Implication of Major Adverse Postoperative Events and Myocardial Injury on Disability and Survival: A Planned Subanalysis of the ENIGMA-II Trial.

BACKGROUND: Globally, >300 million patients have surgery annually, and ≤20% experience adverse postoperative events. We studied the impact of both cardiac and noncardiac adverse events on 1-year disability-free survival after noncardiac surgery. METHODS: We used the study cohort from the Evaluation of Nitrous oxide in Gas Mixture of Anesthesia (ENIGMA-II) trial, an international randomized trial of 6992 noncardiac surgical patients. All were ≥45 years of age and had moderate to high cardiac risk. The primary outcome was mortality within 1 postoperative year. We defined 4 separate types of postoperative adverse events. Major adverse cardiac events (MACEs) included myocardial infarction (MI), cardiac arrest, and myocardial revascularization with or without troponin elevation. MI was defined using the third Universal Definition and was blindly adjudicated. A second cohort consisted of patients with isolated troponin increases who did not meet the definition for MI. We also considered a cohort of patients who experienced major adverse postoperative events (MAPEs), including unplanned admission to intensive care, prolonged mechanical ventilation, wound infection, pulmonary embolism, and stroke. From this cohort, we identified a group without troponin elevation and another with troponin elevation that was not judged to be an MI. Multivariable Cox proportional hazard models for death at 1 year and assessments of proportionality of hazard functions were performed and expressed as an adjusted hazard ratio (aHR) and 95% confidence intervals (CIs). RESULTS: MACEs were observed in 469 patients, and another 754 patients had isolated troponin increases. MAPEs were observed in 631 patients. Compared with control patients, patients with a MACE were at increased risk of mortality (aHR, 3.36 [95% CI, 2.55-4.46]), similar to patients who suffered a MAPE without troponin elevation (n = 501) (aHR, 2.98 [95% CI, 2.26-3.92]). Patients who suffered a MAPE with troponin elevation but without MI had the highest risk of death (n = 116) (aHR, 4.29 [95% CI, 2.89-6.36]). These 4 types of adverse events similarly affected 1-year disability-free survival. CONCLUSIONS: MACEs and MAPEs occur at similar frequencies and affect survival to a similar degree. All 3 types of postoperative troponin elevation in this analysis were associated, to varying degrees, with increased risk of death and disability.

A nondestructive method for obtaining maternal DNA from avian eggshells and its application to embryonic viability determination in herring gulls (Larus argentatus).

Many avian studies, aimed at collecting samples for genetic analysis, rely upon invasive procedures involving the capture and handling of parents and their offspring. Our goal was to develop a nondestructive method for sampling maternal DNA that would not require blood collection from the mother. Herein, we describe a method for isolating genomic DNA from eggshell powder, obtained by filing the outer shell of an avian egg. Comparison of microsatellite profiles, obtained from genomic DNA found within eggshell matrices and their corresponding parents, verified the presence of maternal DNA in the eggshell matrix in 100% of the herring gull nests assessed (n= 11). In addition, the microsatellite profiles of eggshell DNA were identical among eggs from the same clutch. The ability to rapidly obtain a DNA sample from an avian eggshell in a noninvasive manner could aid in a wide range of genetic sampling studies, and in this study, we provide one potential application of this finding: assessing the fertilization status of nonviable herring gull (Larus argentatus) eggs from the Laurentian Great Lakes. Detection of fertilization was successful as the microsatellite profiles of eggshell powder (maternal only) and the fertilized embryonic contents of those eggs did not match. Ideally, the application of such an approach will help to discriminate unfertilized eggs from embryos aborted early in development and provide insights into avian reproductive health.

Reducing ingress of organic vapours into homes situated on contaminated land.

The efficacy of current landfill gas and radon mitigation measures for the prevention of ingress of organic vapours was investigated by the study of four houses situated on contaminated land in North West England. The chemical present in the ground of greatest concern for health due to exposure to vapour in the indoor air was hexachlorobutadiene (HCBD) and the concentration of this compound was used to assess the effectiveness of the remedial measures. A two stage remediation was undertaken. For a house with a solid floor the top surface of the floor was sealed and then for the second stage a fan was used to pressurise the soil gas beneath the house. In a house with a suspended timber floor, extra air bricks were installed to increase ventilation of the floor void and then a fan to further increase air exchange in the void. HCBD in air was monitored by both pumped and diffusive sampling methods. Control houses were also monitored that were not subject to remediation. It is concluded that the remedial measures used for radon protection of a suspended floor have the potential to reduce indoor HCBD concentrations by about 80%, at least in downstairs rooms (where initial levels were highest). The two techniques used for properties with solid floors do not appear to be as effective, and no benefit at all was seen without making allowances for changes in concentration that occurred in the control house over the same period. Further work is required to test the efficacy of the techniques over a longer period and under different circumstances of type of contamination and building characteristics.

