2007-2008, we examined the flight responses of wood-boring beetles (Coleoptera: Cerambycidae and Buprestidae) to multiple-funnel traps baited with the pine volatiles, ethanol, and α-pinene [85% (-)], and the bark beetle pheromones, racemic ipsenol and racemic ipsdienol. Experiments were conducted in mature pine stands in Canada (Ontario and New Brunswick) and the United States (Arkansas, Florida, Michigan, New Hampshire, North Carolina, Ohio, Tennessee, and Wisconsin). At each location, traps were deployed in 10 replicate blocks of four traps per block. The trap treatments were: 1) blank control; 2) ipsenol and ipsdienol; 3) ethanol and α-pinene; and 4) a quaternary blend of ipsenol, ipsdienol, ethanol, and α-pinene. Traps baited with the quaternary blend caught the greatest numbers of Acanthocinus nodosus (F.), Acanthocinus obsoletus (Olivier), Acmaeops proteus (Kirby), Astylopsis sexguttata (Say), Rhagium inquisitor (L.) (Cerambycidae), and Buprestis lineata (F.) (Buprestidae). Traps baited with ethanol and α-pinene caught the greatest numbers of Arhopalus rusticus (LeConte), Asemum striatum (L.), Tetropium spp., Xylotrechus sagittatus (Germar) (Cerambycidae), and Buprestis maculipennis Gory (Buprestidae) with minimal interruption by ipsenol and ipsdienol. Our results suggest that multiple-funnel traps baited with the quaternary lure blend of ipsenol, ipsdienol, ethanol, and α-pinene are effective for trapping various species of wood-boring beetles in pine forests of eastern North America, and may have utility in detection programs for adventive species in North America and overseas.

Responses of Cerambycidae and Other Insects to Traps Baited With Ethanol, 2,3-Hexanediol, and 3,2-Hydroxyketone Lures in North-Central Georgia.

In north-central Georgia, 13 species of woodboring beetles (Coleoptera: Cerambycidae: Cerambycinae) were attracted to multiple-funnel traps baited with ethanol and one of the following pheromones: (1) racemic 3-hydroxyhexan-2-one; (2) racemic 3-hydroxyoctan-2-one; and (3) syn-2,3-hexanediol. The following species were attracted to traps baited with ethanol and 3-hydroxyhexan-2-one: Anelaphus pumilus (Newman), Eburia quadrigeminata (Say), Euderces pini (Olivier), Knulliana cincta (Drury), Neoclytus mucronatus (F.), Neoclytus scutellaris (Olivier), and Xylotrechus colonus (F.). Clytus marginicollis Castelnau & Gory, and Anelaphus parallelus (Newman) were attracted to traps baited with ethanol and 3-hydroxyoctan-2-one, whereas traps baited with ethanol and syn-2,3-hexanediol were attractive to Anelaphus villosus (F.), A. parallelus, Neoclytus acuminatus (F.), Neoclytus jouteli jouteli Davis, and Megacyllene caryae (Gahan). Ethanol enhanced catches of seven cerambycid species in traps baited with syn-2,3-hexanediol and 3,2-hydroxyketones. Catches of bark and ambrosia beetles (Curculionidae: Scolytinae) in ethanol-baited traps were largely unaffected by the addition of syn-2,3-hexanediol and 3,2-hydroxyketone lures, except for two species. The mean catches of Hypothenemus rotundicollis Wood & Bright and Dryoxylon onoharaensum (Murayama) in ethanol-baited traps increased and decreased, respectively, with the addition of racemic 3-hydroxyoctan-2-one. Traps baited with ethanol and syn-2,3-hexanediol were attractive to Xylobiops basilaris (Say) (Bostrichidae) and Chariessa pilosa (Forster) (Cleridae), whereas Temnoscheila virescens (F.) (Trogossitidae) were attracted to traps baited with ethanol and 3-hydroxyhexan-2-one. The assassin bug, Apiomerus crassipes (F.) (Hemiptera: Reduviidae), was attracted to traps baited with ethanol and 3,2-hydroxyketones.

Spatial localization of electrotactile stimuli on the fingertip in humans.

