Abstract P153: Intensive Lifestyle Intervention in Type 2 Diabetes Mellitus Results in a More Favorable Sex Hormone Profile in Both Post-Menopausal Females and Older Males (The Look AHEAD Trial Sex Hormone Study)

Background: Prior studies showed an association between some adverse cardiometabolic outcomes and lower testosterone in males and higher estrogen in both males and post-menopausal females. However, few studies of sex hormones focused on people with type 2 diabetes (T2DM), assessed hormone changes over time or applied highly sensitive laboratory assays. Given the importance of lifestyle modification (i.e., diet, exercise and weight loss) in preventing cardiometabolic complications in people with T2DM, we examined the impact of an Intensive Lifestyle Intervention (ILI) on sex hormones over time and differences by sex.

Methods: The Look AHEAD (Action for Health in Diabetes) Study was a randomized control trial of 5,145 individuals with BMI ≥25 and T2D to evaluate the effect of ILI compared to the Diabetes Support and Education (DSE) control group on incident cardiovascular events. We selected a sample of 472 males and 426 post-menopausal female participants (mean age 60 years [SD 6.3], 20.5% Black) to examine sex hormones (estradiol - E2, total testosterone - T) and sex hormone binding globulin (SHBG) at baseline and year 1. E2 and T were measured using mass spectrometry analysis and SHBG was measured using an immunoassay.

Results: In males, ILI increased SHBG by 17.3% and T by 10.6% compared to the DSE group (Table). In postmenopausal females, ILI increased SHBG by 12.0% and decreased E2 by 23.4% compared to the DSE group (Table). The change in the sex hormone levels from baseline to 1-year follow up was attenuated when adjusted for change in BMI.

Conclusion: ILI resulting in weight loss increased T in males and decreased E2 in postmenopausal females and increased SHBG in both sexes. We plan further analysis with a larger sample and longer follow-up to examine the role of weight loss either as a co-occurring metabolic process or as a mediator for the change in sex hormones to better understand the impact of lifestyle changes and sex diffrences.

Characterization of D-amino acids in colostral, transitional, and mature preterm human milk

D-Amino acids are regulatory molecules that affect biological processes. Therefore, being able to accurately detect and quantify these compounds is important for understanding their impact on nutrition and health. There is a paucity of information regarding D-amino acids in human milk. We developed a fast method for simultaneous analysis of amino acid enantiomers in human milk using liquid chromatography with tandem mass spectrometry. The method enables the separation of 41 amino acids without chemical derivatization. Our results revealed that human milk from mothers of preterm infants contains concentrations of D-amino acids that range from 0.5 to 45% that of their L-counterparts and that levels of most D-amino acids decrease as the milk production matures. Moreover, we found that Holder pasteurization of milk does not cause racemization of L-amino acids. To our knowledge, this is the first study to describe percentages of D-amino acid levels in human milk; changes in D-amino acid concentration as the milk matures; and the effect of Holder pasteurization on D- and L-amino acid concentrations in human milk.

Cyclohexanone Exposure in Children on Extracorporeal Membrane Oxygenation Support

The aim of this study was to determine if plasma cyclohexanone and metabolites are associated with clinical outcomes of children on extracorporeal membrane oxygenation (ECMO) support. We performed a secondary analysis of a prospective observational study of children on ECMO support at two academic centers between July 2010 and June 2015. We measured plasma cyclohexanone and metabolites on the first and last days of ECMO support. Unfavorable outcome was defined as in-hospital death or discharge Pediatric Cerebral Performance Category score > 2 or decline ≥ 1 from baseline. Among 90 children included, 49 (54%) had unfavorable outcome at discharge. Cyclohexanediol, a cyclohexanone metabolite, was detected in all samples and at both time points; concentrations on the first ECMO day were significantly higher in those with unfavorable versus favorable outcome at hospital discharge (median, 5.7 ng/µl; interquartile range [IQR], 3.3-10.6 ng/µl vs. median, 4.2 ng/µl; IQR, 1.7-7.3 ng/µl; p = 0.04). Twofold higher cyclohexanediol concentrations on the first ECMO day were associated with increased risk of unfavorable outcome at hospital discharge (multivariable-adjusted hazard ratio [HR], 1.24 [95% CI, 1.05-1.48]). Higher cyclohexanediol concentrations on the first ECMO day were not significantly associated with new abnormal neuroimaging or 1-year Vineland Adaptive Behavior Scales-II score < 85 or death among survivors.