Personal exposure to benzene and the influence of attached and integral garages.

Benzene is an air pollutant that is a recognised human carcinogen. An air quality standard has been established for ambient air in the UK to reduce the population's exposure. It has been estimated that about 70% of benzene emissions to air in the UK come from petrol vehicles. A number of studies, including the Avon Longitudinal Study of Pregnancy and Childhood in the UK, have found that benzene concentrations in homes with attached or integral garages tend to be higher than in those without such garages. The present paper reviews these studies and reports a detailed investigation of five homes with either an attached or an integral garage. Indoor and outdoor locations were monitored using diffusive sampling to determine the average benzene concentration over approximately 28 days each month for 18 consecutive months (June 1998-November 1999). For one of these homes, ten years of data had shown the indoor benzene concentration to be consistently higher than outdoors. Personal exposure monitoring of one adult in this home showed that the benzene concentration in the main bedroom was a better predictor of personal exposure than the concentration outdoors. In the homes where a car was regularly parked in the garage, 18-month average benzene concentrations of up to 101.3 micrograms m-3 were measured in the garage, which is more than six times the ambient air quality standard for benzene (16.25 micrograms m-3 running annual average). Mean benzene values in all cars and most of the garages studied exceeded the benzene standard. Mean benzene concentrations in the room above the garage ranged from 3.7 micrograms m-3 in one home, where the car was rarely parked in the garage, to 39.9 micrograms m-3 in another home where a car with high benzene emissions was parked in the garage for six of the 18 months monitored. The mean benzene concentration in the room above the garage in this latter home was nearly 2.5 times the ambient air standard. The study demonstrates that there is a potential for people to have a higher exposure to benzene as a result of living in a home with an attached or integral garage. An understanding of routes of personal exposure is important to develop effective policies to reduce risks to health.

Improving the number of mothers breastfeeding in the postpartum period.

The objective of this study was to review an experience at Jackson Memorial Hospital, Miami, Florida that has resulted in an increase in the percentage of mothers breastfeeding at postpartum discharge. Data was obtained from postpartum interviews in 1993, which provided the percentage of mothers breastfeeding at discharge. Staff members and personnel involved in the care of postpartum mothers and babies were educated about breastfeeding, and rounds were made to problem solve and reinforce. Patients who elected to breastfeed from April to September 1994 were followed for a duration of 3 months. These early efforts led to the implementation of a Baby-Friendly initiative and intent in 1996 and the formation of a mother-baby unit in 1997. Ten percent of mothers were breastfeeding at postpartum discharge. After implementing a program in 1994, 41% were breastfeeding at discharge. There was a decline in the number of mothers breastfeeding during the postpartum period from discharge. At 3 days postpartum, 80% of patients were breastfeeding followed by 64%, 37%, and 17% at 2 weeks, 6 weeks, and 3 months from discharge, respectively. The percentage of mothers opting not to breastfeed at 3 days after discharge was 20%, followed by 12% from 3 days to 2 weeks postdischarge, by 21% 2 weeks to 6 weeks postdischarge, and finally by 16% from 6 weeks to 3 months postdischarge. In 1998, 70% of patients were breastfeeding, and in 1999, 71% of patients were breastfeeding upon postpartum discharge. The data show that by implementing programs to promote breastfeeding, through education, encouragement, and reinforcement, one can increase the number of mothers who breastfeed at postpartum discharge. However, there is an inverse relationship between the duration of the postdischarge period and the number of mothers breastfeeding.

Influence of UV radiation on four freshwater invertebrates.

