A frontal cortical network is critical for language planning during spoken interaction

Many brain areas exhibit activity correlated with language planning, but the impact of these dynamics on spoken interaction remains unclear. Here we use direct electrical stimulation to transiently perturb cortical function in neurosurgical patient-volunteers performing a question-answer task. Stimulating structures involved in speech motor function evoked diverse articulatory deficits, while perturbations of caudal inferior and middle frontal gyri - which exhibit preparatory activity during conversational turn-taking - led to response errors. Perturbation of the same planning-related frontal regions slowed inter-speaker timing, while faster responses could result from stimulation of sites located in other areas. Taken together, these findings further indicate that caudal inferior and middle frontal gyri constitute a critical planning network essential for interactive language use.

Biomechanical assessment of the effect of sublaminar band tensioning on lumbar motion

OBJECTIVE

Adjacent-segment disease (ASD) proximal to lumbosacral fusion is assumed to result from increased stress and motion that extends above or below the fusion construct. Sublaminar bands (SBs) have been shown to potentially mitigate stresses in deformity constructs. A similar application of SBs in lumbar fusions is not well described yet may potentially mitigate against ASD.

METHODS

Eight fresh-frozen human cadaveric spine specimens were instrumented with transforaminal lumbar interbody fusion (TLIF) cages at L3-4 and L4-5, and pedicle screws from L3 to S1. Bilateral SBs were applied at L2 and tightened around the rods extending above the L3 pedicle screws. After being mounted on a testing frame, the spines were loaded at L1 to 6 Nm in all 3 planes, i.e., flexion/extension, right and left lateral bending, and right and left axial rotation. Motion and intradiscal pressures (IDPs) at L2-3 were measured for 5 conditions: intact, instrumentation (L3-S1), band tension (BT) 30%, BT 50%, and BT 100%.

RESULTS

There was significant increase in motion at L2-3 with L3-S1 instrumentation compared with the intact spine in flexion/extension (median 8.78°, range 4.07°-10.81°, vs median 7.27°, range 1.63°-9.66°; p = 0.016). When compared with instrumentation, BT 100% reduced motion at L2-3 in flexion/extension (median 8.78°, range 4.07°-10.81°, vs median 3.61°, range 1.11°-9.39°; p < 0.001) and lateral bending (median 6.58°, range 3.67°-8.59°, vs median 5.62°, range 3.28°-6.74°; p = 0.001). BT 50% reduced motion at L2-3 only in flexion/extension when compared with instrumentation (median 8.78°, range 4.07°-10.81°, vs median 5.91°, range 2.54°-10.59°; p = 0.027). There was no significant increase of motion at L1-2 with banding when compared with instrumentation, although an increase was seen from the intact spine with BT 100% in flexion/extension (median 5.14°, range 2.47°-9.73°, vs median 7.34°, range 4.22°-9.89°; p = 0.005). BT 100% significantly reduced IDP at L2-3 from 25.07 psi (range 2.41-48.08 psi) before tensioning to 19.46 psi (range -2.35 to 29.55 psi) after tensioning (p = 0.016).

CONCLUSIONS

In this model, the addition of L2 SBs reduced motion and IDP at L2-3 after the L3-S1 instrumentation. There was no significant increase in motion at L1-2 in response to band tensioning compared with instrumentation alone. The application of SBs may have a clinical application in reducing the incidence of ASD.

Predation strongly limits demography of a keystone migratory herbivore in a recovering transfrontier ecosystem

Large herbivore migrations are imperiled globally; however the factors limiting a population across its migratory range are typically poorly understood. Zambia's Greater Liuwa Ecosystem (GLE) contains one of the largest remaining blue wildebeest (Connochaetes taurinus taurinus) migrations, yet the population structure, vital rates, and limiting factors are virtually unknown. We conducted a long‐term demographic study of GLE wildebeest from 2012 to 2019 of 107 collared adult females and their calves, 7352 herd observations, 12 aerial population surveys, and concurrent carnivore studies. We applied methods of vital rate estimation and survival analysis within a Bayesian estimation framework. From herd composition observations, we estimated rates of fecundity, first‐year survival, and recruitment as 68%, 56%, and 38% respectively, with pronounced interannual variation. Similar rates were estimated from calf‐detections with collared cows. Adult survival rates declined steadily from 91% at age 2 years to 61% at age 10 years thereafter dropping more sharply to 2% at age 16 years. Predation, particularly by spotted hyena, was the predominant cause of death for all wildebeest ages and focused on older animals. Starvation only accounted for 0.8% of all unbiased known natural causes of death. Mortality risk differed substantially between wet and dry season ranges, reflecting strong spatio‐temporal differences in habitat and predator densities. There was substantial evidence that mortality risk to adults was 27% higher in the wet season, and strong evidence that it was 45% higher in the migratory range where predator density was highest. The estimated vital rates were internally consistent, predicting a stable population trajectory consistent with aerial estimates. From essentially zero knowledge of GLE wildebeest dynamics, this work provides vital rates, age structure, limiting factors, and a plausible mechanism for the migratory tendency, and a robust model‐based foundation to evaluate the effects of potential restrictions in migratory range, climate change, predator–prey dynamics, and poaching.

Risk factors for delirium in elderly patients after lumbar spinal fusion

OBJECTIVE

To identify perioperative risk factors for postoperative delirium (POD) in patients aged 65 or older undergoing lumbar spinal fusion procedures.

PATIENTS AND METHODS

A retrospective cohort analysis was performed on patients undergoing lumbar spinal fusion over an approximately three-year period at a single institution. Demographic and perioperative data were obtained from electronic medical records. The primary outcome was the presence of postoperative delirium assayed by the Delirium Observation Screening Scale (DOSS) and Confusion Assessment Method for the ICU (CAM-ICU). Univariate and multivariate analyses were performed on the data.

RESULTS

Of the 702 patients included in the study, 173 (24.6%) developed POD. Our analysis revealed that older age (p < 0.001), lower preoperative hemoglobin (p < 0.001), and higher ASA status (p < 0.001), were significant preoperative risk factors for developing POD. The only significant intraoperative risk factor was a higher number of spinal levels that were instrumented (p < 0.001). Higher pain scores on postoperative day 1 (p < 0.001), and lower postoperative hemoglobin (p < 0.001) were associated with increased POD; as were ICU admission (p < 0.001) and increased length of ICU stay (p < 0.001). Patients who developed POD had a longer hospital stay (p < 0.001) with lower rates of discharge to home as opposed to an inpatient facility (p < 0.001).

CONCLUSION

Risk factors for POD in older adults undergoing lumbar spinal fusion surgery include advanced age, diabetes, lower preoperative and postoperative hemoglobin, higher ASA grade, greater extent of surgery, and higher postoperative pain scores. Patients with delirium had a higher incidence of postoperative ICU admission, increased length of stay, decreased likelihood of discharge to home and increased mortality, all consistent with prior studies. Further studies may determine whether adequate management of anemia and pain lead to a reduction in the incidence of postoperative delirium in these patients.