1191 The Use of CT Urography to Diagnose Upper Tract Urothelial Carcinomas (UTUC); Managing Surgical Resources During The COVID-19 Pandemic

Introduction

Upper tract urothelial carcinomas (UTUC) account for 5-10% of urothelial malignancies. Rapid diagnosis is essential as 60% are invasive at diagnosis and confer poor prognoses. European Association of Urology (EAU) guidelines recommend CT urography (CTU) for initial diagnosis and staging of UTUCs. Diagnostic ureteroscopy (URS) is used second line where diagnosis is unclear. The COVID-19 pandemic has limited theatre access and may delay diagnosis of suspected UTUC. Our aim was to evaluate specific CTU findings in predicting UTUC to aid prompt diagnosis and risk stratification in a tertiary centre.

Method

A retrospective analysis was performed on 122 patients who underwent CTU with diagnostic URS over two years from 2018-2019 for possible UTUC. Data including demographics, imaging and histology were collected from our electronic database.

Results

57 patients had confirmed UTUC, all had CT changes. CTU had an overall positive predictive value (PPV) of 45%. CT findings were divided into: hydronephrosis; filling defect/lesion; urothelial thickening; normal; or other. The PPV was highest for filling defects/lesions at 60%, hydronephrosis was 38%, urothelial thickening was 30%, and other was 33%. Of those with high-grade histology, 61% had evidence of filling defects/lesions and 24% had hydronephrosis.

Conclusions

A specific CTU finding of filling defect/lesion in combination with cytology can aid diagnosis and risk stratification of UTUC. This may enable us to reduce use of diagnostic URS, as well as associated risks of intravesical seeding, necessary in the COVID-19 pandemic. With other CTU findings of hydronephrosis or urothelial thickening, a diagnostic URS may be required.

In vitro prediction of clinical signs of respiratory toxicity in rats following inhalation exposure

To date there are no OECD validated alternative approaches to study toxicity following inhalation exposure to airborne chemicals. The available OECD test guidelines for acute inhalation toxicity aim to estimate a value of the lethal air concentration of the test chemical leading to the death of 50% of the exposed animals (LC50), to satisfy hazard classification and labelling requirements. This paper explores the view that alternative approaches must compare to outcomes of existing guideline methods to become accepted and implemented in a regulatory context. This case study describes the initiatives taken to validate the lung surfactant bioassay, an in vitro cell-free method, and discusses the challenges faced. While the lung surfactant bioassay could not predict the GHS classification for acute inhalation toxicity of 26 chemicals, the assay successfully predicted the clinical signs of respiratory toxicity observed during or shortly after exposure in vivo as reported in registration dossiers. The lung surfactant bioassay is a promising alternative approach to assess the potential of chemicals to cause changes to respiration remaining after exposure (indicating decreased lung function), and can be combined with other test methods in an integrated approach to testing and assessment of inhaled substances.

Association of Neurodevelopmental Outcomes With Environmental Exposure to Cyclohexanone During Neonatal Congenital Cardiac Operations: A Secondary Analysis of a Randomized Clinical Trial

IMPORTANCE

Cyclohexanone is an industrial solvent used as a coupling agent in medical plastics. Perioperative exposure to cyclohexanone could play a role in lower scores on measures of neurodevelopmental outcomes after neonatal cardiac operations.