Laboratory tests confirmed a negative and variable response of the following four species to artificial UV radiation: Cypridopsis vidua, an ostracode; Chironomus riparius, a midge larvae; Hyalella azteca, an amphipod; and Daphnia magna, a daphnid. Severe damage occurred at UV-B irradiance ranging from 50 to 80% of incident summer values. Under constant exposure to UV and photosynthetically active radiation (PAR) the acute lethal response was recorded at 0.3, 0.8, 0.8 and 4.9 W m-2 UV-B for D. magna, H. azteca, C. riparius and C. vidua, respectively. Sublethal UV-B damage to invertebrates included impaired movement, partial paralysis, changes in pigmentation and altered water balance (bloating). A series of UV-B, UV-A and PAR treatments, applied separately and in combination, revealed a positive role for both UV-A and PAR in slowing down UV-B damage. Mean lethal concentration values of the species typically more tolerant to UV and PAR (Cypridopsis, Chironomus) decreased conspicuously when both UV-A and PAR were eliminated. For UV-B-sensitive species (Hyalella, Daphnia) these differences were notably smaller. We suggest that this gradation of sensitivity among the tested species demonstrates potential differences in repairing mechanisms which seem to work more efficiently for ostracodes and chironomids than for amphipods and daphnids. Manipulations with a cellulose acetate filter showed that lower range UV-B (280-290 nm), produced by FS-40 lamps, may cause excessive UV damage to invertebrates.

The role of amino acid neurotransmitters in the regulation of pituitary gonadotropin release in fish.

Both glutamate and gamma-aminobutyric acid (GABA) are involved in pituitary hormone release in fish. Glutamate serves 2 purposes, both as a neurotransmitter and as a precursor for GABA synthesis. Glutamate can be catabolized to GABA by the actions of 2 distinct but related enzymes, glutamate decarboxylase 65 (GAD65) and GAD67. They derive from 2 different genes that likely arose from an early gene duplication prior to the emergence of teleosts more than 400 million years ago. There is good evidence for the involvement of GABA in luteinizing hormone (LH) release in fish. The mechanism of GABA action to stimulate LH release appears to be a combination of effects on GnRH release, potentiation of gonadotropin hormone-releasing hormone (GnRH) action, and in some cases directly at the LH cell. These actions appear to be dependent on such factors as sex or sex steroid levels, and there may also be species differences. Nevertheless, the stimulatory effects of GABA on LH are present in at least 4 fish species. In contrast, convincing data for the inhibitory effects of GABA on LH release have only been observed in 1 fish species. The sites and mechanisms of action of amino acid neurotransmitters on LH release have yet to be fully characterized. Both 130N-methyl-D-aspartic acid (NMDA) and S-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) type glutamate receptors are likely to have important roles. We suggest that it is a receptor similar to the GABA(A) type which mediates the effects of GABA on LH release in fish, at least partially acting on the GnRH neuron, but likely directly acting at the gonadotroph as well. GABA may also be involved in regulating the release of other pituitary hormones in fish, namely follicle stimulating hormone (FSH = GTH-I), prolactin, and growth hormone. Based on the findings described in this review, a working model for the involvement of glutamate and GABA in the regulation of LH release in teleost fish is proposed.

A Study of the Antitumour Activity of Four Triorganophosphinegold(I) Thiolates: R(3) PAu(SR'), R = Ph, Cy, Et; SR'H = 6-Mercaptopurine and R = Et; SR'H = 6-Thioguanine.

The antitumour activities of four triorganophosphinegold(I) thiolates, R(2)PAu(S'R) [R = Ph, Cy, Et; SR'H = 6-mercaptopurine and R Et; SR'H = 6-thioguanine] against the National Cancer Institute (NCI) panel of 60 cell lines are reported The [Cy(3)PAu(6-MP)] complex proved to be the more cytotoxic of the four complexes tested. For the 6-MP series, an order of cytotoxicity was established such that the activity followed the order R = Cy > Ph > Et. Sub-panel selectivity against the Leukemia cell lines was found for each of [Cy(3) PAu(6-MP)] and [Et(3)PAu(6-TG)].

LIF (AM424), a promising growth factor for the treatment of ALS.