This study was designed to determine the extent to which sensations elicited by discrete electrotactile stimulation can be spatially localized, with a qualitative comparison to mechanical stimulation, in a 2 x 2 electrode array on the fingertip. Electrotactile stimulation was delivered in two modes: (1) same current to all locations (constant) or (2) current adjusted to perceptual threshold of each location (varied). For each stimulus location, subjects were asked to identify the location of the stimulus. Mechanical stimulation of the same locations on the fingerpad was delivered through von Frey hairs (0.07, 0.2 and 0.4 g). The percentage of accurate responses was computed for all stimulation modes. We found that the accuracy of discrimination of stimulus location in both the constant (46%) and varied (40%) electrotactile stimulation modes was significantly higher than chance level (25%; p < 0.01). Furthermore, subjects were significantly more accurate in discriminating electrotactile stimuli in the constant than in the varied mode (p < 0.05). We also found that the accuracy of spatial discrimination was dependent on stimulation site for mechanical, but not electrotactile stimulation. Finally, we found a significant difference in accuracy over the duration of the experiment only for mechanical modes, which may indicate that electrotactile stimuli are less biased over time. These results suggest that, although low in accuracy, human subjects are able to extract spatial information from electrotactile stimuli. Further research is needed to optimize the amount of the information that can be delivered through electrotactile stimulation.

Programmable arbitrary waveform generator for internal defibrillation research.

A programmable arbitrary waveform generator for creation of experimental defibrillation shocks is described. The system is capable of delivering shocks for internal defibrillation via 10 channels at 1000 Volts and 30 Amps. A microcontroller driven system that can receive waveform commands from a laptop was designed to be able to deliver shocks to any combination of electrodes. Waveforms are controllable down to 100 microsecond intervals and each channel is capable of serving as anode or cathode. This system can be used to verify predictions for defibrillation waveform efficacy as predicted by modeling efforts or to test new experimental waveforms tuned to parameters from an individual subject.

L-carnitine decreases glycolysis in liquid-stored platelets.

BACKGROUND: The platelet storage lesion is characterized metabolically by a pH decrease associated with lactic acid generation; a change in platelet morphology from discoid to spherical; a diminished response to in vitro challenge tests, such as the hypotonic shock response (HSR) and extent of shape change (ESC); increased surface P-selectin expression; and decreased in vivo recovery and survival. Altering storage conditions to improve these measures could allow for extension of the duration of in vitro storage. STUDY DESIGN AND METHODS: ABO-identical paired platelet concentrates were pooled and then equally divided into two plastic bags. Either L-carnitine (LC) or an equal volume of saline (control) was added to one container of each pair. Platelets were stored at 20 to 24 degrees C for 5 to 10 days or at 1 to 6 degrees C for 5 days at various concentrations of LC between 0.1 and 15 mM: At the end of storage, pH, glucose consumption, lactate generation, HSR, ESC, and surface P-selectin expression were measured. In different experiments, paired platelet concentrates were spiked with a Staphylococcus epidermidis suspension in the presence and absence of L-carnitine at a concentration of 5 mM: RESULTS: At 20 to 24 degrees C and concentrations of LC between 0.1 and 5 mM:, there was evidence of better pH preservation, less glucose consumption, and less lactate generation. Only with storage beyond 5 days was a difference present in either surface P-selectin expression or HSR. An L-carnitine concentration of 5 mM: appeared optimal. L-carnitine did not enhance the growth of bacteria after 7 to 8 days of storage. CONCLUSION: LC at 5 mM: may improve the quality of platelet concentrates that are stored beyond 5 days. There was no indication that LC at this concentration would promote bacterial growth. It may be a useful additive to platelet preservation.

A comparison of prestorage WBC-reduced whole-blood-derived platelets and bedside-filtered whole-blood-derived platelets in autologous progenitor cell transplant.