OBJECTIVE

To examine the presence and association of serum cyclohexanone level with neonatal cardiac operations and neurodevelopmental outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This ad hoc secondary analysis used data from the Corticosteroid Therapy in Neonates Undergoing Cardiopulmonary Bypass randomized clinical trial. The cohort included neonates younger than 31 days and with at least 37 weeks postgestational age at surgical treatment who were enrolled at a single center between June 1, 2012, and October 31, 2016, and who had completed a neurodevelopmental assessment at age 12 months. Data were analyzed from July 8 to August 20, 2019.

EXPOSURES

Serum cyclohexanone and its metabolites were measured preoperatively (prior to skin incision), postoperatively (immediately after the surgical procedure was completed), and 12 hours postoperatively. Cyclohexanone and the molar sum of its metabolites were examined at each point and as a geometric mean of all 3 points.

MAIN OUTCOMES AND MEASURES

Neurodevelopment was assessed at age 12 months with the Bayley Scales of Infant and Toddler Development III, assessing cognitive, language, and motor function composite scores standardized to a population mean (SD) of 100 (15). Linear regression models were used to determine covariate-adjusted differences in 12-month cognitive, language, and motor composite scores per interquartile range increase in cyclohexanone level or summed metabolite molar concentrations.

RESULTS

Among 85 included neonates, mean (SD) age at surgical treatment was 9.7 (5.3) days, 49 (58%) were boys, and 54 (64%) underwent corrective repair. Mean (SD) Bayley Scales of Infant and Toddler Development III composite scores were 108.2 (12.2) for cognitive function, 104.7 (11.0) for language function, and 94.7 (15.7) for motor function. Median (interquartile range) cyclohexanone levels increased approximately 3-fold from immediately prior to surgical treatment to immediately after surgical treatment (572 [389-974] vs 1744 [1469-2291] μg/L; P = .001). In adjusted analyses, higher geometric mean cyclohexanone levels were associated with significantly lower composite scores for cognitive (-4.23; 95% CI, -7.39 to -1.06; P = .01) and language (-3.65; 95% CI, -6.41 to -0.88; P = .01) function. The difference in composite scores for motor function among infants with higher geometric mean cyclohexanone levels was not statistically significant(-3.93, 95% CI: -8.19 to 0.33, P = .07).

CONCLUSIONS AND RELEVANCE

The findings of this secondary analysis of a randomized clinical trial suggest that infants who underwent neonatal cardiac surgical treatment with cardiopulmonary bypass had substantial cyclohexanone levels, which were associated with adverse neurodevelopmental function at age 12 months.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01579513.

Inspiring Change: a report on acute non-invasive ventilation

The British Thoracic Society audit of non-invasive ventilation has shown that mortality rates are higher than expected and increasing. The National Confidential Enquiry into Patient Outcome and Death undertook a detailed analysis of data from 432 patients treated with acute non-invasive ventilation to identify how clinical aspects of non-invasive ventilation treatment could be improved. The study 'Inspiring Change' was published in July 2017. This review summarizes some of the important findings and associated recommendations that will improve treatment of patients and help to reduce mortality rates.

Abstract P5-14-10: Weekly doxorubicin and daily oral cyclophosphamide followed by nab-paclitaxel for adjuvant therapy of high-risk localized breast cancer

BACKGROUND: The addition of taxanes to anthracycline-based adjuvant chemotherapy has improved disease free survival (DFS) in women with high-risk early-stage breast cancer. Many studies have sought to optimize the dose intensity and density of these agents to produce improvements in outcome and tolerability. The purpose of this study was to assess the use of metronomic doxorubicin plus daily oral cyclophosphamide (AC) for 12 weeks followed by nab-paclitaxel (nP) for 12 weeks in this population. Those patients with Her2 positive disease were also given adjuvant trastuzumab.

