Clinical Outcomes with MiniMedTM 780G Advanced Hybrid Closed-Loop Therapy in 2- to 6-Year-Old Children with Type 1 Diabetes

Advanced hybrid closed-loop (AHCL) therapy with the Medtronic MiniMed™ 780G system improves glycemia; however, the clinical outcomes in younger children remain less established. This pilot study aimed to explore the continuous glucose monitoring (CGM) metrics in very young children on AHCL. Children between 2 and 7 years of age and on insulin pump therapy were recruited. A 2-week phase in manual mode was followed by a 6-week AHCL phase. CGM metrics were analyzed to review glycemic outcomes. Out of 11 participants enrolled [mean (standard deviation [SD]) age 5.3 (0.8) years], 10 completed the study. Time in closed loop was 96.7 (3.9)%. In AHCL, participants had a mean (SD) time in range of 72.6 (7.4)% and spent 3.0 (1.74)% and 0.63 (0.46)% in time <70 and <54 mg/dL, respectively. AHCL is a feasible option for management of young children with type 1 diabetes.

Improved Glycemic Outcomes With Diabetes Technology Use Independent of Socioeconomic Status in Youth With Type 1 Diabetes

OBJECTIVE

Technology use in type 1 diabetes (T1D) is impacted by socioeconomic status (SES). This analysis explored relationships between SES, glycemic outcomes, and technology use.

RESEARCH DESIGN AND METHODS

A cross-sectional analysis of HbA1c data from 2,822 Australian youth with T1D was undertaken. Residential postcodes were used to assign SES based on the Index of Relative Socio-Economic Disadvantage (IRSD). Linear regression models were used to evaluate associations among IRSD quintile, HbA1c, and management regimen.

RESULTS

Insulin pump therapy, continuous glucose monitoring, and their concurrent use were associated with lower mean HbA1c across all IRSD quintiles (P < 0.001). There was no interaction between technology use and IRSD quintile on HbA1c (P = 0.624), reflecting a similar association of lower HbA1c with technology use across all IRSD quintiles.

CONCLUSIONS

Technology use was associated with lower HbA1c across all socioeconomic backgrounds. Socioeconomic disadvantage does not preclude glycemic benefits of diabetes technologies, highlighting the need to remove barriers to technology access.

Socioeconomic status and diabetes technology use in youth with type 1 diabetes: a comparison of two funding models

Background

Technology use, including continuous glucose monitoring (CGM) and insulin pump therapy, is associated with improved outcomes in youth with type 1 diabetes (T1D). In 2017 CGM was universally funded for youth with T1D in Australia. In contrast, pump access is primarily accessed through private health insurance, self-funding or philanthropy. The study aim was to investigate the use of diabetes technology across different socioeconomic groups in Australian youth with T1D, in the setting of two contrasting funding models.

Methods

A cross-sectional evaluation of 4957 youth with T1D aged <18 years in the national registry was performed to determine technology use. The Index of Relative Socio-Economic Disadvantage (IRSD) derived from Australian census data is an area-based measure of socioeconomic status (SES). Lower quintiles represent greater disadvantage. IRSD based on most recent postcode of residence was used as a marker of SES. A multivariable generalised linear model adjusting for age, diabetes duration, sex, remoteness classification, and location within Australia was used to determine the association between SES and device use.

Results

CGM use was lower in IRSD quintile 1 in comparison to quintiles 2 to 5 (p<0.001) where uptake across the quintiles was similar. A higher percentage of pump use was observed in the least disadvantaged IRSD quintiles. Compared to the most disadvantaged quintile 1, pump use progressively increased by 16% (95% CI: 4% to 31%) in quintile 2, 19% (6% to 33%) in quintile 3, 35% (21% to 50%) in quintile 4 and 51% (36% to 67%) in the least disadvantaged quintile 5.

Conclusion

In this large national dataset, use of diabetes technologies was found to differ across socioeconomic groups. For nationally subsidised CGM, use was similar across socioeconomic groups with the exception of the most disadvantaged quintile, an important finding requiring further investigation into barriers to CGM use within a nationally subsidised model. User pays funding models for pump therapy result in lower use with socioeconomic disadvantage, highlighting inequities in this funding approach. For the full benefits of diabetes technology to be realised, equitable access to pump therapy needs to be a health policy priority.

Reproducibility of plasma glucose responses to moderate-intensity exercise in individuals with type 1 diabetes

AIM

To examine the within-person variability in plasma glucose responses to moderate-intensity morning exercise in young individuals with type 1 diabetes after overnight fasting and under basal insulin conditions.

METHODS

In this pilot study, eight participants completed 40 min of moderate-intensity exercise at 60% V̇O₂ peak on three separate days. The within-person standard deviation (SDw) in plasma glucose response was analysed both during and 1 h after exercise using the two visits per participant most closely matched by pre-exercise plasma glucose level.

RESULTS

When the two closest matched visits per individual were included for analysis, mean (±SD) change in plasma glucose level was -1.8 ± 1.1 mmoL/L during exercise and -0.6 ± 1.0 mmoL/L during recovery, with the SDw of these changes being 0.5 mmol (95% CI 0.2, 0.8) during exercise and 0.8 mmoL/L (95% CI 0.4, 1.3) during recovery. The median intra-individual difference in plasma glucose level change was 0.3 mmoL/L [IQR 0.1, 0.7] during exercise and 0.8 mmoL/L [IQR 0.4, 1.0] during recovery.

CONCLUSION

Within-person plasma glucose responses to moderate-intensity exercise may be reproducible under fasting and basal insulin conditions and similar pre-exercise plasma glucose levels. This finding may assist the design of future studies investigating both the reproducibility of glycaemic responses to exercise and blood glucose management for individuals with type 1 diabetes.

Phosphorus and iron-oxide transport from a hydrologically isolated grassland hillslope

Dissolved reactive phosphorus (DRP) loss from agricultural soils can negatively affect water quality. Shallow subsurface pathways can dominate P losses in grassland soils, especially in wetter months when waterlogging is common. This study investigated the processes controlling intra- and inter-event and seasonal DRP losses from poorly drained permanent grassland hillslope plots. Temporal flow related water samples were taken from surface runoff and subsurface (in-field pipe) discharge, analysed, and related to the likelihood of anaerobic conditions and redoximorphic species including nitrate (NO₃^-) over time. Subsurface drainage accounted for 89% of total losses. Simple linear regression and correlation matrices showed positive relationships between DRP and iron and soil moisture deficit; and negative relationships between these three factors and NO₃^- concentrations in drainage. These data indicate that waterlogging and low NO₃^- concentrations control the release of P in drainage, potentially via reductive dissolution. The relationship between DRP and metal release was less obvious in surface runoff, as nutrients gathered from P-rich topsoil camoflaged redox reactions. The data suggest a threshold in NO₃^- concentrations that could exacerbate P losses, even in low P soils. Knowledge of how nutrients interact with soil drainage throughout the year can be used to better time soil N and P inputs via, for example, fertiliser or grazing to avoid to excessive P loss that could harm water quality.

The relationship between meal carbohydrate quantity and the insulin to carbohydrate ratio required to maintain glycaemia is non-linear in young people with type 1 diabetes: A randomized crossover trial

OBJECTIVE

To determine if the relationship between meal carbohydrate quantity and the insulin to carbohydrate ratio (ICR) required to maintain glycaemia is linear in people with type 1 diabetes.