Physiological consequences of consuming low-energy foods: herbivory coincides with a stress response in Yellowstone bears

Meat, fruit, seeds and other high-energy bear foods are often highly localized and briefly available and understanding which factors influence bear consumption of these foods is a common focus of bear conservation and ecology. However, the most common bear foods, graminoids and forbs, are more widespread but of lower quality. We poorly understand how herbage consumption impacts bear physiology, such as endocrine system function that regulates homeostasis and stress responses. Here, we described bear diets with a novel approach, measuring the concentration of chlorophyll in bear scats (faecal chlorophyll) to index the proportion of the recent diet that was composed of leaves from graminoids and forbs. We measured faecal chlorophyll and faecal cortisol in 351 grizzly (Ursus arctos, n = 255) and black bear (Ursus americanus, n = 96) scats from Yellowstone National Park in 2008-2009. We compared models of faecal chlorophyll and faecal cortisol concentrations considering the effects of spatial, dietary, scat and bear-specific factors including species. Faecal chlorophyll levels were the strongest predictor of faecal cortisol in a manner that suggested an endocrine response to a low-energy diet. Both compounds were highest during the spring and early summer months, overlapping the breeding season when higher energy foods were less available. Effects of scat composition, scat weathering, bear age, bear sex, species and other factors that have previously been shown to influence faecal cortisol in bears were not important unless faecal chlorophyll was excluded from models. The top models of faecal chlorophyll suggested grazing was primarily influenced by spatial attributes, with greater grazing closer to recreational trails, implying that elevated cortisol with grazing could be a response to anthropogenic activity. Our results confirm that higher stress hormone concentrations correspond with lower quality diets in bears, particularly grazing, and that faecal chlorophyll shows promise as a metric for studying grazing behaviour and its consequences.

Do protection gradients explain patterns in herbivore densities? An example with ungulates in Zambia's Luangwa Valley

Ungulate populations face declines across the globe, and populations are commonly conserved by using protected areas. However, assessing the effectiveness of protected areas in conserving ungulate populations has remained difficult. Using herd size data from four years of line transect surveys and distance sampling models, we modeled population densities of four important herbivore species across a gradient of protection on the edge of Zambia's South Luangwa National Park (SLNP) while accounting for the role of various ecological and anthropogenic variables. Our goal was to test whether protection was responsible for density dynamics in this protection gradient, and whether a hunting moratorium impacted herbivore densities during the studies. For all four species, we estimated lower densities in partially protected buffer areas adjacent to SLNP (ranging from 4.5-fold to 13.2-fold lower) compared to protected parklands. Density trends through the study period were species-specific, with some species increasing, decreasing, or remaining stable in all or some regions of the protection gradient. Surprisingly, when controlling for other covariates, we found that these observed differences were not always detectably related to the level of protection or year. Our findings highlight the importance of accounting for variables beyond strata of interest in evaluating the effectiveness of a protected area. This study highlights the importance of comprehensively modeling ungulate population density across protection gradients, identifies lands within an important protection gradient for targeted conservation and monitoring, documents prey depletion and expands our understanding on the drivers in a critical buffer area in Zambia.

Functionalized silk dental floss as a vehicle for delivery of bioactive minerals and ions to the tooth surface

PURPOSE

To enable the commercially available silk dental floss to carry a series of desensitizing, alkalizing, and tooth strengthening pharmacons.

METHODS

The hydroxy-groups of the serine and tyrosine residues of the commercial silk dental floss were exposed by degumming, and employed as the chemical anchors for the introduction of carboxy-groups to the surface. The affinity of the silk dental floss to a set of bioactive species was studied by SEM, EDS, and XFS. The acetylated silk was used as a control sample for the experiments elucidating the effect of the surface carboxy-groups on its affinity to a series of pharmacons.

RESULTS

While unmodified silk has affinity to microcrystals of sodium carbonate, some affinity to hydroxyapatite particles and Sr2+, its carboxylation drastically increased the affinity to hydroxyapatite, Sr2+, Ca2+ and K+. The unmodified silk had some affinity to existing hydroxyapatite particles, but did not initiate the growth of hydroxyapatite on the surface. Carboxylation of silk enabled the growth of hydroxyapatite on its surface, and significantly increased its affinity to the existing hydroxyapatite particles. The unmodified silk had significant affinity to Zn2+, which exceeded its acylated derivatives.

CLINICAL SIGNIFICANCE

The ability of the commercial and modified silk floss to carry a series of pharmacons makes them precursors for a series of new versatile materials with a potential for delivering small doses of bioactive agents in a targeted manner.

Foraging investment in a long-lived herbivore and vulnerability to coursing and stalking predators

Allocating resources to growth and reproduction requires grazers to invest time in foraging, but foraging promotes dental senescence and constrains expression of proactive antipredator behaviors such as vigilance. We explored the relationship between carnivore prey selection and prey foraging effort using incisors collected from the kills of coursing and stalking carnivores. We predicted that prey investing less effort in foraging would be killed more frequently by coursers, predators that often exploit physical deficiencies. However, such prey could expect delayed dental senescence. We predicted that individuals investing more effort in foraging would be killed more frequently by stalkers, predators that often exploit behavioral vulnerabilities. Further these prey could expect earlier dental senescence. We tested these predictions by comparing variation in age-corrected tooth wear, a proxy of cumulative foraging effort, in adult (3.4-11.9 years) wildebeest killed by coursing and stalking carnivores. Predator type was a strong predictor of age-corrected tooth wear within each gender. We found greater foraging effort and earlier expected dental senescence, equivalent to 2.6 additional years of foraging, in female wildebeest killed by stalkers than in females killed by coursers. However, male wildebeest showed the opposite pattern with the equivalent of 2.4 years of additional tooth wear in males killed by coursers as compared to those killed by stalkers. Sex-specific variation in the effects of foraging effort on vulnerability was unexpected and suggests that behavioral and physical aspects of vulnerability may not be subject to the same selective pressures across genders in multipredator landscapes.

Quantifying lion (Panthera leo) demographic response following a three-year moratorium on trophy hunting

Factors that limit African lion populations are manifold and well-recognized, but their relative demographic effects remain poorly understood, particularly trophy hunting near protected areas. We identified and monitored 386 individual lions within and around South Luangwa National Park, Zambia, for five years (2008-2012) with trophy hunting and for three additional years (2013-2015) during a hunting moratorium. We used these data with mark-resight models to estimate the effects of hunting on lion survival, recruitment, and abundance. The best survival models, accounting for imperfect detection, revealed strong positive effects of the moratorium, with survival increasing by 17.1 and 14.0 percentage points in subadult and adult males, respectively. Smaller effects on adult female survival and positive effects on cub survival were also detected. The sex-ratio of cubs shifted from unbiased during trophy-hunting to female-biased during the moratorium. Closed mark-recapture models revealed a large increase in lion abundance during the hunting moratorium, from 116 lions in 2012 immediately preceding the moratorium to 209 lions in the last year of the moratorium. More cubs were produced each year of the moratorium than in any year with trophy hunting. Lion demographics shifted from a male-depleted population consisting mostly of adult (≥4 years) females to a younger population with more (>29%) adult males. These data show that the three-year moratorium was effective at growing the Luangwa lion population and increasing the number of adult males. The results suggest that moratoria may be an effective tool for improving the sustainability of lion trophy hunting, particularly where systematic monitoring, conservative quotas, and age-based harvesting are difficult to enforce.

Estimating Sonoran pronghorn abundance and survival with fecal DNA and capture-recapture methods

Population abundance estimates are important for management but can be challenging to determine in low-density, wide-ranging, and endangered species, such as Sonoran pronghorn (Antilocapra americana sonoriensis). The Sonoran pronghorn population has been increasing; however, population estimates are currently derived from a biennial aerial count that does not provide survival or recruitment estimates. We identified individuals through noninvasively collected fecal DNA and used robust-design capture-recapture to estimate abundance and survival for Sonoran pronghorn in the United States from 2013 to 2014. In 2014 we generated separate population estimates for pronghorn gathered near 13 different artificial water holes and for pronghorn not near water holes. The population using artificial water holes had 116 (95% CI 102-131) and 121 individuals (95% CI 112-132) in 2013 and 2014, respectively. For all locations, we estimated there were 144 individuals (95% CI 132-157). Adults had higher annual survival probabilities (0.83, 95% CI 0.69-0.92) than fawns (0.41, 95% CI 0.21-0.65). Our use of targeted noninvasive genetic sampling and capture-recapture with Sonoran pronghorn fecal DNA was an effective method for monitoring a large proportion of the population. Our results provided the first survival estimates for this population in over 2 decades and precise estimates of the population using artificial water holes. Our method could be used for targeted sampling of broadly distributed species in other systems, such as in African savanna ecosystems, where many species congregate at watering sites.