METHODS: A non-randomized phase II clinical trial was designed to (1) test the DFS at 2 years compared to historical controls, (2) assess dose intensity delivered, (3) assess use of nP in the adjuvant setting, and (4) evaluate toxicities associated with the regimen. Overall survival (OS) was a secondary outcome. The dosing of A was 24mg/m2 IV qweek and C was 60mg/m2 oral daily; nP, 100mg/m2 IV qweek.

RESULTS: Sixty patients were enrolled on the study with a median follow-up of 6 years and a median age of 50 (range 30-69). 58% of patients had node positive disease. Receptor categories included hormone receptor positive (ER positive or PR positive) and HER2 negative (n=24; 40%); ER negative, PR negative, and HER2 negative (triple negative; n=19; 32%); or HER2 positive (n=17; 28%). DFS at 2 years was 93% (1 death, 3 recurrence) and at 6 years was 82%, comparable to historical controls. OS at 2 years and 6 years was 98% and 88%, respectively. Mean dose intensity was greater than 90% for AC and 88% for nP. Treatment was well-tolerated with the most common grade ≥3 toxicity being neutropenia and a 2% incidence of febrile neutropenia.

Disease-free survival and overall survival at 2 and 6 years 2 year 6 year  DFS %OS %DFS %OS %All patients93988288ER+ or PR+, HER2-921007979Triple negative89957989HER2+10010088100

CONCLUSSIONS: Patients achieved similar DFS to that seen in historical controls with similar rates of adverse events. Since nP dosing was 100 mg/m2, even with 88% dose intensity, the delivered taxane dose is greater than standard weekly paclitaxel. Notably disease control was particularly impressive in the triple negative subtype, which has been shown to benefit from nP over standard paclitaxel in the neoadjuvant setting in the GeparSepto (GBG 69) trial. Metronomic AC followed by nP is a safe, effective option for delivery of adjuvant chemotherapy for high-risk patients.

Citation Format: Cho E, Wu Q, Rubinstein L, Linden H, Gralow J, Specht J, Gadi V, Ellis G. Weekly doxorubicin and daily oral cyclophosphamide followed by nab-paclitaxel for adjuvant therapy of high-risk localized breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-14-10.

The use of urological hospital services by nonagenarians

INTRODUCTION

The super-elderly population is a small but expanding group of patients who will pose a significant challenge to future healthcare resources. A snapshot audit was completed of all emergency and elective urological nonagenarian activity in a UK general hospital, including surgical outcomes in this group of patients.

METHODS

Prospective and retrospective databases and clinical records were examined to identify all patients aged 90-99 years who had patient episodes between January 2006 and August 2012. Patient outcomes were compared with those for a similar cohort of 80-89-year-olds during the same time period.

RESULTS

A total of 653 nonagenarian patient episodes were identified (including 138 emergency admissions, 25 emergency surgical procedures, 71 elective surgical procedures, 173 local anaesthetic procedures and 270 outpatient visits). The in-hospital mortality rate for emergency admissions was 10%. The mean length of hospital stay was significantly longer for nonagenarians than for octogenarians (14.4 vs 6.5 days, p<0.00001). The postoperative mortality rate following emergency and elective surgery was 16% and 1% for nonagenarians and octogenarians respectively.

CONCLUSIONS

Nonagenarian patients often have complex medical co-morbidities and challenging social circumstances that contribute to delayed recovery from acute illness and surgery as well as long periods of hospitalisation. Adopting a multidisciplinary approach with formal input from specialist geriatric surgical services may improve patient outcomes and allow patients to be discharged to their former places of residence.