METHODS

We used an open labelled randomized four-arm cross-over study design. Participants (N = 31) aged 12-27 years, HbA1c ≤ 64 mmol/mol (8.0%) received insulin doses based on the individual's ICR and the study breakfast carbohydrate quantity and then consumed four breakfasts containing 20, 50, 100 and 150 g of carbohydrate over four consecutive days in randomized order. The breakfast fat and protein percentages were standardized. Postprandial glycaemia was assessed by 5 h continuous glucose monitoring. The primary outcome was percent time in range (TIR) and secondary outcomes included hypoglycaemia, glucose excursion and incremental area under the curve. Statistical analysis included linear mixed modelling and Wilcoxon signed rank tests.

RESULTS

The 20 g carbohydrate breakfast had the largest proportion of TIR (0.74 ± 0.29 p < 0.04). Hypoglycaemia was more frequent in the 50 g (n = 13, 42%) and 100 g (n = 15, 50%) breakfasts compared to the 20 g (n = 6, 20%) and 150 g (n = 7, 26%) breakfasts (p < 0.029). The 150 g breakfast glucose excursion pattern was different from the smaller breakfasts with the lowest glucose excursion 0-2 h and the highest excursion from 3.5 to 5 h.

CONCLUSIONS

A non-linear relationship between insulin requirement and breakfast carbohydrate content was observed, suggesting that strengthened ICRs are needed for meals with ≤20 and ≥150 g of carbohydrate. Meals with ≥150 g of carbohydrate may benefit from dual wave bolusing.

Demographic and clinical characteristics of a population-based pediatric cohort of type 1 and type 2 diabetes in Western Australia (1999-2019)

OBJECTIVES

To determine demographic and clinical characteristics of youth diagnosed with type 1 (T1D) or type 2 (T2D) diabetes aged ≤15 years from 1999 to 2019 in Western Australia, and examine time to first diagnosis of diabetes complications.

METHODS

A retrospective cohort study was conducted of patients identified from the population-based, prospective Western Australian Children's Diabetes Database and longitudinal data extracted for available demographic and clinical variables. Patients were followed from diagnosis to transition to adult services, death, or December 31, 2019. Cox proportional hazards regression models were used to analyse time to first diagnosis of hypertension, high cholesterol or microalbuminuria, after adjusting for sex, age at diagnosis, time period of diagnosis, hemoglobin A1_c , and body max index Z-score.

RESULTS

2438 eligible patients were identified (2209 [91%] T1D: 229 [9%] T2D). The mean age at diagnosis was lower in patients with T1D (8.5 [±4.0] vs. 12.7 [±2.0] years). A higher proportion of patients with T2D were female (58% vs. 47%) and of Aboriginal ethnicity (59% vs. 2%). The median HbA1c (interquartile range) at diagnosis was lower 8.9% [6.7, 11.5] (74 mmol/mol [50, 102]) versus 11.6% [10.1, 13.3] (103 mmol/mol [87, 122]) and mean body max index Z-score higher (2.05 [±0.66] vs. 0.37 [±0.95]), in patients with T2D compared to T1D. Patients with T2D had a higher risk of hypertension, high cholesterol, and microalbuminuria (aHR 3.39 [95%CI:2.04, 5.63], 2.69 [95%CI:1.21, 5.98], and 19.79 [95%CI:10.99, 35.64] respectively).

Effect of a Hybrid Closed-Loop System on Glycemic and Psychosocial Outcomes in Children and Adolescents With Type 1 Diabetes: A Randomized Clinical Trial

IMPORTANCE

Hybrid closed-loop (HCL) therapy has improved glycemic control in children and adolescents with type 1 diabetes; however, the efficacy of HCL on glycemic and psychosocial outcomes has not yet been established in a long-term randomized clinical trial.

OBJECTIVE

To determine the percentage of time spent in the target glucose range using HCL vs current conventional therapies of continuous subcutaneous insulin infusion or multiple daily insulin injections with or without continuous glucose monitoring (CGM).

DESIGN, SETTING, AND PARTICIPANTS

This 6-month, multicenter, randomized clinical trial included 172 children and adolescents with type 1 diabetes; patients were recruited between April 18, 2017, and October 4, 2019, in Australia. Data were analyzed from July 25, 2020, to February 26, 2021.

INTERVENTIONS

Eligible participants were randomly assigned to either the control group for conventional therapy (continuous subcutaneous insulin infusion or multiple daily insulin injections with or without CGM) or the intervention group for HCL therapy.

MAIN OUTCOMES AND MEASURES

The primary outcome was the percentage of time in range (TIR) within a glucose range of 70 to 180 mg/dL, measured by 3-week masked CGM collected at the end of the study in both groups. Secondary outcomes included CGM metrics for hypoglycemia, hyperglycemia, and glycemic variability and psychosocial measures collected by validated questionnaires.

RESULTS

A total of 135 patients (mean [SD] age, 15.3 [3.1] years; 76 girls [56%]) were included, with 68 randomized to the control group and 67 to the HCL group. Patients had a mean (SD) diabetes duration of 7.7 (4.3) years and mean hemoglobin A1c of 64 (11) mmol/mol, with 110 participants (81%) receiving continuous subcutaneous insulin infusion and 72 (53%) receiving CGM. In the intention-to-treat analyses, TIR increased from a mean (SD) of 53.1% (13.0%) at baseline to 62.5% (12.0%) at the end of the study in the HCL group and from 54.6% (12.5%) to 56.1% (12.2%) in the control group, with a mean adjusted difference between the 2 groups of 6.7% (95% CI, 2.7%-10.8%; P = .002). Hybrid closed-loop therapy also reduced the time that patients spent in a hypoglycemic (<70 mg/dL) range (difference, -1.9%; 95% CI, -2.5% to -1.3%) and improved glycemic variability (coefficient of variation difference, -5.7%; 95% CI, -10.2% to -0.9%). Hybrid closed-loop therapy was associated with improved diabetes-specific quality of life (difference, 4.4 points; 95% CI, 0.4-8.4 points), with no change in diabetes distress. There were no episodes of severe hypoglycemia or diabetic ketoacidosis in either group.

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, 6 months of HCL therapy significantly improved glycemic control and quality of life compared with conventional therapy in children and adolescents with type 1 diabetes.

TRIAL REGISTRATION

ANZCTR identifier: ACTRN12616000753459.

A Novel Mobile Health App to Educate and Empower Young People With Type 1 Diabetes to Exercise Safely: Prospective Single-Arm Mixed Methods Pilot Study

BACKGROUND

Empowering young people with type 1 diabetes (T1D) to manage their blood glucose levels during exercise is a complex challenge faced by health care professionals due to the unpredictable nature of exercise and its effect on blood glucose levels. Mobile health (mHealth) apps would be useful as a decision-support aid to effectively contextualize a blood glucose result and take appropriate action to optimize glucose levels during and after exercise. A novel mHealth app acT1ve was recently developed, based on expert consensus exercise guidelines, to provide real-time support for young people with T1D during exercise.

OBJECTIVE

Our aim was to pilot acT1ve in a free-living setting to assess its acceptability and functionality, and gather feedback on the user experience before testing it in a larger clinical trial.

METHODS

A prospective single-arm mixed method design was used. Ten participants with T1D (mean age 17.7 years, SD 4.2 years; mean HbA_1c, 54 mmol/mol, SD 5.5 mmol/mol [7.1%, SD 0.5%]) had acT1ve installed on their phones, and were asked to use the app to guide their exercise management for 6 weeks. At the end of 6 weeks, participants completed both a semistructured interview and the user Mobile Application Rating Scale (uMARS). All semistructured interviews were transcribed. Thematic analysis was conducted whereby interview transcripts were independently analyzed by 2 researchers to uncover important and relevant themes. The uMARS was scored for 4 quality subscales (engagement, functionality, esthetics, and information), and a total quality score was obtained from the weighted average of the 4 subscales. Scores for the 4 objective subscales were determined by the mean score of each of its individual questions. The perceived impact and subjective quality of acT1ve for each participant were calculated by averaging the scores of their related questions, but were not considered in the total quality score. All scores have a maximal possible value of 5, and they are presented as medians, IQRs, and ranges.