Combinatorial materials research applied to the development of new surface coatings XVI: fouling-release properties of amphiphilic polysiloxane coatings

High-throughput methods were used to prepare and characterize the fouling-release (FR) properties of an array of amphiphilic polysiloxane-based coatings possessing systematic variations in composition. The coatings were derived from a silanol-terminated polydimethylsiloxane, a silanol-terminated polytrifluorpropylmethylsiloxane (CF3-PDMS), 2-[methoxy(polyethyleneoxy)propyl]-trimethoxysilane (TMS-PEG), methyltriacetoxysilane and hexamethyldisilazane-treated fumed silica. The variables investigated were the concentration of TMS-PEG and the concentration of CF3-PDMS. In general, it was found that the TMS-PEG and the CF3-PDMS had a synergist effect on FR properties with these properties being enhanced by combining both compounds into the coating formulations. In addition, reattached adult barnacles removed from coatings possessing both TMS-PEG and relatively high levels of CF3-PDMS displayed atypical base-plate morphologies. The majority of the barnacles removed from these coatings exhibited a cupped or domed base-plate as compared to the flat base-plate observed for the control coating that did not contain TMS-PEG or CF3-PDMS. Coating surface analysis using water contact angle measurements indicated that the presence of CF3-PDMS facilitated migration of TMS-PEG to the coating/air interface during the film formation/curing process. In general, coatings containing both TMS-PEG and relatively high levels of CF3-PDMS possessed excellent FR properties.

Photosynthetic pigments estimate diet quality in forage and feces of elk (Cervus elaphus)

Understanding the nutritional dynamics of herbivores living in highly seasonal landscapes remains a central challenge in foraging ecology with few tools available for describing variation in selection for dormant versus growing vegetation. Here, we tested whether the concentrations of photosynthetic pigments (chlorophylls and carotenoids) in forage and feces of elk (Cervus elaphus L., 1785) were correlated with other commonly used indices of forage quality (digestibility, energy content, neutral detergent fiber (NDF), and nitrogen content) and diet quality (fecal nitrogen, fecal NDF, and botanical composition of the diet). Photosynthetic pigment concentrations were strongly correlated with nitrogen content, gross energy, digestibility, and NDF of elk forages, particularly in spring. Winter and spring variation in fecal pigments and fecal nitrogen was explained with nearly identical linear models estimating the effects of season, sex, and day-of-spring, although models of fecal pigments were consistently a better fit (r2adjusted = 0.379–0.904) and estimated effect sizes more precisely than models of fecal nitrogen (r2adjusted = 0.247–0.773). A positive correlation with forage digestibility, nutrient concentration, and (or) botanical composition of the diet implies fecal photosynthetic pigments may be a sensitive and informative descriptor of diet selection in free-ranging herbivores.

Ecosystem scale declines in elk recruitment and population growth with wolf colonization: a before-after-control-impact approach

The reintroduction of wolves (Canis lupus) to Yellowstone provided the unusual opportunity for a quasi-experimental test of the effects of wolf predation on their primary prey (elk--Cervus elaphus) in a system where top-down, bottom-up, and abiotic forces on prey population dynamics were closely and consistently monitored before and after reintroduction. Here, we examined data from 33 years for 12 elk population segments spread across southwestern Montana and northwestern Wyoming in a large scale before-after-control-impact analysis of the effects of wolves on elk recruitment and population dynamics. Recruitment, as measured by the midwinter juvenile∶female ratio, was a strong determinant of elk dynamics, and declined by 35% in elk herds colonized by wolves as annual population growth shifted from increasing to decreasing. Negative effects of population density and winter severity on recruitment, long recognized as important for elk dynamics, were detected in uncolonized elk herds and in wolf-colonized elk herds prior to wolf colonization, but not after wolf colonization. Growing season precipitation and harvest had no detectable effect on recruitment in either wolf treatment or colonization period, although harvest rates of juveniles∶females declined by 37% in wolf-colonized herds. Even if it is assumed that mortality due to predation is completely additive, liberal estimates of wolf predation rates on juvenile elk could explain no more than 52% of the total decline in juvenile∶female ratios in wolf-colonized herds, after accounting for the effects of other limiting factors. Collectively, these long-term, large-scale patterns align well with prior studies that have reported substantial decrease in elk numbers immediately after wolf recolonization, relatively weak additive effects of direct wolf predation on elk survival, and decreased reproduction and recruitment with exposure to predation risk from wolves.

Underestimating the frequency, strength and cost of antipredator responses with data from GPS collars: an example with wolves and elk

Field studies that rely on fixes from GPS-collared predators to identify encounters with prey will often underestimate the frequency and strength of antipredator responses. These underestimation biases have several mechanistic causes. (1) Step bias: The distance between successive GPS fixes can be large, and encounters that occur during these intervals go undetected. This bias will generally be strongest for cursorial hunters that can rapidly cover large distances (e.g., wolves and African wild dogs) and when the interval between GPS fixes is long relative to the duration of a hunt. Step bias is amplified as the path travelled between successive GPS fixes deviates from a straight line. (2) Scatter bias: Only a small fraction of the predators in a population typically carry GPS collars, and prey encounters with uncollared predators go undetected unless a collared group-mate is present. This bias will generally be stronger for fission–fusion hunters (e.g., spotted hyenas, wolves, and lions) than for highly cohesive hunters (e.g., African wild dogs), particularly when their group sizes are large. Step bias and scatter bias both cause underestimation of the frequency of antipredator responses. (3) Strength bias: Observations of prey in the absence of GPS fix from a collared predator will generally include a mixture of cases in which predators were truly absent and cases in which predators were present but not detected, which causes underestimation of the strength of antipredator responses. We quantified these biases with data from wolves and African wild dogs and found that fixes from GPS collars at 3-h intervals underestimated the frequency and strength of antipredator responses by a factor >10. We reexamined the results of a recent study of the nonconsumptive effects of wolves on elk in light of these results and confirmed that predation risk has strong effects on elk dynamics by reducing the pregnancy rate.

Glucocorticoid stress responses of lions in relationship to group composition, human land use, and proximity to people

Large carnivore populations are in global decline, and conflicts between large carnivores and humans or their livestock contribute to low tolerance of large carnivores outside of protected areas. African lions (Panthera leo) are a conflict-prone species, and their continental range has declined by 75% in the face of human pressures. Nonetheless, large carnivore populations persist (or even grow) in some areas that are occupied by humans. Lions attain locally high density in the Olkiramatian and Shompole Group Ranches of Kenya's South Rift region, despite residence by pastoralist Maasai people and their sheep, goats, and cattle. We have previously found that these lions respond to seasonal movements of people by moving away from occupied settlements, shifting into denser habitats when people are nearby, and moving into a protected conservation area when people move into the adjacent buffer zone. Here, we examined lion stress responses to anthropogenic activities, using enzyme-linked immunoassay to measure the concentration of faecal glucocorticoid metabolites in 136 samples collected from five lion groups over 2 years. Faecal glucocorticoid metabolite concentrations were significantly lower for lions in the conservation area than for lions in the human-settled buffer zone, and decreased significantly with increasing distance to the nearest occupied human settlement. Faecal glucocorticoid metabolite concentrations were not detectably related to fine-scaled variation in prey or livestock density, and surprisingly, faecal glucocorticoid metabolite concentrations were higher in the wet season, when regional prey abundance was high. Lions coexist with people and livestock on this landscape by adjusting their movements, but they nonetheless mount an appreciable stress response when conditions do not allow them to maintain adequate separation. Thus, physiological data confirm inferences from prior data on lion movements and habitat use, showing that access to undisturbed and protected areas facilitates human-lion coexistence in a broader landscape that is used by people and livestock.