BACKGROUND: Prestorage WBC-reduced platelet concentrates (PCs) can be manufactured from platelet-rich plasma (PRP) by in-line filtration of PRP. There are few published data on the clinical use of these products, as compared to bedside-filtered pools of standard PCs (S-PCs) manufactured from PRP. STUDY DESIGN AND METHODS: A prospective, randomized trial was conducted in autologous progenitor cell transplant patients requiring platelet transfusions with each patient as his or her own control who was given a pool of 5 units of WBC-reduced PCs and a pool of 6 units of S-PCs within a 3-hour period. The pools were characterized before transfusion for platelet and WBC content, P-selectin expression, and IL-8. The patients were monitored with platelet counts and vital signs and observed for reactions. Data were analyzed using Mann-Whitney U tests. RESULTS: Thirty-three transfusions were administered to 13 patients. Median platelet content in the WBC-reduced PC pools was lower than that in the S-PC pools (3.3 vs. 4.0 x 10(11), p<0.01). Median WBC content was 4 to 5 log less in the WBC-reduced PC pools (2.5 x 10(4) vs. 4.6 x 10(8), p<0.01). Median IL-8 levels (pg/mL) were lower in the WBC-reduced PC pools (2 vs. 36, p<0.01). No differences were observed in CCI, but the median absolute increase after transfusion of the S-PC pools was higher (25 vs. 19 x 10(9)/L, p<0.01), which reflected the larger size of the S-PC pools. No overall differences in vital signs were recorded. Two reactions were observed, both in temporal association with the transfusion of pools of S-PCs. CONCLUSIONS: A pool consisting of 5 units of WBC-reduced PCs gave a median platelet increment of 19 x 10(9) per L in these thrombocytopenic patients and has a median WBC content 1 to 2 log below the accepted threshold for primary alloimmunization or CMV transmission.

Anomaly of the des-Arg9-bradykinin metabolism associated with severe hypotensive reactions during blood transfusions: a preliminary study.

BACKGROUND: Severe hypotensive reactions have been described after the transfusion of platelets or red cells through negatively-charged bedside white cell-reduction filters. The possibility of a role for bradykinin (BK) in the genesis of these reactions has been raised. STUDY DESIGN AND METHODS: To understand if an anomaly of BK metabolism is associated with these reactions, the metabolism of BK and des-Arg9-BK was studied in the sera of four patients who presented with a severe hypotensive transfusion reaction. Tests were performed in the absence and the presence of complete in vitro inhibition of angiotensin-converting enzyme (ACE) activity by enalaprilat. RESULTS: In the presence of ACE inhibition (enalaprilat), the half-life (t1/2) of BK measured in the sera of patients who presented with a severe hypotensive transfusion reaction (361 +/- 90 sec) was not significantly different from that measured in the sera of normal controls (249 +/- 16 sec). In the presence of ACE inhibition (enalaprilat), the t1/2 of des-Arg9-BK was significantly greater in patients who presented with a severe hypotensive transfusion reaction (1549 +/- 319 sec) than in normal controls (661 +/- 38 sec) (p < 0.001). CONCLUSION: A metabolic anomaly mainly affecting the degradation of des-Arg9-BK could be responsible for its accumulation in vivo. Des-Arg9-BK could be responsible, at least in part, for severe hypotensive transfusion reactions.

Spontaneous venous thrombosis in a young patient with combined factor V Leiden and lupus anticoagulant.

We describe a case of a 28-year-old man who developed an extensive spontaneous deep venous thrombosis. Testing revealed heterozygotic factor V Leiden mutation, and the presence of both lupus anticoagulant (LA) and elevated IgM anticardiolipin antibody (ACA). Several family members were found to be heterozygous for factor V Leiden. A paternal aunt had the factor V Leiden mutation, an elevated plasma homocysteine and a borderline increased IgG ACA level. No other family member had a history of a venous thrombotic event. This case illustrates that evaluation of young patients who present with venous thrombosis should be performed for both hereditary and acquired thrombophilic defects. The family studies suggest that the presence of a lupus anticoagulant may be more clinically significant than elevated ACA in risk assessment. Although screening family members when the proband carries factor V Leiden is controversial, psychological reassurance of those who test negative and simple advice on occupations or social habits (e.g., smoking) for those who test positive may be important benefits.

Non-thiazolidinedione antihyperglycaemic agents. Part 3: The effects of stereochemistry on the potency of alpha-methoxy-beta-phenylpropanoic acids.