RESULTS

The main themes arising from the interview analysis were "increased knowledge," "increased confidence to exercise," and "suitability" for people who were less engaged in exercise. The uMARS scores for acT1ve were high (out of 5) for its total quality (median 4.3, IQR 4.2-4.6), engagement (median 3.9, IQR 3.6-4.2), functionality (median 4.8, IQR 4.5-4.8), information (median 4.6, IQR 4.5-4.8), esthetics (median 4.3, IQR 4.0-4.7), subjective quality (median 4.0, IQR 3.8-4.2), and perceived impact (median 4.3, IQR 3.6-4.5).

CONCLUSIONS

The acT1ve app is functional and acceptable, with a high user satisfaction. The efficacy and safety of this app will be tested in a randomized controlled trial in the next phase of this study.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12619001414101; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=378373.

Acute hyperglycaemia does not have a consistent adverse effect on exercise performance in recreationally active young people with type 1 diabetes: a randomised crossover in-clinic study

AIMS/HYPOTHESIS

In individuals with type 1 diabetes, chronic hyperglycaemia impairs aerobic fitness. However, the effect of acute marked hyperglycaemia on aerobic fitness is unclear, and the impact of insulin level has not been examined. In this study, we explored if acute hyperglycaemia with higher or low insulin levels affects [Formula: see text] and other exercise performance indicators in individuals with type 1 diabetes.

METHODS

Eligible participants were aged 14 to 30 years, with complication-free, type 1 diabetes and HbA_1c ≤ 75 mmol/mol (≤9%). Participants exercised in a clinical laboratory under three clamp (constant insulin, variable glucose infusion) conditions: euglycaemia (5 mmol/l) with 20 mU [m² BSA]^-1 min^-1 insulin (where BSA is body surface area) (Eu20); hyperglycaemia (17 mmol/l) with 20 mU [m² BSA]^-1 min^-1 insulin (Hyper20); and hyperglycaemia (17 mmol/l) with 5 mU [m² BSA]^-1 min^-1 insulin (Hyper5) on separate days. Participants and the single testing assessor were blinded to condition, with participants allocated to randomised testing condition sequences as they were consecutively recruited. Standardised testing (in order) conducted on each of the three study days included: triplicate 6 second sprint cycling, grip strength, single leg static balance, vertical jump and modified Star Excursion Balance Test, ten simple and choice reaction times and one cycle ergometer [Formula: see text] test. The difference between conditions in the aforementioned testing measures was analysed, with the primary outcome being the difference in [Formula: see text].

RESULTS

Twelve recreationally active individuals with type 1 diabetes (8 male, mean ± SD 17.9 ± 3.9 years, HbA_1c 61 ± 11 mmol/mol [7.7 ± 1.0%], 7 ± 3 h exercise/week) were analysed. Compared with Eu20, [Formula: see text] was lower in Hyper20 (difference 0.17 l/min [95% CI 0.31, 0.04; p = 0.02] 6.6% of mean Eu20 level), but Hyper5 was not different (p = 0.39). Compared with Eu20, sprint cycling peak power was not different in Hyper20 (p = 0.20), but was higher in Hyper5 (64 W [95% CI 13, 115; p = 0.02] 13.1%). Hyper20 reaction times were not different (simple: p = 0.12) but Hyper5 reaction times were slower (simple: 11 milliseconds [95% CI 1, 22; p = 0.04] 4.7%) than Eu20. No differences between Eu20 and either hyperglycaemic condition were observed for the other testing measures (p > 0.05).

CONCLUSIONS/INTERPRETATION

Acute marked hyperglycaemia in the higher but not low insulin state impaired [Formula: see text] but to a small extent. Acute hyperglycaemia had an insulin-dependent effect on sprint cycling absolute power output and reaction time but with differing directionality (positive for sprint cycling and negative for reaction time) and no effect on the other indicators of exercise performance examined. We find that acute hyperglycaemia is not consistently adverse and does not impair overall exercise performance to an extent clinically relevant for recreationally active individuals with type 1 diabetes.

FUNDING

This research was funded by Diabetes Research Western Australia and Australasian Paediatric Endocrine Group grants.

Impact of Hybrid Closed Loop Therapy on Hypoglycemia Awareness in Individuals with Type 1 Diabetes and Impaired Hypoglycemia Awareness

Objective: This study evaluated the efficacy of using a hybrid closed loop (HCL) system in restoring hypoglycemia awareness in individuals with impaired awareness of hypoglycemia (IAH). Research Design and Methods: Participants with IAH (Gold score ≥4) were recruited into a randomized crossover pilot study. They participated in two 8-week periods using a HCL system (Medtronic 670G™) (intervention) and standard insulin pump therapy (control). Hyperinsulinemic hypoglycemic clamp studies were undertaken at baseline and at the end of each study period for the evaluation of the counter-regulatory hormonal and symptomatic responses to hypoglycemia. Results: Seventeen participants (mean age [standard deviation] 35.8 years [11.2 years]) were included in the study. Peak epinephrine levels (median, interquartile range [IQR]) in response to hypoglycemia were similar postintervention and control periods; 234.7 pmol/L (109.2; 938.9) versus 188.3 pmol/L (133.7; 402.9), P = 0.233. However, both peak adrenergic and neuroglycopenic symptom scores were higher after intervention; 5.0 (4.5; 9.0) versus 4.0 (4.0; 5.5), P = 0.009, and 8.5 (6.0; 15.0) versus 6.5 (6.0; 7.0) P = 0.014, respectively. Self-reported hypoglycemia awareness improved: median (IQR) Gold score was 4.0 (3.0; 5.5) versus 5.5 (4.5; 6.0); intervention versus control, P = 0.033. Time spent <3.9 and <3.0 mmol/L was lower in the intervention group than in control, P = 0.002. Other patient-reported outcomes (hypoglycemia fear and diabetes treatment satisfaction) did not change. Conclusions: A short-term use of a HCL system failed to demonstrate an improvement in counter-regulatory hormonal responses. However, higher hypoglycemia symptom scores during controlled hypoglycemia, better self-reported hypoglycemia awareness, and less time spent in hypoglycemia suggest the potential benefits of a HCL system in people with IAH. Trial Registration: anzctr.org.au Identifier: ACTRN12616000909426.

Effect of frequency of sensor use on glycaemic control in individuals on sensor-augmented pump therapy with and without Predictive Low Glucose Management System

Improved frequency of sensor use improves glycaemic control. Furthermore, there is no deterioration of glycaemic control with increased sensor use in individuals on Predictive Low Glucose Management (PLGM) system. Younger children are more likely to have better sensor uptake than older children.

Effect of combining pre-exercise carbohydrate intake and repeated short sprints on the blood glucose response to moderate-intensity exercise in young individuals with Type 1 diabetes

AIMS

To determine whether pre-exercise ingestion of carbohydrates to maintain stable glycaemia during moderate-intensity exercise results in excessive hyperglycaemia if combined with repeated sprints in individuals with Type 1 diabetes.

METHODS

Eight overnight-fasted people with Type 1 diabetes completed the following four 40-min exercise sessions on separate days in a randomized counterbalanced order under basal insulinaemic conditions: continuous moderate-intensity exercise at 50% V ˙ O 2 peak; intermittent high-intensity exercise (moderate-intensity exercise interspersed with 4-s sprints every 2 min and a final 10-s sprint); continuous moderate-intensity exercise with prior carbohydrate intake (~10 g per person); and intermittent high-intensity exercise with prior carbohydrate intake. Venous blood was sampled during and 2 h after exercise to measure glucose and lactate levels.