Abstract P5-20-08: Phase II trial of ixabepilone (Ixa) and dasatinib (D) for treatment of metastatic breast cancer (MBC)

Background: Ixa is a novel semi-synthetic epothilone microtubule blocking agent with activity in taxane and anthracycline-resistant MBC. D is a potent small molecule tyrosine kinase inhibitor with substantial activity against SRC family non-receptor kinases, known to play multiple roles in promoting tumor growth and metastases. D inhibits cellular SRC autophosphorylation in cell lines that highly express SRC and inhibits in vivo activation in a broad array of tumors in nude mice. Ixa and D have synergistic effects in preclinical models suggesting this strategy would be of clinical benefit as combination therapy. A phase I trial of the combination determined the maximally tolerated doses of ixabepilone at 20 mg/m2 weekly and dasatinib 100 mg po daily with objective responses seen. Neutropenia was the dose limiting toxicity.

Methods: Multicenter single arm phase II trial. Eligibility: Measurable or evaluable disease by RECIST 1.0, ECOG PS 0–2, HER2− or HER2 refractory, no CYP 3A4 inducers or inhibitors, no H2 blockers or PPIs, no pleural/pericardial effusion, exposure to 1 or 2 prior lines of chemotherapy in the metastatic setting, peripheral neuropathy ≤ grade 1. The primary endpoint was progression-free survival (PFS). Assessment for response was performed every 8 weeks. The treatment schedule was D at 100 mg po daily starting day 1, and Ixa 20 mg/m2 Day 1, 8, 15 every 28 days (1 cycle).

Results: The study met its accrual goal with 50 patients (pts) enrolled on the phase II dosing, including six from the phase I portion. As of May 21, 2012, 47 pts are evaluable. The median age was 55 (range, 34–70), 19 African-American, 46 ECOG PS 0–1, median number of metastatic sites, three. Forty pts had prior taxanes, 24 prior anthracyclines. Median PFS was 6.0 months (95% CI, 2.9–8.0), achieving pre-specified value of interest for further study of the combination. The overall unconfirmed response rate was 14.9% with a clinical benefit rate (CR+PR + stable at 24 weeks) of 25.5%. Six pts continued D monotherapy after eight cycles of Ixa + D. All-grade adverse events (AEs) occurring in &gt;15% of pts included anemia (45%), neutropenia (32%), nausea (51%), vomiting (32%) diarrhea (51%), fatigue (53%), anorexia (25%) dysgeusia (32%), headache (28%), peripheral neuropathy (34%) cough (28%) alopecia (21%) and hypokalemia (19%). Grade 3/4 adverse events occurred in 30 patients, with only four experiencing grade 4 AEs, three neutropenia and one chest pain. No grade 3/4 febrile neutropenia occurred. Grade 3 AEs of interest included two pts with peripheral neuropathy and 1 with pleural effusion.

Conclusions: The combination of Ixabepilone weekly + Dasatinib orally daily is an active and well tolerated regimen in pretreated MBC with manageable toxicity. Updated results will be reported.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-20-08.

Abstract B16: Development of potent and selective indomethacin analogs for the inhibition of AKR1C3 (type 5 17β-hydroxysteroid dehydrogenase) in CRPC

Castrate-resistant prostate cancer (CRPC) is a fatal metastatic form of prostate cancer that accounts for 30,000 deaths in the U.S. annually. Patients with advanced prostate cancer that initially respond to hormonal ablative therapy (orchiectomy or chemical castration) invariably develop CRPC. CRPC is characterized by reactivation of the androgen axis due to changes in androgen receptor (AR) signaling and/or adaptive intratumoral androgen biosynthesis. The latter is targeted with the new agent abiraterone acetate (a P450 17α-hydroxylase/17,20-lyase inhibitor) which prevents the production of the adrenal androgen precursor, dehydroepiandrosterone but has the unintended consequence of building up the potent mineralocortcoid, desoxycorticosterone. To circumvent this side effect, abiraterone acetate is co-administered with prednisone. AKR1C3 is among the most upregulated genes in CRPC and in soft tissue metastasis where its 17β-hydroxysteroid dehydrogenase activity converts the weak androgens, 4-androstene-3,17-dione and 5α-androstane-3,17-dione to the potent androgens, testosterone and 5α-dihydrotestosterone, respectively. The role of AKR1C3 in the pre-receptor regulation of ligands for the AR makes it a more selective target than abiraterone for the treatment of CRPC. Inhibitors of AKR1C3 should not inhibit the related isoforms, AKR1C1 and AKR1C2 since these enzymes inactivate 5α-dihydrotestosterone. Indomethacin, a therapeutic agent used to inhibit cyclooxygenase (COX) also inhibits AKR1C3 potently and displays selectivity over AKR1C1 and AKR1C2. Parallel synthetic strategies were used to generate libraries of indomethacin analogs which based on known structure-activity relationships should no longer inhibit COX enzymes but may retain AKR1C3 inhibitory potency and selectivity. Three classes of AKR1C3 inhibitors were discovered, that had the desired properties: indomethacin analogs (in which the 3′-side chain was modified), 2′-desmethyl-indomethacin analogs (which had either an acid or trifluoromethylsulfonamide substituent at the 3′-position), and 3′-alkyl-indomethacin analogs (which had either an acid or trifluoromethylsulfonamide substituent at the 2′-position). The lead compounds inhibited AKR1C3 with nanomolar potency, displayed over 100-fold selectivity for AKR1C3 over AKR1C1/AKR1C2 and produced robust inhibition of testosterone formation in an LNCaP-AKR1C3 prostate cancer cell line. Several had minimal inhibitory affects on COX-1 and COX-2. In a separate study, indomethacin blocked PSA and ERG expression, and cell proliferation in a VCaP xenograft model of CRPC providing in vivo efficacy data (Cai at al., Cancer Res. 71: 6503, 2011). 2′-Desmethyl-indomethacin 1 was crystallized in complex with AKR1C3 and NADP+, and diffraction data were obtained at 1.8 A resolution. The structure showed that in the absence of the 2′-methyl group the compound assumes a different binding mode to indomethacin. Compound 1 binds perpendicular to indomethacin such that the carboxylic acid on its indole ring is tethered to the oxyanion site and protrudes into a SP1 pocket as seen with the other NSAIDs like flufenamic acid. This model provides a binding pose for the 2′-desmethyl indomethacin analogs and also predicts a possible binding pose for the 3′-alkyl indomethacin series. The compounds reported are promising agents for the preclinical development of therapeutics for CRPC, which by targeting AKR1C3 will be more selective than P450 17α-hydroxylase/17,20-lyase inhibitors, and will not have to be co-administered with prednisone. The agents disclosed in this abstract are protected by US Provisional Patent Application No. 61/548,004. [Supported by R01-CA90744 and a Prostate Cancer Foundation Challenge Award to TMP and R01-CA889450 to LJM]

Citation Format: Adegoke Adeniji, Andrew Liedkte, Michael C. Byrns, M Chen, Yi Jin, David Christianson, Lawrence J. Marnett, Trevor M. Penning. Development of potent and selective indomethacin analogs for the inhibition of AKR1C3 (type 5 17β-hydroxysteroid dehydrogenase) in CRPC [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr B16.