Use of an aggregate exposure model to estimate consumer exposure to fragrance ingredients in personal care and cosmetic products

Ensuring the toxicological safety of fragrance ingredients used in personal care and cosmetic products is essential in product development and design, as well as in the regulatory compliance of the products. This requires an accurate estimation of consumer exposure which, in turn, requires an understanding of consumer habits and use of products. Where ingredients are used in multiple product types, it is important to take account of aggregate exposure in consumers using these products. This publication investigates the use of a newly developed probabilistic model, the Creme RIFM model, to estimate aggregate exposure to fragrance ingredients using the example of 2-phenylethanol (PEA). The output shown demonstrates the utility of the model in determining systemic and dermal exposure to fragrances from individual products, and aggregate exposure. The model provides valuable information not only for risk assessment, but also for risk management. It should be noted that data on the concentrations of PEA in products used in this article were obtained from limited sources and not the standard, industry wide surveys typically employed by the fragrance industry and are thus presented here to illustrate the output and utility of the newly developed model. They should not be considered an accurate representation of actual exposure to PEA.

Hydrocarbons in Deep-Sea Sediments following the 2010 Deepwater Horizon Blowout in the Northeast Gulf of Mexico

The Deepwater Horizon (DWH) spill released 4.9 million barrels of oil into the Gulf of Mexico (GoM) over 87 days. Sediment and water sampling efforts were concentrated SW of the DWH and in coastal areas. Here we present geochemistry data from sediment cores collected in the aftermath of the DWH event from 1000-1500 m water depth in the DeSoto Canyon, NE of the DWH wellhead. Cores were analyzed at high-resolution (at 2 mm and 5 mm intervals) in order to evaluate the concentration, composition and input of hydrocarbons to the seafloor. Specifically, we analyzed total organic carbon (TOC), aliphatic, polycyclic aromatic hydrocarbon (PAHs), and biomarker (hopanes, steranes, diasteranes) compounds to elucidate possible sources and transport pathways for deposition of hydrocarbons. Results showed higher hydrocarbon concentrations during 2010-2011 compared to years prior to 2010. Hydrocarbon inputs in 2010-2011 were composed of a mixture of sources including terrestrial, planktonic, and weathered oil. Our results suggest that after the DWH event, both soluble and highly insoluble hydrocarbons were deposited at enhanced rates in the deep-sea. We proposed two distinct transport pathways of hydrocarbon deposition: 1) sinking of oil-particle aggregates (hydrocarbon-contaminated marine snow and/or suspended particulate material), and 2) advective transport and direct contact of the deep plume with the continental slope surface sediments between 1000-1200 m. Our findings underline the complexity of the depositional event observed in the aftermath of the DWH event in terms of multiple sources, variable concentrations, and spatial (depth-related) variability in the DeSoto Canyon, NE of the DWH wellhead.

Psychological distress in out-patients undergoing flexible cystoscopy for the investigation of bladder cancer

Objectives:

Flexible cystoscopy can cause patients significant psychological distress, especially when utilised in the diagnostic pathway for suspected bladder cancer. We aimed to assess the prevalence of general anxiety and depression, as well as procedure-related worry and pain in patients undergoing local anaesthetic flexible cystoscopy and to determine whether these conditions occur more frequently in subsets of the population.

Patients and methods:

Patients referred for flexible cystoscopy were invited to participate. Patients were asked to complete a questionnaire containing the Hospital Anxiety and Depression Scale (HADS), a worry score and a question regarding the most stressful event in the diagnostic pathway. Following the procedure patients were also asked to complete a pain score.

Results:

A total of 175 patients participated in the study. The prevalence of significant anxiety was 15% and depression 3.5%. This was higher in younger, female and unmarried patients. Procedure-related worry and pain were generally low.

Conclusions:

We found the prevalence of anxiety and depression in patients undergoing flexible cystoscopy to be raised compared to a similar cohort of patients undergoing TRUS-guided prostate biopsy. We have identified subgroups more likely to experience these symptoms and have also identified the sections of the diagnostic pathway that are most likely to cause anxiety and depression. By doing this we can target those patients who are more likely to suffer during the diagnostic process and aim to improve their experience. We can also implement targeted changes to the pathway to reduce the impact it may have on patients’ mental health.