RESULTS

The difference in marginal mean time-averaged area under the blood glucose curve between continuous moderate-intensity exercise + prior carbohydrate and intermittent high-intensity exercise + prior carbohydrate during exercise and recovery was not significant [0.2 mmol/l (95% CI -0.7, 1.1); P = 0.635], nor was the difference in peak blood glucose level after adjusting for baseline level [0.2 mmol/l (95% CI -0.7, 1.1); P = 0.695]. The difference in marginal mean time-averaged area under the blood glucose curve between continuous moderate-intensity and intermittent high-intensity exercise during exercise and recovery was also not significant [-0.2 mmol/l (95% CI -1.2, 0.8); P = 0.651].

CONCLUSIONS

When carbohydrates are ingested prior to moderate-intensity exercise, adding repeated sprints is not significantly detrimental to glycaemic management in overnight fasted people with Type 1 diabetes under basal insulin conditions.

Dietary protein affects both the dose and pattern of insulin delivery required to achieve postprandial euglycaemia in Type 1 diabetes: a randomized trial

AIM

To quantify the insulin requirement for a high-protein meal compared with a low-protein meal, controlling for carbohydrate and fat content.

METHODS

In this crossover study, young people with Type 1 diabetes were randomized to consume a high- (60 g) or low-protein meal (5 g), each containing 30 g carbohydrate and 8 g fat. A variation of the insulin clamp technique was used to determine the insulin requirements to maintain euglycaemia for the following 5 h.

RESULTS

A total of 11 participants (mean ± sd age 16.5 ± 2.7 years, HbA_1c 52 ± 8.7 mmol/mol [6.9 ± 0.8%], diabetes duration 6.9±5.1 years) completed the study. The mean insulin requirements for the high-protein meal were higher than for the low-protein meal [10.3 (CI 8.2, 12.57) vs 6.7 units (CI 4.7, 8.8); P=0.001], with inter-individual requirements ranging from 0.9 to six times the low-protein meal requirement. Approximately half the additional insulin [1.1 units/h (CI 0.5, 1.8; P=0.001)] was given in the first 2 h, compared with an additional 0.5 units/h (CI -0.2, 1.2; P=0.148) in the second 2 h and 0.1 units (CI -0.6, 0.8; P=0.769) in the final hour.

CONCLUSIONS

A high-protein meal requires ~50% more insulin to maintain euglycaemia than a low-protein meal that contains the same quantity of carbohydrate. The majority is required within the first 2 h. Inter-individual differences exist in insulin requirements for dietary protein.

Characteristics of Automated Insulin Suspension and Glucose Responses with the Predictive Low-Glucose Management System

BACKGROUND

The Predictive Low-Glucose Management (PLGM) system suspends basal insulin when hypoglycemia is predicted and reduces hypoglycemia. The aim of this analysis was to explore the characteristics of automated insulin suspension and sensor glucose (SG) responses following PLGM-initiated pump suspension.

RESEARCH DESIGN AND METHODS

Children and adolescents with type 1 diabetes used the Medtronic MiniMed™ 640G pump as part of a randomized controlled trial. Data collected on a subgroup of participants on PLGM (suspend before low enabled) from CareLink^® Therapy Management Software were analyzed to explore the time and duration of PLGM-initiated pump suspension. Day and nighttime were defined as 06:00 am to 10:00 pm and 10:00 pm to 6:00 am, respectively.

RESULTS

There were 20,183 suspend before low events in 8523 days (2.37 events/day). The mean suspend duration was 55.0 ± 32.7 min (day 50.0 ± 30.1, night 71.7 ± 35.1; P < 0.001). Although a 2-h pump suspension was more frequent at night (day 5%, night 18%), a patient-initiated resumption occurred more during day (day 34%, night 12%). SG values did not reach <3.5 and <3 mmol/L in 79% and 91% of the events, respectively. The 2-h SG following pump resumption was higher following autoresumption during the day (day vs. night 9.3 mmol/L vs. 8.4 mmol/L; P < 0.001).

CONCLUSIONS

Longer suspends and fewer glycemic excursions occur at night compared with day. The higher glycemic daytime excursions could be due to carbohydrate consumption to increase glucose levels and highlights the need for health care professionals to educate patients about carbohydrate intake around pump suspension.

Use of Continuous Glucose Monitoring Trends to Facilitate Exercise in Children with Type 1 Diabetes

Diabetes care during exercise frequently requires interruptions to activity and adds extra challenges particularly for young individuals with type 1 diabetes (T1D). This study investigated the use of a carbohydrate (CHO) intake algorithm based on continuous glucose monitoring (CGM) trends during physical activity. Children with T1D diagnosed for >1 year, ages 8-12 years, with a glycated hemoglobin of <10% were recruited into a randomized crossover study. They attended two similar mornings of fun-based physical activity and adhered to either a CHO intake algorithm based on CGM trends (intervention) or to standard exercise guidelines (consumption of 0.5 g CHO/kg/h when glucose <8 mmol/L) (control). Outcome measures included events such as exercise interruptions, CHO intake, and hypoglycemia events and percentage time spent in different sensor glucose ranges. Fourteen children completed the study. No episodes of significant hypoglycemia (sensor glucose level <3.0 mmol/L) occurred in either arm. Mean CHO intake was the same in both arms, 0.3 ± 0.2 g/kg/h. However, the intervention algorithm resulted in fewer CHO intake events per day: rate [95% confidence interval] 2.4 [1.6-2.3] versus 0.9 [0.4-1.5], P < 0.001, and exercise interruptions: 7.2 [5.9-8.8] versus 1.4 [0.8-2.1], P < 0.001, compared with control. There was no evidence of a difference in percentage time in range (3.9-10 mmol/L) and percentage time spent high between study arms. Both control and intervention protocols prevented significant hypoglycemia. Using a CHO intake algorithm based on CGM trends resulted in fewer CHO intake events and fewer interruptions to exercise. Use of this algorithm may reduce the burden of diabetes management with potential to facilitate activity in young people with T1D.

Real-world outcomes of insulin pump compared to injection therapy in a population-based sample of children with type 1 diabetes

BACKGROUND

Long-term glycemic outcomes in people with type 1 diabetes (T1D) on insulin pump therapy (continuous subcutaneous insulin infusion [CSII]) with appropriate control data are limited. Randomized controlled studies of technology in diabetes care are generally limited in duration and likely to have a selection bias. Hence, evaluation of population-based data provides a robust alternative evaluation of the benefits of insulin pump therapy.

AIM

To investigate the outcomes of insulin pump therapy, as compared to injection therapy, in children with T1D attending a state-wide diabetes service in Western Australia.

METHODS

Patients using insulin pump therapy between January 1999 and July 2016 were matched to patients on injection therapy on the basis of age, date of diagnosis, and hemoglobin A1C (HbA1c) at the start of pump therapy.

RESULTS

A total of 513 pump-injection matches were identified. The pump cohort had a significantly lower mean HbA1c for the first 6 years of follow-up. The difference in HbA1c between the cohorts was observed by 6 months (3 mmol/mol [0.3%], standard error of the mean (SEM) 0.05, N = 463 matched pairs, P < 0.001) and was sustained with the greatest difference in HbA1c at 6 years (4 mmol/mol [0.4%], SEM 0.21, N = 112 matched pairs, P = 0.04). Beyond 6 years of follow-up, the HbA1c was not significantly lower in the pump cohort (N < 70 matched pairs).