Neonatal mortality of elk driven by climate, predator phenology and predator community composition

1. Understanding the interaction among predators and between predation and climate is critical to understanding the mechanisms for compensatory mortality. We used data from 1999 radio-marked neonatal elk (Cervus elaphus) calves from 12 populations in the north-western United States to test for effects of predation on neonatal survival, and whether predation interacted with climate to render mortality compensatory. 2. Weibull survival models with a random effect for each population were fit as a function of the number of predator species in a community (3-5), seven indices of climatic variability, sex, birth date, birth weight, and all interactions between climate and predators. Cumulative incidence functions (CIF) were used to test whether the effects of individual species of predators were additive or compensatory. 3. Neonatal elk survival to 3 months declined following hotter previous summers and increased with higher May precipitation, especially in areas with wolves and/or grizzly bears. Mortality hazards were significantly lower in systems with only coyotes (Canis latrans), cougars (Puma concolor) and black bears (Ursus americanus) compared to higher mortality hazards experienced with gray wolves (Canis lupus) and grizzly bears (Ursus horribilis). 4. In systems with wolves and grizzly bears, mortality by cougars decreased, and predation by bears was the dominant cause of neonatal mortality. Only bear predation appeared additive and occurred earlier than other predators, which may render later mortality by other predators compensatory as calves age. Wolf predation was low and most likely a compensatory source of mortality for neonatal elk calves. 5. Functional redundancy and interspecific competition among predators may combine with the effects of climate on vulnerability to predation to drive compensatory mortality of neonatal elk calves. The exception was the evidence for additive bear predation. These results suggest that effects of predation by recovering wolves on neonatal elk survival, a contentious issue for management of elk populations, may be less important than the composition of the predator community. Future studies would benefit by synthesizing overwinter calf and adult-survival data sets, ideally from experimental studies, to test the roles of predation in annual compensatory and additive mortality of elk.

Abstract 4714: Phase I/II trial of ixabepilone (Ixa) and dasatinib (D) for treatment of metastatic breast cancer (MBC)

Background: Ixa is a novel microtubule blocking epothilone with activity in taxane and anthracycline-resistant MBC. D is a potent small molecule tyrosine kinase inhibitor with substantial activity against SRC family non-receptor kinases, known to play multiple roles in promoting tumor growth and metastases. D inhibits cellular SRC autophosphorylation in cell lines that highly express SRC and inhibits in vivo activation in a broad array of tumors in nude mice. D was safe as a single agent in MBC with modest single agent activity. Ixa and D have synergistic effects in preclinical models suggesting this strategy would be of clinical benefit as combination therapy. Methods: Open label multicenter dose escalation trial determining the maximally tolerated dose (MTD) and the dose-limiting toxicity (DLT) of the combination of Ixa + D followed by a phase II component evaluating efficacy. In phase I, up to four dose range cohorts were planned. In each dose level (DL), three patients (pts) initially enrolled and escalated until &gt; 1/3 pts on a DL exhibited DLT. The MTD was defined at the DL at which &lt; 1/6 pts experienced DLT. Eligibility included MBC previously treated with 1-2 prior lines of therapy, Grade &lt; 1 peripheral neuropathy, ability to take oral medications, HER2- or HER2-directed therapy resistant, ECOG PS 0-2, no pleural/pericardial effusions, QTc interval &lt;450 msec. DL 0 was Ixa 16 mg/m2 IV day 1, 8, 15 of a 28-day cycle with D100 mg QD PO daily. DL 1: Ixa 20 mg/m2; D100 mg QD; DL2: Ixa 20 mg/m2; D140 mg QD. Adverse event grading by CTCAE 3.0. Results: Twelve pts were treated during the phase I portion, 3 at DL 0, 6 at DL 1 and 3 at DL 2. Median age was 52.3, 25% African-American, ECOG 0 three pts, ECOG 1, 9 pts. Prior chemotherapy: 10 received two lines, 2 one line. The MTD was established at DL 1, Ixa 20 mg/m2 day 1, 8, 15, and D 100 mg QD daily Q 28 days. At DL 2, DLT of leucopenia and thrombocytopenia occurred in 2 patients. Grade 3 non-hematologic adverse events occurring in &gt;1 pt included diarrhea in 2 and fatigue in 2. No grade 4 non-hematologic toxicity was seen. One pt developed grade1 pleural effusion and 2 had grade 1/2 peripheral neuropathy. Other grade 1/2 AEs included rash, cough, dyspnea, muscle pain, pyrexia and anorexia. 2/12 pts achieved a partial response (25%) and 4 (33%) achieved stable disease. Two pts remain on study at cycle 10+ and at cycle 7+. Dose delays /reductions were not required during DL 0 until cycle 4 but dose delays occurred from cycle 1 onward in DL 1 and 2. Conclusions: Ixa + D can be safely delivered at clinically relevant doses to pts with MBC. A MTD of Ixa at 20 mg/m2 weekly 3/4 wks and D at 100 mg QD was established with clinical activity seen at this dose level. The phase II portion is actively accruing pts.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4714. doi:10.1158/1538-7445.AM2011-4714

Environmental and genetic factors that contribute to Escherichia coli K-12 biofilm formation

Biofilms are communities of bacteria whose formation on surfaces requires a large portion of the bacteria's transcriptional network. To identify environmental conditions and transcriptional regulators that contribute to sensing these conditions, we used a high-throughput approach to monitor biofilm biomass produced by an isogenic set of Escherichia coli K-12 strains grown under combinations of environmental conditions. Of the environmental combinations, growth in tryptic soy broth at 37 degrees C supported the most biofilm production. To analyze the complex relationships between the diverse cell-surface organelles, transcriptional regulators, and metabolic enzymes represented by the tested mutant set, we used a novel vector-item pattern-mining algorithm. The algorithm related biofilm amounts to the functional annotations of each mutated protein. The pattern with the best statistical significance was the gene ontology 'pyruvate catabolic process,' which is associated with enzymes of acetate metabolism. Phenotype microarray experiments illustrated that carbon sources that are metabolized to acetyl-coenzyme A, acetyl phosphate, and acetate are particularly supportive of biofilm formation. Scanning electron microscopy revealed structural differences between mutants that lack acetate metabolism enzymes and their parent and confirmed the quantitative differences. We conclude that acetate metabolism functions as a metabolic sensor, transmitting changes in environmental conditions to biofilm biomass and structure.

A nutritionally mediated risk effect of wolves on elk

Though it is widely argued that antipredator responses carry nutritional costs, or risk effects, these costs are rarely measured in wild populations. To quantify risk effects in elk, a species that strongly responds to the presence of wolves, we noninvasively monitored diet selection and nutrient balance in wintering elk in the Upper Gallatin, Montana, USA, over three winters while quantifying the local presence of wolves at a fine spatiotemporal scale. Standard nutritional indices based on the botanical and chemical composition of 786 fecal samples, 606 snow urine samples, and 224 forage samples showed that elk were generally malnourished throughout winter. Increased selection for dietary nitrogen within forage types (e.g., grasses) led to approximately 8% higher fecal nitrogen in the presence of wolves. However, urinary allantoin : creatinine and potassium : creatinine ratios decreased in the presence of wolves, suggesting large declines in energy intake, equal to 27% of maintenance requirements. Urinary nitrogen : creatinine ratios confirmed that deficiencies in nitrogen and/or energy were exacerbated in the presence of wolves, leading to increased endogenous protein catabolism. Overall, the nutritional effects of wolf presence may be of sufficient magnitude to reduce survival and reproduction in wintering elk. Nutritionally mediated risk effects may be important for understanding predator-prey dynamics in wild populations, but such effects could be masked as bottom-up forces if antipredator responses are not considered.