Growth factors are theoretically promising agents for ALS therapy, but have been disappointing in subcutaneous delivery due to either toxicity or lack of major efficacy. Leukaemia inhibitory factor (LIF), was named after its effect on haemopoietic cells, and belongs to a group of cytokines which includes CNTF, IL-6, CT-1, OM and IL-11. All group members use the gp130 signal transducing subunit for intracellular signalling, but show differences in biological effect. In vitro and in vivo studies on axotomy and nerve crush models demonstrate a powerful effect of LIF in the survival of both motor and sensory neurones, while reducing denervation induced muscle atrophy. Its effects in muscle also include stimulating myoblast proliferation in vitro, and up-regulation after muscle injury. LIF will also stimulate muscle regeneration in vivo when applied exogenously after injury. In published studies of both axotomy induced neuronal death and in the Wobbler mouse models LIF is active at doses of 10 microg/kg delivered systemically, well below the expected maximum tolerated dose suggested by primate safety studies. LIF is expressed in low levels by spinal cord neurones with significant up-regulation when the neurones are damaged by BOAA toxin, an excitatory amino acid associated with a form of ALS. This augments other evidence suggesting LIF is a trauma factor playing a role in the injury response of adult neuronal tissue, and may be more effective than related growth factors. Taken together, the data suggests LIF is a physiologically relevant trophic factor with implications in clinical medicine as a therapy for ALS, and a human recombinant form (AM424), entered human clinical trials during 1998.

Design and evaluation of a flow phantom.

RATIONALE AND OBJECTIVES: We constructed a near-anatomically correct large-vessel phantom to perform repeatable flow dynamics research examinations by angiography, magnetic resonance (MR) angiography, and computed tomography (CT) angiography. METHODS: An internal carotid artery was constructed within a head phantom. The internal carotid artery branches into a middle and an anterior cerebral artery; the former trifurcates and ends in the superior sagittal sinus, and the latter ends in the inferior sagittal sinus. A transverse and sigmoid sinus drains the model. All four vessels connecting the arterial and venous vessels have variable flow-constricting ligatures placed around them. These ligatures are accessible on the skull surface. The skull cavity is filled with a silicone polymer that is isodense to brain on CT scans and isointense on most MR images. RESULTS: The flow in the phantom's vessels may be varied in a repeatable manner. Multiple scan sequences may be performed without the image degradation caused by patient motion. The homogeneity of the filler polymer allows visualization of flow-related artifacts that may be hidden by complex human anatomy. CONCLUSION: Preliminary images of each modality show promise for use of the phantom in imaging research on large-vessel flow dynamics.

Use of predator odors to protect chick-peas from predation by laboratory and wild mice.

Synthetic stoat odor (3-propyl-1,2-dithiolane and 2-propylthietane) and fox fecal odor (2,5-dihydro-2,4,5-trimethylthiazoline) at various concentrations were applied to chick-peas (Cicer arietinum) at sowing in an investigation aimed at reducing damage caused by house mice (Mus musculus). Stoat odor at 10% concentration exerted a measure of protection, as did 1% fox odor against predation by laboratory mice. Wild mice were less affected by synthetic predator odor and appeared to have a shorter memory for it. Laboratory mice cannot be regarded as surrogate wild mice, when used in experimental situations such as those employed here.

Speech rate, loudness, and cardiovascular reactivity.

This paper reports the results of two studies that investigated the relationship between speech rate, loudness, and cardiovascular reactivity (CVR). One study involved the separate manipulation of speech rate and loudness and assessed its effects on CVR during a routine reading task. The second study involved the simultaneous manipulation of both loudness and speech rate and studied its effects on CVR within the context of a personal interview. In both studies, the reduction of speech rate and/or loudness was associated with a significant reduction in CVR. On the other hand, increasing speech rate and/or loudness had no, or only a very minimal, effect on CVR. It is suggested that in the absence of emotional arousal, especially anger-arousal, rapid and loud speech per se is not associated with significant cardiovascular hyperreactivity. On the other hand, our findings suggest that training people to speak slowly and softly may be an effective approach for the control of cardiovascular hyperreactivity.

Influence of the plant antifeedant, pinosylvin, on suppression of feeding by snowshoe hares.

This study investigated the influence of the plant antifeedants, pinosylvin and pinosylvin methyl ether (PME), on suppression of feeding by snowshoe hares (Lepus americanus). Screening bioassays showed clearly that pinosylvin suppressed feeding by hares when sprayed directly on coniferous tree seedlings. Pinosylvin odor, when associated with food (but not mixed with it), also significantly reduced consumption of rabbit chow by hares. Large pen bioassays indicated that both pinosylvin and PME significantly reduced feeding on tree seedlings by hares when the antifeedants were sprayed directly on trees. In field bioassays near Prince George, British Columbia, Canada, pinosylvin sprayed on trees and encapsulated in controlled-release devices of PVC plastic, with an internal wire as a twist-tie for attachment to tree, significantly reduced feeding by hares. Thus, pinosylvin will generate an "avoidance response" in terms of feeding by snowshoe hares. This response is likely triggered by an olfactory pathway based on positive results with controlledrelease devices attached to seedlings. Our study reports the first practical utilization of plant antifeedants for forest crop protection and wildlife management.