CONCLUSIONS

Patients using insulin pump therapy had a better long-term glycemic control relative to the matched injection therapy cohort. Large population-based cohort studies using real-world data provide a valuable perspective on evaluation of new technologies in children with T1D.

The Use of Continuous Glucose Monitoring With Remote Monitoring Improves Psychosocial Measures in Parents of Children With Type 1 Diabetes: A Randomized Crossover Trial

OBJECTIVE

This study aimed to explore the effect of continuous glucose monitors with remote monitoring on psychosocial outcomes in parents of children with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Children with type 1 diabetes, aged 2-12 years, along with their parents, were studied in a randomized crossover study. They participated in two 3-month periods using conventional blood glucose monitoring (control) or the Dexcom G5 Mobile continuous glucose monitoring (CGM) system with remote monitoring (intervention). The primary outcome was parental fear of hypoglycemia score assessed by the Hypoglycemia Fear Survey.

RESULTS

Parental Hypoglycemia Fear Survey scores were lower while the child was using CGM with remote monitoring (P < 0.001). Furthermore, parental health-related quality of life and family functioning, stress, anxiety, and sleep measures also improved significantly after intervention.

CONCLUSIONS

CGM with remote monitoring was found to improve multiple measures of quality of life, reduce family stress, and improve parental sleep.

Reduction in Hypoglycemia With the Predictive Low-Glucose Management System: A Long-term Randomized Controlled Trial in Adolescents With Type 1 Diabetes

OBJECTIVE

Short-term studies with automated systems that suspend basal insulin when hypoglycemia is predicted have shown a reduction in hypoglycemia; however, efficacy and safety have not been established in long-term trials.

RESEARCH DESIGN AND METHODS

We conducted a 6-month, multicenter, randomized controlled trial in children and adolescents with type 1 diabetes using the Medtronic MiniMed 640G pump with Suspend before low (predictive low-glucose management [PLGM]) compared with sensor-augmented pump therapy (SAPT) alone. The primary outcome was percentage time in hypoglycemia with sensor glucose (SG) <3.5 mmol/L (63 mg/dL).

RESULTS

In an intent-to-treat analysis of 154 subjects, 74 subjects were randomized to SAPT and 80 subjects to PLGM. At baseline, the time with SG <3.5 mmol/L was 3.0% and 2.8% in the SAPT and PLGM groups, respectively. During the study, PLGM was associated with a reduction in hypoglycemia compared with SAPT (% time SG <3.5 mmol/L: SAPT vs. PLGM, 2.6 vs. 1.5, P < 0.0001). A similar effect was also noted in time with SG <3 mmol/L (P < 0.0001). This reduction was seen both during day and night (P < 0.0001). Hypoglycemic events (SG <3.5 mmol/L for >20 min) also declined with PLGM (SAPT vs. PLGM: events/patient-year 227 vs. 139, P < 0.001). There was no difference in glycated hemoglobin (HbA_1c) at 6 months (SAPT 7.6 ± 1.0% vs. PLGM 7.8 ± 0.8%, P = 0.35). No change in quality of life measures was reported by participants/parents in either group. There were no PLGM-related serious adverse events.

CONCLUSIONS

In children and adolescents with type 1 diabetes, PLGM reduced hypoglycemia without deterioration in glycemic control.

Reduced prevalence of impaired awareness of hypoglycemia in a population-based clinic sample of youth with type 1 diabetes

BACKGROUND

Impaired awareness of hypoglycemia (IAH) is associated with an increased risk for severe hypoglycemia (SH). However, reduced rates of SH raise the question as to whether there has been a reduction in IAH. The aim of this study was to determine the change in prevalence of IAH in a population-based cohort of adolescents with Type 1 diabetes (T1D).

METHODS

Children older than 12 years with T1D documented their responses to hypoglycemia based on the modified Clarke questionnaire. The prevalence of IAH was also analyzed in a similar population-based cohort using the same questionnaire in 2002. The clinical details of the participants and the number of SH events in the preceding year were determined from the Western Australian diabetes database.

RESULTS

The questionnaire was administered to 413 children in 2002 and to 444 children in 2015 with similar baseline characteristics. The prevalence of IAH was 33% in 2002 and 21% in 2015 (P < .001). A lower HbA1c, younger age at diagnosis and longer duration of diabetes correlated with IAH in 2002 but not in 2015. There was a significant decline in the rates of SH in 2015 compared with 2002 (P < .001) despite a reduced HbA1c in 2015. IAH increased the risk of SH in both cohorts (52 vs 16 events/100 patient years in 2002 and 8 vs 2 events/100 patient years in 2015).

CONCLUSIONS

Although IAH has reduced, IAH is still prevalent in a substantial minority of adolescents and continues to be associated with an increased risk of SH.

A 10-second sprint does not blunt hormonal counter-regulation to subsequent hypoglycaemia

AIM

To investigate whether a 10-second (s) sprint impairs the counter-regulatory response to subsequent hypoglycaemia.

METHODS

Nine people (five male, four female) with Type 1 diabetes, aged 21.1 ± 4.5 years, performed a 10-s rest or a 10-s maximum-effort sprint in random order on different days, while subjected to an euinsulinaemic-euglycaemic clamp. This was followed by a hyperinsulinaemic-hypoglycaemic glucose clamp 2.5 h later to induce hypoglycaemia for 40 min. At timed intervals, the counter-regulatory hormonal responses to hypoglycaemia were measured. Blood pressure, heart rate and hypoglycaemic symptoms were also assessed.

RESULTS

During the hypoglycaemic clamp, epinephrine, norepinephrine, growth hormone and cortisol levels increased significantly from baseline, and their responses were similar after both rest and sprint conditions. In particular, plasma epinephrine rose eightfold, from 197 ± 103 pmol/l to 1582 ± 1118 pmol/l after the rest condition, and from 219 ± 119 pmol/l to 1900 ± 898 pmol/l after the sprint condition.

CONCLUSION

A 10-s sprint is unlikely to blunt the subsequent hormonal counter-regulation to hypoglycaemia in individuals with Type 1 diabetes.

Evaluation of the Metasin assay for intraoperative assessment of sentinel lymph node metastases in breast cancer

AIMS

Sentinel lymph node (SLN) biopsy is the preferred surgical technique for staging the axilla in clinically node-negative breast cancer. Accurate intraoperative staging allows for the immediate performance of an axillary clearance in node-positive patients. We assessed the Metasin assay for the intraoperative analysis of SLNs in a prospective evaluation of 250 consecutive patients undergoing intraoperative SLN analysis at the Breast Unit, University Hospital, Southampton, UK.

METHODS

Metasin uses a quantitative reverse transcription PCR to detect two markers of metastasis: cytokeratin 19 (CK19) an epithelial marker and mammaglobin (MGB) a breast specific marker. Metasin results were compared with the results from routine paraffin block histopathology.

RESULTS

Metasin was robust, with a failure rate of <1%, and demonstrated excellent accuracy and reproducibility. The average turnaround time for the Metasin assay was 42 min, the largest variable being the number of nodes assayed. A total of 533 SLNs were evaluated with 75 patients testing positive for MGB and/or CK19. Based on the analysis of individual SLNs, the overall concordance between Metasin and histology was 92.3% (sensitivity 88.7%, specificity 92.9%). When adjusted for tissue allocation bias, the concordance was 93.8% (sensitivity 89.8%, specificity 94.6%). In this evaluation, 57/250 patients (23%) proceeded to axillary clearance based on Metasin results and were considered spared a second operative procedure.