TIMES-SS--recent refinements resulting from an industrial skin sensitisation consortium

The TImes MEtabolism Simulator platform for predicting Skin Sensitisation (TIMES-SS) is a hybrid expert system, first developed at Bourgas University using funding and data from a consortium of industry and regulators. TIMES-SS encodes structure-toxicity and structure-skin metabolism relationships through a number of transformations, some of which are underpinned by mechanistic 3D QSARs. The model estimates semi-quantitative skin sensitisation potency classes and has been developed with the aim of minimising animal testing, and also to be scientifically valid in accordance with the OECD principles for (Q)SAR validation. In 2007 an external validation exercise was undertaken to fully address these principles. In 2010, a new industry consortium was established to coordinate research efforts in three specific areas: refinement of abiotic reactions in the skin (namely autoxidation) in the skin, refinement of the manner in which chemical reactivity was captured in terms of structure-toxicity rules (inclusion of alert reliability parameters) and defining the domain based on the underlying experimental data (study of discrepancies between local lymph node assay Local Lymph Node Assay (LLNA) and Guinea Pig Maximisation Test (GPMT)). The present paper summarises the progress of these activities and explains how the insights derived have been translated into refinements, resulting in increased confidence and transparency in the robustness of the TIMES-SS predictions.

The first 100 thrombolysis cases in a novel Scottish mesh telestroke system

Stroke thrombolysis has been a major driver for change within stroke services. However, until recently its widespread application has been limited to tertiary centres. Transfer to tertiary care can lead to significant delays in thrombolysis. We developed a novel mesh telestroke network, which allows stroke specialists to make videoconference-based thrombolysis decisions either from one of three stroke units or from home. We report data on the first 100 patients treated using this model and retrospectively review the first 100 strokes thrombolysed with tissue plasminogen activator across three stroke units. Prospectively collected data were extracted from the Stroke Audit In Lanarkshire database. Case notes were retrieved for clarification when necessary. Outcome measures were timings from symptom onset to infusion, post-thrombolysis symptomatic intracerebral haemorrhage and death. Fifty-one percent of cases were assessed by telestroke link. Median symptom onset to thrombolysis was 160 min (IQR 125–190). There were two symptomatic intracerebral haemorrhages, both in patients assessed face-to-face. Overall mortality was 14%. Our experience of tissue plasminogen activator is comparable to UK data extracted from SITS-MOST in overall timings and complication rates. This model of telemedicine could be replicated to provide safe thrombolysis to areas with challenging infrastructure, geography or insufficient stroke specialist cover.

Preoperative assessment in the elderly: evaluation of a new clinical service

Older people represent the fastest growing sector of society and a growing proportion of those undergoing elective surgery. Older people are at the highest risk of increased length of stay and postoperative complications. We evaluated the development of a nurse-led multidimensional preoperative assessment for older people. An older people's preassessment nurse reviewed consecutive patients undergoing elective surgery who met the inclusion criteria. In the first five months control phase, assessment was not acted on. Following the intervention, patients were referred to appropriate specialties for input. A total of 141 patients were reviewed before and 172 patients reviewed after the introduction of the pilot. Length of stay was reduced from 8.9 to 4.9 days after the introduction of the pilot ( P < 0.001). Delays were reduced from 9.9% to 2.3% ( P = 0.004) and fewer procedures were cancelled at pre-assessment (17.7% before, 5.2% after; P < 0.001). Serious postoperative complications were reduced from 8.5% to 2.3% ( P = 0.01). Coordinated multidisciplinary preoperative assessment in the elderly may reduce complications and length of stay.