Response of pocket gophers (Thomomys talpoides) to an operational application of synthetic semiochemicals of stoat (Mustela erminea).

This paper reports on laboratory bioassays and a large-scale field trial of synthetic mustelid anal-gland compounds in controlled-release devices designed for operational application to burrow systems of northern pocket gophers (Thomomys talpoides). The field study was conducted in an apple orchard in the Okanagan Valley of British Columbia. In laboratory bioassays, a 1∶1 mixture of 2-propylthietane and 3-propyl-1,2-dithiolane from the stoat (Mustela erminea) and 3,3-dimethyl-1,2-dithiolane from the ferret (M. putorius), dispensed in clay pellets (activated alumina), produced a significant avoidance response by gophers. All resident gophers were permanently removed from 4-ha control and treatment blocks prior to placement of stoat odor in burrows. As indexed by soil mounds, significantly fewer gophers colonized the treatment (40) than the control (68) removal area during a 5.5-month overwinter experiment. There was also a significant difference when comparing the number of mounds between pre-(79) and posttreatment (40) censuses. In addition, most gopher activity tended to occur on the perimeter of the treatment block. Abundance of gophers showed little difference between additional 4-ha control and treatment blocks where gophers had not been removed. The results of this study provide an alternative technique to toxicants for pocket gopher control on forest and agricultural land.

Comparison of release devices for stoat (Mustela ermined) semiochemicals used as montane vole (Microtus montanus) repellents.

Fenced enclosures were used to simulate peak populations of montane voles (Microtus montanus) for field bioassays of a stoat (Mustela erminea) scent mixture in various controlled-release devices. A 1∶ 1 mixture of 2-propylthietane and 3-propyl-1,2-dithiolane was dispensed in capillary tubes, clay pellets (activated alumina), rubber septa, and plastic rope. Release devices were placed near, or attached to, young apple trees planted in blocks in two enclosures containing high populations of voles. The stoat scent mixture in rubber septa and plastic rope significantly reduced vole attack of trees compared with a control, pellets, and capillary tubes. In terms of complete girdling (tree mortality), this odor in septa and rope also significantly reduced feeding compared with the control, and the rubber septa formulation was more effective than either the pellets or capillary tubes. Fenced populations of voles may be used effectively to conduct field bioassays during low years in vole cycles. Variations of release devices (with this stoat scent mixture) based on rubber septa for broadcast application to depress vole population density and survival, and plastic rope attached to individual trees to generate an avoidance response, should be used for forest and agricultural crop protection.

Inotropic responses to cyclic nucleotide phosphodiesterase inhibitors in immature and adult rabbit myocardium.

Contractile dose-response relationships for amrinone, milrinone, piroximone, and sulmazole were compared in right ventricular papillary muscles isolated from adult and 14-16-day-old immature rabbits. These drugs were effective inotropic agents in immature myocardium as evidenced by substantial increases in the maximal rate of tension development. The rank order of maximum inotropic effect in the immature muscles was milrinone = sulmazole greater than piroximone greater than amrinone. Compared with adults, the relative magnitude of the inotropic response for each drug was greater in immature myocardium. Profiles of ventricular cytosolic cyclic nucleotide phosphodiesterase (PDE) activities resolved by anion exchange chromatography were similar for the two age groups. Immature myocardium was found to contain the Type IV (Peak III) high-affinity cAMP PDE that has been implicated in the mechanism of action of these drugs. Partially purified cytosolic Type IV PDE from immature and adult myocardium exhibited similar kinetic characteristics (cAMP Km = 0.9 microM; Vmax = 17 nmol/min/mg) and sensitivity to inhibition by cGMP. Except for piroximone, the inhibitory effect of each drug on cytosolic Type IV PDE activity from immature myocardium did not differ from the adult, as indexed by comparable concentrations required to inhibit activity by 50% (IC50) and Ki values (piroximone IC50 and Ki values were higher in the immature compared with the adult group). Thus, these studies demonstrated significant age-related differences in the contractile responses to amrinone, milrinone, piroximone, and sulmazole. These differences are not attributable to differences in myocardial cytosolic Type IV high-affinity cAMP PDE activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Scent lures from anal sac secretions of the ferretMustela furo L.