CONCLUSIONS

Metasin has proven to be an accurate, reproducible and reliable laboratory test. The analysis time is acceptable for intraoperative use, and in comparison to routine histology demonstrates acceptable concordance, sensitivity and specificity.

Intrinsic nanostructure in Zr2-xFe4Si16-y(x = 0.81, y = 6.06)

We present a study of the crystal structure and physical properties of single crystals of a new Fe-based ternary compound, Zr2-xFe4Si16-y(x = 0.81, y = 6.06). Zr1.19Fe4Si9.94 is a layered compound, where stoichiometric β-FeSi2-derived slabs are separated by Zr-Si planes with substantial numbers of vacancies. High resolution transmission electron microscopy (HRTEM) experiments show that these Zr-Si layers consist of 3.5 nm domains where the Zr and Si vacancies are ordered within a supercell sixteen times the volume of the stoichiometric cell. Within these domains, the occupancies of the Zr and Si sites obey symmetry rules that permit only certain compositions, none of which by themselves reproduce the average composition found in x-ray diffraction experiments. Magnetic susceptibility and magnetization measurements reveal a small but appreciable number of magnetic moments that remain freely fluctuating to 1.8 K, while neutron diffraction confirms the absence of bulk magnetic order with a moment of 0.2μB or larger down to 1.5 K. Electrical resistivity measurements find that Zr1.19Fe4Si9.94 is metallic, and the modest value of the Sommerfeld coefficient of the specific heat γ = C/T suggests that quasi-particle masses are not particularly strongly enhanced. The onset of superconductivity at Tc ≃ 6 K results in a partial resistive transition and a small Meissner signal, although a bulk-like transition is found in the specific heat. Sharp peaks in the ac susceptibility signal the interplay of the normal skin depth and the London penetration depth, typical of a system in which nano-sized superconducting grains are separated by a non-superconducting host. Ultra low field differential magnetic susceptibility measurements reveal the presence of a surprisingly large number of trace magnetic and superconducting phases, suggesting that the Zr-Fe-Si ternary system could be a potentially rich source of new bulk superconductors.

Sucker bet or sure thing: A critical analysis of sports lotteries

A paradox currently exists regarding legal sports gambling in North America: various forms are flourishing in Nevada, Oregon, and several Canadian provinces, while at the same time the United States Congress is conducting hearings on two bills that would prohibit any new state-sponsored sports gambling initiatives. This study examines the issue of why some jurisdictions are enthusiastic about legal sports gambling while others strongly resist the concept. In reviewing these divergent viewpoints, a case study of the newfledged Canadian "Sport Select" gambling format is presented. This example is used to highly the perils and payoffs of a typical state-sponsored sports gambling scheme, with a view toward broadening our understanding of how they work and how they might be fairer to the public.

Disordered gambling among higher-frequency gamblers: who is at risk?

BACKGROUND

When gambling opportunities are made available to the public in a given jurisdiction, some individuals participate occasionally and others more frequently. Among frequent gamblers, some individuals develop problematic involvement and some do not. This study addresses the association among demographic and social risk factors, frequency of gambling and gambling disorders.

METHOD

Data from an adult community sample (n=1372) were used to identify risk factors for higher-frequency gambling and disordered gambling involvement.

RESULTS

Individuals with higher intelligence, older individuals and more religious individuals were less frequent gamblers. Males, single individuals and those exposed to gambling environments (friends and family who gamble) and those who started to gamble at a younger age were more frequent gamblers. Excitement-seeking personality traits were also higher among more frequent gamblers. A different set of risk factors was associated with the likelihood of gambling disorder among these higher-frequency gamblers. These variables included mental health indicators, childhood maltreatment and parental gambling involvement. Among higher-frequency gamblers, individuals who smoke cigarettes, those with a diagnosis of alcohol or drug dependence or obsessive-compulsive disorder, those with higher anxiety or depression and those with higher impulsivity and antisocial personality traits were more likely to report gambling-related problems. These individuals were also more likely to report gambling on electronic gambling machines (e.g. slot machines).

CONCLUSIONS

These data suggest a model in which higher-frequency gambling, particularly with electronic gambling machines, when combined with any type of emotional vulnerability increased the likelihood of gambling disorder.

ADHD is associated with a "Western" dietary pattern in adolescents

OBJECTIVE

To examine the relationship between dietary patterns and ADHD in a population-based cohort of adolescents.

METHOD

The Raine Study is a prospective study following 2,868 live births. At the 14-year follow-up, the authors collected detailed adolescent dietary data, allowing for the determination of major dietary patterns using factor analysis. ADHD diagnoses were recorded according to International Classification of Deiseases, 9th Revision coding conventions. Logistic regression was used to assess the relationship between scores for major dietary pattern and ADHD diagnoses.

RESULTS

Data were available for 1,799 adolescents, and a total of 115 adolescents had an ADHD diagnosis. Two major dietary patterns were identified: "Western" and "Healthy." A higher score for the Western dietary pattern was associated with ADHD diagnosis (odds ratio=2.21, 95% confidence interval=1.18, 4.13) after adjusting for known confounding factors from pregnancy to 14 years. ADHD diagnosis was not associated with the "Healthy" dietary pattern.

CONCLUSION

A Western-style diet may be associated with ADHD.

Perturbation and change in coral reef communities

Ninety-six percent of surveyed shallow-water Dry Tortugas reef corals died during the severe winter of 1976-1977. Data from skeletal stains indicate that death occurred during the mid-January intrusion of 14 degrees C water onto the reef. In deeper water, community parameters such as percent cover, species number, and relative abundance showed no significant change. However, an analysis of competitive interactions at the growing edges of adjacent colonies reveals a 70% reduction in space competition during this environmental disturbance. These results can explain high variability in the growth rate of Floridian reefs and demonstrate the importance of obtaining long-term spatial information to interpret successional dynamics of complex communities.

Molecular detection of a novel human influenza (H1N1) of pandemic potential by conventional and real-time quantitative RT-PCR assays

BACKGROUND

Influenza A viruses are medically important viral pathogens that cause significant mortality and morbidity throughout the world. The recent emergence of a novel human influenza A virus (H1N1) poses a serious health threat. Molecular tests for rapid detection of this virus are urgently needed.

METHODS

We developed a conventional 1-step RT-PCR assay and a 1-step quantitative real-time RT-PCR assay to detect the novel H1N1 virus, but not the seasonal H1N1 viruses. We also developed an additional real-time RT-PCR that can discriminate the novel H1N1 from other swine and human H1 subtype viruses.

RESULTS

All of the assays had detection limits for the positive control in the range of 1.0 x 10(-4) to 2.0 x 10(-3) of the median tissue culture infective dose. Assay specificities were high, and for the conventional and real-time assays, all negative control samples were negative, including 7 human seasonal H1N1 viruses, 1 human H2N2 virus, 2 human seasonal H3N2 viruses, 1 human H5N1 virus, 7 avian influenza viruses (HA subtypes 4, 5, 7, 8, 9, and 10), and 48 nasopharyngeal aspirates (NPAs) from patients with noninfluenza respiratory diseases; for the assay that discriminates the novel H1N1 from other swine and human H1 subtype viruses, all negative controls were also negative, including 20 control NPAs, 2 seasonal human H1N1 viruses, 2 seasonal human H3N2 viruses, and 2 human H5N1 viruses.

CONCLUSIONS

These assays appear useful for the rapid diagnosis of cases with the novel H1N1 virus, thereby allowing better pandemic preparedness.

Hydatid pulmonary emboli

A case of secondary hydatosis, initially misdiagnosed as pulmonary metastases, is presented. The dissemination of hydatid cysts within the lungs in this case was the consequence of direct rupture of a hepatic hydatid into the inferior vena cava. A brief overview of the pathophysiology of hydatid disease, including a discussion of the types of hydatid rupture (contained, communicating and direct), is presented.