Rhizopus delemar lipase catalysed ester hydrolysis of the alpha-methoxy-beta-phenylpropanoate 1 affords the (R)-(+) and (S)-(-) isomers in > 84% enantiomeric excess. Absolute stereochemistry was determined by a single crystal X-ray analysis of a related synthetic analogue. The activity of these two enantiomers on glucose transport in vitro and as anti-diabetic agents in vivo is reported and their unexpected equivalence attributed to an enzyme-mediated stereospecific isomerisation of the (R)-(+) isomer. Binding studies using recombinant human PPARgamma (peroxisomal proliferator activated receptor gamma), now established as a molecular target for this compound class, indicate a 20-fold higher binding affinity for the (S) antipode relative to the (R) antipode.

Viability and in vitro properties of AS-1 red cells after gamma irradiation.

BACKGROUND: Irradiation has been shown to adversely affect both in vivo 24-hour recovery (recovery [%]) and in vitro properties of stored red cells (RBCs). There is uncertainty as to how these changes are related to the day of irradiation and the length of storage after irradiation. STUDY DESIGN AND METHODS: Four protocols used day of irradiation and storage time after irradiation as the independent variables. At the conclusion of the storage period, viability was measured with radiolabeled RBCs as the recovery and the long-term survival time for RBCs that were circulating beyond 24 hours. In addition, in vitro values including RBC ATP, hemolysis level, and supernatant potassium were measured. Each subject donated 2 units of whole blood (CPD) and received autologous irradiated and untreated control RBCs (AS-1) on two separate occasions. RESULTS: Reduced recovery in irradiated units was noted when compared to that in control units, and the reduction was most apparent with long periods of storage after irradiation, irrespective of the day of irradiation. With irradiation on Day 1 of storage and a total storage period of 28 days, mean +/- SD recovery (single label) was 84.2 +/- 5.1 percent for control RBCs and 78.6 +/- 5.9 percent for irradiated RBCs (n = 16; p<0.01). With irradiation on Day 14 and storage through Day 42, the recoveries were 76.3 +/- 7.0 percent for control RBCs and 69.5 +/- 8.6 percent for irradiated RBCs (n = 16; p<0.01). Less reduction in recovery was observed with shortening of the postirradiation storage time. When the total storage period was reduced to 28 days after Day 14 irradiation, the recoveries were not significantly different. With an additional 2-day storage period after irradiation on Day 26, the recoveries were also comparable. Long-term survival times for control and irradiated RBCs were not significantly different in any of the four protocols. RBC ATP levels and hemolysis were minimally, but significantly influenced by irradiation. Supernatant potassium levels, however, were substantially increased after irradiation in each of the four protocols. CONCLUSION: Irradiation has only a small effect on the properties of RBCs treated and stored according to the utilized protocols. Longer storage times after irradiation resulted in progressively reduced recovery while long-term survival remained unaffected.

The results of diagnostic studies for thrombophilia in a large group of patients with a personal or family history of thrombosis.

The range of tests used in the evaluation of thrombophilia has been altered by the recent recognition of common genetic defects predisposing to thrombosis such as factor VLeiden (FVR506Q), enzyme deficiencies causing hyperhomocysteinemia, and improvement in the sensitivity and utilization of assays for antiphospholipid antibodies. In this study, the outcomes of laboratory evaluation of 402 patients with thrombophilia were reviewed and correlated with clinical data. A predisposing factor was present (positive diagnosis, group A) in 110 patients (27%), the test results of 111 patients (28%) could not be definitively interpreted (equivocal results, group B), and the test results of 181 (45%) were normal (group C). The median age of the group A patients was 48 years (range, 3.7-88 years), suggesting that evaluation of patients over the age of 50 is worthwhile. Of the 110 patients in group A, 84% had single defects and 16% had combined defects. The most common defect was factor VLeiden (44 patients). Equal numbers of patients presenting with arterial and venous thromboses were evaluated. Patients with arterial events were less likely to have a definable laboratory defect (33 of 132 [25%]) than were those with venous events (50 of 136 [37%]). Factor VLeiden was the most frequent finding in patients with venous events, and lupus anticoagulant or anticardiolipin antibodies were the most frequent findings in patients with arterial events. Positive diagnoses were made in patients on anticoagulants, indicating that this should not preclude investigation. Our study confirms the need for thorough evaluation to assess thrombotic risk, and it reflects the impact of newly identified thrombophilic disorders on the expected outcome of laboratory evaluation for thrombophilia.