A bioassay of eight synthetic anal sac compounds showed that ferrets were most attracted to a mixture of 2-propylthietane andtrans- andcis-2,3-dimethylthietane. This mixture was used as the basis of an artificial scent lure. Trapping experiments used two traps at each site. In comparing trap success, ferrets chose artificial lure in preference to no odor, and chose both food baits and natural-product anal sac odor over artificial lure. However, the effectiveness of artificial lure was demonstrated by comparison between trap sites with bait-lure pairs and those with lure only. The comparison indicated that scent lures should be as effective as bait in attracting ferrets, and this was confirmed in a field program. We conclude that scent lures are valuable additions to the current techniques used in mustelid control operations, but more work is needed to increase the inherent species specificity of scent lures for mustelids and to develop a simple means of making a lure that will release odor for a long time.

Use of predator odors as repellents to reduce feeding damage by herbivores : III. Montane and meadow voles (Microtus montanus andMicrotus pennsylvanicus).

This study investigated the influence of the major anal-gland compounds from the stoat (Mustela erminea) and fecal and urine compounds from the red fox (Vulpes vulpes) in generating an avoidance response by montane voles (Microtus montanus), as well as suppressing feeding by montane and meadow (M. pennsylvanicus) voles on apple trees in orchards. In trap bioassays, a 1∶1 mixture of 2-propylthietane and 3-propyl-1,2-dithiolane significantly reduced vole captures. Other mixtures of stoat compounds reduced the number of new voles captured but not total individuals. 2,5-Dihydro-2,4,5-trimethylthiazoline, a component of fox feces, significantly reduced vole captures in one of two bioassays. Deer mice (Peromyscus maniculatus) did not show a negative response to any predator odor. In overwinter field bioassays, mixtures of 2-propylthietane and 3-propyl-1,2-dithiolane clearly reduced vole feeding on apple trees in four test blocks. 2,5-Dihydro-2,4,5-trimethylthiazoline and a synthetic fox urine mixture also significantly reduced vole attack in respective orchard blocks. Similarly, the intensity of vole feeding, in terms of amount of bark and vascular tissues removed from trees, was reduced by 60% to 97% in predator odor treatments compared with the control. Our study reports the first long-term (four to five months) use of synthetic semiochemicals as area repellents for crop protection from vole feeding damage.

Use of predator odors as repellents to reduce feeding damage by herbivores : IV. Northern pocket gophers (Thomomys talpoides).

This study investigated the influence of the major anal-gland compounds from the stoat (Mustela erminea) and ferret (M. putorius) in generating an avoidance response by northern pocket gophers (Thomomys talpoides) in tree fruit orchards in the Okanagan Valley of British Columbia, Canada. A secondary objective assessed the impact of additional predator odors on gopher avoidance behavior in laboratory bioassays. In field bioassays, a 1: 1 mixture of 2-propylthietane and 3-propyl-1,2-dithiolane, as well as 3,3-dimethyl-1,2-dithiolane, placed in gopher burrows did not reduce the number of gophers colonizing treatment versus control grids in orchard blocks. However, these predator gophers did dramatically alter the distribution of gophers. Significantly more gophers were captured at perimeter than nonperimeter trap stations on treatment versus control grids in two of three orchards. In all orchards, significantly more gophers were captured at perimeter stations after the predator odors had been placed in burrows than prior to the start of the experiment. Gophers clearly avoided 2,5-dihydro-2,4,5-trimethylthiazoline, a component of fox (Vulpes vulpes) feces, but did not avoid 2,2-dimethylthietane from the mink (M. vison) or 3-methyl-3-butenyl methyl sulfide from fox urine in laboratory bioassays. Poor avoidance was also recorded for 3,3-dimethyl-1,2-dithiolane, although this may be due to the state of polymerization of this compound. An improved formulation is required to dispense these semiochemicals in controlled-release devices within orchards and other forest-agricultural areas.

Identification of trail pheromone of larva of eastern tent caterpillarMalacosoma americanum (Lepidoptera: Lasiocampidae).

Previous studies have shown that larvae of the eastern tent caterpillar (Malacosoma americanum F.) mark trails, leading from their tent to feeding sites on host trees, with a pheromone secreted from the posterior tip of the abdominal sternum. 5ß-Cholestane-3,24-dione (1) has been identified as an active component of the trail. The larvae have a threshold sensitivity to the pheromone of 10(-11) g/mm of trail. Several related compounds elicit the trail-following response. Two other species of tent caterpillars also responded positively to the pheromone in preliminary laboratory tests.