Establishment of short-term primary human prostate xenografts for the study of prostate biology and cancer

Human tissue xenograft models are currently the only tool for conducting in vivo analyses of intact human tissue. The goal of the present study was to develop reliable methods for successful generation of short-term primary tissue xenografts from benign and tumor-derived human prostate tissue. Primary human prostate xenografts were established in athymic nu/nu mice from eight of eight benign and five of five prostate cancer tissues, collected from a total of 10 patients who underwent radical prostatectomy for the treatment of prostate cancer. An average of 13 xenografts was established per specimen. Two tissue specimens were cryopreserved for >1 month before successful generation of prostate xenografts. After 1 month in vivo, xenograft tissues were harvested and examined regarding: gross evidence of vascularization; tissue morphology; proliferation; apoptosis; and expression of androgen receptor, prostate-specific antigen, and high molecular weight cytokeratins specific for basal cells in the prostate. Direct comparison of the original tissue specimen and the 1-month xenografts revealed similar histology; similar apoptotic and proliferative fractions in most cases; and comparable expression levels and expression patterns of androgen receptor, prostate-specific antigen, and high molecular weight cytokeratins. These data demonstrate that primary human prostate xenografts, benign and malignant, can be established routinely from human prostate tissue surgical specimens, and that the xenografts maintain tissue architecture and expression of key prostatic markers. The development of this methodology, including the technique for cryopreservation of human tissue, will allow multiple (successive) analyses of human prostate tissue to be conducted throughout time using a tissue sample derived from a single patient; and simultaneous analysis of human prostate tissues derived from a cohort of patients.

Aberrant cell cycle checkpoint function in transformed hepatocytes and WB-F344 hepatic epithelial stem-like cells

Cell cycle checkpoints are barriers to carcinogenesis as they function to maintain genomic integrity. Attenuation or ablation of checkpoint function may enhance tumor formation by permitting outgrowth of unstable cells with damaged DNA. To examine the function of cell cycle checkpoints in rat hepatocarcinogenesis, we analyzed the responses of the G (1), G (2) and mitotic spindle assembly checkpoints in normal rat hepatocytes, hepatic epithelial stem-like cells (WB-F344) and transformed derivatives of both. Normal rat hepatocytes (NRH) displayed a 73% reduction in the fraction of nuclei in early S-phase 6-8 h following 8 Gy of ionizing radiation (IR) as a quantitative measure of G (1) checkpoint function. Chemically and virally transformed hepatocyte lines displayed significant attenuation of G (1) checkpoint function, ranging from partial to complete ablation. WB-F344 rat hepatic epithelial cell lines at low, mid and high passage levels expressed G (1) checkpoint function comparable with NRH. Only one of four malignantly transformed WB-F344 cell lines displayed significant attenuation of G (1) checkpoint function. Attenuation of G (1) checkpoint function in transformed hepatocytes and WB-F344 cells was associated with alterations in p53, ablated/attenuated induction of p21 (Waf1) by IR, as well as aberrant function of the spindle assembly checkpoint. NRH displayed 93% inhibition of mitosis 2 h after 1 Gy IR as a quantitative measure of G (2) checkpoint function. All transformed hepatocyte and WB-F344 cell lines displayed significant attenuation of the G (2) checkpoint. Moreover, the parental WB-F344 line displayed significant age-related attenuation of G (2) checkpoint function. Abnormalities in the function of cell cycle checkpoints were detected in transformed hepatocytes and WB-F344 cells at stages of hepatocarcinogenesis preceding tumorigenicity, sustaining a hypothesis that aberrant checkpoint function contributes to carcinogenesis.

Chromatographic separations as a prelude to two-dimensional electrophoresis in proteomics analysis

Current methods of proteome analysis rely almost solely on two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) followed by the excision of individual spots and protein identification using mass spectrometry (MS) and database searching. 2-D PAGE is denaturing in both dimensions and, thus, cannot indicate functional associations between individual proteins. Moreover, less abundant proteins are difficult to identify. To simplify the proteome, and explore functional associations, nondenaturing anion exchange column chromatography was used to separate a soluble protein extract from Escherichia coli. Successive fractions were then analysed using 2-D PAGE and selected spots from both the gels for the start material and the fractionated material were quantified and identified by peptide mass fingerprinting using a MALDI-TOF mass spectrometer. Enrichments of up to 13-fold were attained for individual protein spots and peptide mass fingerprints were of significantly higher quality after chromatographic separation. The marked anomalies between predicted p/and column elution position contrasted with the almost perfect correlation with migration distance on isoelectric focusing (IEF) and were explored further for basic proteins.

The troubled self in women with severe eating disorders (anorexia nervosa and bulimia nervosa). A study using interviews, self-reports, and percept-genetic methods

Fifteen anorectic (A) and 13 bulimic (B) patients aged 20-49 years, all seriously ill, and 21 controls were studied, using a half-structured interview, the Tennessee Self Concept Scale, the tachistoscopic Identity Test (IT), and two other percept-genetic tests. The differences between A and B were not particularly pronounced, A patients being on the whole more sensitive and self-directed, and B patients more depressive and object-directed. The IT differentiated between patients and controls very powerfully with regard to alexithymia. A type of response in that test, emphasizing the eyes, was seen as a search for guidance. Descriptions of mother were generally negative.

A novel series of 4-piperidinopyridine and 4-piperidinopyrimidine inhibitors of 2,3-oxidosqualene cyclase-lanosterol synthase

A novel series of 4-piperidinopyridines and 4-piperidinopyrimidines showed potent and selective inhibition of rat 2,3-oxidosqualene cyclase-lanosterol synthase (OSC) (e.g. 26 IC(50) rat = 398 +/- 25 nM, human = 112 +/- 25 nM) and gave selective oral inhibition of rat cholesterol biosynthesis (26 ED(80) = 1.2 +/- 0.3 mg/kg, n = 5; HMGCoA reductase inhibitor simvastatin ED(80) = 1.2 +/- 0.3 mg/kg, n = 5). The piperidinopyrimidine OSC inhibitors have a significantly lower pK(a) than the corresponding pyridine or the previously reported quinuclidine OSC inhibitor series. This indicates that other novel OSC inhibitors may be found in analogues of this series across a broader pK(a) range (6.0-9.0). These series may yield novel hypocholesterolemic agents for the treatment of cardiovascular disease.

Diagnoses, demographics, and utilization of care as encountered by three U.S. Navy general medical officers

U.S. Navy general medical officers (GMOs) are physicians serving as general practitioners. Although exceptions exist, most GMOs are not board-certified in a specialty. They are post-graduate year 1 (PGY-1)-trained, state-licensed physicians analogous to civilian general practitioners. We conducted a retrospective study using data generated from patient visits with active duty males and females from June 1 to 30, 1998, to describe diagnoses, demographics, and utilization of care patterns encountered by three PGY-1-trained GMOs at an ambulatory clinic. A total of 781 patient encounters with 123 diagnoses from a patient population of 3,178 were recorded. This is an average of 260 patient encounters per GMO, at a rate of 2.52 patients seen per patient-care hour. Fifty-seven consultations/referrals were requested (7.3% of encounters, 1.8% of the patient population). Personnel assigned to the clinic accounted for 4.2% of visits (2% of the patient population). Patient satisfaction was rated as "excellent" to "satisfactory," and no significant morbidity was observed at 1.5-year follow-up. With PGY-1 training, GMOs provide primary care to a substantial volume of prescreened patients and treat patients with a majority of diagnoses without referral or unacceptable complications. The role of GMOs, and perhaps other physicians without specialty training (i.e., general practitioners), in selected settings seems valid and may have advantageous medicoeconomic implications for military and civilian managed care systems.