Fecal chlorophyll describes the link between primary production and consumption in a terrestrial herbivore

Spatiotemporal variation in primary productivity is known to have strong and far-reaching effects on herbivore ecology, but this relationship is often studied indirectly at broad scales, in part due to the difficulty in measuring selection for green biomass by individual animals. In aquatic systems, the concentration of chlorophyll in herbivore feces has been used as a direct measure of the consumption of photosynthetic primary production, but this method has not been applied to terrestrial systems. We measured chlorophyll concentration in feces from elk (Cervus elaphus) experiencing large fluctuations in primary production in the winter to spring transition over three years. We compared temporal trends in fecal chlorophyll with trends in fecal nitrogen, grass chlorophyll, grass digestible nitrogen, and landscape-level primary productivity (as described by the normalized difference vegetation index or NDVI). We also directly examined the relationship between fecal chlorophyll and NDVI. Temporal trends in fecal chlorophyll were strong and well described by piecewise regression (adjusted coefficient of determination, r(2)a = 0.881-0.888), showing uniformly low concentrations throughout winter followed by an abrupt, rapid increase beginning on different Julian days (88, 91, or 110) each year. Changes in fecal chlorophyll closely matched the temporal trend in the chlorophyll and digestible nitrogen concentration of forage grasses collected directly from elk feeding sites. Fecal chlorophyll also tracked broad temporal patterns in fecal nitrogen and NDVI, but discrepancies between the indexes may highlight preferences or constraints on selectivity for green biomass in elk. Spatially and temporally matched NDVI and fecal chlorophyll estimates were uncorrelated until NDVI reached approximately half its seasonal range. Combined, these data describe important patterns in selection for nutritious, green biomass in a temperate herbivore that would be difficult to study without data on fecal chlorophyll. Fecal chlorophyll produced novel and precise descriptions of (and detected large interannual differences in) winter length, severity, and the rate of spring green-up, as they were experienced by a large, grazing herbivore. Measuring fecal chlorophyll provides a noninvasive, inexpensive, and direct approach to describe an important aspect of foraging ecology in terrestrial herbivores and may be particularly powerful for studying climate effects in seasonal environments.

Relationships between direct predation and risk effects

Risk effects arise when prey alter their behavior in response to predators, and these responses carry costs. Empirical studies have found that risk effects can be large. Nonetheless, studies of predation in vertebrate conservation and management usually consider only direct predation. Given the ubiquity and strength of behavioral responses to predators by vertebrate prey, it is not safe to assume that risk effects on dynamics can be ignored. Risk effects can be larger than direct effects. Risk effects can exist even when the direct rate of predation is zero. Risk effects and direct effects do not necessarily change in parallel. When risk effects reduce reproduction rather than survival, they are easily mistaken for limitation by food supply.

Barnacle reattachment: a tool for studying barnacle adhesion

Standard approaches for measuring adhesion strength of fouling organisms use barnacles, tubeworms or oysters settled and grown in the field or laboratory, to a measurable size. These approaches suffer from the vagaries of larval supply, settlement behavior, predation, disturbance and environmental stress. Procedures for reattaching barnacles to experimental surfaces are reported. When procedures are followed, adhesion strength measurements on silicone substrata after 2 weeks are comparable to those obtained using standard methods. Hydrophilic surfaces require reattachment for 2-4 weeks. The adhesion strength of barnacles in reattachment assays was positively correlated to results obtained from field testing a series of experimental polysiloxane fouling-release coatings (r = 0.89). The reattachment method allows for precise barnacle orientation, enabling the use of small surfaces and the potential for automation. The method enables down-selection of coatings from combinatorial approaches to manageable levels for definitive field testing. Reattachment can be used with coatings that combine antifouling and fouling-release technologies.

Combinatorial materials research applied to the development of new surface coatings VII: an automated system for adhesion testing

An automated, high-throughput adhesion workflow that enables pseudobarnacle adhesion and coating/substrate adhesion to be measured on coating patches arranged in an array format on 4x8 in.(2) panels was developed. The adhesion workflow consists of the following process steps: (1) application of an adhesive to the coating array; (2) insertion of panels into a clamping device; (3) insertion of aluminum studs into the clamping device and onto coating surfaces, aligned with the adhesive; (4) curing of the adhesive; and (5) automated removal of the aluminum studs. Validation experiments comparing data generated using the automated, high-throughput workflow to data obtained using conventional, manual methods showed that the automated system allows for accurate ranking of relative coating adhesion performance.

Predation Risk Affects Reproductive Physiology and Demography of Elk

Elk (Cervus elaphus) in the Greater Yellowstone Ecosystem alter patterns of aggregation, habitat selection, vigilance, and foraging in the presence of wolves (Canis lupus). Antipredator behaviors like these can reduce predation risk but are also likely to carry costs. Data from five elk populations studied for 16 site years showed that progesterone concentrations (from 1489 fecal samples) declined with the ratio of elk to wolves. In turn, progesterone concentrations were a good predictor of calf recruitment in the subsequent year. Together, these data suggest that wolves indirectly affect the reproductive physiology and the demography of elk through the costs of antipredator behavior.

Combinatorial materials research applied to the development of new surface coatings III. Utilisation of a high-throughput multiwell plate screening method to rapidly assess bacterial biofilm retention on antifouling surfaces

The authors recently reported on the development of a novel multiwell plate screening method for the high-throughput assessment of bacterial biofilm retention on surfaces. Two series of biocide containing coatings were prepared to assess the ability of the developed assay to adequately discern differences in antifouling performance: i) a commercially available poly(methyl methacrylate) (PMMA) and silicone elastomer (DC) physically blended with an organic antifouling biocide Sea-Nine 211 (SN211) (4,5-dichloro-2-n-octyl-3(2H)-isothiazolone), and ii) a silanol-terminated polydimethylsiloxane (PDMS-OH) reacted with an alkoxy silane-modified polyethylenimine containing bound ammonium salt groups (PEI-AmCl). Three marine bacteria were utilised to evaluate the SN211 blended coatings (Pseudoalteromonas atlantica ATCC 19262, Cobetia marina ATCC 25374, Halomonas pacifica ATCC 27122) and the marine bacterium Cytophaga lytica was utilised to evaluate the PEI-AmCl/PDMS-OH coatings. The SN211 blended coatings showed a general trend of decreasing biofilm retention as the concentration of SN211 increased in both PMMA and DC. HPLC analysis revealed that reduction in biofilm retention was positively correlated with the amount of SN211 released into the growth medium over the length of the bacterial incubation. When compared to PMMA, DC consistently showed an equal or greater percent reduction in biofilm retention as the level of SN211 loading increased, although at lower loading concentrations. Evaluations of the PEI-AmCl/PDMS-OH coatings with C. lytica showed that all PEI-AmCl loading concentrations significantly reduced biofilm retention (p<0.0001) by a surface contact phenomenon. The high-throughput bacterial biofilm growth and retention assay has been shown to be useful as an effective primary screening tool for the rapid assessment of antifouling materials.

Combinatorial materials research applied to the development of new surface coatings IV. A high-throughput bacterial biofilm retention and retraction assay for screening fouling-release performance of coatings

A high-throughput bacterial biofilm retention screening method has been augmented to facilitate the rapid analysis and down-selection of fouling-release coatings for identification of promising candidates. Coatings were cast in modified 24-well tissue culture plates and inoculated with the marine bacterium Cytophaga lytica for attachment and biofilm growth. Biofilms retained after rinsing with deionised water were dried at ambient laboratory conditions. During the drying process, retained biofilms retracted through a surface de-wetting phenomenon on the hydrophobic silicone surfaces. The retracted biofilms were stained with crystal violet, imaged, and analysed for percentage coverage. Two sets of experimental fouling-release coatings were analysed with the high-throughput biofilm retention and retraction assay (HTBRRA). The first set consisted of a series of model polysiloxane coatings that were systematically varied with respect to ratios of low and high MW silanol-terminated PDMS, level of cross-linker, and amount of silicone oil. The second set consisted of cross-linked PDMS-polyurethane coatings varied with respect to the MW of the PDMS and end group functionality. For the model polysiloxane coatings, HTBRRA results were compared to data obtained from field immersion testing at the Indian River Lagoon at the Florida Institute of Technology. The percentage coverage calculations of retracted biofilms correlated well to barnacle adhesion strength in the field (R(2)=0.82) and accurately identified the best and poorest performing coating compositions. For the cross-linked PDMS-polyurethane coatings, the HTBRRA results were compared to combinatorial pseudobarnacle pull-off adhesion data and good agreement in performance was observed. Details of the developed assay and its implications in the rapid discovery of new fouling-release coatings are discussed.