Self-reported ability assessment in rock climbing

Level of ability within rock climbing is generally expressed in terms of a "best ascent", rated using various grading systems within the sport. The most common method of obtaining this information is via self-report. The aim of this study was to examine the validity of self-reported climbing grades. Twenty-nine competitive rock climbers (17 males, 12 females) were first asked to report their current (defined as within the last 12 months) best on-sight lead ascent grade (Aus/NZ). The participants then climbed a specifically designed indoor route, under on-sight conditions (one attempt, no route practice or preview), to obtain an assessed grade. The route increased in difficulty, and was such that the distance achieved by the climber corresponded to a particular grade. The mean (±standard deviation) self-reported and assessed grade was 22.6 ± 3.4 and 22.0 ± 3.0 (Aus/NZ) respectively. Despite slight over- and underestimations in males and females respectively, there was no statistically significant difference between self-reported and assessed on-sight climbing grades. The results of this study suggest that self-reported climbing grades provide a valid and accurate reflection of climbing ability.

Sport-specific power assessment for rock climbing

AIM

The popularity of rock climbing has resulted in a growing research base for the sport. However, at present there is a lack of sport-specific measures of performance in the field. The aim of this study was to examine the use of the powerslap test as a sport specific power measure.

METHODS

The participants in this study were categorised into four different ability groups (novice, intermediate, advanced and elite) based on self reported lead grade. Two separate experiments were conducted to determine validity and reliability. The powerslap test was conducted on a revolution board with two variations - wide and narrow grip, for both sides of the body. The test started with the climber hanging at full extension from two holds from which a pull up movement was made releasing one hand to slap a scaled score board above.

RESULTS

There was a significant relationship between powerslap scores and climbing ability (Left Wide: r=0.7, P<0.0005; right wide: r=0.69, P<0.0005; left narrow: r=0.73, P<0.0005; right narrow: r =0.72, P<0.0005). Further to this, scores on the powerslap narrow test were significantly differentiated by climber ability (LEFT: F(3,37)=15.74, P<0.0005; right: F(3,37)=12.16, P<0.0005). Limits of agreement and intra-class correlation indicated that the powerslap test is a reliable performance measure.

CONCLUSION

According to the present findings the narrow grip variation of the powerslap test is a useful sport-specific power test that is related to climbing performance.

Comparison of lactate sampling sites for rock climbing

Comparisons of capillary blood lactate concentrations pre and post climb have featured in the protocols of many rock climbing studies, with most researchers obtaining samples from the fingertip. The nature of rock climbing, however, places a comparatively high physiological loading on the foreaand fingertips. Indeed, the fingertips are continually required for gripping and this makes pre-climb sampling at this site problematic. The purpose of our study was to examine differences in capillary blood lactate concentrations from samples taken at the fingertip and first (big) toe in a rock climbing context. 10 participants (9 males and 1 female) completed climbing bouts at 3 different angles (91°, 100° and 110°). Capillary blood samples were taken simultaneously from the fingertip and first toe pre and post climb. A limit of agreement plot revealed all data points to be well within the upper and lower bounds of the 95% population confidence interval. Subsequent regression analysis revealed a strong relationship (R (2)=0.94, y=0.940x + 0.208) between fingertip and first toe capillary blood lactate concentrations. Findings from our study suggest that the toe offers a valid alternative site for capillary blood lactate concentration analysis in a rock climbing context.

Crystalline transformations in nylon-6/single-walled carbon nanotube nanocomposites

Nylon-6/single-walled carbon nanotube (SWNT) nanocomposites with different SWNTs loadings were prepared by melt-blending. An efficient dispersion of SWNTs into the nylon-6 matrix was confirmed by scanning electron microscopy. DSC and time-resolved synchrotron X-ray diffraction were used to provide detailed information on the effect of SWNTs on the crystalline phase transition of nylon-6 in the nanocomposites. The incorporation of SWNTs accelerated the crystallization rate of nylon-6 due to a nucleating effect. The variable-temperature WAXS experiments, in both neat nylon-6 and nylon-6 nanocomposites, showed that the crystallization from the melt occured through the formation of the pseudo-hexagonal crystal form (gamma) and its transformation to the monoclinic form (alpha) on cooling. Additionally, this crystalline transition was reversible as observed upon heating. The alpha-gamma crystalline transformation temperature of nylon-6 was dependent on heating rate and, more importantly, on the SWNT content.