Determination of plasma concentrations of losartan in patients by HPLC using solid phase extraction and UV detection

PURPOSE

To establish a HPLC assay for plasma losartan and its active metabolite EXP3174 to facilitate clinical pharmacokinetic studies.

METHODS

the HPLC system consisted of a 250 x 2 mm i.d. C18 reversed phase column preceded by a 4 x 4 mm guard column, a UV detector set at 254 nm, and an integrator. The mobile phase was a mixture of 0.01 M ammonium phosphate: acetonitrile: methanol (6:3:1) containing 0.02 % sodium azide and 0.04% TEA, with pH adjusted to 3.2. The system was operated isocratically at ambient temperature at a flow rate of 0.3 ml/min. Losartan and its active metabolite EXP3174 were extracted from plasma using C2 bonded silica gel standard solid phase extraction.

RESULTS

recoveries of losartan and EXP3174 from plasma were greater than 70%. Using 0.5 ml of plasma sample, standard curves were linear from 10 to 300 ng/ml (r2 = 0.996 and 0.997 for losartan and EXP 3174, respectively). Sensitivity of the assay was < 10 ng/ml. Intra-and inter-assay variations were < 10 and 15%. respectively. The assay has been successfully applied to measuring plasma concentrations of losartan and EXP3174 in patients receiving a daily dose of losartan (50-100 mg).

CONCLUSION

The HPLC assay has adequate sensitivity, reproducibility, and specificity for clinical pharmacokinetic studies.

Aggression: destructive and constructive aspects

The concept of aggression was long relegated to the shadow of the libido in psychoanalytic theory, placed among the negative affects by some theoreticians, denied the role of a primary drive among leading writers in clinical psychology, brought to the fore as an adaptive force in ethology, and proved to be a decisive factor in the development of psychosomatic ailments. The second part of the paper reviews experiments using projective techniques, showing that highly creative subjects as opposed to ones low in creativity seem inclined to accept their aggressive impulses. A total denial of these impulses has been typical of women with breast cancer.

The fluorescent oxidation products of dihydroxyphenylalanine and its esters

Dihydroxyphenylalanine (DOPA), its methyl ester (DOPAM) and the N-acetylated derivative of the ester (DOPAMNA) are found to undergo rapid oxidation in air-saturated alkaline solution. Some of the products of oxidation exhibit fluorescent emission in the 300-500 nm spectral range and their excitation-emission spectra have been determined in acidic and alkaline aqueous solutions. The spectral distributions and positions of the maxima depend on the pH of the solution. Excitation-emission maxima associated with the protonated phenolic form of the compounds occur at shorter wavelengths than those of the conjugate base. At some pH values the phenolic forms of these molecules are excited and undergo rapid deprotonation in the excited state; as a consequence, emission is observed from the phenolate anion. The fluorescence excitation-emission spectrum of an authentic sample of 3,4-dihydroxycinnamic (caffeic) acid has also been determined and features of the fluorescence spectra of the principal oxidation products are consistent with the presence of 3,4-hydroxycinnamoyl compounds in solutions of oxidized DOPAM and DOPAMNA.

Cytometric quantification of nitrate reductase by immunolabeling in the marine diatom Skeletonema costatum

BACKGROUND

The uptake of nitrate by phytoplankton is a central issue in biological oceanography due to its importance to primary production and vertical flux of biogenic carbon. Nitrate reductase catalyzes the first step of nitrate assimilation, the reduction of NO(3) to NO(2). A cytometric protocol to detect and quantify relative changes in nitrate reductase (NR) protein content of the marine centric diatom Skeletonema costatum is presented.

METHODS

Immunolabeling of NR protein was achieved with polyclonal antibodies raised against S.costatum NR. Antisera specific to a NR protein subunit and to a NR polypeptide sequence were compared, and cytometric results of NR protein abundance were related to Western analyses. Changes in cellular NR abundance and activity were followed during an upwelling simulation experiment in which S. costatum was exposed to a shift from ammonia to nitrate as major nitrogen source.

RESULTS

NR protein could be detected in NO(3)-grown cells and at extremely low levels hardly discernible by Western Blot densiometry in NH(4)-grown cells. The protocol allowed observation of early stages of NR induction during an upwelling simulation. NR abundance increased after the nutrient shift to reach a new physiological "steady-state" 96 hrs later. NR activity exhibited diel variation with maxima at mid-day. NR abundance as estimated by both flow cytometry and Western analysis exhibited a hyperbolic relationship to NR activity. This pattern suggests post-translational activation of NR protein.

CONCLUSIONS

The presented protocol allows the differentiation of NH(4)- versus NO(3)-grown algae as well as the monitoring of early stages in the induction of nitrate assimilatory capacities.

Teaching a long sequence of behavior using whole task training, forward chaining, and backward chaining

Whole task training, forward chaining, and backward chaining techniques were compared in teaching two different 120-step sequences of behavior to college students. In Exp. 1 participants learned a sequence that began with easy movements, progressed through more difficult movements, and ended with easy movements. Whole task training resulted in more errors than either forward or backward chaining. Differences were found in the location of errors. Both whole task training and forward chaining resulted in fewer errors at the beginning of the sequence and backward chaining resulted in fewer errors at the end of the sequence. Because the results of Exp. 1 may have been affected by the increased difficulty of the middle of the sequence, Exp. 2 was undertaken using a sequence of behavior where all segments were of equal difficulty. Whole task training and forward chaining resulted in fewer errors than backward chaining. The location of errors was similar to that found in Exp. 1.

Isolation and partial characterization of an epithelial cell line (RPE-F344) from the regenerating prostate of a normal adult male rat

Normal prostate epithelial cells are difficult to propagate in vitro without experimental immortalization. The goal of this study was to isolate and characterize a propagable epithelial cell line from normal adult rat prostate. Enrichment of proliferation-competent cells was accomplished in vivo by initiating a single cycle of prostatic involution/regeneration. The RPE-F344 cell line was established from an androgen-deprived, involuted prostate four days after the initiation of regeneration by administration of testosterone. The cell line has been cultured in vitro for >50 passages, forms a uniform monolayer in culture, exhibits contact inhibition at confluence, and does not form colonies in soft agar. Immunocytochemical and RT-PCR analyses demonstrated that the RPE-F344 cells express anti-apoptotic genes associated with cell survival, and several growth factor receptors important in prostate development and homeostasis. RPE-F344 cells are p27kip1 negative, telomerase positive, and express high molecular weight cytokeratins specific for prostatic basal cells. They also express low levels of androgen receptor (AR) and prostatic acid phosphatase (PAP); features associated with secretory luminal epithelial cells. RPE-F344 cells are maintained in vitro without androgen supplementation, but addition of 15nM dihydrotesterone (DHT) to the culture media results in a significant but transient enhancement of cellular proliferation. Establishment of RPE-F344-like colonies from rat prostate is limited to the ventral and dorsal lobes of the prostate 2-4 days after initiation of regeneration, suggesting that RPE-F344 cells may originate from a stem cell-like compartment that is responsible for regenerative repopulation.

Mechanical thrombectomy in acute venous thrombosis using an Amplatz thrombectomy device

Three cases of percutaneous mechanical thrombectomy using the Amplatz thrombectomy device are presented. All cases involve the application of the device in a major thoracic or abdominal vein in situations in which chemothrombolysis was contraindicated. The method of operation of the Amplatz thrombectomy device, as well as a brief overview of its clinical applications, are presented.