Environmental public health surveillance: possible estuary-associated syndrome

Public health surveillance involves the collection, analysis, and dissemination of data for use in public health practice. A surveillance system includes the capacity to collect and analyze data as well as the ability to disseminate the data to public health agencies that can undertake effective prevention and control activities. An emerging issue in environmental public health surveillance involves human exposure to the toxins produced by microorganisms present in oceans and estuaries. One of these organisms is Pfiesteria piscicida Steidinger & Burkholder, a dinoflagellate found in estuaries along the Atlantic and gulf coasts of the United States. There have been reports of both human illness associated with occupational exposures to concentrated laboratory cultures of P. piscicida and massive fill kills associated with the presence of the organism in rivers and estuaries. These reports, and anecdotal reports from people who worked on rivers where the organism has been found, generated concern that environmental exposures to P. piscicida, similar organisms, or perhaps a toxin or toxins produced by the organism(s), could cause adverse human health effects. To begin to evaluate the public health burden associated with P. piscicida, investigators from the National Center for Environmental Health at Centers for Disease Control and Prevention and health agencies from states along the Atlantic coast collaborated to develop a passive surveillance system for collecting, classifying, and tracking public inquiries about the organism. Specifically, the group developed exposure and symptom criteria and developed data collection and reporting capabilities to capture the human health parameters collectively referred to as possible estuary-associated syndrome (PEAS). The surveillance system was implemented in six states (Delaware, Florida, Maryland, North Carolina, South Carolina, Virginia) beginning in June 1998. From 1 June 1998 through 30 June 2001, the six state health agencies participating in the PEAS surveillance system received 3,859 calls: 3,768 callers requested information and 91 callers reported symptoms. Five individuals have been identified as meeting PEAS criteria.

Atovaquone and azithromycin for the treatment of babesiosis

BACKGROUND

Babesiosis is a tick-borne, malaria-like illness known to be enzootic in southern New England. A course of clindamycin and quinine is the standard treatment, but this regimen frequently causes adverse reactions and occasionally fails. A promising alternative treatment is atovaquone plus azithromycin.

METHODS

We conducted a prospective, nonblinded, randomized trial of the two regimens in 58 subjects with non-life-threatening babesiosis on Nantucket, on Block Island, and in southern Connecticut. The subjects were assigned to receive either atovaquone (750 mg every 12 hours) and azithromycin (500 mg on day 1 and 250 mg per day thereafter) for seven days (40 subjects) or clindamycin (600 mg every 8 hours) and quinine (650 mg every 8 hours) for seven days (18 subjects).

RESULTS

Adverse effects were reported by 15 percent of the subjects who received atovaquone and azithromycin, as compared with 72 percent of those who received clindamycin and quinine (P<0.001). The most common adverse effects with atovaquone and azithromycin were diarrhea and rash (each in 8 percent of the subjects); with clindamycin and quinine the most common adverse effects were tinnitus (39 percent), diarrhea (33 percent), and decreased hearing (28 percent). Symptoms had resolved three months after the start of therapy in 65 percent of those who received atovaquone and azithromycin and 73 percent of those who received clindamycin and quinine (P=0.66), and after six months no patient in either group had symptoms. Three months after the completion of the assigned regimen, no parasites could be seen on microscopy, and no Babesia microti DNA was detected in the blood of any subject.

CONCLUSIONS

For the treatment of babesiosis, a regimen of atovaquone and azithromycin is as effective as a regimen of clindamycin and quinine and is associated with fewer adverse reactions.

Effects of transdermal nicotine on craving, withdrawal and premenstrual symptomatology in short-term smoking abstinence during different phases of the menstrual cycle

Gender differences in nicotine response with regard to nicotine sensitivity and withdrawal symptomatology have been reported, with the suggestion that ovarian hormones play a role. Few studies, however, have directly assessed hormonal influences on nicotine response. This study focused on the effects of a transdermal nicotine patch in women during acute smoking abstinence when tested in different phases of their menstrual cycle. Thirty women were randomized to order of menstrual cycle phase (late luteal or follicular) and patch condition (active or placebo). Two 7-day outpatient-testing periods were conducted with 2 days of ad lib baseline smoking and 5 days of smoking abstinence. Dependent measures included scores from the Minnesota Nicotine Withdrawal Scale, Questionnaire on Smoking Urges, and Premenstrual Assessment Form, as well as weight. The severity of both premenstrual symptomatology and nicotine withdrawal symptoms was greater in the late luteal phase. Correlation coefficients confirmed overlap between premenstrual and withdrawal symptomatology, especially for the affect subscale. A significant patch effect was observed, showing diminished craving and premenstrual affect on pain subscale scores for women on active patch. Results showed that nicotine craving and premenstrual pain and water retention symptoms were diminished in women on transdermal patch, and that this effect was greatest in the late luteal phase. In addition, the greatest weight gain was demonstrated for participants in the late luteal phase, placebo condition. In summary, during short-term smoking abstinence in women, transdermal nicotine appears to have a more pronounced effect in the late luteal phase than in the follicular phase in reducing craving and certain premenstrual symptoms.

Energy intake and energy expenditure during the menstrual cycle in short-term smoking cessation

The effect of short-term smoking abstinence on energy intake and expenditure parameters was investigated for women in different phases of the menstrual cycle (follicular or late luteal) in a rigorous inpatient laboratory setting. Twenty-one participants were randomized to a continued smoking (n = 5) or a smoking abstinence (n = 16) group and admitted for 2 7-day inpatient periods during alternate cycle phases. The smoking abstinence group experienced 2 days of baseline smoking and 5 days of smoking abstinence. Measurements included caloric intake (kcal/24 hours), energy expenditure (by indirect calorimetry), and weight. Results of within-subject analyses indicated no smoking abstinence effect on mean daily total kilocalorie intake, sweet kilocalorie intake, or resting metabolic rate. However, a significant cycle phase effect was observed, with increased kilocalorie intake and expenditure-as well as minor weight gain-occurring during the late luteal phase when premenstrual symptoms are highest. In light of this phase effect, women smokers might benefit by attempting to quit smoking during the follicular phase of their cycle.

Withdrawal and pre-menstrual symptomatology during the menstrual cycle in short-term smoking abstinence: effects of menstrual cycle on smoking abstinence

This study employs a rigorous inpatient laboratory setting to test the hypothesis that withdrawal symptomatology in short-term smoking cessation in women is increased in the late luteal phase when pre-menstrual symptomatology is the highest. Twenty-one female smokers with clinical, anatomical, and hormonal verification of their menstrual cycle phase were randomized to either a smoking abstinence group (n = 16) or a continued smoking group (n = 5). Participants were admitted to the General Clinical Research Center during alternate phases of their cycle for two 7-day admissions with a 1-month interim period when they resumed smoking. Dependent measures, i.e., Minnesota Nicotine Withdrawal Scale scores, Questionnaire on Smoking Urges scores and Pre-menstrual Assessment Form scores were collected during 2 days of baseline and 5 days of smoking deprivation. Smoking behavior was documented by self-report, breath CO levels and saliva cotinine measurements. Withdrawal symptomatology was not affected by menstrual cycle phase during short-term cessation in spite of increased pre-menstrual changes seen in the late luteal phase. In addition, no phase effect on smoking behavior was detected and cigarette consumption remained stable across the cycle in both groups. These results suggest that for some smoking cessation studies, complex strategies to control for menstrual cycle effects may not be necessary. However, Smoking Urges scores did suggest increased desire to smoke and desire to relieve negative affect in the late luteal phase when women have higher pre-menstrual symptomatology. This suggests women may have greater difficulty quitting smoking in late luteal phase, and it seems prudent to recommend that women quit during the follicular phase of their cycle.

Persistent parasitemia after acute babesiosis

BACKGROUND

Babesiosis, a zoonosis caused by the protozoan Babesia microti, is usually not treated when the symptoms are mild, because the parasitemia appears to be transient. However, the microscopical methods used to diagnose this infection are insensitive, and few infected people have been followed longitudinally. We compared the duration of parasitemia in people who had received specific antibabesial therapy with that in silently infected people who had not been treated.

METHODS

Forty-six babesia-infected subjects were identified from 1991 through 1996 in a prospective, community-based study designed to detect episodes of illness and of seroconversion among the residents of southeastern Connecticut and Block Island, Rhode Island. Subjects with acute babesial illness were monitored every 3 months for up to 27 months by means of thin blood smears, Bab. microti polymerase-chain-reaction assays, serologic tests, and questionnaires.

RESULTS

Babesial DNA persisted in the blood for a mean of 82 days in 24 infected subjects without specific symptoms who received no specific therapy. Babesial DNA persisted for 16 days in 22 acutely ill subjects who received clindamycin and quinine therapy (P=0.03), of whom 9 had side effects from the treatment. Among the subjects who did not receive specific therapy, symptoms of babesiosis persisted for a mean of 114 days in five subjects with babesial DNA present for 3 or more months and for only 15 days in seven others in whom the DNA was detectable for less than 3 months (P<0.05); one subject had recrudescent disease after two years.

CONCLUSIONS

When left untreated, silent babesial infection may persist for months or even years. Although treatment with clindamycin and quinine reduces the duration of parasitemia, infection may still persist and recrudesce and side effects are common. Improved treatments are needed.

Comparison of PCR with blood smear and inoculation of small animals for diagnosis of Babesia microti parasitemia

The specific diagnosis of babesiosis, which is caused by the piroplasm Babesia microti, is made by microscopic identification of the organism in Giemsa-stained thin blood smears, detection of babesial antibody in acute-and convalescent-phase sera, or identification of the organism following the injection of patient blood into laboratory animals. Although rapid diagnosis can be made with thin blood smears, parasites are often not visualized early in the course of infection. PCR is a new, rapid diagnostic technique for the detection of Babesia spp. that has not yet been systematically evaluated. We conducted a blinded study of the sensitivity, specificity, and reproducibility of the PCR-based test with patients with babesiosis and a group of asymptomatic subjects residing in a region in southern New England where babesiosis is enzootic. Among 19 patients with recent babesial illness, we found that PCR was as sensitive and specific as the use of Giemsa-stained blood smears and inoculation of hamsters. Among asymptomatic subjects, the PCR result was positive for 3 persons with recent babesial infection and was negative for 41 persons without previous babesial infection. We conclude that the B. microti PCR procedure is sufficiently sensitive, specific, and reproducible for use in the diagnosis of acute babesiosis.

Concurrent Lyme disease and babesiosis. Evidence for increased severity and duration of illness

OBJECTIVE

To determine whether patients coinfected with Lyme disease and babesiosis in sites where both diseases are zoonotic experience a greater number of symptoms for a longer period of time than those with either infection alone.

DESIGN

Community-based, yearly serosurvey and clinic-based cohort study.

SETTING

Island community in Rhode Island and 2 Connecticut medical clinics from 1990 to 1994.

STUDY PARTICIPANTS

Long-term residents of the island community and patients seeking treatment at the clinics.

MAIN OUTCOME MEASURES

Seroreactivity to the agents of Lyme disease and babesiosis and number and duration of symptoms.

RESULTS

Of 1156 serosurvey subjects, 97 (8.4%) were seroreactive against Lyme disease spirochete antigen, of whom 14 (14%) also were seroreactive against babesial antigen. Of 240 patients diagnosed with Lyme disease, 26 (11%) were coinfected with babesiosis. Coinfected patients experienced fatigue (P = .002), headache (P < .001), sweats (P < .001), chills (P = .03), anorexia (P = .04), emotional lability (P = .02), nausea (P = .004), conjunctivitis (P = .04), and splenomegaly (P = .01) more frequently than those with Lyme disease alone. Thirteen (50%) of 26 coinfected patients were symptomatic for 3 months or longer compared with 7 (4%) of the 184 patients with Lyme disease alone from whom follow-up data were available (P < .001). Patients coinfected with Lyme disease experienced more symptoms and a more persistent episode of illness than did those (n = 10) experiencing babesial infection alone. Circulating spirochetal DNA was detected more than 3 times as often in coinfected patients as in those with Lyme disease alone (P = .06).

CONCLUSIONS

Approximately 10% of patients with Lyme disease in southern New England are coinfected with babesiosis in sites where both diseases are zoonotic. The number of symptoms and duration of illness in patients with concurrent Lyme disease and babesiosis are greater than in patients with either infection alone. In areas where both Lyme disease and babesiosis have been reported, the possibility of concomitant babesial infection should be considered when moderate to severe Lyme disease has been diagnosed.

Symptomatology and energy intake during the menstrual cycle in smoking women

This study extends our understanding of smoking behavior, withdrawal, and premenstrual symptomatology in smoking women, as well as energy intake as a function of cycle phase. Thirty-two women age 18 to 40 years, smoking ad lib, were followed for an average of two menstrual cycles with hormonal verification. Withdrawal and premenstrual symptomatology as well as energy intake were reported during the follicular (F), luteal (L), and late luteal (LL) cycle phases. Both premenstrual symptomatology and withdrawal symptomatology were higher during the LL phase. Subject response on measurements of craving, irritability, restlessness, increased appetite, and depressed mood tended to be higher in the LL phase. Energy intake did not vary as a function of cycle phase. Participants perceived that they smoked more and had increased appetite in the LL phase but related measurements did not confirm this. Premenstrual and withdrawal symptoms are highly correlated and one needs to be cautious in interpreting cycle effects on withdrawal. Overall symptomatology seems to be lower during the F phase, indicating that this may be a more opportune time for women to quit smoking.

The sex-related difference in serum thyrotropin concentration is androgen mediated

Studies were carried out on various aspects of hypothalamic-pituitary-thyroid function in normal and gonadectomized adult male and female rats. Consistent increases in the serum TSH concentration and the serum TSH response to TRH were observed in the male rat compared to values in the female. Orchiectomy induced a decrease in the serum TSH concentration and the serum TSH response to TRH, and these functions were equal in gonadectomized male and female rats. Oophorectomy did not affect basal and TRH-stimulated serum TSH concentrations. Replacement doses of testosterone (0.33 mg/day) to orchiectomized rats increased and restored these values to those observed in the normal male rat, while replacement doses of estradiol (0.33 microgram/day) to the oophorectomized rat had no effect on basal or TRH-stimulated TSH concentrations. No sex-related differences in pituitary TSH and hypothalamic TRH contents or in serum T4 and T3 concentrations were observed. The present studies strongly suggest that the increased TSH responsiveness observed in male compared to female rats is due to the presence of testosterone. (Endocrinology 108: 529, 1981)